Arrhythmia during extracorporeal shock wave lithotripsy.

Science.gov (United States)

Zeng, Z R; Lindstedt, E; Roijer, A; Olsson, S B

1993-01-01

A prospective study of arrhythmia during extracorporeal shock wave lithotripsy (ESWL) was performed in 50 patients, using an EDAP LT01 piezoelectric lithotriptor. The 12-lead standard ECG was recorded continuously for 10 min before and during treatment. One or more atrial and/or ventricular ectopic beats occurred during ESWL in 15 cases (30%). The occurrence of arrhythmia was similar during right-sided and left-sided treatment. One patient developed multifocal ventricular premature beats and ventricular bigeminy; another had cardiac arrest for 13.5 s. It was found that various irregularities of the heart rhythm can be caused even by treatment with a lithotriptor using piezoelectric energy to create the shock wave. No evidence was found, however, that the shock wave itself rather than vagal activation and the action of sedo-analgesia was the cause of the arrhythmia. For patients with severe underlying heart disease and a history of complex arrhythmia, we suggest that the ECG be monitored during treatment. In other cases, we have found continuous monitoring of oxygen saturation and pulse rate with a pulse oximeter to be perfectly reliable for raising the alarm when depression of respiration and vaso-vagal reactions occur.

Sleep Apnea and Nocturnal Cardiac Arrhythmia: A Populational Study

Directory of Open Access Journals (Sweden)

Fatima Dumas Cintra

2014-11-01

Full Text Available Background: The mechanisms associated with the cardiovascular consequences of obstructive sleep apnea include abrupt changes in autonomic tone, which can trigger cardiac arrhythmias. The authors hypothesized that nocturnal cardiac arrhythmia occurs more frequently in patients with obstructive sleep apnea. Objective: To analyze the relationship between obstructive sleep apnea and abnormal heart rhythm during sleep in a population sample. Methods: Cross-sectional study with 1,101 volunteers, who form a representative sample of the city of São Paulo. The overnight polysomnography was performed using an EMBLA® S7000 digital system during the regular sleep schedule of the individual. The electrocardiogram channel was extracted, duplicated, and then analyzed using a Holter (Cardio Smart® system. Results: A total of 767 participants (461 men with a mean age of 42.00 ± 0.53 years, were included in the analysis. At least one type of nocturnal cardiac rhythm disturbance (atrial/ventricular arrhythmia or beat was observed in 62.7% of the sample. The occurrence of nocturnal cardiac arrhythmias was more frequent with increased disease severity. Rhythm disturbance was observed in 53.3% of the sample without breathing sleep disorders, whereas 92.3% of patients with severe obstructive sleep apnea showed cardiac arrhythmia. Isolated atrial and ventricular ectopy was more frequent in patients with moderate/severe obstructive sleep apnea when compared to controls (p < 0.001. After controlling for potential confounding factors, age, sex and apnea-hypopnea index were associated with nocturnal cardiac arrhythmia. Conclusion: Nocturnal cardiac arrhythmia occurs more frequently in patients with obstructive sleep apnea and the prevalence increases with disease severity. Age, sex, and the Apnea-hypopnea index were predictors of arrhythmia in this sample.

Remote Arrhythmia Monitoring System Developed

Science.gov (United States)

York, David W.; Mackin, Michael A.; Liszka, Kathy J.; Lichter, Michael J.

2004-01-01

Telemedicine is taking a step forward with the efforts of team members from the NASA Glenn Research Center, the MetroHealth campus of Case Western University, and the University of Akron. The Arrhythmia Monitoring System is a completed, working test bed developed at Glenn that collects real-time electrocardiogram (ECG) signals from a mobile or homebound patient, combines these signals with global positioning system (GPS) location data, and transmits them to a remote station for display and monitoring. Approximately 300,000 Americans die every year from sudden heart attacks, which are arrhythmia cases. However, not all patients identified at risk for arrhythmias can be monitored continuously because of technological and economical limitations. Such patients, who are at moderate risk of arrhythmias, would benefit from technology that would permit long-term continuous monitoring of electrical cardiac rhythms outside the hospital environment. Embedded Web Technology developed at Glenn to remotely command and collect data from embedded systems using Web technology is the catalyst for this new telemetry system (ref. 1). In the end-to-end system architecture, ECG signals are collected from a patient using an event recorder and are transmitted to a handheld personal digital assistant (PDA) using Bluetooth, a short-range wireless technology. The PDA concurrently tracks the patient's location via a connection to a GPS receiver. A long distance link is established via a standard Internet connection over a 2.5-generation Global System for Mobile Communications/General Packet Radio Service (GSM/GPRS)1 cellular, wireless infrastructure. Then, the digital signal is transmitted to a call center for monitoring by medical professionals.

Cardiac arrhythmias in adult patients with asthma

DEFF Research Database (Denmark)

Warnier, Miriam J; Rutten, Frans H; Kors, Jan A

2012-01-01

OBJECTIVE: The pathogenesis of cardiac arrhythmias in asthma patients has not been fully elucidated. Adverse drug effects, particularly those of β2-mimetics, may play a role. The aim of this study was to determine whether asthma is associated with the risk of cardiac arrhythmias and electrocardio......OBJECTIVE: The pathogenesis of cardiac arrhythmias in asthma patients has not been fully elucidated. Adverse drug effects, particularly those of β2-mimetics, may play a role. The aim of this study was to determine whether asthma is associated with the risk of cardiac arrhythmias...... and electrocardiographic characteristics of arrhythmogenicity (ECG) and to explore the role of β2-mimetics. METHODS: A cross-sectional study was conducted among 158 adult patients with a diagnosis of asthma and 6303 participants without asthma from the cohort of the Utrecht Health Project-an ongoing, longitudinal, primary...... or flutter). Secondary outcomes were tachycardia, bradycardia, PVC, atrial fibrillation or flutter, mean heart rate, mean corrected QT (QTc) interval length, and prolonged QTc interval. RESULTS: Tachycardia and PVCs were more prevalent in patients with asthma (3% and 4%, respectively) than those without...

QTc-prolonging drugs and hospitalizations for cardiac arrhythmias

DEFF Research Database (Denmark)

De Bruin, Marie L; Hoes, Arno W; Leufkens, Hubert G M

2003-01-01

Cardiac arrhythmia as an adverse effect of noncardiac drugs has been an issue of growing importance during the past few years. In this population-based study, we evaluated the risk for serious cardiac arrhythmias during the use of several noncardiac QTc-prolonging drugs in day-to-day practice......, and subsequently focused on several specific groups of patients who could be extremely vulnerable for drug-induced arrhythmias. We performed a case-control study in which patients (cases), hospitalized for nonatrial cardiac arrhythmias from 1987 to 1998, were compared with their matched controls regarding current...... use of QTc-prolonging drugs. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate conditional logistic regression, adjusting for potential confounding factors. Data were obtained from the PHARMO record linkage system. We identified 501 cases, 39 of whom used QTc...

Electrical Signs predictors of malignant ventricular arrhythmias

International Nuclear Information System (INIS)

Aleman Fernandez, Ailema Amelia; Dorantes Sanchez, Margarita

2012-01-01

Recurrence of malignant ventricular arrhythmia is frequent in cardioverter-defibrillators related patients. The risk stratification is difficult, there are numerous electrocardiographic predictors but his sensibility and specificity are not absolute. The limit between normal and pathological is not defined, besides the complexity of ventricular arrhythmias. We expose different electrocardiographic predictors that can help to better individual risk stratification

[Idiopathic ventricular arrhythmia in children. Apropos of 24 cases].

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Coeurderoy, A; Almange, C; Laurent, M; Biron, Y; Leborgne, P

1985-12-01

The severity and prognosis of idiopathic ventricular arrhythmias in childhood were studied in 24 patients (12 boys, 12 girls) with an average age of 8 years at the time of diagnosis of the arrhythmia. Investigations included clinical assessment and analysis of basal ECG (morphology of the arrhythmias) and dynamic recordings (Holter and exercise stress testing). The clinical course was followed for an average of 3.8 years. The patients were classified in two groups: monomorphic arrhythmias (Group I) and polymorphic arrhythmias (Group II). Group I was divided into 4 subgroups: isolated ventricular extrasystoles (IA), 11 patients; ventricular extrasystoles with bursts of ventricular tachycardia (IB), 6 patients; sustained ventricular tachycardia without intercritical extrasystoles (IC), 1 patient; accelerated idioventricular rhythm (ID), 2 patients. Subgroups IA, IB and ID were characterised by the absence of symptoms, the disappearance of the arrhythmia on exercise, the decreased efficacy of antiarrhythmic drugs and an excellent prognosis. Therapeutic abstention was the rule in these patients. Patients in Group IC were characterised by the variability of their symptoms, the absence of exercise induced arrhythmias, the need for treatment in most cases and a good long-term prognosis. Group II was divided into 2 subgroups: adrenergic polymorphic ventricular tachycardia (IIA), 2 patients, and non-adrenergic polymorphic ventricular tachycardia (IIB), 2 patients. Patients in Subgroup IIA were characterised by syncope on exercise or emotion, the need for betablocker therapy which considerably improved the patients symptoms but which did not usually prevent sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular function in patients with ventricular arrhythmias and aortic valve disease

International Nuclear Information System (INIS)

Santinga, J.T.; Kirsh, M.M.; Brady, T.J.; Thrall, J.; Pitt, B.

1983-01-01

Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease

Qt interval prolongation and ventricular arrhythmias in patients with chronic heart failure

International Nuclear Information System (INIS)

Sarwar, M.; Majeed, S.M.I.; Khan, M.A.; Majeed, S.M.

2014-01-01

To determine the association of QTc interval prolongation with ventricular arrhythmias in patients with chronic heart failure. Study Design: Descriptive study. Place and Duration of Study: This study was conducted at Armed Forces Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi, Pakistan from April 2013 to August 2013. Patients and Methods: Fifty three heart failure patients were monitored for 48 hours using ambulatory holter electrocardiography recorders. Digital ECG data was analyzed for QTc interval along with frequency and severity of arrhythmias. Association of prolonged QTc interval with ventricular arrhythmias and severity of arrhythmias was analyzed. Results: Cardiac arrhythmias were observed in 79.2% patients. QT analysis revealed that 69.8% patients had prolonged QTc interval, 86.4% patients with prolonged QTc had ventricular arrhythmias. Of these 66% patients were found to have severe ventricular arrhythmias. Comparison of mean QTc interval of our study population with a reference value showed significantly higher QTc interval of our study group than the test value. Conclusion: Arrhythmia frequency and severity significantly increases with an increase in QTc interval in heart failure demonstrating association of prolonged QTc interval with high risk of severe ventricular arrhythmias and sudden cardiac death in chronic heart failure. (author)

QTc-prolonging drugs and hospitalizations for cardiac arrhythmias

NARCIS (Netherlands)

De Bruin, ML; Hoes, AW; Leufkens, HGM

2003-01-01

Cardiac arrhythmia as an adverse effect of noncardiac drugs has been an issue of growing importance during the past few years. In this population-based study, we evaluated the risk for serious cardiac arrhythmias during the use of several noncardiac QTc-prolonging drugs in day-to-day practice, and

Andrographolide inhibits arrhythmias and is cardioprotective in rabbits.

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Zeng, Mengliu; Jiang, Wanzhen; Tian, Youjia; Hao, Jie; Cao, Zhenzhen; Liu, Zhipei; Fu, Chen; Zhang, Peihua; Ma, Jihua

2017-09-22

Andrographolide has a protective effect on the cardiovascular system. To study its cardic-electrophysiological effects, action potentials and voltage-gated Na + (I Na ), Ca 2+ (I CaL ), and K + (I K1 , I Kr , I to and I Kur ) currents were recorded using whole-cell patch clamp and current clamp techniques. Additionally, the effects of andrographolide on aconitine-induced arrhythmias were assessed on electrocardiograms in vivo . We found that andrographolide shortened action potential duration and reduced maximum upstroke velocity in rabbit left ventricular and left atrial myocytes. Andrographolide attenuated rate-dependence of action potential duration, and reduced or abolished delayed afterdepolarizations and triggered activities induced by isoproterenol (1 μM) and high calcium ([Ca 2+ ] o =3.6 mM) in left ventricular myocytes. Andrographolide also concentration-dependently inhibited I Na and I CaL , but had no effect on I to , I Kur , I K1 , or I Kr in rabbit left ventricular and left atrial myocytes. Andrographolide treatment increased the time and dosage thresholds of aconitine-induced arrhythmias, and reduced arrhythmia incidence and mortality in rabbits. Our results indicate that andrographolide inhibits cellular arrhythmias (delayed afterdepolarizations and triggered activities) and aconitine-induced arrhythmias in vivo , and these effects result from I Na and I CaL inhibition. Andrographolide may be useful as a class I and IV antiarrhythmic therapeutic.

Atrial Arrhythmias in Astronauts. Summary of a NASA Summit

Science.gov (United States)

Barr, Yael; Watkins, Sharmila; Polk, J. D.

2011-01-01

This slide presentation reviews the findings of a panel of heart experts brought together to study if atrial arrhythmias more prevalent in astronauts, and potential risk factors that may predispose astronauts to atrial arrhythmias. The objective of the panel was to solicit expert opinion on screening, diagnosis, and treatment options, identify gaps in knowledge, and propose relevant research initiatives. While Atrial Arrhythmias occur in approximately the same percents in astronauts as in the general population, they seem to occur at younger ages in astronauts. Several reasons for this predisposition were given: gender, hypertension, endurance training, and triggering events. Potential Space Flight-Related Risk factors that may play a role in precipitating lone atrial fibrillation were reviewed. There appears to be no evidence that any variable of the space flight environment increases the likelihood of developing atrial arrhythmias during space flight.

Frequency of Cardiac Arrhythmias in Patients with Aluminum Phosphide Poisoning

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Umair Aziz

2015-12-01

Full Text Available Background: Cardiac failure is the major lethal consequence of aluminum phosphide (AlP poisoning. This study was designed to determine the frequency of cardiac arrhythmias in patients with AlP poisoning. Methods: In this prospective cross-sectional study, patients with definitive history of AlP poisoning treated at emergency department of Allied Hospital Faisalabad, Faisalabad, Pakistan, from July 2013 to November 2014 were included. On admission, twelve-lead electrocardiogram (ECG was performed for all patients. During admission, all patients underwent continuous cardiac monitoring using a cardiac monitor. If an arrhythmia was suspected on the cardiac monitor, another ECG was obtained immediately.  Results: During the study period, 100 patients with AlP poisoning (63% men were treated at Allied Hospital Faisalabad. Mean age of the patients was 26.7 ± 7.9 years ranging from 16 to 54 years. Tachycardia was detected in 68 patients and bradycardia in 12 patients. Hypotension was observed in 75 patients. Eighty patients developed cardiac arrhythmia. The most frequent arrhythmia was atrial fibrillation (31% of patients followed by ventricular fibrillation (20%, ventricular tachycardia (17%, 3rd degree AV block (7% and 2nd degree AV block (5%. In total, 78 patients died, depicting a 78% mortality rate following wheat pill poisoning. Among those who died, seventy-one patients had cardiac arrhythmia. Comparison of death rate between patients with and without cardiac arrhythmia showed a significant difference (71/80 (88.8% vs. 7/20 (35%; P < 0.001.  Conclusion: Wheat pill poisoning causes a very high mortality, and circulatory collapse is the major cause of death among these patients. Most of the patients with AlP poisoning develop cardiac arrhythmias which are invariably life threatening. Early detection of cardiac disorders and proper management of arrhythmias may reduce mortalities.

Channelopathies - emerging trends in the management of inherited arrhythmias

NARCIS (Netherlands)

Chockalingam, Priya; Mizusawa, Yuka; Wilde, Arthur A. M.

2015-01-01

In spite of their relative rarity, inheritable arrhythmias have come to the forefront as a group of potentially fatal but preventable cause of sudden cardiac death in children and (young) adults. Comprehensive management of inherited arrhythmias includes diagnosing and treating the proband and

Arrhythmia phenotype in mouse models of human long QT.

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Salama, Guy; Baker, Linda; Wolk, Robert; Barhanin, Jacques; London, Barry

2009-03-01

Enhanced dispersion of repolarization (DR) was proposed as a unifying mechanism, central to arrhythmia genesis in the long QT (LQT) syndrome. In mammalian hearts, K(+) channels are heterogeneously expressed across the ventricles resulting in 'intrinsic' DR that may worsen in long QT. DR was shown to be central to the arrhythmia phenotype of transgenic mice with LQT caused by loss of function of the dominant mouse K(+) currents. Here, we investigated the arrhythmia phenotype of mice with targeted deletions of KCNE1 and KCNH2 genes which encode for minK/IsK and Merg1 (mouse homolog of human ERG) proteins resulting in loss of function of I(Ks) and I(Kr), respectively. Both currents are important human K(+) currents associated with LQT5 and LQT2. Loss of minK, a protein subunit that interacts with KvLQT1, results in a marked reduction of I(Ks) giving rise to the Jervell and Lange-Nielsen syndrome and the reduced KCNH2 gene reduces MERG and I(Kr). Hearts were perfused, stained with di-4-ANEPPS and optically mapped to compare action potential durations (APDs) and arrhythmia phenotype in homozygous minK (minK(-/-)) and heterozygous Merg1 (Merg(+/-)) deletions and littermate control mice. MinK(-/-) mice has similar APDs and no arrhythmias (n = 4). Merg(+/-) mice had prolonged APDs (from 20 +/- 6 to 32 +/- 9 ms at the base, p mice (60% vs. 10%). A comparison of mouse models of LQT based on K(+) channel mutations important to human and mouse repolarization emphasizes DR as a major determinant of arrhythmia vulnerability.

Understand Your Risk for Arrhythmia

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... is likely monitoring your heart rhythm with regular EKGs ( electrocardiograms ). But arrhythmias that occur infrequently may not ... patient sheets Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

[Analysis of the heart sound with arrhythmia based on nonlinear chaos theory].

Science.gov (United States)

Ding, Xiaorong; Guo, Xingming; Zhong, Lisha; Xiao, Shouzhong

2012-10-01

In this paper, a new method based on the nonlinear chaos theory was proposed to study the arrhythmia with the combination of the correlation dimension and largest Lyapunov exponent, through computing and analyzing these two parameters of 30 cases normal heart sound and 30 cases with arrhythmia. The results showed that the two parameters of the heart sounds with arrhythmia were higher than those with the normal, and there was significant difference between these two kinds of heart sounds. That is probably due to the irregularity of the arrhythmia which causes the decrease of predictability, and it's more complex than the normal heart sound. Therefore, the correlation dimension and the largest Lyapunov exponent can be used to analyze the arrhythmia and for its feature extraction.

Calcium-dependent arrhythmias in transgenic mice with heart failure.

Science.gov (United States)

London, Barry; Baker, Linda C; Lee, Joon S; Shusterman, Vladimir; Choi, Bum-Rak; Kubota, Toru; McTiernan, Charles F; Feldman, Arthur M; Salama, Guy

2003-02-01

Transgenic mice overexpressing the inflammatory cytokine tumor necrosis factor (TNF)-alpha (TNF-alpha mice) in the heart develop a progressive heart failure syndrome characterized by biventricular dilatation, decreased ejection fraction, atrial and ventricular arrhythmias on ambulatory telemetry monitoring, and decreased survival compared with nontransgenic littermates. Programmed stimulation in vitro with single extra beats elicits reentrant ventricular arrhythmias in TNF-alpha (n = 12 of 13 hearts) but not in control hearts. We performed optical mapping of voltage and Ca(2+) in isolated perfused ventricles of TNF-alpha mice to study the mechanisms that lead to the initiation and maintenance of the arrhythmias. When compared with controls, hearts from TNF-alpha mice have prolonged of action potential durations (action potential duration at 90% repolarization: 23 +/- 2 ms, n = 7, vs. 18 +/- 1 ms, n = 5; P < 0.05), no increased dispersion of refractoriness between apex and base, elevated diastolic and depressed systolic [Ca(2+)], and prolonged Ca(2+) transients (72 +/- 6 ms, n = 10, vs. 54 +/- 5 ms, n = 8; P < 0.01). Premature beats have diminished action potential amplitudes and conduct in a slow, heterogeneous manner. Lowering extracellular [Ca(2+)] normalizes conduction and prevents inducible arrhythmias. Thus both action potential prolongation and abnormal Ca(2+) handling may contribute to the initiation of reentrant arrhythmias in this heart failure model by mechanisms distinct from enhanced dispersion of refractoriness or triggered activity.

Dobutamine use for arrhythmia induction during electrical programmed heart stimulation

International Nuclear Information System (INIS)

Vanegas, Diego I; Perez, Climaco de J; Montenegro, Juan de J; Orjuela, Alejandro

2006-01-01

isoproterenol is the traditionally used drug for incrementing arrhythmia induction when this induction is not achieved during electric programmed heart stimulation under basal conditions. Dobutamine is an adrenergic agent, chemical precursor of isoproterenol, which can be an alternative for inducing arrhythmia during electrical programmed heart stimulation (PES). Patients and methods: a retrospective comparative study of the experience with dobutamine for inducing arrhythmia during electrical programmed heart stimulation was performed. The following data were collected: number of studies, data about the patient (medical record, age, gender, and study indication) protocol of programmed electrical stimulation, basal and under dobutamine or isoproterenol, and result of the study. Isoproterenol was used in doses of 1 to 3 micrograms per minute until the basal heart rate was incremented at least in 25%. Dobutamine was used in doses of 10 to 40 micrograms per kg of body weight, until obtaining the same increment in the basal heart rate. Results: 1054 electrophysiological studies were evaluated. In 144 patients (group A) isoproterenol was used and in 140, dobutamine (group B). In A group the mean age was 39.2 ± 16.2 and 58.3% were females. In-group B, mean age was 41.9 ± 18.6 and 51% were females. The most frequent symptom was palpitation and the most commonly induced arrhythmia was AV nodal reentry tachycardia in both groups. The induction of arrhythmia during the electrical programmed heat stimulation under drugs was similar in-group A (isoproterenol) respect to group B (dobutamine). Conclusions: There were no statistical significant differences in the induction of arrhythmia during electrical programmed heart stimulation using dobutamine or isoproterenol. Dobutamine may be safe and may be successfully used as an alternative to isoproterenol for arrhythmia induction during electrical programmed stimulation

Increasing Prevalence of Atrial Fibrillation and Permanent Atrial Arrhythmias in Congenital Heart Disease.

Science.gov (United States)

Labombarda, Fabien; Hamilton, Robert; Shohoudi, Azadeh; Aboulhosn, Jamil; Broberg, Craig S; Chaix, Marie A; Cohen, Scott; Cook, Stephen; Dore, Annie; Fernandes, Susan M; Fournier, Anne; Kay, Joseph; Macle, Laurent; Mondésert, Blandine; Mongeon, François-Pierre; Opotowsky, Alexander R; Proietti, Anna; Rivard, Lena; Ting, Jennifer; Thibault, Bernard; Zaidi, Ali; Khairy, Paul

2017-08-15

Atrial arrhythmias are the most common complication encountered in the growing and aging population with congenital heart disease. This study sought to assess the types and patterns of atrial arrhythmias, associated factors, and age-related trends. A multicenter cohort study enrolled 482 patients with congenital heart disease and atrial arrhythmias, age 32.0 ± 18.0 years, 45.2% female, from 12 North American centers. Qualifying arrhythmias were classified by a blinded adjudicating committee. The most common presenting arrhythmia was intra-atrial re-entrant tachycardia (IART) (61.6%), followed by atrial fibrillation (28.8%), and focal atrial tachycardia (9.5%). The proportion of arrhythmias due to IART increased with congenital heart disease complexity from 47.2% to 62.1% to 67.0% in patients with simple, moderate, and complex defects, respectively (p = 0.0013). Atrial fibrillation increased with age to surpass IART as the most common arrhythmia in those ≥50 years of age (51.2% vs. 44.2%; p congenital heart disease, with a predominantly paroxysmal pattern. However, atrial fibrillation increases in prevalence and atrial arrhythmias progressively become permanent as the population ages. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Dual chamber arrhythmia detection in the implantable cardioverter defibrillator.

Science.gov (United States)

Dijkman, B; Wellens, H J

2000-10-01

Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PRarrhythmias. Dual chamber detection algorithms evaluated in a subset of diagnostically difficult arrhythmias allow safe detection of double tachycardias but require further extension and programmability to

Types of Arrhythmia in Children

Science.gov (United States)

... even though they may need to keep taking medicine. Your child will probably need periodic check-ups but will ... minute. Understand and manage medications Parents of a child taking medicine for an arrhythmia should give the medicine at ...

Pharmacogenetics of drug-induced arrhythmias

DEFF Research Database (Denmark)

De Bruin, Marie L; van Puijenbroek, Eugene P; Bracke, Madelon

2006-01-01

PURPOSE: The bottleneck in pharmacogenetic research on rare adverse drug reactions (ADR) is retrieval of patients. Spontaneous reports of ADRs may form a useful source of patients. We investigated the feasibility of a pharmacogenetic study, in which cases were selected from the database...... of a spontaneous reporting system for ADRs, using drug-induced arrhythmias as an example. METHODS: Reports of drug-induced arrhythmias to proarrhythmic drugs were selected from the database of the Netherlands Pharmacovigilance Centre (1996-2003). Information on the patient's general practitioner (GP) was obtained...... be included in the study, giving an overall participation rate of 9% (4/45). The main reason for GPs not being willing to participate was lack of time. Variants were identified in KCNH2, SCN5A and KCNE1. CONCLUSIONS: Spontaneous reporting systems for ADRs may be used for pharmacogenetic research. The methods...

A Proposal for Cardiac Arrhythmia Classification using Complexity Measures

Directory of Open Access Journals (Sweden)

AROTARITEI, D.

2017-08-01

Full Text Available Cardiovascular diseases are one of the major problems of humanity and therefore one of their component, arrhythmia detection and classification drawn an increased attention worldwide. The presence of randomness in discrete time series, like those arising in electrophysiology, is firmly connected with computational complexity measure. This connection can be used, for instance, in the analysis of RR-intervals of electrocardiographic (ECG signal, coded as binary string, to detect and classify arrhythmia. Our approach uses three algorithms (Lempel-Ziv, Sample Entropy and T-Code to compute the information complexity applied and a classification tree to detect 13 types of arrhythmia with encouraging results. To overcome the computational effort required for complexity calculus, a cloud computing solution with executable code deployment is also proposed.

P wave detector with PP rhythm tracking: evaluation in different arrhythmia contexts

International Nuclear Information System (INIS)

Portet, François

2008-01-01

Automatic detection of atrial activity (P waves) in an electrocardiogram (ECG) is a crucial task to diagnose the presence of arrhythmias. The P wave is difficult to detect and most of the approaches in the literature have been evaluated on normal sinus rhythms and rarely considered arrhythmia contexts other than atrial flutter and fibrillation. A novel knowledge-based P wave detector algorithm is presented. It is self-adaptive to the patient and able to deal with certain arrhythmias by tracking the PP rhythm. The detector has been tested on 12 records of the MIT-BIH arrhythmia database containing several ventricular and supra-ventricular arrhythmias. On the overall records, the detector demonstrates Se = 96.60% and Pr = 95.46%; for the normal sinus rhythm, it reaches Se = 97.76% and Pr = 96.80% and, in the case of Mobitz type II, it demonstrates Se = 72.79% and Pr = 99.51%. It also shows good performance for trigeminy and bigeminy, and outperforms some more sophisticated techniques. Although the results emphasize the difficulty of P wave detection in difficult arrhythmias (supra and ventricular tachycardias), it shows that domain knowledge can efficiently support signal processing techniques

Epidemiology of Arrhythmias in Children

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R Prem Sekar

2008-05-01

Full Text Available Unlike the adult population, arrhythmias occur less commonly in childhood. Only 5% of the emergency hospital admissions in the paediatric population is attributed to symptomatic arrhythmias. Majority of these tend to be accessory pathway mediated supraventricular tachyarrhythmias such as Wolff-Parkinson-White (WPW syndrome, permanent junctional reciprocating tachycardia (PJRT and Mahaim tachycardia. The non accessory pathway mediated supraventricular tachyarrhythmias commonly seen in children are junctional ectopic tachycardia (JET and automatic ectopic atrial tachycardia (AET and occur mostly in the post operative period after intracardiac repair for a structural heart defect. Ventricular tachycardia (VT although uncommon, occurs in the paediatric age group in association with hypertrophic cardiomyopathy (HCM, long QT syndrome (LQTS and Brugada syndrome. Occasionally, VT can also present symptomatically as incessant idiopathic infant ventricular tachycardia, right ventricular outflow tract tachycardia, benign VT, catecholaminic VT, idiopathic left ventricular tachycardia and in post cardiac surgical patients.

Multi-arrhythmias detection with an XML rule-based system from 12-Lead Electrocardiogram.

Science.gov (United States)

Khelassi, Abdeldjalil; Yelles-Chaouche, Sarra-Nassira; Benais, Faiza

2017-05-01

The computer-aided detection of cardiac arrhythmias stills a crucial application in medical technologies. The rule based systems RBS ensure a high level of transparency and interpretability of the obtained results. To facilitate the diagnosis of the cardiologists and to reduce the uncertainty made in this diagnosis. In this research article, we have realized a classification and automatic recognition of cardiac arrhythmias, by using XML rules that represent the cardiologist knowledge. Thirteen experiments with different knowledge bases were realized for improving the performance of the used method in the detection of 13 cardiac arrhythmias. In the first 12 experiments, we have designed a specialized knowledge base for each cardiac arrhythmia, which contains just one arrhythmia detection rule. In the last experiment, we applied the knowledge base which contains rules of 12 arrhythmias. We used, for the experiments, an international data set with 279 features and 452 records characterizing 12 leads of ECG signal and social information of patients. The data sets were constructed and published at Bilkent University of Ankara, Turkey. In addition, the second version of the self-developed software "XMLRULE" was used; the software can infer more than one class and facilitate the interpretability of the obtained results. The 12 first experiments give 82.80% of correct detection as the mean of all experiments, the results were between 19% and 100% with a low rate in just one experiment. The last experiment in which all arrhythmias are considered, the results of correct detection was 38.33% with 90.55% of sensibility and 46.24% of specificity. It was clearly show that in these results the good choice of the classification model is very beneficial in terms of performance. The obtained results were better than the published results with other computational methods for the mono class detection, but it was less in multi-class detection. The RBS is the most transparent method for

Disease and drug-induced arrhythmias : the example of obstructive pulmonary disease

NARCIS (Netherlands)

Warnier, M.J.

2014-01-01

Notwithstanding the clinical importance of cardiac arrhythmias, relevant information about the background risk and the exact underlying mechanisms of cardiac arrhythmias in patients with obstructive pulmonary disease (asthma and chronic obstructive pulmonary disease [COPD]) is still lacking. The

[Catheter ablation in patients with refractory cardiac arrhythmias with radiofrequency techniques].

Science.gov (United States)

de Paola, A A; Balbão, C E; Silva Netto, O; Mendonça, A; Villacorta, H; Vattimo, A C; Souza, I A; Guiguer Júnior, N; Portugal, O P; Martinez Filho, E E

1993-02-01

evaluate the efficacy of radiofrequency catheter ablation in patients with refractory cardiac arrhythmias. twenty patients with refractory cardiac arrhythmias were undertaken to electrophysiologic studies for diagnosis and radiofrequency catheter ablation of their reentrant arrhythmias. Ten patients were men and 10 women with ages varying from 13 to 76 years (mean = 42.4 years). Nineteen patients had supraventricular tachyarrhythmias: One patient had atrial tachycardia and 1 atrial fibrillation with rapid ventricular rate, 5 patients had reentrant nodal tachycardia, 12 patients had reentrant atrioventricular tachycardia and 1 patient had right ventricular outflow tract tachycardia. the mean time of the procedure was 4.1 hours. The radiofrequency current energy applied was 40-50 V for 30-40 seconds. Ablation was successful in 18/20 (90%) patients; in 15/18 (83%) of successfully treated patients the same study was done for diagnosis and radiofrequency ablation. One patient had femoral arterial occlusion and was treated with no significant sequelae. During a mean follow-up of 4 months no preexcitation or reentrant tachycardia occurred. the results of our experience with radiofrequency catheter ablation of cardiac arrhythmias suggest that this technique can benefit an important number of patients with cardiac arrhythmias.

Illicit drugs and cardiac arrhythmias in athletes.

Science.gov (United States)

Furlanello, Francesco; Serdoz, Laura Vitali; Cappato, Riccardo; De Ambroggi, Luigi

2007-08-01

The current management of athletes with cardiac arrhythmias has become complicated by the widespread use of illicit drugs, which can be arrhythmogenic. The World Anti-Doping Agency annually updates a list of prohibited substances and methods banned by the International Olympic Committee that includes different classes of substances namely, anabolic androgenic steroids, hormones and related substances, beta2-agonists, diuretics, stimulants, narcotics, cannabinoids, glucocorticosteroids, alcohol, beta-blockers and others. Almost all illicit drugs may cause, through a direct or indirect arrhythmogenic effect, a wide range of cardiac arrhythmias (focal or reentry type, supraventricular and/or ventricular) that can even be lethal and which are frequently sport activity related. A large use of illicit drugs has been documented in competitive athletes, but the arrhythmogenic effect of specific substances is not precisely known. Precipitation of cardiac arrhythmias, particularly in the presence of a latent electrophysiologic substrate including some inherited cardiomyopathies, at risk of sudden death or due to long-term consumption of the substances, should raise the suspicion that illicit drugs may be a possible cause and lead cardiologists to investigate carefully this relationship and appropriately prevent the clinical consequences.

Gene Therapy in Cardiac Arrhythmias

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Praveen S.V

2006-04-01

Full Text Available Gene therapy has progressed from a dream to a bedside reality in quite a few human diseases. From its first application in adenosine deaminase deficiency, through the years, its application has evolved to vascular angiogenesis and cardiac arrhythmias. Gene based biological pacemakers using viral vectors or mesenchymal cells tested in animal models hold much promise. Induction of pacemaker activity within the left bundle branch can provide stable heart rates. Genetic modification of the AV node mimicking beta blockade can be therapeutic in the management of atrial fibrillation. G protein overexpression to modify the AV node also is experimental. Modification and expression of potassium channel genes altering the delayed rectifier potassium currents may permit better management of congenital long QT syndromes. Arrhythmias in a failing heart are due to abnormal calcium cycling. Potential targets for genetic modulation include the sarcoplasmic reticulum calcium pump, calsequestrin and sodium calcium exchanger.Lastly the ethical concerns need to be addressed.

Gated cardiac blood pool studies in arrhythmias

International Nuclear Information System (INIS)

Itti, R.; Casset, D.; Philippe, L.; Cosnay, P.; Fauchier, J.P.

1988-01-01

Biventricular phase analysis a gated blood pool studies may help to solve two fundamental questions raised by patients suffering from arrhythmias: localization of an electrical cardiac activation abnormality by means of contraction mapping and assesment of an underlying organic disease using the phase histograms and their standard deviations. Three groups of patients have been evaluated to demonstrate the usefulness of radioisotopic techniques in arrhythmias: 36 patients with a Wolff-Parkinson-White syndrom, 27 patients studied during a ventricular tachycardia attack and 32 patients suspected of arrhythmogenic ventricular dysplasia. Correlations with invasive electrophysiologic studies are presented and the diagnostic and therapeutic implications of these results are discussed [fr

Gated cardiac blood pool studies in arrhythmias

Energy Technology Data Exchange (ETDEWEB)

Itti, R.; Casset, D.; Philippe, L.; Cosnay, P.; Fauchier, J.P.

1988-01-01

Biventricular phase analysis a gated blood pool studies may help to solve two fundamental questions raised by patients suffering from arrhythmias: localization of an electrical cardiac activation abnormality by means of contraction mapping and assesment of an underlying organic disease using the phase histograms and their standard deviations. Three groups of patients have been evaluated to demonstrate the usefulness of radioisotopic techniques in arrhythmias: 36 patients with a Wolff-Parkinson-White syndrom, 27 patients studied during a ventricular tachycardia attack and 32 patients suspected of arrhythmogenic ventricular dysplasia. Correlations with invasive electrophysiologic studies are presented and the diagnostic and therapeutic implications of these results are discussed.

Targeting sodium channels in cardiac arrhythmia

NARCIS (Netherlands)

Remme, Carol Ann; Wilde, Arthur A. M.

2014-01-01

Cardiac voltage-gated sodium channels are responsible for proper electrical conduction in the heart. During acquired pathological conditions and inherited sodium channelopathies, altered sodium channel function causes conduction disturbances and ventricular arrhythmias. Although the clinical,

Use of bipolar radiofrequency catheter ablation in treatment of cardiac arrhythmias.

Science.gov (United States)

Soucek, Filip; Starek, Zdenek

2018-05-23

Background Arrhythmia management is a complex process involving both pharmacological and non-pharmacological approaches. Radiofrequency ablation is the pillar of non-pharmacological arrhythmia treatment. Unipolar ablation is considered to be the gold standard in the treatment of the majority of arrhythmias; however, its efficacy is limited to specific cases. In particular, the creation of deep or transmural lesions to eliminate intramurally originating arrhythmias remains inadequate. Bipolar ablation is proposed as an alternative to overcome unipolar ablation boundaries. Results Despite promising results gained from in vitro and animal studies showing that bipolar ablation is superior in creating transmural lesions, the use of bipolar ablation in daily clinical practice is limited. Several studies have been published showing that bipolar ablation is effective in the treatment of clinical arrhythmias after failed unipolar ablation, however there is inconsistency regarding safety of bipolar ablation within the available research papers. According to research evidence the most common indications for bipolar ablation use are ventricular originating rhythmic disorders in patients with structural heart disease resistant to standard radiofrequency ablation. Conclusions To allow wider clinical application the efficiency and safety of bipolar ablation need to be verified in future studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The association of air temperature with cardiac arrhythmias

Science.gov (United States)

Čulić, Viktor

2017-11-01

The body response to meteorological influences may activate pathophysiological mechanisms facilitating the occurrence of cardiac arrhythmias in susceptible patients. Putative underlying mechanisms include changes in systemic vascular resistance and blood pressure, as well as a network of proinflammatory and procoagulant processes. Such a chain reaction probably occurs within the time window of several hours, so use of daily average values of meteorological elements do not seem appropriate for investigation in this area. In addition, overall synoptic situation, and season-specific combinations of meteorological elements and air pollutant levels probably cause the overall effect rather than a single atmospheric element. Particularly strong interrelations have been described among wind speed, air pressure and temperature, relative air humidity, and suspended particulate matter. This may be the main reason why studies examining the association between temperature and ventricular arrhythmias have found linear positive, negative, J-shaped or no association. Further understanding of the pathophysiological adaptation to atmospheric environment may help in providing recommendations for protective measures during "bad" weather conditions in patients with cardiac arrhythmias.

ECG scaling properties of cardiac arrhythmias using detrended fluctuation analysis

International Nuclear Information System (INIS)

Rodriguez, E; Echeverria, J C; Alvarez-Ramirez, J; Lerma, C

2008-01-01

We applied detrended fluctuation analysis to characterize at very short time scales during episodes of cardiac arrhythmias the raw electrocardiogram (ECG) waveform, aiming to get a global insight into its dynamical behaviour in patients who experienced sudden death. We found that in 15 recordings involving different types of arrhythmias (taken from PhysioNet's Sudden Cardiac Death Holter Database), the ECG waveform, besides showing a less-random dynamics, becomes more regular during bigeminy, ventricular tachycardia or even atrial fibrillation and ventricular fibrillation. The ECG waveform scaling properties thus suggest that reduced complexity dominates the underlying mechanisms of arrhythmias. Among other explanations, this may result from shorted or restricted (i.e. less diverse) pathways of conduction of the electrical activity within ventricles

Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

International Nuclear Information System (INIS)

Sultana, R.; Sultana, N.; Rashid, A.; Rasheed, S.Z.; Ahmed, M.; Ishaq, M.; Samad, A.

2010-01-01

Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

Energy Technology Data Exchange (ETDEWEB)

Sultana, R; Sultana, N; Rashid, A; Rasheed, S Z; Ahmed, M; Ishaq, M; Samad, A [Karachi Institute of Heart Diseases, Karachi (Pakistan)

2010-10-15

Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

Channelopathies - Emerging Trends in The Management of Inherited Arrhythmias

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Priya Chockalingam, MBBS, MRCPCH, PhD

2015-01-01

Full Text Available In spite of their relative rarity, inheritable arrhythmias have come to the forefront as a group of potentially fatal but preventable cause of sudden cardiac death in children and (young adults. Comprehensive management of inherited arrhythmias includes diagnosing and treating the proband and identifying and protecting affected family members. This has been made possible by the vast advances in the field of molecular biology enabling better understanding of the genetic underpinnings of some of these disease groups, namely congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. The ensuing knowledge of the genotype-phenotype correlations enables us to risk-stratify, prognosticate and treat based on the genetic test results. The various diagnostic modalities currently available to us, including clinical tools and genetic technologies, have to be applied judiciously in order to promptly identify those affected and to spare the emotional burden of a potentially lethal disease in the unaffected individuals. The therapeutic armamentarium of inherited arrhythmias includes pharmacological agents, device therapies and surgical interventions. A treatment strategy keeping in mind the risk profile of the patients, the local availability of drugs and the expertise of the treating personnel is proving effective. While opportunities for research are numerous in this expanding field of medicine, there is also tremendous scope for incorporating the emerging trends in managing patients and families with inherited arrhythmias in the Indian subcontinent.

Effect of different doses of oxytocin on cardiac electrophysiology and arrhythmias induced by ischemia.

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Houshmand, Fariba; Faghihi, Mahdieh; Imani, Alireza; Kheiri, Soleiman

2017-01-01

The onset of acute myocardial ischemia (MI) is accompanied by a rapid increase in electrical instability and often fatal ventricular arrhythmias. This study investigated that whether oxytocin (OT) can modulate ischemia-induced arrhythmias and considered relationships between the severity of arrhythmia and the electrocardiogram parameters during ischemia. OT (0.0001-1 μg) was administrated intraperitoneally 30 min before ischemia. To examine receptor involved, a selective OT-receptor antagonist, atosiban (ATO), was infused 10 min before OT. OT caused a significant and biphasic dose-dependent reduction in ectopic heart activity and arrhythmia score. OT doses that reduced ventricular arrhythmia elicited significant increase in QT interval. OT attenuated the electrophysiological changes associated with MI and there was significant direct relationship between QRS duration and arrhythmia score. ATO treatment reduced beneficial effects of OT on arrhythmogenesis. Nevertheless, ATO failed to alter OT effects on premature ventricular contractions. We assume that the ability of OT to modulate the electrical activity of the heart may play an important role in the antiarrhythmic actions of OT.

Effect of different doses of oxytocin on cardiac electrophysiology and arrhythmias induced by ischemia

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Fariba Houshmand

2017-01-01

Full Text Available The onset of acute myocardial ischemia (MI is accompanied by a rapid increase in electrical instability and often fatal ventricular arrhythmias. This study investigated that whether oxytocin (OT can modulate ischemia-induced arrhythmias and considered relationships between the severity of arrhythmia and the electrocardiogram parameters during ischemia. OT (0.0001–1 μg was administrated intraperitoneally 30 min before ischemia. To examine receptor involved, a selective OT-receptor antagonist, atosiban (ATO, was infused 10 min before OT. OT caused a significant and biphasic dose-dependent reduction in ectopic heart activity and arrhythmia score. OT doses that reduced ventricular arrhythmia elicited significant increase in QT interval. OT attenuated the electrophysiological changes associated with MI and there was significant direct relationship between QRS duration and arrhythmia score. ATO treatment reduced beneficial effects of OT on arrhythmogenesis. Nevertheless, ATO failed to alter OT effects on premature ventricular contractions. We assume that the ability of OT to modulate the electrical activity of the heart may play an important role in the antiarrhythmic actions of OT.

The risk of arrhythmias following coronary artery bypass surgery: do smokers have a paradox effect?

LENUS (Irish Health Repository)

Al-Sarraf, Nael

2010-11-01

Smoking is reported to increase the risk of arrhythmias. However, there are limited data on its effects on arrhythmias following coronary artery bypass graft (CABG). This is a retrospective review of a prospective database of all CABG patients over an eight-year period. Our cohort (n=2813) was subdivided into: current (n=1169), former (n=837), and non-smokers (n=807). Predictors of arrhythmias following CABG in relation to smoking status were analysed. Atrial arrhythmias occurred in 942 patients (33%). Ventricular arrhythmias occurred in 48 patients (2%) and high-grade atrioventricular block occurred in five patients (0.2%). Arrhythmias were lower in current smokers than former and non-smokers (29% vs. 40% vs. 39%, respectively P<0.001). Logistic regression analysis showed 30% arrhythmia risk reduction in smokers compared to non-smokers [odds ratio (OR) 0.7, 95% confidence intervals (CI) 0.5-0.8] and this effect persisted after accounting for potential confounders while former smokers had the same risk as non-smokers (OR 1.04, CI 0.9-1.3). There were no significant differences in mortality. Smokers are less prone to develop arrhythmias following CABG. This paradox effect is lost in former smokers. This effect is possibly due to a lower state of hyper adrenergic stimulation observed in smokers than non-smokers following the stress of surgery.

Carbon monoxide induces cardiac arrhythmia via induction of the late Na+ current.

Science.gov (United States)

Dallas, Mark L; Yang, Zhaokang; Boyle, John P; Boycott, Hannah E; Scragg, Jason L; Milligan, Carol J; Elies, Jacobo; Duke, Adrian; Thireau, Jérôme; Reboul, Cyril; Richard, Sylvain; Bernus, Olivier; Steele, Derek S; Peers, Chris

2012-10-01

Clinical reports describe life-threatening cardiac arrhythmias after environmental exposure to carbon monoxide (CO) or accidental CO poisoning. Numerous case studies describe disruption of repolarization and prolongation of the QT interval, yet the mechanisms underlying CO-induced arrhythmias are unknown. To understand the cellular basis of CO-induced arrhythmias and to identify an effective therapeutic approach. Patch-clamp electrophysiology and confocal Ca(2+) and nitric oxide (NO) imaging in isolated ventricular myocytes was performed together with protein S-nitrosylation to investigate the effects of CO at the cellular and molecular levels, whereas telemetry was used to investigate effects of CO on electrocardiogram recordings in vivo. CO increased the sustained (late) component of the inward Na(+) current, resulting in prolongation of the action potential and the associated intracellular Ca(2+) transient. In more than 50% of myocytes these changes progressed to early after-depolarization-like arrhythmias. CO elevated NO levels in myocytes and caused S-nitrosylation of the Na(+) channel, Na(v)1.5. All proarrhythmic effects of CO were abolished by the NO synthase inhibitor l-NAME, and reversed by ranolazine, an inhibitor of the late Na(+) current. Ranolazine also corrected QT variability and arrhythmias induced by CO in vivo, as monitored by telemetry. Our data indicate that the proarrhythmic effects of CO arise from activation of NO synthase, leading to NO-mediated nitrosylation of Na(V)1.5 and to induction of the late Na(+) current. We also show that the antianginal drug ranolazine can abolish CO-induced early after-depolarizations, highlighting a novel approach to the treatment of CO-induced arrhythmias.

Ventricular arrhythmias in the absence of structural heart disease.

Science.gov (United States)

Prystowsky, Eric N; Padanilam, Benzy J; Joshi, Sandeep; Fogel, Richard I

2012-05-15

Ventricular arrhythmia (VA) in structurally normal hearts can be broadly considered under non-life-threatening monomorphic and life-threatening polymorphic rhythms. Monomorphic VA is classified on the basis of site of origin in the heart, and the most common areas are the ventricular outflow tracts and left ventricular fascicles. The morphology of the QRS complexes on electrocardiogram is an excellent tool to identify the site of origin of the rhythm. Although these arrhythmias are common and generally carry an excellent prognosis, rare sudden death events have been reported. Very frequent ventricular ectopy may also result in a cardiomyopathy in a minority of patients. Suppression of VA may be achieved using calcium-channel blockers, beta-adrenergic blockers, and class I or III antiarrhythmic drugs. Radiofrequency ablation has emerged as an excellent option to eliminate these arrhythmias, although certain foci including aortic cusps and epicardium may be technically challenging. Polymorphic ventricular tachycardia (VT) is rare and generally occurs in patients with genetic ion channel disorders including long QT syndrome, Brugada syndrome, catecholaminergic polymorphic VT, and short QT syndrome. Unlike monomorphic VT, these arrhythmic syndromes are associated with sudden death. While the cardiac gross morphology is normal, suggesting a structurally normal heart, abnormalities exist at the molecular level and predispose them to arrhythmias. Another fascinating area, idiopathic ventricular fibrillation and early repolarization syndrome, are undergoing research for a genetic basis. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The predictive value of CHADS₂ risk score in post myocardial infarction arrhythmias - a Cardiac Arrhythmias and RIsk Stratification after Myocardial infArction (CARISMA) substudy

DEFF Research Database (Denmark)

Ruwald, Anne-Christine Huth; Gang, Uffe; Thomsen, Poul Erik Bloch

2014-01-01

BACKGROUND: Previous studies have shown substantially increased risk of cardiac arrhythmias and sudden cardiac death in post-myocardial infarction (MI) patients. However it remains difficult to identify the patients who are at highest risk of arrhythmias in the post-MI setting. The purpose...... of this study was to investigate if CHADS₂ score (congestive heart failure, hypertension, age ≥75 years, diabetes and previous stroke/TCI [doubled]) can be used as a risk tool for predicting cardiac arrhythmias after MI. METHODS: The study included 297 post-MI patients from the CARISMA study with left....... Patients were stratified according to CHADS₂ score at enrollment. Congestive heart failure was defined as LVEF ≤40% and NYHA class II, III or IV. RESULTS: We found significantly increased risk of an arrhythmic event with increasing CHADS₂ score (CHADS₂ score=1-2: HR=2.1 [1.1-3.9], p=0.021, CHADS₂ score ≥ 3...

Importance of the atrial channel for ventricular arrhythmia therapy in the dual chamber implantable cardioverter defibrillator.

Science.gov (United States)

Dijkman, B; Wellens, H J

2000-12-01

Performance of dual chamber implantable cardioverter defibrillator (ICD) systems has been judged based on functioning of the ventricular tachycardia:supraventricular tachycardia (VT:SVT) discrimination criteria and DDD pacing. The purpose of this study was to evaluate the use of dual chamber diagnostics to improve the electrical and antiarrhythmic therapy of ventricular arrhythmias. Information about atrial and ventricular rhythm in relation to ventricular arrhythmia occurrence and therapy was evaluated in 724 spontaneous arrhythmia episodes detected and treated by three types of dual chamber ICDs in 41 patients with structural heart disease. Device programming was based on clinically documented and induced ventricular arrhythmias. In ambulatory patients, sinus tachycardia preceded ventricular arrhythmias more often than in the hospital during exercise testing. The incidence of these VTs could be reduced by increasing the dose of a beta-blocking agent in only two patients. In five patients in whom sinus tachycardia developed after onset of hemodynamic stable VT, propranolol was more effective than Class III antiarrhythmics combined with another beta-blocking agent with regard to the incidence of VT and pace termination. In all but three cases, atrial arrhythmias were present for a longer time before the onset of ventricular arrhythmias. During atrial arrhythmias, fast ventricular rates before the onset of ventricular rate were observed more often than RR irregularities and short-long RR sequences. Dual chamber diagnostics allowed proper interpretation of detection and therapy outcome in patients with different types of ventricular arrhythmia. The advantages of the dual chamber ICD system go further than avoiding the shortcomings of the single chamber system. Information from the atrial chamber allows better device programming and individualization of drug therapy for ventricular arrhythmia.

Protective effects of isorhynchophylline on cardiac arrhythmias in rats and guinea pigs.

Science.gov (United States)

Gan, Runtao; Dong, Guo; Yu, Jiangbo; Wang, Xu; Fu, Songbin; Yang, Shusen

2011-09-01

As one important constituent extracted from a traditional Chinese medicine, Uncaria Rhynchophylla Miq Jacks, isorhynchophylline has been used to treat hypertension, epilepsy, headache, and other illnesses. Whether isorhynchophylline protects hearts against cardiac arrhythmias is still incompletely investigated. This study was therefore aimed to examine the preventive effects of isorhynchophylline on heart arrhythmias in guinea pigs and rats and then explore their electrophysiological mechanisms. In vivo, ouabain and calcium chloride were used to establish experimental arrhythmic models in guinea pigs and rats. In vitro, the whole-cell patch-lamp technique was used to study the effect of isorhynchophylline on action potential duration and calcium channels in acutely isolated guinea pig and rat cardiomyocytes. The dose of ouabain required to induce cardiac arrhythmias was much larger in guinea pigs administered with isorhynchophylline. Additionally, the onset time of cardiac arrhythmias induced by calcium chloride was prolonged, and the duration was shortened in rats pretreated with isorhynchophylline. The further study showed that isorhynchophylline could significantly decrease action potential duration and inhibit calcium currents in isolated guinea pig and rat cardiomyocytes in a dose-dependent manner. In summary, isorhynchophylline played a remarkably preventive role in cardiac arrhythmias through the inhibition of calcium currents in rats and guinea pigs. © Georg Thieme Verlag KG Stuttgart · New York.

Patient characteristics associated with false arrhythmia alarms in intensive care

Directory of Open Access Journals (Sweden)

Harris PR

2017-04-01

Full Text Available Patricia R Harris,1,2 Jessica K Zègre-Hemsey,3,4 Daniel Schindler,5 Yong Bai,6 Michele M Pelter,2,7 Xiao Hu2,8 1Department of Nursing, School of Health and Natural Sciences, Dominican University of California, San Rafael, 2Department of Physiological Nursing, School of Nursing, University of California, San Francisco, CA, 3School of Nursing, 4Department of Emergency Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, 5Intensive Care Unit, The Neuroscience Center, Sutter Eden Medical Center, Castro Valley, 6Hu Research Laboratory, Department of Physiological Nursing, School of Nursing, University of California, San Francisco, 7ECG Monitoring Research Lab, Department of Physiological Nursing, School of Nursing, 8Physiological Nursing and Neurological Surgery, Affiliate Faculty of Institute for Computational Health Sciences Core Faculty UCB/UCSF Joint Bio-Engineering Graduate Program, University of California, San Francisco, CA, USA Introduction: A high rate of false arrhythmia alarms in the intensive care unit (ICU leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective: The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods: This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and

Risk of arrhythmia induced by psychotropic medications

DEFF Research Database (Denmark)

Fanoe, Søren; Kristensen, Diana; Fink-Jensen, Anders

2014-01-01

with psychotropic medications. The algorithm integrates the risk categories of the individual drugs and pre-disposing risk factors and suggests a prudent follow-up for patients with an increased risk. We believe this clinically manageable guideline might improve safety in the many and rapidly increasing number...... of the major mental disorders are associated with a large risk of suicide if untreated. The observed risk of malignant arrhythmia associated with treatment with psychotropic drugs calls for clinical guidelines integrating the risk of the individual drug and other potentially interacting risk factors......Several drugs used in the treatment of mental diseases are associated with an increased risk of sudden cardiac death (SCD). A general cause-relationship between the intake of these drugs and SCD is unattainable, but numerous case reports of drug-induced malignant arrhythmia and epidemiological...

Effect of Cardiac Arrhythmia Simulation on Nursing Students' Knowledge Acquisition and Retention.

Science.gov (United States)

Tubaishat, Ahmad; Tawalbeh, Loai I

2015-09-01

The realistic and practical environment that simulation provides is an extremely useful part of the teaching process. Simulation is widely used in health and nursing education today. This study aims to evaluate the effect of simulation-based teaching on the acquisition and retention of arrhythmia-related knowledge among nursing students. A randomized controlled design involving a pretest-posttest was used. Nursing students were allocated randomly either to the experimental group (n = 47), who attended simulation scenarios on cardiac arrhythmia, or to the control group (n = 44) who received a traditional lecture on the same topic. A paired t test showed that the mean knowledge score at the posttest was significantly higher than at the pretest for both groups. However, participants in the experimental group demonstrated significantly increased knowledge of cardiac arrhythmia in the first and the second posttest compared with those in the control group. Thus, simulation is superior and significantly improves students' arrhythmia knowledge. © The Author(s) 2014.

Interactions between pacing and arrhythmia detection algorithms in the dual chamber implantable cardioverter defibrillator.

Science.gov (United States)

Dijkman, B; Wellens, H J

2001-09-01

Dual chamber implantable cardioverter defibrillator (ICD) combines the possibility to detect and treat ventricular and atrial arrhythmias with the possibility of modern heart stimulation techniques. Advanced pacing algorithms together with extended arrhythmia detection capabilities can give rise to new types of device-device interactions. Some of the possible interactions are illustrated by four cases documented in four models of dual chamber ICDs. Functioning of new features in dual chamber devices is influenced by the fact that the pacemaker is not a separate device but a part of the ICD system and that both are being used in a patient with arrhythmia. Programming measures are suggested to optimize use of new pacing algorithms while maintaining correct arrhythmia detection.

Risk of Ventricular Arrhythmia with Citalopram and Escitalopram: A Population-Based Study.

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Elena Qirjazi

Full Text Available The risk of ventricular arrhythmia with citalopram and escitalopram is controversial. In this study we investigated the association between these two drugs and the risk of ventricular arrhythmia.We conducted a population-based retrospective cohort study of older adults (mean age 76 years from 2002 to 2012 in Ontario, Canada, newly prescribed citalopram (n = 137 701 or escitalopram (n = 38 436, compared to those prescribed referent antidepressants sertraline or paroxetine (n = 96 620. After inverse probability of treatment weighting using a propensity score, the baseline characteristics of the comparison groups were similar. The primary outcome was a hospital encounter with ventricular arrhythmia within 90 days of a new prescription, assessed using hospital diagnostic codes. The secondary outcome was all-cause mortality within 90 days.Citalopram was associated with a higher risk of a hospital encounter with ventricular arrhythmia compared with referent antidepressants (0.06% vs. 0.04%, relative risk [RR] 1.53, 95% confidence intervals [CI]1.03 to 2.29, and a higher risk of mortality (3.49% vs. 3.12%, RR 1.12, 95% CI 1.06 to 1.18. Escitalopram was not associated with a higher risk of ventricular arrhythmia compared with the referent antidepressants (0.03% vs. 0.04%, RR 0.84, 95% CI 0.42 to 1.68, but was associated with a higher risk of mortality (2.86% vs. 2.63%, RR 1.09, 95% CI 1.01 to 1.18.Among older adults, initiation of citalopram compared to two referent antidepressants was associated with a small but statistically significant increase in the 90-day risk of a hospital encounter for ventricular arrhythmia.

Risk of Ventricular Arrhythmia with Citalopram and Escitalopram: A Population-Based Study.

Science.gov (United States)

Qirjazi, Elena; McArthur, Eric; Nash, Danielle M; Dixon, Stephanie N; Weir, Matthew A; Vasudev, Akshya; Jandoc, Racquel; Gula, Lorne J; Oliver, Matthew J; Wald, Ron; Garg, Amit X

2016-01-01

The risk of ventricular arrhythmia with citalopram and escitalopram is controversial. In this study we investigated the association between these two drugs and the risk of ventricular arrhythmia. We conducted a population-based retrospective cohort study of older adults (mean age 76 years) from 2002 to 2012 in Ontario, Canada, newly prescribed citalopram (n = 137 701) or escitalopram (n = 38 436), compared to those prescribed referent antidepressants sertraline or paroxetine (n = 96 620). After inverse probability of treatment weighting using a propensity score, the baseline characteristics of the comparison groups were similar. The primary outcome was a hospital encounter with ventricular arrhythmia within 90 days of a new prescription, assessed using hospital diagnostic codes. The secondary outcome was all-cause mortality within 90 days. Citalopram was associated with a higher risk of a hospital encounter with ventricular arrhythmia compared with referent antidepressants (0.06% vs. 0.04%, relative risk [RR] 1.53, 95% confidence intervals [CI]1.03 to 2.29), and a higher risk of mortality (3.49% vs. 3.12%, RR 1.12, 95% CI 1.06 to 1.18). Escitalopram was not associated with a higher risk of ventricular arrhythmia compared with the referent antidepressants (0.03% vs. 0.04%, RR 0.84, 95% CI 0.42 to 1.68), but was associated with a higher risk of mortality (2.86% vs. 2.63%, RR 1.09, 95% CI 1.01 to 1.18). Among older adults, initiation of citalopram compared to two referent antidepressants was associated with a small but statistically significant increase in the 90-day risk of a hospital encounter for ventricular arrhythmia.

Cardiac Arrhythmia Classification by Multi-Layer Perceptron and Convolution Neural Networks

Directory of Open Access Journals (Sweden)

Shalin Savalia

2018-05-01

Full Text Available The electrocardiogram (ECG plays an imperative role in the medical field, as it records heart signal over time and is used to discover numerous cardiovascular diseases. If a documented ECG signal has a certain irregularity in its predefined features, this is called arrhythmia, the types of which include tachycardia, bradycardia, supraventricular arrhythmias, and ventricular, etc. This has encouraged us to do research that consists of distinguishing between several arrhythmias by using deep neural network algorithms such as multi-layer perceptron (MLP and convolution neural network (CNN. The TensorFlow library that was established by Google for deep learning and machine learning is used in python to acquire the algorithms proposed here. The ECG databases accessible at PhysioBank.com and kaggle.com were used for training, testing, and validation of the MLP and CNN algorithms. The proposed algorithm consists of four hidden layers with weights, biases in MLP, and four-layer convolution neural networks which map ECG samples to the different classes of arrhythmia. The accuracy of the algorithm surpasses the performance of the current algorithms that have been developed by other cardiologists in both sensitivity and precision.

Cardiac Arrhythmia Classification by Multi-Layer Perceptron and Convolution Neural Networks.

Science.gov (United States)

Savalia, Shalin; Emamian, Vahid

2018-05-04

The electrocardiogram (ECG) plays an imperative role in the medical field, as it records heart signal over time and is used to discover numerous cardiovascular diseases. If a documented ECG signal has a certain irregularity in its predefined features, this is called arrhythmia, the types of which include tachycardia, bradycardia, supraventricular arrhythmias, and ventricular, etc. This has encouraged us to do research that consists of distinguishing between several arrhythmias by using deep neural network algorithms such as multi-layer perceptron (MLP) and convolution neural network (CNN). The TensorFlow library that was established by Google for deep learning and machine learning is used in python to acquire the algorithms proposed here. The ECG databases accessible at PhysioBank.com and kaggle.com were used for training, testing, and validation of the MLP and CNN algorithms. The proposed algorithm consists of four hidden layers with weights, biases in MLP, and four-layer convolution neural networks which map ECG samples to the different classes of arrhythmia. The accuracy of the algorithm surpasses the performance of the current algorithms that have been developed by other cardiologists in both sensitivity and precision.

Hypertension and Cardiac Arrhythmias

DEFF Research Database (Denmark)

Lip, Gregory Y H; Coca, Antonio; Kahan, Thomas

2017-01-01

Hypertension (HTN) is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease (CAD), stroke, peripheral artery disease and chronic renal failure. Hypertensive heart disease can manifest as many types of cardiac arrhythmias, most commonly being atrial fibrillation......) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit of comprehensively reviewing the available evidence...

Exercising arrhythmias and sudden cardiac death in horses: Review of the literature and comparative aspects.

Science.gov (United States)

Navas de Solis, C

2016-07-01

Arrhythmias are common in equine athletes during and immediately after exercise. Many of these rhythm variations are not clinically relevant. In horses, a link between different exercising arrhythmias and poor performance or between exercising arrhythmias and sudden cardiac death (SCD) is strongly suspected but not fully understood or proven. SCD during races or competitions is rare, but has catastrophic consequences for the safety of the human partner and public perceptions of welfare during equestrian sports. This review summarises current knowledge of equine exercise arrhythmias and their implications in SCD and compares existing principles and recommendations for equine subjects with those for human athletes. © 2016 EVJ Ltd.

Thyroid hormones and cardiac arrhythmias

Czech Academy of Sciences Publication Activity Database

Tribulová, N.; Knezl, V.; Shainberg, A.; Seki, S.; Soukup, Tomáš

2010-01-01

Roč. 52, 3-4 (2010), s. 102-112 ISSN 1537-1891 R&D Projects: GA ČR(CZ) GA304/08/0256 Grant - others:VEGA(SK) 2/0049/09; APVV(SK) 51-059505; APVV(SK) 51-017905 Institutional research plan: CEZ:AV0Z50110509 Keywords : thyroid hormone * arrhythmias * ion channels * connexin-43 Subject RIV: FA - Cardiovascular Disease s incl. Cardiotharic Surgery Impact factor: 2.174, year: 2010

Quantitative Assessment of Arrhythmia Using Non-linear Approach: A Non-invasive Prognostic Tool

Science.gov (United States)

Chakraborty, Monisha; Ghosh, Dipak

2018-04-01

Accurate prognostic tool to identify severity of Arrhythmia is yet to be investigated, owing to the complexity of the ECG signal. In this paper, we have shown that quantitative assessment of Arrhythmia is possible using non-linear technique based on "Hurst Rescaled Range Analysis". Although the concept of applying "non-linearity" for studying various cardiac dysfunctions is not entirely new, the novel objective of this paper is to identify the severity of the disease, monitoring of different medicine and their dose, and also to assess the efficiency of different medicine. The approach presented in this work is simple which in turn will help doctors in efficient disease management. In this work, Arrhythmia ECG time series are collected from MIT-BIH database. Normal ECG time series are acquired using POLYPARA system. Both time series are analyzed in thelight of non-linear approach following the method "Rescaled Range Analysis". The quantitative parameter, "Fractal Dimension" (D) is obtained from both types of time series. The major finding is that Arrhythmia ECG poses lower values of D as compared to normal. Further, this information can be used to access the severity of Arrhythmia quantitatively, which is a new direction of prognosis as well as adequate software may be developed for the use of medical practice.

Inhibition of Rac1 reduces store overload-induced calcium release and protects against ventricular arrhythmia.

Science.gov (United States)

Zhang, Lili; Lu, Xiangru; Gui, Le; Wu, Yan; Sims, Stephen M; Wang, Guoping; Feng, Qingping

2016-08-01

Rac1 is a small GTPase and plays key roles in multiple cellular processes including the production of reactive oxygen species (ROS). However, whether Rac1 activation during myocardial ischaemia and reperfusion (I/R) contributes to arrhythmogenesis is not fully understood. We aimed to study the effects of Rac1 inhibition on store overload-induced Ca(2+) release (SOICR) and ventricular arrhythmia during myocardial I/R. Adult Rac1(f/f) and cardiac-specific Rac1 knockdown (Rac1(ckd) ) mice were subjected to myocardial I/R and their electrocardiograms (ECGs) were monitored for ventricular arrhythmia. Myocardial Rac1 activity was increased and ventricular arrhythmia was induced during I/R in Rac1(f/f) mice. Remarkably, I/R-induced ventricular arrhythmia was significantly decreased in Rac1(ckd) compared to Rac1(f/f) mice. Furthermore, treatment with Rac1 inhibitor NSC23766 decreased I/R-induced ventricular arrhythmia. Ca(2+) imaging analysis showed that in response to a 6 mM external Ca(2+) concentration challenge, SOICR was induced with characteristic spontaneous intracellular Ca(2+) waves in Rac1(f/f) cardiomyocytes. Notably, SOICR was diminished by pharmacological and genetic inhibition of Rac1 in adult cardiomyocytes. Moreover, I/R-induced ROS production and ryanodine receptor 2 (RyR2) oxidation were significantly inhibited in the myocardium of Rac1(ckd) mice. We conclude that Rac1 activation induces ventricular arrhythmia during myocardial I/R. Inhibition of Rac1 suppresses SOICR and protects against ventricular arrhythmia. Blockade of Rac1 activation may represent a new paradigm for the treatment of cardiac arrhythmia in ischaemic heart disease. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Immediate postoperative digitalization in the prophylaxis of supraventricular arrhythmias following coronary artery bypass.

Science.gov (United States)

Csicsko, J F; Schatzlein, M H; King, R D

1981-03-01

Regimens of acute preoperative digitalization have been evaluated previously in the prophylaxis of supraventricular tachycardias (SVT) following coronary artery bypass operations, with equivocal results. This study assesses the effectiveness of immediate postoperative digitalization on the incidence of arrhythmias in 407 consecutive patients recovering from myocardial revascularization. In 137 patients treated by our regimen, which begins digitalization within 4 hours postoperatively, the incidence of supraventricular tachyarrhythmias was 2%, while the corresponding figure for 270 untreated patients was 15%. Digitalization reduced the incidence of supraventricular arrhythmias significantly (p less than 0.01), whereas death, ventricular ectopy, and infarction rates were similar in the two groups. The few patients who did have supraventricular arrhythmias while receiving prophylactic digoxin were no more easily treated than patients in the undigitalized group. The timing of administration of digoxin for SVT prophylaxis may be more important than previously recognized. Immediately postoperative digitalization, theoretically preferable to preoperative regimens, is a safe, effective way to reduce the incidence of supraventricular arrhythmias following myocardial revascularization.

[Observation of antiarrhythmic effects of Cinnamomum migao H. W. Li on experimental arrhythmia].

Science.gov (United States)

Sui, Y; Qiu, D; Xie, C; Chen, K

1998-08-01

To investigate the effects of Cinnamomum migao on experimental arrhythmia. Arrhythmic models of mice, rabbits, guinea pigs and rats were built using chloroform(Chl), adrenalin(Adr), strophanthin-K (Spt-K) and barium chloride (BaCl2). The affected animals were divided randomly into three groups: control group, Cinnamomum migao (CV-3) group and mexiletine (MXL) group, so as to observe and compare the antiarrhythmic effects. CV-3 could reduce the incidence of ventricular fibrillation caused by ch1 in mice and the ventricular tachycardia induced by Adr in rabbits, delay the onset time of this arrhythmia, increase the arrhythmic doses of Spt-K in guinea pigs, reduce the incidence of some arrhythmia caused by BaCl2 in rats and slow down their heart rate. CV-3 has obvious antiarrhythmic effects on experimental arrhythmia. The mechanism of these effects is probably related to the arrest of the intraflow of Na+, Ca2+ in the cardiac cells and the depression of their cardiac autoarrhythmicity and conductivity.

Gene Therapy in Cardiac Arrhythmias

OpenAIRE

Praveen, S.V; Francis, Johnson; Venugopal, K

2006-01-01

Gene therapy has progressed from a dream to a bedside reality in quite a few human diseases. From its first application in adenosine deaminase deficiency, through the years, its application has evolved to vascular angiogenesis and cardiac arrhythmias. Gene based biological pacemakers using viral vectors or mesenchymal cells tested in animal models hold much promise. Induction of pacemaker activity within the left bundle branch can provide stable heart rates. Genetic modification of the AV...

Long-term neurodevelopmental outcome after fetal arrhythmia

NARCIS (Netherlands)

Lopriore, Enrico; Aziz, Muhammed I.; Nagel, Helene T.; Blom, Nico A.; Rozendaal, Lieke; Kanhai, Humphrey H. H.; Vandenbussche, Frank P. H. A.

2009-01-01

OBJECTIVE: The purpose of this study was to determine the long-term neurodevelopmental outcome in fetuses with severe tachy- or bradyarrhythmia. STUDY DESIGN: This was a follow-up study to assess the neurologic, mental, and psychomotor development in cases with fetal cardiac arrhythmia. RESULTS: A

Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

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Tassi, Eduardo Marinho, E-mail: etassi@ibest.com.br [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Continentino, Marcelo Abramoff [Hospital Frei Galvão, Guaratinguetá, SP (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Coppe - Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia - UFRJ, Rio de Janeiro, RJ (Brazil); Pedrosa, Roberto Coury [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

2014-05-15

Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups.

Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

International Nuclear Information System (INIS)

Tassi, Eduardo Marinho; Continentino, Marcelo Abramoff; Nascimento, Emília Matos do; Pereira, Basílio de Bragança; Pedrosa, Roberto Coury

2014-01-01

Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups

Non-sedating antihistamine drugs and cardiac arrhythmias -- biased risk estimates from spontaneous reporting systems?

DEFF Research Database (Denmark)

De Bruin, M L; van Puijenbroek, E P; Egberts, A C G

2002-01-01

AIMS: This study used spontaneous reports of adverse events to estimate the risk for developing cardiac arrhythmias due to the systemic use of non-sedating antihistamine drugs and compared the risk estimate before and after the regulatory action to recall the over-the-counter status of some...... of these drugs. METHODS: All suspected adverse drug reactions (ADRs) reported until July 1999 to the Netherlands Pharmacovigilance Foundation Lareb were used to calculate the ADR reporting odds ratio, defined as the ratio of exposure odds among reported arrhythmia cases, to the exposure odds of other ADRs (non......-sedating antihistamines. In general non-sedating antihistamines are associated with cardiac arrhythmia to a higher extent in comparison with other drugs (ADR reporting odds ratio 2.05 [95% CI: 1.45, 2.89]). The association between arrhythmias and non-sedating antihistamine drugs calculated before 1998...

Non-sedating antihistamine drugs and cardiac arrhythmias -- biased risk estimates from spontaneous reporting systems?

DEFF Research Database (Denmark)

De Bruin, M L; van Puijenbroek, E P; Egberts, A C G

2002-01-01

of these drugs. METHODS: All suspected adverse drug reactions (ADRs) reported until July 1999 to the Netherlands Pharmacovigilance Foundation Lareb were used to calculate the ADR reporting odds ratio, defined as the ratio of exposure odds among reported arrhythmia cases, to the exposure odds of other ADRs (non......-sedating antihistamines. In general non-sedating antihistamines are associated with cardiac arrhythmia to a higher extent in comparison with other drugs (ADR reporting odds ratio 2.05 [95% CI: 1.45, 2.89]). The association between arrhythmias and non-sedating antihistamine drugs calculated before 1998...

Chronic cardiac arrhythmias produced by focused cobalt-60 gamma irradiation of the canine atria

International Nuclear Information System (INIS)

Dick, H.L.H.; Saylor, C.B.; Reeves, M.M.; Davies, M.J.

1979-01-01

Cardiac arrhythmias following exposure of the human heart to ionizing radiation have been reported. Earlier experiments involving irradiation of the hearts of various animals failed to consistently produce similar arrhythmias. In the present work, cobalt-60 irradiation was focused on the interatrial septum of the hearts of 12 dogs. Ten animals developed arrhythmias: These were repetive junctional and atrial tachycardias, repetitive atrial fibrillation, and type one, second-degree atrial ventricular block. The duration varied from 1 to 52 days, with onsets varying from 48 to 146 days postirradiation

Cardiac arrhythmias associated with spinal cord injury

DEFF Research Database (Denmark)

Hector, Sven Magnus; Biering-Sørensen, Tor; Krassioukov, Andrei

2013-01-01

CONTEXT/OBJECTIVES: To review the current literature to reveal the incidence of cardiac arrhythmias and its relation to spinal cord injury (SCI). METHODS: Data source: MEDLINE database, 304 hits, and 32 articles were found to be relevant. The relevant articles all met the inclusion criteria: (1...

The Effect of PM 10 on Ischemia- Reperfusion Induced Arrhythmias in Rats

Directory of Open Access Journals (Sweden)

Esmat Radmanesh

Full Text Available ABSTRACT Epidemiological studies show that particulate matter (PM is the principal instigator of some adverse clinical symptoms involving cardiovascular diseases. PM exposure can increase experimental infarct size and potentiate myocardial ischemia and arrhythmias in experimental MI models such as ischemia-reperfusion (I/R injury.The present study was aimed to evaluate the effects of particulate matter (PM10 on ischemia- reperfusion induced arrhythmias with emphasis on the protective role of VA as an antioxidant on them. Male Wistar rats were divided into 8 groups (n=10: Control, VAc, Sham, VA, PM1 (0.5 mg/kg, PM2 (2.5 mg/kg, PM3 group (5 mg/kg, PM3 + VA group. Within 48 hours, PM10 was instilled into trachea in two stages. Then the hearts were isolated, transferred to a Langendorff apparatus, and subjected to global ischemia (30 minutes followed by reperfusion (60 minutes. The ischemia- reperfusion induced ventricular arrhythmias were assessed according to the Lambeth conventions.In the present study,the number, incidence and duration of arrhythmiasduring30 minutes ischemia were demonstrated to be more than those in the reperfusion stage. PM exposure increased significantly the number, incidence and duration of arrhythmias in the ischemia and reperfusion duration. Vanillic acid reduced significantly the number, incidence and duration of arrhythmias during the ischemia and reperfusion period.In summary, the results of this study demonstrated that the protective and dysrhythmic effects of VA in the PM exposure rats in I/R model are probably related to its antioxidant properties.

A Novel Automatic Detection System for ECG Arrhythmias Using Maximum Margin Clustering with Immune Evolutionary Algorithm

Directory of Open Access Journals (Sweden)

Bohui Zhu

2013-01-01

Full Text Available This paper presents a novel maximum margin clustering method with immune evolution (IEMMC for automatic diagnosis of electrocardiogram (ECG arrhythmias. This diagnostic system consists of signal processing, feature extraction, and the IEMMC algorithm for clustering of ECG arrhythmias. First, raw ECG signal is processed by an adaptive ECG filter based on wavelet transforms, and waveform of the ECG signal is detected; then, features are extracted from ECG signal to cluster different types of arrhythmias by the IEMMC algorithm. Three types of performance evaluation indicators are used to assess the effect of the IEMMC method for ECG arrhythmias, such as sensitivity, specificity, and accuracy. Compared with K-means and iterSVR algorithms, the IEMMC algorithm reflects better performance not only in clustering result but also in terms of global search ability and convergence ability, which proves its effectiveness for the detection of ECG arrhythmias.

Electromechanical wave imaging for arrhythmias

International Nuclear Information System (INIS)

Provost, Jean; Nguyen, Vu Thanh-Hieu; Legrand, Diégo; Okrasinski, Stan; Costet, Alexandre; Konofagou, Elisa E; Gambhir, Alok; Garan, Hasan

2011-01-01

Electromechanical wave imaging (EWI) is a novel ultrasound-based imaging modality for mapping of the electromechanical wave (EW), i.e. the transient deformations occurring in immediate response to the electrical activation. The correlation between the EW and the electrical activation has been established in prior studies. However, the methods used previously to map the EW required the reconstruction of images over multiple cardiac cycles, precluding the application of EWI for non-periodic arrhythmias such as fibrillation. In this study, new imaging sequences are developed and applied based on flash- and wide-beam emissions to image the entire heart at very high frame rates (2000 fps) during free breathing in a single heartbeat. The methods are first validated by imaging the heart of an open-chest canine while simultaneously mapping the electrical activation using a 64-electrode basket catheter. Feasibility is then assessed by imaging the atria and ventricles of closed-chest, conscious canines during sinus rhythm and during right-ventricular pacing following atrio-ventricular dissociation, i.e., during a non-periodic rhythm. The EW was validated against electrode measurements in the open-chest case, and followed the expected electrical propagation pattern in the closed-chest setting. These results indicate that EWI can be used for the characterization of non-periodic arrhythmias in conditions similar to the clinical setting, in a single heartbeat, and during free breathing. (fast track communication)

Emerging molecular therapies targeting myocardial infarction-related arrhythmias

NARCIS (Netherlands)

Driessen, Helen E.; van Veen, Toon A. B.; Boink, Gerard J. J.

2017-01-01

Cardiac disease is the leading cause of death in the developed world. Ventricular arrhythmias associated with myocardial ischaemia and/or infarction are a major contributor to cardiovascular mortality, and require improved prevention and treatment. Drugs, devices, and radiofrequency catheter

Multiclass Classification of Cardiac Arrhythmia Using Improved Feature Selection and SVM Invariants.

Science.gov (United States)

Mustaqeem, Anam; Anwar, Syed Muhammad; Majid, Muahammad

2018-01-01

Arrhythmia is considered a life-threatening disease causing serious health issues in patients, when left untreated. An early diagnosis of arrhythmias would be helpful in saving lives. This study is conducted to classify patients into one of the sixteen subclasses, among which one class represents absence of disease and the other fifteen classes represent electrocardiogram records of various subtypes of arrhythmias. The research is carried out on the dataset taken from the University of California at Irvine Machine Learning Data Repository. The dataset contains a large volume of feature dimensions which are reduced using wrapper based feature selection technique. For multiclass classification, support vector machine (SVM) based approaches including one-against-one (OAO), one-against-all (OAA), and error-correction code (ECC) are employed to detect the presence and absence of arrhythmias. The SVM method results are compared with other standard machine learning classifiers using varying parameters and the performance of the classifiers is evaluated using accuracy, kappa statistics, and root mean square error. The results show that OAO method of SVM outperforms all other classifiers by achieving an accuracy rate of 81.11% when used with 80/20 data split and 92.07% using 90/10 data split option.

Dofetilide: a new drug to control cardiac arrhythmia

DEFF Research Database (Denmark)

Elming, Hanne; Brendorp, Bente; Pedersen, Ole Dyg

2003-01-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Mortality, and especially morbidity caused by AF, are major and growing health problems in the western world. AF is strongly associated with arterial hypertension, congestive heart failure, valvular heart disease, ischaemic heart...

Surgical outcome of Fontan conversion and arrhythmia surgery: Need a pacemaker?

Science.gov (United States)

Terada, Takafumi; Sakurai, Hajime; Nonaka, Toshimichi; Sakurai, Takahisa; Sugiura, Junya; Taneichi, Tetsuyoshi; Ohtsuka, Ryohei

2014-07-01

Atrial tachyarrhythmias are frequent complications in the late period after the Fontan procedure, and important risk factors for a poor prognosis. The impact of Fontan conversion and arrhythmia surgery in failed Fontan patients has been described in many reports. We evaluated our experience with Fontan conversion procedures, concomitant arrhythmia surgery, and pacemaker implantation. We reviewed the hospital records of 25 consecutive patients who underwent a Fontan conversion procedure from January 2004 to March 2012. Twenty-four patients had arrhythmia surgery using cryoablation and radiofrequency ablation at the time of conversion. A bilateral atrial maze procedure was performed in 6 patients, right-side maze in 15, and isthmus block in 3. Three patients with a diagnosis of corrected transposition of the great arteries underwent simultaneous pacemaker implantation electively. There was no early death and one late death during a mean follow-up period of 21.2 months. Three tachyarrhythmia recurrences developed, and there were 4 occurrences of sinus bradycardia. Five of these patients required postoperative pacemaker implantation. The mid-term results of Fontan conversion and arrhythmia surgery in our institute were satisfactory. The occurrence of unexpected postoperative pacemaker requirement was high in the patients who underwent a right atrial or bilateral atrial maze procedure. Pacemaker or lead implantation is recommended for patients planned to undergo a right-side or full maze procedure. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Prediction of tonic parasympathetic cardiac control using respiratory sinus arrhythmia: the need for respiratory control

NARCIS (Netherlands)

GROSSMAN, P.; Karemaker, J.; Wieling, W.

1991-01-01

Respiratory sinus arrhythmia (RSA) has received much attention in recent years due to the large body of evidence indicating that variations in this phenomenon represent alterations in parasympathetic cardiac control. Although it appears that respiratory sinus arrhythmia is mediated by vagal

Cardiac arrhythmia detection using combination of heart rate variability analyses and PUCK analysis.

Science.gov (United States)

Mahananto, Faizal; Igasaki, Tomohiko; Murayama, Nobuki

2013-01-01

This paper presents cardiac arrhythmia detection using the combination of a heart rate variability (HRV) analysis and a "potential of unbalanced complex kinetics" (PUCK) analysis. Detection performance was improved by adding features extracted from the PUCK analysis. Initially, R-R interval data were extracted from the original electrocardiogram (ECG) recordings and were cut into small segments and marked as either normal or arrhythmia. HRV analyses then were conducted using the segmented R-R interval data, including a time-domain analysis, frequency-domain analysis, and nonlinear analysis. In addition to the HRV analysis, PUCK analysis, which has been implemented successfully in a foreign exchange market series to characterize change, was employed. A decision-tree algorithm was applied to all of the obtained features for classification. The proposed method was tested using the MIT-BIH arrhythmia database and had an overall classification accuracy of 91.73%. After combining features obtained from the PUCK analysis, the overall accuracy increased to 92.91%. Therefore, we suggest that the use of a PUCK analysis in conjunction with HRV analysis might improve performance accuracy for the detection of cardiac arrhythmia.

Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy

International Nuclear Information System (INIS)

Saragoca, M.A.; Canziani, M.E.; Gil, M.A.; Castiglioni, M.L.; Cassiolato, J.L.; Barbieri, A.; Lima, V.C.; Draibe, S.A.; Martinez, E.E.

1991-01-01

In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, the authors investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. They observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of their patients with positive DTTs had unimpaired coronary circulations, they conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program

Arrhythmia recognition and classification using combined linear and nonlinear features of ECG signals.

Science.gov (United States)

Elhaj, Fatin A; Salim, Naomie; Harris, Arief R; Swee, Tan Tian; Ahmed, Taqwa

2016-04-01

Arrhythmia is a cardiac condition caused by abnormal electrical activity of the heart, and an electrocardiogram (ECG) is the non-invasive method used to detect arrhythmias or heart abnormalities. Due to the presence of noise, the non-stationary nature of the ECG signal (i.e. the changing morphology of the ECG signal with respect to time) and the irregularity of the heartbeat, physicians face difficulties in the diagnosis of arrhythmias. The computer-aided analysis of ECG results assists physicians to detect cardiovascular diseases. The development of many existing arrhythmia systems has depended on the findings from linear experiments on ECG data which achieve high performance on noise-free data. However, nonlinear experiments characterize the ECG signal more effectively sense, extract hidden information in the ECG signal, and achieve good performance under noisy conditions. This paper investigates the representation ability of linear and nonlinear features and proposes a combination of such features in order to improve the classification of ECG data. In this study, five types of beat classes of arrhythmia as recommended by the Association for Advancement of Medical Instrumentation are analyzed: non-ectopic beats (N), supra-ventricular ectopic beats (S), ventricular ectopic beats (V), fusion beats (F) and unclassifiable and paced beats (U). The characterization ability of nonlinear features such as high order statistics and cumulants and nonlinear feature reduction methods such as independent component analysis are combined with linear features, namely, the principal component analysis of discrete wavelet transform coefficients. The features are tested for their ability to differentiate different classes of data using different classifiers, namely, the support vector machine and neural network methods with tenfold cross-validation. Our proposed method is able to classify the N, S, V, F and U arrhythmia classes with high accuracy (98.91%) using a combined support

Ischaemic stroke in hyperthyroidism without cardiac arrhythmia - A ...

African Journals Online (AJOL)

BACKGROUND: The relationship between hyperthyroidism and stroke is well established in the setting of atrial fibrillation. However there is limited literature for ischaemic stroke occurring in hyperthyroidism without cardiac arrhythmia. No such case had been described in South East Nigeria. METHOD: This report highlights ...

Detection of Life Threatening Ventricular Arrhythmia Using Digital Taylor Fourier Transform.

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Tripathy, Rajesh K; Zamora-Mendez, Alejandro; de la O Serna, José A; Paternina, Mario R Arrieta; Arrieta, Juan G; Naik, Ganesh R

2018-01-01

Accurate detection and classification of life-threatening ventricular arrhythmia episodes such as ventricular fibrillation (VF) and rapid ventricular tachycardia (VT) from electrocardiogram (ECG) is a challenging problem for patient monitoring and defibrillation therapy. This paper introduces a novel method for detection and classification of life-threatening ventricular arrhythmia episodes. The ECG signal is decomposed into various oscillatory modes using digital Taylor-Fourier transform (DTFT). The magnitude feature and a novel phase feature namely the phase difference (PD) are evaluated from the mode Taylor-Fourier coefficients of ECG signal. The least square support vector machine (LS-SVM) classifier with linear and radial basis function (RBF) kernels is employed for detection and classification of VT vs. VF, non-shock vs. shock and VF vs. non-VF arrhythmia episodes. The accuracy, sensitivity, and specificity values obtained using the proposed method are 89.81, 86.38, and 93.97%, respectively for the classification of Non-VF and VF episodes. Comparison with the performance of the state-of-the-art features demonstrate the advantages of the proposition.

Loperamide Induced Life Threatening Ventricular Arrhythmia

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Ankit Upadhyay

2016-01-01

Full Text Available Loperamide is over-the-counter antidiarrheal agent acting on peripherally located μ opioid receptors. It is gaining popularity among drug abusers as opioid substitute. We report a case of a 46-year-old male that was presented after cardiac arrest. After ruling out ischemia, cardiomyopathy, pulmonary embolism, central nervous system pathology, sepsis, and other drug toxicity, we found out that patient was using around 100 mg of Loperamide to control his chronic diarrhea presumably because of irritable bowel syndrome for last five years and consumed up to 200 mg of Loperamide daily for last two days before the cardiac arrest. We hypothesize that the patient’s QTc prolongation and subsequent cardiac arrest are due to Loperamide toxicity. Patient experienced gradual resolution of tachyarrhythmia and gradual decrease in QTc interval during hospitalization which supports the evidence of causal relationship between Loperamide overdose and potentially fatal arrhythmias. It also provided the clue that patient may have congenital long QT syndrome which was unmasked by Loperamide causing ventricular arrhythmias. This case adds one more pearl in the literature to support that Loperamide overdose related cardiac toxicity does exist and it raises concerns over Loperamide abuse in the community.

Statins as anti-arrhythmics: a systematic review part II: effects on risk of ventricular arrhythmias.

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Abuissa, Hussam; O'Keefe, James H; Bybee, Kevin A

2009-10-01

Recent studies have demonstrated that statins may possess anti-arrhythmic properties in addition to their lipid-lowering effects. Studies which reported the association of statins with the incidence of ventricular arrhythmias were identified through a systematic review of the published literature. Statins have been associated with a significant reductions in ventricular arrhythmia in cardiomyopathy patients with an implantable cardioverter defibrillator, although randomized trials have not been completed. Published data suggests that statins may possess anti-arrhythmic properties that reduce the propensity for ventricular arrhythmias. Most of this data is observational; more randomized, placebo-controlled trials are needed.

Double hazards of ischemia and reperfusion arrhythmias in a patient with variant angina pectoris.

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Xu, Mingzhu; Yang, Xiangjun

2015-01-01

Variant angina pectoris, also called Prinzmetal's angina, is a syndrome caused by vasospasms of the coronary arteries. It can lead to myocardial infarction, ventricular arrhythmias, atrioventricular block and even sudden cardiac death. We report the case of a 53 year-old male patient with recurrent episodes of chest pain and arrhythmias in the course of related variant angina pectoris. It is likely that the reperfusion following myocardial ischemia was responsible for the ventricular fibrillation while the ST-segment returned to the baseline. This case showed that potential lethal arrhythmias could arise due to variant angina pectoris. It also indicated that ventricular fibrillation could be self-terminated. Copyright © 2015 Elsevier Inc. All rights reserved.

Decreasing the false alarm rate of arrhythmias in intensive care using a machine learning approach

NARCIS (Netherlands)

Eerikäinen, L.M.; Vanschoren, J.; Rooijakkers, M.J.; Vullings, R.; Aarts, R.M.

2015-01-01

We present a novel algorithm for classifying true and false alarms of five life-threatening arrhythmias in intensive care. This algorithm was entered in the PhysioNet/Computing in Cardiology Challenge 2015 Reducing False Arrhythmia Alarms in the ICU. The algorithm performs a binary classification of

Risk prediction of ventricular arrhythmias and myocardial function in Lamin A/C mutation positive subjects

DEFF Research Database (Denmark)

Hasselberg, Nina E; Edvardsen, Thor; Petri, Helle

2014-01-01

Mutations in the Lamin A/C gene may cause atrioventricular block, supraventricular arrhythmias, ventricular arrhythmias (VA), and dilated cardiomyopathy. We aimed to explore the predictors and the mechanisms of VA in Lamin A/C mutation-positive subjects.METHODS AND RESULTS: We included 41 Lamin A/C...

Automated testing of arrhythmia monitors using annotated databases.

Science.gov (United States)

Elghazzawi, Z; Murray, W; Porter, M; Ezekiel, E; Goodall, M; Staats, S; Geheb, F

1992-01-01

Arrhythmia-algorithm performance is typically tested using the AHA and MIT/BIH databases. The tools for this test are simulation software programs. While these simulations provide rapid results, they neglect hardware and software effects in the monitor. To provide a more accurate measure of performance in the actual monitor, a system has been developed for automated arrhythmia testing. The testing system incorporates an IBM-compatible personal computer, a digital-to-analog converter, an RS232 board, a patient-simulator interface to the monitor, and a multi-tasking software package for data conversion and communication with the monitor. This system "plays" patient data files into the monitor and saves beat classifications in detection files. Tests were performed using the MIT/BIH and AHA databases. Statistics were generated by comparing the detection files with the annotation files. These statistics were marginally different from those that resulted from the simulation. Differences were then examined. As expected, the differences were related to monitor hardware effects.

[Clinical aspects of reperfusion arrhythmia following intravenous thrombolysis in acute myocardial infarct].

Science.gov (United States)

Kettner, W; Klein, E; Schulz, W; Götze, C

1987-05-15

In accordance with the majority of the reports in the literature reperfusion arrhythmias were observed in more than 30% of the patients with acute myocardial infarction (n = 25) under or immediately after a highly dosed short-term infusion with streptokinase. With reference to indirect signs the recanalisation rate was assumed with 75%. Only one third of the reperfusion arrhythmias had haemodynamically significant characteristics and required an influence. Though in literature from animal experimental findings directive conclusions for the therapy are to be derived, the procedure in practice is still vastly empirical. In the ventricular tachycardia lidocaine, procainamide and ajmalin may be recommended. In ineffectiveness or particularly threatening situations the electrotherapy (cardioversion, DC-shock) is to be preferred. The concept inaugurated by Corr and Witkowski apply alpha-adrenoreceptor blockers has not yet entered the clinical practice. Possible problems in the treatment of reperfusion arrhythmias in the prehospital phase should at present still be a reason not to antedate the thrombolytic therapy into this phase.

Ubiquitous health monitoring and real-time cardiac arrhythmias detection: a case study.

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Li, Jian; Zhou, Haiying; Zuo, Decheng; Hou, Kun-Mean; De Vaulx, Christophe

2014-01-01

As the symptoms and signs of heart diseases that cause sudden cardiac death, cardiac arrhythmia has attracted great attention. Due to limitations in time and space, traditional approaches to cardiac arrhythmias detection fail to provide a real-time continuous monitoring and testing service applicable in different environmental conditions. Integrated with the latest technologies in ECG (electrocardiograph) analysis and medical care, the pervasive computing technology makes possible the ubiquitous cardiac care services, and thus brings about new technical challenges, especially in the formation of cardiac care architecture and realization of the real-time automatic ECG detection algorithm dedicated to care devices. In this paper, a ubiquitous cardiac care prototype system is presented with its architecture framework well elaborated. This prototype system has been tested and evaluated in all the clinical-/home-/outdoor-care modes with a satisfactory performance in providing real-time continuous cardiac arrhythmias monitoring service unlimitedly adaptable in time and space.

Metabolic Syndrome Remodels Electrical Activity of the Sinoatrial Node and Produces Arrhythmias in Rats

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Albarado-Ibañez, Alondra; Avelino-Cruz, José Everardo; Velasco, Myrian; Torres-Jácome, Julián; Hiriart, Marcia

2013-01-01

In the last ten years, the incidences of metabolic syndrome and supraventricular arrhythmias have greatly increased. The metabolic syndrome is a cluster of alterations, which include obesity, hypertension, hypertriglyceridemia, glucose intolerance and insulin resistance, that increase the risk of developing, among others, atrial and nodal arrhythmias. The aim of this study is to demonstrate that metabolic syndrome induces electrical remodeling of the sinus node and produces arrhythmias. We induced metabolic syndrome in 2-month-old male Wistar rats by administering 20% sucrose in the drinking water. Eight weeks later, the rats were anesthetized and the electrocardiogram was recorded, revealing the presence of arrhythmias only in treated rats. Using conventional microelectrode and voltage clamp techniques, we analyzed the electrical activity of the sinoatrial node. We observed that in the sinoatrial node of “metabolic syndrome rats”, compared to controls, the spontaneous firing of all cells decreased, while the slope of the diastolic depolarization increased only in latent pacemaker cells. Accordingly, the pacemaker currents If and Ist increased. Furthermore, histological analysis showed a large amount of fat surrounding nodal cardiomyocytes and a rise in the sympathetic innervation. Finally, Poincaré plot denoted irregularity in the R-R and P-P ECG intervals, in agreement with the variability of nodal firing potential recorded in metabolic syndrome rats. We conclude that metabolic syndrome produces a dysfunction SA node by disrupting normal architecture and the electrical activity, which could explain the onset of arrhythmias in rats. PMID:24250786

Magnesium sulphate and amiodarone prophylaxis for prevention of postoperative arrhythmia in coronary by-pass operations

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Huysal Kagan

2009-02-01

Full Text Available Abstract Background The aim of this study was to investigate the use of prophylactic magnesium sulphate and amiodarone in treating arrhythmias that may occur following coronary bypass grafting operations. Methods The study population consisted of 192 consecutive patients who were undergoing coronary artery bypass grafting (CABG. Sixty-four patients were given 3 g of magnesium sulphate (MgSO4 [20 ml = 24.32 mEq/L Mg+2] in 100 cc of isotonic 0.9% solution over 2 hours intravenously at the following times: 12 hours prior to the operation, immediately following the operation, and on postoperative days 1, 2, and 3 (Group 1. Another group of 64 patients was given a preoperative infusion of amiodarone (1200 mg on first post-operative day (Group 2. After the operation amiodarone was administered orally at a dose of 600 mg/day. Sixty-four patients in group 3 (control group had 100 cc. isotonic 0.9% as placebo, during the same time periods. Results In the postoperative period, the magnesium values were significantly higher in Group 1 than in Group 2 for all measurements. The use of amiodarone for total arrhythmia was significantly more effective than prophylactic treatment with magnesium sulphate (p = 0.015. There was no difference between the two drugs in preventing supraventricular arrhythmia, although amiodarone significantly delayed the revealing time of atrial fibrillation (p = 0.026. Ventricular arrhythmia, in the form of ventricular extra systole, was more common in the magnesium prophylaxis group. The two groups showed no significant differences in other operative or postoperative measurements. No side effects of the drugs were observed. Conclusion Prophylactic use of magnesium sulphate and amiodarone are both effective at preventing arrhythmia that may occur following coronary by-pass operations. Magnesium sulphate should be used in prophylactic treatment since it may decrease arrhythmia at low doses. If arrhythmia should occur despite this

Life threatening arrhythmias: Knowledge and skills among nurses ...

African Journals Online (AJOL)

Conclusion: Although the majority of the participants scored highly in their level of knowledge regarding life threatening arrhythmias, they scored poorly in most of the observed skills when identifying and treating this patient group. It is important that hospital administration take into consideration the identified areas of ...

Life threatening arrhythmias: Knowledge and skills among nurses ...

African Journals Online (AJOL)

User

this study was to assess knowledge and skills of nurses in identifying life ... Much of the literature considers ventricular tachycardia, ventricular fibrillation, ... In critical care settings, bedside nurses play a critical role in arrhythmia identification and ..... Lambert, V.A. & Lambert, C.E. (2008) Nurses' workplace stressors and ...

Intracoronary infusion of catecholamines causes focal arrhythmias in pigs.

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Doppalapudi, Harish; Jin, Qi; Dosdall, Derek J; Qin, Hao; Walcott, Gregory P; Killingsworth, Cheryl R; Smith, William M; Ideker, Raymond E; Huang, Jian

2008-09-01

Acute ischemia causes myriad changes including increased catecholamines. We tested the hypothesis that elevated catecholamines alone are arrhythmogenic. A 504 electrode sock was placed over both ventricles in six open-chest pigs. During control infusion of saline through a catheter in the left anterior descending coronary artery (LAD), no sustained arrhythmias occurred, and the refractory period estimated by the activation recovery interval (ARI) was 175 +/- 14 ms in the LAD bed below the catheter. After infusion of isoproterenol at 0.1 microg/kg/min through the catheter, the ARI in this bed was significantly reduced to 109 +/- 10 ms. A sharp gradient of refractoriness of 43 +/- 10 ms was at the border of the perfused bed. Sustained monomorphic ventricular tachycardia occurred after drug infusion in the perfused bed or near its boundary in all animals with a cycle length of 329 +/- 26 ms and a focal origin. The maximum slope of the ARI restitution curve at the focal origins of the tachyarrhythmias was always <1 (0.62 +/- 0.15). Similar results with a focal arrhythmia origin occurred in two additional pigs in which intramural mapping was performed with 36 plunge needle electrodes in the left ventricular perfused bed. Regional elevation of a catecholamine, which is one of the alterations produced by acute ischemia, can by itself cause tachyarrhythmias. These arrhythmias are closely associated with a shortened refractory period and a large gradient of the spatial distribution of refractoriness but not with a steep restitution curve.

Evaluation of heart rhythm variability and arrhythmia in children with systemic and localized scleroderma.

Science.gov (United States)

Wozniak, Jacek; Dabrowski, Rafal; Luczak, Dariusz; Kwiatkowska, Malgorzata; Musiej-Nowakowska, Elzbieta; Kowalik, Ilona; Szwed, Hanna

2009-01-01

To evaluate possible disturbances in autonomic regulation and cardiac arrhythmias in children with localized and systemic scleroderma. There were 40 children included in the study: 20 with systemic and 20 with localized scleroderma. The control group comprised 20 healthy children. In 24-hour Holter recording, the average rate of sinus rhythm was significantly higher in the groups with systemic and localized scleroderma than in the control group, but there was no significant difference between them. The variability of heart rhythm in both groups was significantly decreased. In the group with systemic scleroderma, single supraventricular ectopic beats were observed in 20% and runs were seen in 40% of patients. In the group with localized scleroderma, supraventricular single ectopic beats occurred in 35% of patients and runs in 45% of those studied. Ventricular arrhythmia occurred in 2 children with systemic scleroderma, but in 1 child, it was complex. The most frequent cardiac arrhythmias in both types of scleroderma in children were of supraventricular origin, whereas ventricular arrhythmias did not occur very often. There were no significant differences in autonomic disturbances manifesting as a higher heart rate and decreased heart rate variability between localized and systemic scleroderma.

Discrete potentials guided radiofrequency ablation for idiopathic outflow tract ventricular arrhythmias.

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Liu, Enzhao; Xu, Gang; Liu, Tong; Ye, Lan; Zhang, Qitong; Zhao, Yanshu; Li, Guangping

2015-03-01

Discrete potentials (DPs) have been recorded and targeted as the site of ablation of the outflow tract arrhythmias. The aim of the present study was to investigate the significance of DPs with respect to mapping and ablation for idiopathic outflow tract premature ventricular contractions (PVCs) or ventricular tachycardias (VTs). Seventeen consecutive patients with idiopathic right or left ventricular outflow tract PVCs/VTs who underwent radiofrequency catheter ablation were included. Intracardiac electrograms during the mapping and ablation were analysed. During sinus rhythm, sharp high-frequency DPs that displayed double or multiple components were recorded following or buried in the local ventricular electrograms in all of the 17 patients, peak amplitude 0.51 ± 0.21 mV. The same potential was recorded prior to the local ventricular potential of the PVCs/VTs. Spontaneous reversal of the relationship of the DPs to the local ventricular electrogram during the arrhythmias was noted. The DPs were related to a region of low voltage showed by intracardiac high-density contact mapping. At the sites with DPs, lower unipolar and bipolar ventricular voltage of sinus beats were noted compared with the adjacent regions without DPs (unipolar: 6.1 ± 1.8 vs. 8.3 ± 2.3 mV, P Discrete potentials were not present in seven controls. Discrete potentials and related low-voltage regions were common in idiopathic outflow tract ventricular arrhythmias. Discrete potential- and substrate-guided ablation strategy will help to reduce the recurrence of idiopathic outflow tract arrhythmias. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Temporal abstraction and inductive logic programming for arrhythmia recognition from electrocardiograms.

Science.gov (United States)

Carrault, G; Cordier, M-O; Quiniou, R; Wang, F

2003-07-01

This paper proposes a novel approach to cardiac arrhythmia recognition from electrocardiograms (ECGs). ECGs record the electrical activity of the heart and are used to diagnose many heart disorders. The numerical ECG is first temporally abstracted into series of time-stamped events. Temporal abstraction makes use of artificial neural networks to extract interesting waves and their features from the input signals. A temporal reasoner called a chronicle recogniser processes such series in order to discover temporal patterns called chronicles which can be related to cardiac arrhythmias. Generally, it is difficult to elicit an accurate set of chronicles from a doctor. Thus, we propose to learn automatically from symbolic ECG examples the chronicles discriminating the arrhythmias belonging to some specific subset. Since temporal relationships are of major importance, inductive logic programming (ILP) is the tool of choice as it enables first-order relational learning. The approach has been evaluated on real ECGs taken from the MIT-BIH database. The performance of the different modules as well as the efficiency of the whole system is presented. The results are rather good and demonstrate that integrating numerical techniques for low level perception and symbolic techniques for high level classification is very valuable.

Controversies in Cardiovascular Research: Induced pluripotent stem cell-derived cardiomyocytes – boutique science or valuable arrhythmia model?

Science.gov (United States)

Knollmann, Björn C

2013-01-01

As part of the series on Controversies in Cardiovascular Research, the article reviews the strengths and limitations of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) as models of cardiac arrhythmias. Specifically, the article attempts to answer the following questions: Which clinical arrhythmias can be modeled by iPSC-CM? How well can iPSC-CM model adult ventricular myocytes? What are the strengths and limitations of published iPSC-CM arrhythmia models? What new mechanistic insight has been gained? What is the evidence that would support using iPSC-CM to personalize anti-arrhythmic drug therapy? The review also discusses the pros and cons of using the iPSC-CM technology for modeling specific genetic arrhythmia disorders such as long QT syndrome, Brugada Syndrome or Catecholaminergic Polymorphic Ventricular Tachycardia. PMID:23569106

Electroversion in treatment of arrhythmia in a patient with Wolff-Parkinson-White syndrome and cervical spinal cord injury

Directory of Open Access Journals (Sweden)

SHEN Peng

2013-06-01

Full Text Available 【Abstract】We report electroversion in treatment of atrial fibrillation (AF and atrioventricular nodal reentry ta-chycardia (AVNRT in a patient with Wolff-Parkinson-White syndrome and cervical spinal cord injury. At first, the pa-tient sustained respiratory failure and weak cough reflex, thereafter repeated bronchoscopy was used to aspirate the sputum as well as control the pneumonia, which resulted in arrhythmia (AF and AVNRT. Two doses of intravenous amiodarone failed to correct the arrhythmia. After restora-tion of sinus rhythm by electroversion, he was successfully weaned from mechanical ventilation and discharged from the intensive care unit without recurrent arrhythmia. Key words: Arrhythmia, cardiac; Atrial fibrillation; Electric countershock; Wolff-Parkinson-White syndrome; Spinal cord injuries

The effect of Cardiac Arrhythmias Simulation Software on the nurses' learning and professional development.

Science.gov (United States)

Bazrafkan, Leila; Hemmati, Mehdi

2018-04-01

One of the important tasks of nurses in intensive care unit is interpretation of ECG. The use of training simulator is a new paradigm in the age of computers. This study was performed to evaluate the impact of cardiac arrhythmias simulator software on nurses' learning in the subspecialty Vali-Asr Hospital in 2016. This study was conducted by quasi-experimental randomized Salomon four group design with the participation of 120 nurses in subspecialty Vali-Asr Hospital in Tehran, Iran in 2016 that were selected purposefully and allocated in 4 groups. By this design other confounding factors such as the prior information, maturation and the role of sex and age were controlled by Solomon 4 design. The valid and reliable multiple choice test tools were used to gather information; the validity of the test was approved by experts and its reliability was obtained by Cronbach's alpha coefficient 0.89. At first, the knowledge and skills of the participants were assessed by a pre-test; following the educational intervention with cardiac arrhythmias simulator software during 14 days in ICUs, the mentioned factors were measured for the two groups again by a post-test in the four groups. Data were analyzed using the two way ANOVA. The significance level was considered as ptest results, using cardiac arrhythmias simulator software as an intervention was effective in the nurses' learning since a significant difference was found between pre-test and post-test in the first group (ptest showed that there was no interaction between pre-test and intervention in all of the three knowledge areas of cardiac arrhythmias, their treatments and their diagnosis (P>0.05). The use of software-based simulator for cardiac arrhythmias was effective in nurses' learning in light of its attractive components and interactive method. This intervention increased the knowledge of the nurses in cognitive domain of cardiac arrhythmias in addition to their diagnosis and treatment. Also, the package can be

Novel energy modalities for catheter ablation of cardiac arrhythmias : Pitfalls and possibilities of potent power sources

NARCIS (Netherlands)

Neven, K.G.E.J.

2014-01-01

The acceptance of catheter ablation as treatment for cardiac arrhythmias is amongst others dependent on its success rate, a high initial success rate will increase physician and patient acceptance. One of the reasons why recurrence of arrhythmia after ablation is substantial is non-transmurality of

Effects of short-term administration of estradiol on reperfusion arrhythmias in rats of different ages

International Nuclear Information System (INIS)

Savergnini, S.Q.; Reis, A.M.; Santos, R.A.S.; Santos, P.E.B.; Ferreira, A.J.; Almeida, A.P.

2012-01-01

Little is known about age-related differences in short-term effects of estradiol on ischemia-reperfusion (I/R) insults. The present study was designed to evaluate the effects of short-term treatment with estradiol on reperfusion arrhythmias in isolated hearts of 6-7-week-old and 12-14-month-old female rats. Wistar rats were sham-operated, ovariectomized and treated with vehicle or ovariectomized and treated with 17β-estradiol (E 2 ; 5 µg·100 g −1 ·day −1 ) for 4 days. Hearts were perfused by the Langendorff technique. Reperfusion arrhythmias, i.e., ventricular tachycardia and/or ventricular fibrillation, were induced by 15 min of left coronary artery ligation and 30 min of reperfusion. The duration and incidence of I/R arrhythmias were significantly higher in young rats compared to middle-aged rats (arrhythmia severity index: 9.4 ± 1.0 vs 3.0 ± 0.3 arbitrary units, respectively, P < 0.05). In addition, middle-aged rats showed lower heart rate, systolic tension and coronary flow. Four-day E 2 treatment caused an increase in uterine weight. Although E 2 administration had no significant effect on the duration of I/R arrhythmias in middle-aged rats, it induced a marked reduction in the rhythm disturbances of young rats accompanied by a decrease in heart rate of isolated hearts. Also, this reduction was associated with an increase in QT interval. No significant changes were observed in the QT interval of middle-aged E 2 -treated rats. These data demonstrate that short-term estradiol treatment protects against I/R arrhythmias in hearts of young female rats. The anti-arrhythmogenic effect of estradiol might be related to a lengthening of the QT interval

Effects of short-term administration of estradiol on reperfusion arrhythmias in rats of different ages

Energy Technology Data Exchange (ETDEWEB)

Savergnini, S.Q.; Reis, A.M. [Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Santos, R.A.S. [1Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Santos, P.E.B. [Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Ferreira, A.J. [Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Almeida, A.P. [Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

2012-11-01

Little is known about age-related differences in short-term effects of estradiol on ischemia-reperfusion (I/R) insults. The present study was designed to evaluate the effects of short-term treatment with estradiol on reperfusion arrhythmias in isolated hearts of 6-7-week-old and 12-14-month-old female rats. Wistar rats were sham-operated, ovariectomized and treated with vehicle or ovariectomized and treated with 17β-estradiol (E{sub 2}; 5 µg·100 g{sup −1}·day{sup −1}) for 4 days. Hearts were perfused by the Langendorff technique. Reperfusion arrhythmias, i.e., ventricular tachycardia and/or ventricular fibrillation, were induced by 15 min of left coronary artery ligation and 30 min of reperfusion. The duration and incidence of I/R arrhythmias were significantly higher in young rats compared to middle-aged rats (arrhythmia severity index: 9.4 ± 1.0 vs 3.0 ± 0.3 arbitrary units, respectively, P < 0.05). In addition, middle-aged rats showed lower heart rate, systolic tension and coronary flow. Four-day E{sub 2} treatment caused an increase in uterine weight. Although E{sub 2} administration had no significant effect on the duration of I/R arrhythmias in middle-aged rats, it induced a marked reduction in the rhythm disturbances of young rats accompanied by a decrease in heart rate of isolated hearts. Also, this reduction was associated with an increase in QT interval. No significant changes were observed in the QT interval of middle-aged E{sub 2}-treated rats. These data demonstrate that short-term estradiol treatment protects against I/R arrhythmias in hearts of young female rats. The anti-arrhythmogenic effect of estradiol might be related to a lengthening of the QT interval.

Symmetrical compression distance for arrhythmia discrimination in cloud-based big-data services.

Science.gov (United States)

Lillo-Castellano, J M; Mora-Jiménez, I; Santiago-Mozos, R; Chavarría-Asso, F; Cano-González, A; García-Alberola, A; Rojo-Álvarez, J L

2015-07-01

The current development of cloud computing is completely changing the paradigm of data knowledge extraction in huge databases. An example of this technology in the cardiac arrhythmia field is the SCOOP platform, a national-level scientific cloud-based big data service for implantable cardioverter defibrillators. In this scenario, we here propose a new methodology for automatic classification of intracardiac electrograms (EGMs) in a cloud computing system, designed for minimal signal preprocessing. A new compression-based similarity measure (CSM) is created for low computational burden, so-called weighted fast compression distance, which provides better performance when compared with other CSMs in the literature. Using simple machine learning techniques, a set of 6848 EGMs extracted from SCOOP platform were classified into seven cardiac arrhythmia classes and one noise class, reaching near to 90% accuracy when previous patient arrhythmia information was available and 63% otherwise, hence overcoming in all cases the classification provided by the majority class. Results show that this methodology can be used as a high-quality service of cloud computing, providing support to physicians for improving the knowledge on patient diagnosis.

Combination of opium smoking and hypercholesterolemia augments susceptibility for lethal cardiac arrhythmia and atherogenesis in rabbit.

Science.gov (United States)

Najafipour, Hamid; Joukar, Siyavash

2012-09-01

Opium consumption is increasing in some eastern societies, where it is grown. We investigated the effect of opium smoking on plasma atherogenic index and incidence of lethal cardiac arrhythmia, i.e. ventricular tachycardia (VT) and ventricular fibrillation (VF) in rabbits. Animals were divided into two-, normo- and hyper-cholesterolemic main groups fed with normal or high cholesterol diet prior and during short-term and long-term exposure to opium smoke. Then, isoproterenol (3mg/kg, i.p.) was injected to induce cardiac ischemia and animals were followed for 3h for counting of lethal arrhythmia incidence. Long-term opium smoking significantly increased the plasma atherogenic index. In ischemic hearts, opium smoking along with hypercholesterolemia significantly enhanced the incidence of fatal arrhythmia. This vulnerability was not mediated by changes in QT interval. These data suggest that opium smoking, especially in hypercholesterolemic conditions, can be a predisposing factor for atherogenesis and lethal arrhythmia. Copyright © 2012 Elsevier B.V. All rights reserved.

Arctigenin, a Potential Anti-Arrhythmic Agent, Inhibits Aconitine-Induced Arrhythmia by Regulating Multi-Ion Channels

Directory of Open Access Journals (Sweden)

Zhenying Zhao

2013-11-01

Full Text Available Background/Aims: Arctigenin possesses biological activities, but its underlying mechanisms at the cellular and ion channel levels are not completely understood. Therefore, the present study was designed to identify the anti-arrhythmia effect of arctigenin in vivo, as well as its cellular targets and mechanisms. Methods: A rat arrhythmia model was established via continuous aconitine infusion, and the onset times of ventricular premature contraction, ventricular tachycardia and death were recorded. The Action Potential Duration (APD, sodium current (INa, L-type calcium current (ICa, L and transient outward potassium current (Ito were measured and analysed using a patch-clamp recording technique in normal rat cardiomyocytes and myocytes of arrhythmia aconitine-induced by. Results: Arctigenin significantly delayed the arrhythmia onset in the aconitine-induced rat model. The 50% and 90% repolarisations (APD50 and APD90 were shortened by 100 µM arctigenin; the arctigenin dose also inhibited the prolongation of APD50 and APD90 caused by 1 µM aconitine. Arctigenin inhibited INa and ICa,L and attenuated the aconitine-increased INa and ICa,L by accelerating the activation process and delaying the inactivation process. Arctigenin enhanced Ito by facilitating the activation process and delaying the inactivation process, and recoverd the decreased Ito induced by aconitine. Conclusions: Arctigenin has displayed anti-arrhythmia effects, both in vivo and in vitro. In the context of electrophysiology, INa, ICa, L, and Ito may be multiple targets of arctigenin, leading to its antiarrhythmic effect.

Comparison of two teaching methods for cardiac arrhythmia interpretation among nursing students.

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Varvaroussis, Dimitrios P; Kalafati, Maria; Pliatsika, Paraskevi; Castrén, Maaret; Lott, Carsten; Xanthos, Theodoros

2014-02-01

The aim of this study was to compare the six-stage method (SSM) for instructing primary cardiac arrhythmias interpretation to students without basic electrocardiogram (ECG) knowledge with a descriptive teaching method in a single educational intervention. This is a randomized trial. Following a brief instructional session, undergraduate nursing students, assigned to group A (SSM) and group B (descriptive teaching method), undertook a written test in cardiac rhythm recognition, immediately after the educational intervention (initial exam). Participants were also examined with an unannounced retention test (final exam), one month after instruction. Altogether 134 students completed the study. Interpretation accuracy for each cardiac arrhythmia was assessed. Mean score at the initial exam was 8.71±1.285 for group A and 8.74±1.303 for group B. Mean score at the final exam was 8.25±1.46 for group A vs 7.84±1.44 for group B. Overall results showed that the SSM was equally effective with the descriptive teaching method. The study showed that in each group bradyarrhythmias were identified correctly by more students than tachyarrhythmias. No significant difference between the two teaching methods was seen for any specific cardiac arrhythmia. The SSM effectively develops staff competency for interpreting common cardiac arrhythmias in students without ECG knowledge. More research is needed to support this conclusion and the method's effectiveness must be evaluated if being implemented to trainee groups with preexisting basic ECG interpretation knowledge. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Cardiac Arrhythmia: Atrial Flutter in a Newborn. Case Study

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T.M. Klimenko

2014-09-01

Full Text Available The article gives case report of rare in neonatal period cardiac arrhythmia — atrial flutter. The disease is one of the manifestations of life-threatening heart rhythm disorders, has no characteristic clinical picture, is diagnosed only by means of an electrocardiogram.

[Intravenous nitroglycerin infusion suppresses exercise-induced arrhythmia in patients with ischemic cardiopathy: indications for chronic treatment ].

Science.gov (United States)

Bonetti, F; Margonato, A; Mailhac, A; Vicedomini, G; Cianflone, D; Scarpazza, P; Chierchia, S L

1990-05-01

In patients with ischemic heart disease and arrhythmias, selection of antiarrhythmic treatment is often difficult as it is hard to separate "primary" from ischemic arrhythmias. We studied 20 patients with ischemic heart disease, who developed ventricular arrhythmias consistently during exercise test. Exercise test was performed twice during infusion of placebo and then during intravenous administration of nitroglycerin, titrated to reduce systolic blood pressure by 10 mmHg. Exercise duration was 7.8 +/- 1.7 and 7.9 +/- 1.5 min, in the 2 placebo tests (NS). Angina developed in 5 patients and ischemic ST changes in 10. With nitroglycerin exercise duration increased to 8.4 +/- 20 min (p less than 0.05), diagnostic ST segment depression was observed in 2 patients and only 1 had angina. In all 20 patients, ventricular arrhythmias were consistently present during both tests on placebo, that were markedly reduced by nitroglycerin. In fact, ventricular ectopic beats were 455 (mean 35.8 +/- 16.8) and 418 (mean 34.4 +/- 11.1) in the 2 exercise tests with placebo, and 11 during nitroglycerin infusion (mean 0.6 +/- 0.1; p less than 0.001). Couplets were 28 and 29 during placebo (NS) and 0 during nitroglycerin (p less than 0.001). Ventricular tachycardia was present in 6 and 8 patients during placebo but in none during nitroglycerin (p less than 0.001). Reduction of exercise-induced arrhythmias was maintained during chronic treatment with oral vasodilators. Prevention of exercise-related arrhythmias by nitroglycerin infusion appears a good indicator of their ischemic origin and may provide valuable information for long-term profilaxis with oral vasodilators, then avoiding the use of antiarrhythmic agents and their potential side effects.

Hereditary arrhythmias and cardiomyopathies: decision-making about genetic testing.

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Louis, Clauden; Calamaro, Emily; Vinocur, Jeffrey M

2018-01-01

The modern field of clinical genetics has advanced beyond the traditional teachings familiar to most practicing cardiologists. Increased understanding of the roles of genetic testing may improve uptake and appropriateness of use. Clinical genetics has become integral to the management of patients with hereditary arrhythmia and cardiomyopathy diagnoses. Depending on the condition, genetic testing may be useful for diagnosis, prognosis, treatment, family screening, and reproductive planning. However, genetic testing is a powerful tool with potential for underuse, overuse, and misuse. In the absence of a substantial body of literature on how these guidelines are applied in clinical practice, we use a case-based approach to highlight key lessons and pitfalls. Importantly, in many scenarios genetic testing has become the standard of care supported by numerous class I recommendations; genetic counselors can improve accessibility to and appropriate use and application of testing. Optimal management of hereditary arrhythmias and cardiomyopathies incorporates genetic testing, applied as per consensus guidelines, with involvement of a multidisciplinary team.

Arctigenin, a potential anti-arrhythmic agent, inhibits aconitine-induced arrhythmia by regulating multi-ion channels.

Science.gov (United States)

Zhao, Zhenying; Yin, Yongqiang; Wu, Hong; Jiang, Min; Lou, Jianshi; Bai, Gang; Luo, Guo'an

2013-01-01

Arctigenin possesses biological activities, but its underlying mechanisms at the cellular and ion channel levels are not completely understood. Therefore, the present study was designed to identify the anti-arrhythmia effect of arctigenin in vivo, as well as its cellular targets and mechanisms. A rat arrhythmia model was established via continuous aconitine infusion, and the onset times of ventricular premature contraction, ventricular tachycardia and death were recorded. The Action Potential Duration (APD), sodium current (I(Na)), L-type calcium current (I(Ca, L)) and transient outward potassium current (I(to)) were measured and analysed using a patch-clamp recording technique in normal rat cardiomyocytes and myocytes of arrhythmia aconitine-induced by. Arctigenin significantly delayed the arrhythmia onset in the aconitine-induced rat model. The 50% and 90% repolarisations (APD50 and APD90) were shortened by 100 µM arctigenin; the arctigenin dose also inhibited the prolongation of APD50 and APD90 caused by 1 µM aconitine. Arctigenin inhibited I(Na) and I(Ca,L) and attenuated the aconitine-increased I(Na) and I(Ca,L) by accelerating the activation process and delaying the inactivation process. Arctigenin enhanced Ito by facilitating the activation process and delaying the inactivation process, and recoverd the decreased Ito induced by aconitine. Arctigenin has displayed anti-arrhythmia effects, both in vivo and in vitro. In the context of electrophysiology, I(Na), I(Ca, L), and I(to) may be multiple targets of arctigenin, leading to its antiarrhythmic effect. © 2013 S. Karger AG, Basel.

Possible influence of the polarity reversal of the solar magnetic field on the various types of arrhythmias

International Nuclear Information System (INIS)

Giannaropoulou, E; Papailiou, M; Mavromichalaki, H; Preka-Papadema, P; Gigolashvili, M; Tvildiani, L; Janashia, K; Papadima, Th

2013-01-01

Over the last few years various researches have reached the conclusion that cosmic ray variations and geomagnetic disturbances are related to the condition of the human physiological state. In this study medical data concerning the number of incidents of different types of cardiac arrhythmias for the time period 1983 – 1992 which refer to 1902 patients in Tbilisi, Georgia were used. The smoothing method and the Pearson r-coefficients were used to examine the possible effect of different solar and geomagnetic activity parameters and cosmic ray intensity variations on the different types of arrhythmias. The time interval under examination was separated into two different time periods which coincided with the polarity reversal of the solar magnetic field that occurred in the years 1989-1990 and as a result a different behavior of all the above mentioned parameters as well as of the different types of arrhythmias was noticed during the two time intervals. In addition, changing of polarity sign of the solar magnetic field was found to affect the sign of correlation between the incidence of arrhythmias and the aforementioned parameters. The primary and secondary maxima observed in the solar parameters during the solar cycle 22, also appeared in several types of arrhythmias with a time lag of about five months.

320-detector row CT coronary angiography in patients with arrhythmia

International Nuclear Information System (INIS)

Lu Li; Zhang Zhaoqi; Xu Lei; Yang Lin

2011-01-01

Objective: To evaluate the feasibility of CT coronary angiography (CTCA) in patients with arrhythmia using 320-detector row CT. Methods: Thirty-one patients with persistent atrial fibrillation and 8 patients with premature ventricular contraction were enrolled in this study. All patients underwent 320- detector row CTCA. CT image quality was evaluated with 4-point grading scale by two radiologists. Inter- observer agreement was evaluated by Kappa statistics. The radiation dose was calculated. Results: In total 510 coronary segments, 496 (97.2%) segments met diagnostic standard. The mean effective dose was (12.7±4.8) mSv in this study. There was a good agreement in image quality scoring between the two reviewers (Kappa = 0.72). Conclusion: 320-detector row CTCA is feasible in patients with atrial fibrillation and premature ventricular contraction. Arrhythmia may not be considered as a contraindication to CTCA. (authors)

Unique Association of Rare Cardiovascular Disease in an Athlete With Ventricular Arrhythmias.

Science.gov (United States)

Santomauro, V; Contursi, M; Dellegrottaglie, S; Borsellino, G

2015-01-01

Ventricular arrhythmias are a leading cause of non-elegibility to competitive sport. The failure to detect a significant organic substrate in the initial stage of screening does not preclude the identification of structural pathologies in the follow-up by using advanced imaging techniques. Here we report the case of a senior athlete judged not elegible because an arrhythmia with the morphology consistent with the origin of the left ventricle, in which subsequent execution of a cardiac MR and a thoracic CT scan has allowed the identification of an unique association between an area of myocardial damage, probable site of origine of the arrhythma, and a rare aortic malformation.

Acute effects of sex steroid hormones on susceptibility to cardiac arrhythmias: a simulation study.

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Pei-Chi Yang

2010-01-01

Full Text Available Acute effects of sex steroid hormones likely contribute to the observation that post-pubescent males have shorter QT intervals than females. However, the specific role for hormones in modulating cardiac electrophysiological parameters and arrhythmia vulnerability is unclear. Here we use a computational modeling approach to incorporate experimentally measured effects of physiological concentrations of testosterone, estrogen and progesterone on cardiac ion channel targets. We then study the hormone effects on ventricular cell and tissue dynamics comprised of Faber-Rudy computational models. The "female" model predicts changes in action potential duration (APD at different stages of the menstrual cycle that are consistent with clinically observed QT interval fluctuations. The "male" model predicts shortening of APD and QT interval at physiological testosterone concentrations. The model suggests increased susceptibility to drug-induced arrhythmia when estradiol levels are high, while testosterone and progesterone are apparently protective. Simulations predict the effects of sex steroid hormones on clinically observed QT intervals and reveal mechanisms of estrogen-mediated susceptibility to prolongation of QT interval. The simulations also indicate that acute effects of estrogen are not alone sufficient to cause arrhythmia triggers and explain the increased risk of females to Torsades de Pointes. Our results suggest that acute effects of sex steroid hormones on cardiac ion channels are sufficient to account for some aspects of gender specific susceptibility to long-QT linked arrhythmias.

Design of a hybrid model for cardiac arrhythmia classification based on Daubechies wavelet transform.

Science.gov (United States)

Rajagopal, Rekha; Ranganathan, Vidhyapriya

2018-06-05

Automation in cardiac arrhythmia classification helps medical professionals make accurate decisions about the patient's health. The aim of this work was to design a hybrid classification model to classify cardiac arrhythmias. The design phase of the classification model comprises the following stages: preprocessing of the cardiac signal by eliminating detail coefficients that contain noise, feature extraction through Daubechies wavelet transform, and arrhythmia classification using a collaborative decision from the K nearest neighbor classifier (KNN) and a support vector machine (SVM). The proposed model is able to classify 5 arrhythmia classes as per the ANSI/AAMI EC57: 1998 classification standard. Level 1 of the proposed model involves classification using the KNN and the classifier is trained with examples from all classes. Level 2 involves classification using an SVM and is trained specifically to classify overlapped classes. The final classification of a test heartbeat pertaining to a particular class is done using the proposed KNN/SVM hybrid model. The experimental results demonstrated that the average sensitivity of the proposed model was 92.56%, the average specificity 99.35%, the average positive predictive value 98.13%, the average F-score 94.5%, and the average accuracy 99.78%. The results obtained using the proposed model were compared with the results of discriminant, tree, and KNN classifiers. The proposed model is able to achieve a high classification accuracy.

Perinatal management and long-term cardiac outcome in fetal arrhythmia

NARCIS (Netherlands)

Hahurij, N.D.; Blom, N.A.; Lopriore, E.; Aziz, M.I.; Nagel, H.T.; Rozendaal, L.; Vandenbussche, F.P.H.A.

2011-01-01

BACKGROUND: cardiac arrhythmias are commonly observed in the fetus, however, may have major consequences for fetal development and post natal life. AIMS: to evaluate the perinatal management and cardiac outcome of fetuses with tachy- or bradyarrhythmia. STUDY DESIGN: perinatal management, outcome

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection.

Science.gov (United States)

Son, Junggab; Park, Juyoung; Oh, Heekuck; Bhuiyan, Md Zakirul Alam; Hur, Junbeom; Kang, Kyungtae

2017-06-12

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan-Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities.

Arctigenin, a Potential Anti-Arrhythmic Agent, Inhibits Aconitine-Induced Arrhythmia by Regulating Multi-Ion Channels

OpenAIRE

Zhenying Zhao; Yongqiang Yin; Hong Wu; Min Jiang; Jianshi Lou; Gang Bai; Guo‘an Luo

2013-01-01

Background/Aims: Arctigenin possesses biological activities, but its underlying mechanisms at the cellular and ion channel levels are not completely understood. Therefore, the present study was designed to identify the anti-arrhythmia effect of arctigenin in vivo, as well as its cellular targets and mechanisms. Methods: A rat arrhythmia model was established via continuous aconitine infusion, and the onset times of ventricular premature contraction, ventricular tachycardia and death were reco...

Features of conngestive heart failure development in patients with post infarct cardiosclerosis concomitant with arrhythmias

International Nuclear Information System (INIS)

Zharov, E.I.; Martynov, A.I.; Vertkin, A.L.; Sergeeva, L.I.; Sedov, V.P.

1989-01-01

Two hundred and seventy seven patients with coronary heart disease, includng 182 with postinfarction cardiosclerosis undewent 24-hour Holter monitoring. A significant correlation was found between the number of coupled ventricular arrhythmias, ventricular tachycardia paroxysms and developmet of congestive heart failure in patients with postinfarct cardiosclerosis. With evolving metabolic deficiency as evidenced by thallium-201 myocardial scintigraphy, the incidence of congestive heart failure and ventricular arrhythmias increased among the patients

Spiral Wave Initiation in Reaction-Diffusion-Mechanics Systems: A Model for the Onset of Reentrant Cardiac Arrhythmia

NARCIS (Netherlands)

Weise, L.D.

2012-01-01

Heart failure due to cardiac arrhythmias is a major cause of death in the industrialized world. Cardiac arrhythmia is often caused by spi- ral waves of electrical activity in the cardiac muscle. Therefore, it is a major task in cardiology to understand the mechanisms of spiral wave initiation in the

Noninvasive risk stratification of lethal ventricular arrhythmias and sudden cardiac death after myocardial infarction

Directory of Open Access Journals (Sweden)

Kenji Yodogawa, MD

2014-08-01

Full Text Available Prediction of lethal ventricular arrhythmias leading to sudden cardiac death is one of the most important and challenging problems after myocardial infarction (MI. Identification of MI patients who are prone to ventricular tachyarrhythmias allows for an indication of implantable cardioverter-defibrillator placement. To date, noninvasive techniques such as microvolt T-wave alternans (MTWA, signal-averaged electrocardiography (SAECG, heart rate variability (HRV, and heart rate turbulence (HRT have been developed for this purpose. MTWA is an indicator of repolarization abnormality and is currently the most promising risk-stratification tool for predicting malignant ventricular arrhythmias. Similarly, late potentials detected by SAECG are indices of depolarization abnormality and are useful in risk stratification. However, the role of SAECG is limited because of its low predictive accuracy. Abnormal HRV and HRT patterns reflect autonomic disturbances, which may increase the risk of lethal ventricular arrhythmias, but the existing evidence is insufficient. Further studies of noninvasive assessment may provide a new insight into risk stratification in post-MI patients.

TECRL, a new life-threatening inherited arrhythmia gene associated with overlapping clinical features of both LQTS and CPVT

NARCIS (Netherlands)

Devalla, Harsha D.; Gélinas, Roselle; Aburawi, Elhadi H.; Beqqali, Abdelaziz; Goyette, Philippe; Freund, Christian; Chaix, Marie-A.; Tadros, Rafik; Jiang, Hui; Le Béchec, Antony; Monshouwer-Kloots, Jantine J.; Zwetsloot, Tom; Kosmidis, Georgios; Latour, Frédéric; Alikashani, Azadeh; Hoekstra, Maaike; Schlaepfer, Jurg; Mummery, Christine L.; Stevenson, Brian; Kutalik, Zoltan; de Vries, Antoine Af; Rivard, Léna; Wilde, Arthur Am; Talajic, Mario; Verkerk, Arie O.; Al-Gazali, Lihadh; Rioux, John D.; Bhuiyan, Zahurul A.; Passier, Robert

2016-01-01

Genetic causes of many familial arrhythmia syndromes remain elusive. In this study, whole-exome sequencing (WES) was carried out on patients from three different families that presented with life-threatening arrhythmias and high risk of sudden cardiac death (SCD). Two French Canadian probands

Production of arrhythmias by elevated carboxyhemoglobin in patients with coronary artery disease

International Nuclear Information System (INIS)

Sheps, D.S.; Herbst, M.C.; Hinderliter, A.L.; Adams, K.F.; Ekelund, L.G.; O'Neil, J.J.; Goldstein, G.M.; Bromberg, P.A.; Dalton, J.L.; Ballenger, M.N.

1990-01-01

The object of this study was to assess the effects of exposure to 4% and 6% carboxyhemoglobin on ventricular arrhythmias in patients with coronary artery disease. This was a randomized, double-blind, crossover design. Forty-one nonsmokers with documented coronary artery disease were tested. On day 1, a training session with no exposure, the baseline carboxyhemoglobin level was measured, and a supine bicycle exercise test was done. On days 2 to 4, patients were exposed to room air, 100 ppm carbon monoxide (target, 4% carboxyhemoglobin) or 200 ppm carbon monoxide (target, 6% carboxyhemoglobin), and they then did supine bicycle exercise with radionuclide ventriculography. Ambulatory electrocardiogram recordings were made during the 4 consecutive days to determine the frequency of ventricular premature depolarization (VPD) at various intervals. The frequency of single VPD/h was significantly greater on the 6% carboxyhemoglobin day than on the room air day during the exercise period (167.72 +/- 37.99 for 6% carboxyhemoglobin compared with 127.32 +/- 28.22 for room air, P = 0.03). During exercise, the frequency of multiple VPD/h was greater on the 6% carboxyhemoglobin day compared with room air (9.59 +/- 3.70 on the 6% carboxyhemoglobin compared with 3.18 +/- 1.67 on room air, P = 0.02). Patients who developed increased single VPD during exercise on the 6% carboxyhemoglobin day were significantly older than those who had no increased arrhythmia, whereas patients who developed complex arrhythmias were also older and, in addition, exercised longer and had a higher peak workload during exercise. The number and complexity of ventricular arrhythmias increases significantly during exercise after carbon monoxide exposure producing 6% carboxyhemoglobin compared with room air but not after exposure producing 4% carboxyhemoglobin

Mortality of Inherited Arrhythmia Syndromes Insight Into Their Natural History

NARCIS (Netherlands)

Nannenberg, Eline A.; Sijbrands, Eric J. G.; Dijksman, Lea M.; Alders, Marielle; van Tintelen, J. Peter; Birnie, Martijn; van Langen, Irene M.; Wilde, Arthur A. M.

Background-For most arrhythmia syndromes, the risk of sudden cardiac death for asymptomatic mutation carriers is ill defined. Data on the natural history of these diseases, therefore, are essential. The family tree mortality ratio method offers the unique possibility to study the natural history at

An arrhythmia classification algorithm using a dedicated wavelet adapted to different subjects.

Science.gov (United States)

Kim, Jinkwon; Min, Se Dong; Lee, Myoungho

2011-06-27

Numerous studies have been conducted regarding a heartbeat classification algorithm over the past several decades. However, many algorithms have also been studied to acquire robust performance, as biosignals have a large amount of variation among individuals. Various methods have been proposed to reduce the differences coming from personal characteristics, but these expand the differences caused by arrhythmia. In this paper, an arrhythmia classification algorithm using a dedicated wavelet adapted to individual subjects is proposed. We reduced the performance variation using dedicated wavelets, as in the ECG morphologies of the subjects. The proposed algorithm utilizes morphological filtering and a continuous wavelet transform with a dedicated wavelet. A principal component analysis and linear discriminant analysis were utilized to compress the morphological data transformed by the dedicated wavelets. An extreme learning machine was used as a classifier in the proposed algorithm. A performance evaluation was conducted with the MIT-BIH arrhythmia database. The results showed a high sensitivity of 97.51%, specificity of 85.07%, accuracy of 97.94%, and a positive predictive value of 97.26%. The proposed algorithm achieves better accuracy than other state-of-the-art algorithms with no intrasubject between the training and evaluation datasets. And it significantly reduces the amount of intervention needed by physicians.

An arrhythmia classification algorithm using a dedicated wavelet adapted to different subjects

Directory of Open Access Journals (Sweden)

Min Se Dong

2011-06-01

Full Text Available Abstract Background Numerous studies have been conducted regarding a heartbeat classification algorithm over the past several decades. However, many algorithms have also been studied to acquire robust performance, as biosignals have a large amount of variation among individuals. Various methods have been proposed to reduce the differences coming from personal characteristics, but these expand the differences caused by arrhythmia. Methods In this paper, an arrhythmia classification algorithm using a dedicated wavelet adapted to individual subjects is proposed. We reduced the performance variation using dedicated wavelets, as in the ECG morphologies of the subjects. The proposed algorithm utilizes morphological filtering and a continuous wavelet transform with a dedicated wavelet. A principal component analysis and linear discriminant analysis were utilized to compress the morphological data transformed by the dedicated wavelets. An extreme learning machine was used as a classifier in the proposed algorithm. Results A performance evaluation was conducted with the MIT-BIH arrhythmia database. The results showed a high sensitivity of 97.51%, specificity of 85.07%, accuracy of 97.94%, and a positive predictive value of 97.26%. Conclusions The proposed algorithm achieves better accuracy than other state-of-the-art algorithms with no intrasubject between the training and evaluation datasets. And it significantly reduces the amount of intervention needed by physicians.

Chewing reduces sympathetic nervous response to stress and prevents poststress arrhythmias in rats.

Science.gov (United States)

Koizumi, So; Minamisawa, Susumu; Sasaguri, Kenichi; Onozuka, Minoru; Sato, Sadao; Ono, Yumie

2011-10-01

Reducing stress is important in preventing sudden death in patients with cardiovascular disease, as stressful events may cause autonomic imbalance and trigger fatal arrhythmias. Since chewing has been shown to inhibit stress-induced neuronal responses in the hypothalamus, we hypothesized that chewing could ameliorate stress-induced autonomic imbalance and prevent arrhythmias. To test this hypothesis, we analyzed changes in radiotelemetered electrocardiograms in rats that were allowed to chew a wooden stick during a 1-h period of immobilization stress. Chewing significantly reduced the occurrence of ventricular premature beats (VPBs) and complex ventricular ectopy after immobilization and prevented stress-induced prolongation of the QT interval of VPBs throughout the 10-h experimental period. It also prevented prolongation of the QRS complex and fluctuations in the QT interval in normal sinus rhythm beats preceding VPBs during both immobilization and in the poststress period. Fast Fourier transform-based spectral analysis of heart-rate variability further showed that chewing significantly inhibited the stress-induced increase in the power ratio of low-to-high frequency activity (LF/HF: a marker of sympathetic activity) during immobilization and in addition was associated with blunting of the stress-induced increase in plasma noradrenaline observed at the termination of immobilization. Similar suppressive effects on the occurrence of VPBs and the LF/HF were observed in rats that were administered the β-adrenergic blocker propranolol before immobilization. These results indicate that chewing can ameliorate sympathetic hyperactivity during stress and prevent poststress arrhythmias and suggest that chewing may provide a nonpharmacological and cost-effective treatment option for patients with a high risk of stress-induced fatal arrhythmia.

Arrhythmia Classification Based on Multi-Domain Feature Extraction for an ECG Recognition System

Directory of Open Access Journals (Sweden)

Hongqiang Li

2016-10-01

Full Text Available Automatic recognition of arrhythmias is particularly important in the diagnosis of heart diseases. This study presents an electrocardiogram (ECG recognition system based on multi-domain feature extraction to classify ECG beats. An improved wavelet threshold method for ECG signal pre-processing is applied to remove noise interference. A novel multi-domain feature extraction method is proposed; this method employs kernel-independent component analysis in nonlinear feature extraction and uses discrete wavelet transform to extract frequency domain features. The proposed system utilises a support vector machine classifier optimized with a genetic algorithm to recognize different types of heartbeats. An ECG acquisition experimental platform, in which ECG beats are collected as ECG data for classification, is constructed to demonstrate the effectiveness of the system in ECG beat classification. The presented system, when applied to the MIT-BIH arrhythmia database, achieves a high classification accuracy of 98.8%. Experimental results based on the ECG acquisition experimental platform show that the system obtains a satisfactory classification accuracy of 97.3% and is able to classify ECG beats efficiently for the automatic identification of cardiac arrhythmias.

Use of whole exome sequencing for the identification of Ito-based arrhythmia mechanism and therapy.

Science.gov (United States)

Sturm, Amy C; Kline, Crystal F; Glynn, Patric; Johnson, Benjamin L; Curran, Jerry; Kilic, Ahmet; Higgins, Robert S D; Binkley, Philip F; Janssen, Paul M L; Weiss, Raul; Raman, Subha V; Fowler, Steven J; Priori, Silvia G; Hund, Thomas J; Carnes, Cynthia A; Mohler, Peter J

2015-05-26

Identified genetic variants are insufficient to explain all cases of inherited arrhythmia. We tested whether the integration of whole exome sequencing with well-established clinical, translational, and basic science platforms could provide rapid and novel insight into human arrhythmia pathophysiology and disease treatment. We report a proband with recurrent ventricular fibrillation, resistant to standard therapeutic interventions. Using whole-exome sequencing, we identified a variant in a previously unidentified exon of the dipeptidyl aminopeptidase-like protein-6 (DPP6) gene. This variant is the first identified coding mutation in DPP6 and augments cardiac repolarizing current (Ito) causing pathological changes in Ito and action potential morphology. We designed a therapeutic regimen incorporating dalfampridine to target Ito. Dalfampridine, approved for multiple sclerosis, normalized the ECG and reduced arrhythmia burden in the proband by >90-fold. This was combined with cilostazol to accelerate the heart rate to minimize the reverse-rate dependence of augmented Ito. We describe a novel arrhythmia mechanism and therapeutic approach to ameliorate the disease. Specifically, we identify the first coding variant of DPP6 in human ventricular fibrillation. These findings illustrate the power of genetic approaches for the elucidation and treatment of disease when carefully integrated with clinical and basic/translational research teams. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Frequency of cardiac arrhythmias in high and low- yielding dairy cows

Directory of Open Access Journals (Sweden)

Afshin Jafari Dehkordi

2014-06-01

Full Text Available Electrocardiography (ECG may be used to recognize cardiac disorders. Levels of milk production may change the serum electrolytes which its imbalance has a role in cardiac arrhythmia. Fifty high yielding and fifty low yielding Holstein dairy cows were used in this study. Electrocardiography was recorded by base-apex lead and blood samples were collected from jugular vein for measurement of serum elements such as sodium, potassium, calcium, phosphorous, iron and magnesium. Cardiac dysrhythmias were detected more frequent in low yielding Holstein cows (62.00% compared to high yielding Holstein cows (46.00%. The cardiac dysrhythmias that were observed in low yielding Holstein cows included sinus arrhythmia (34.70%, wandering pacemaker (22.45 %, bradycardia (18.37%, tachycardia (10.20%, atrial premature beat (2.04%, sinoatrial block (2.04%, atrial fibrillation (8.16% and atrial tachycardia (2.04%. The cardiac dysrhythmias were observed in high yielding Holstein cows including, sinus arrhythmia (86.95% and wandering pacemaker (13.05%. Also, notched P wave was observed to be 30% and 14% in high- and low- yielding Holstein cows respectively. The serum calcium concentration of low yielding Holstein cows was significantly lower than that of high yielding Holstein cows. There was not any detectable significant difference in other serum elements between high- and low- yielding Holstein cows. Based on the result of present study, could be concluded that low serum concentration of calcium results to more frequent dysrhythmias in low yielding Holstein cows.

Radiofrequency catheter ablation in the treatment of cardiac arrhythmias (first of two parts)

International Nuclear Information System (INIS)

Kou, W.H; Morady, F.

1997-01-01

The intravenous radiofrequency catheter inside cardiac s chambers, for inspect signals intracardiac s and to encourage, has been developed as diagnostic tool with the purpose to search arrhythmias physiology and physiopathology.Many energy sources has been used: direct energy, radiofrequency 11-15, laser 6,17, and microwave 18,19. A comparison between radiofrequency and electric energy shock has been described in cardiac arrhythmias treatment, in the present article. It has been tested the radiation biological effects and risk in Wolff Parkinson White patients as well as doctors who handling the fluoroscopy for image during the radiofrequency ablation. Has been described the following techniques: Catheter ablation radiofrequency slow way and fast way

The Role of Biologically Active Ingredients from Natural Drug Treatments for Arrhythmias in Different Mechanisms

OpenAIRE

Li, Jie; Hu, Dan; Song, Xiaoli; Han, Tao; Gao, Yonghong; Xing, Yanwei

2017-01-01

Arrhythmia is a disease that is caused by abnormal electrical activity in the heart rate or rhythm. It is the major cause of cardiovascular morbidity and mortality. Although several antiarrhythmic drugs have been used in clinic for decades, their application is often limited by their adverse effects. As a result, natural drugs, which have fewer side effects, are now being used to treat arrhythmias. We searched for all articles on the role of biologically active ingredients from natural drug t...

Andrographolide inhibits arrhythmias and is cardioprotective in rabbits

OpenAIRE

Zeng, Mengliu; Jiang, Wanzhen; Tian, Youjia; Hao, Jie; Cao, Zhenzhen; Liu, Zhipei; Fu, Chen; Zhang, Peihua; Ma, Jihua

2017-01-01

Andrographolide has a protective effect on the cardiovascular system. To study its cardic-electrophysiological effects, action potentials and voltage-gated Na+ (INa), Ca2+ (ICaL), and K+ (IK1, IKr, Ito and IKur) currents were recorded using whole-cell patch clamp and current clamp techniques. Additionally, the effects of andrographolide on aconitine-induced arrhythmias were assessed on electrocardiograms in vivo. We found that andrographolide shortened action potential duration and reduced ma...

Single-Nucleotide Variations in Cardiac Arrhythmias: Prospects for Genomics and Proteomics Based Biomarker Discovery and Diagnostics

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Ayman Abunimer

2014-03-01

Full Text Available Cardiovascular diseases are a large contributor to causes of early death in developed countries. Some of these conditions, such as sudden cardiac death and atrial fibrillation, stem from arrhythmias—a spectrum of conditions with abnormal electrical activity in the heart. Genome-wide association studies can identify single nucleotide variations (SNVs that may predispose individuals to developing acquired forms of arrhythmias. Through manual curation of published genome-wide association studies, we have collected a comprehensive list of 75 SNVs associated with cardiac arrhythmias. Ten of the SNVs result in amino acid changes and can be used in proteomic-based detection methods. In an effort to identify additional non-synonymous mutations that affect the proteome, we analyzed the post-translational modification S-nitrosylation, which is known to affect cardiac arrhythmias. We identified loss of seven known S-nitrosylation sites due to non-synonymous single nucleotide variations (nsSNVs. For predicted nitrosylation sites we found 1429 proteins where the sites are modified due to nsSNV. Analysis of the predicted S-nitrosylation dataset for over- or under-representation (compared to the complete human proteome of pathways and functional elements shows significant statistical over-representation of the blood coagulation pathway. Gene Ontology (GO analysis displays statistically over-represented terms related to muscle contraction, receptor activity, motor activity, cystoskeleton components, and microtubule activity. Through the genomic and proteomic context of SNVs and S-nitrosylation sites presented in this study, researchers can look for variation that can predispose individuals to cardiac arrhythmias. Such attempts to elucidate mechanisms of arrhythmia thereby add yet another useful parameter in predicting susceptibility for cardiac diseases.

Cardiac arrhythmia beat classification using DOST and PSO tuned SVM.

Science.gov (United States)

Raj, Sandeep; Ray, Kailash Chandra; Shankar, Om

2016-11-01

The increase in the number of deaths due to cardiovascular diseases (CVDs) has gained significant attention from the study of electrocardiogram (ECG) signals. These ECG signals are studied by the experienced cardiologist for accurate and proper diagnosis, but it becomes difficult and time-consuming for long-term recordings. Various signal processing techniques are studied to analyze the ECG signal, but they bear limitations due to the non-stationary behavior of ECG signals. Hence, this study aims to improve the classification accuracy rate and provide an automated diagnostic solution for the detection of cardiac arrhythmias. The proposed methodology consists of four stages, i.e. filtering, R-peak detection, feature extraction and classification stages. In this study, Wavelet based approach is used to filter the raw ECG signal, whereas Pan-Tompkins algorithm is used for detecting the R-peak inside the ECG signal. In the feature extraction stage, discrete orthogonal Stockwell transform (DOST) approach is presented for an efficient time-frequency representation (i.e. morphological descriptors) of a time domain signal and retains the absolute phase information to distinguish the various non-stationary behavior ECG signals. Moreover, these morphological descriptors are further reduced in lower dimensional space by using principal component analysis and combined with the dynamic features (i.e based on RR-interval of the ECG signals) of the input signal. This combination of two different kinds of descriptors represents each feature set of an input signal that is utilized for classification into subsequent categories by employing PSO tuned support vector machines (SVM). The proposed methodology is validated on the baseline MIT-BIH arrhythmia database and evaluated under two assessment schemes, yielding an improved overall accuracy of 99.18% for sixteen classes in the category-based and 89.10% for five classes (mapped according to AAMI standard) in the patient

Comparison of real-time classification systems for arrhythmia detection on Android-based mobile devices.

Science.gov (United States)

Leutheuser, Heike; Gradl, Stefan; Kugler, Patrick; Anneken, Lars; Arnold, Martin; Achenbach, Stephan; Eskofier, Bjoern M

2014-01-01

The electrocardiogram (ECG) is a key diagnostic tool in heart disease and may serve to detect ischemia, arrhythmias, and other conditions. Automatic, low cost monitoring of the ECG signal could be used to provide instantaneous analysis in case of symptoms and may trigger the presentation to the emergency department. Currently, since mobile devices (smartphones, tablets) are an integral part of daily life, they could form an ideal basis for automatic and low cost monitoring solution of the ECG signal. In this work, we aim for a realtime classification system for arrhythmia detection that is able to run on Android-based mobile devices. Our analysis is based on 70% of the MIT-BIH Arrhythmia and on 70% of the MIT-BIH Supraventricular Arrhythmia databases. The remaining 30% are reserved for the final evaluation. We detected the R-peaks with a QRS detection algorithm and based on the detected R-peaks, we calculated 16 features (statistical, heartbeat, and template-based). With these features and four different feature subsets we trained 8 classifiers using the Embedded Classification Software Toolbox (ECST) and compared the computational costs for each classification decision and the memory demand for each classifier. We conclude that the C4.5 classifier is best for our two-class classification problem (distinction of normal and abnormal heartbeats) with an accuracy of 91.6%. This classifier still needs a detailed feature selection evaluation. Our next steps are implementing the C4.5 classifier for Android-based mobile devices and evaluating the final system using the remaining 30% of the two used databases.

Monitoring of arrhythmia and sudden death in a hemodialysis population: The CRASH-ILR Study.

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Paul R Roberts

Full Text Available It has been suggested that sudden cardiac death (SCD contributes around 50% of cardiovascular and 27% of all-cause mortality in hemodialysis patients. The true burden of arrhythmias and arrhythmic deaths in this population, however, remains poorly characterised. Cardio Renal Arrhythmia Study in Hemodialysis (CRASH-ILR is a prospective, implantable loop recorder single centre study of 30 established hemodialysis patients and one of the first to provide long-term ambulatory ECG monitoring.30 patients (60% male aged 68±12 years receiving hemodialysis for 45±40 months with varied etiology (diabetes 37%, hypertension 23% and left ventricular ejection fraction (LVEF 55±8% received a Reveal XT implantable loop recorder (Medtronic, USA between August 2011 and October 2014. ECG data from loop recorders were transmitted at each hemodialysis session using a remote monitoring system. Primary outcome was SCD or implantation of a (tachy or bradyarrhythmia controlling device and secondary outcome, the development of arrhythmia necessitating medical intervention.During 379,512 hours of continuous ECG monitoring (mean 12,648±9,024 hours/patient, there were 8 deaths-2 SCD and 6 due to generalised deterioration/sepsis. 5 (20% patients had a primary outcome event (2 SCD, 3 pacemaker implantations for bradyarrhythmia. 10 (33% patients reached an arrhythmic primary or secondary end point. Median event free survival for any arrhythmia was 2.6 years (95% confidence intervals 1.6-3.6 years.The findings confirm the high mortality rate seen in hemodialysis populations and contrary to initial expectations, bradyarrhythmias emerged as a common and potentially significant arrhythmic event.

Privacy-Preserving Electrocardiogram Monitoring for Intelligent Arrhythmia Detection †

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Son, Junggab; Park, Juyoung; Oh, Heekuck; Bhuiyan, Md Zakirul Alam; Hur, Junbeom; Kang, Kyungtae

2017-01-01

Long-term electrocardiogram (ECG) monitoring, as a representative application of cyber-physical systems, facilitates the early detection of arrhythmia. A considerable number of previous studies has explored monitoring techniques and the automated analysis of sensing data. However, ensuring patient privacy or confidentiality has not been a primary concern in ECG monitoring. First, we propose an intelligent heart monitoring system, which involves a patient-worn ECG sensor (e.g., a smartphone) and a remote monitoring station, as well as a decision support server that interconnects these components. The decision support server analyzes the heart activity, using the Pan–Tompkins algorithm to detect heartbeats and a decision tree to classify them. Our system protects sensing data and user privacy, which is an essential attribute of dependability, by adopting signal scrambling and anonymous identity schemes. We also employ a public key cryptosystem to enable secure communication between the entities. Simulations using data from the MIT-BIH arrhythmia database demonstrate that our system achieves a 95.74% success rate in heartbeat detection and almost a 96.63% accuracy in heartbeat classification, while successfully preserving privacy and securing communications among the involved entities. PMID:28604628

Arrhythmia as a cardiac manifestation in MELAS syndrome.

Science.gov (United States)

Thomas, Tamara; Craigen, William J; Moore, Ryan; Czosek, Richard; Jefferies, John L

2015-09-01

A 44-year-old female with a diagnosis of mitochondrial myopathy, encephalopathy and stroke-like episodes (MELAS) syndrome had progressive left ventricular hypertrophy (LVH) on echocardiogram. A Holter monitor demonstrated episodes of non-sustained atrial tachycardia, a finding not been previously described in this population. This unique case of MELAS syndrome demonstrates the known associated cardiac manifestation of LVH and the new finding of atrial tachycardia which may represent the potential for subclinical arrhythmia in this population.

Relationship of serum magnesium level and supplemental magnesium dosage with post coronary artery bypass graft surgery arrhythmias

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Najafi M

2007-06-01

Full Text Available Background: Atrial and ventricular arrhythmias are among the most common complications after coronary artery bypass graft (CABG surgery. Previous studies demonstrated that cardiopulmonary bypass itself results in reduced serum magnesium levels. In this study, we evaluated the effect of total blood magnesium level (TMG on the prevention of perioperative arrhythmias with routine regimens of 2-4 grams supplemental magnesium (SMG. Methods: TMG was measured in patients who were scheduled for CABG on three occasions: just before anesthesia, just after entering the intensive care unit (ICU after completion of the sugery, and on the first morning after the operation. Patients were evaluated for primary cardiac rhythm and other variables that could have an influence on the magnesium level, including serum creatinine, urine output in the operating room and diuretic therapy. The SMG dosage was also recorded in the operating room and ICU. Patients were then evaluated for the rate and type of arrhythmia for the next three days. Results: The mean TMG levels in 174 cases were 2.2 (0.5, 2.6 (0.6 and 2.4 (0.6 mg/dl for the three occasions, respectively. The mean SMG was 2.5 (1.2 grams. Of 164 patients, 51 (31% developed the following post-operative arrhythmias: AF (7.3%, non-AF SVA (15.2% and ventricular (16.5%. The mean serum creatinine level and urine output were 1.2 mg/dl and 1800 ml, respectively. Although there was a significant difference between the TMG levels on the three different occasions (P<0.001, all values were within normal range. When we stratified the TMG levels of the patients based on administered SMG, the Mentel-Haenszel test revealed no significant difference between the first and third TMG (P=0.6. Although the TMG levels were higher in arrhythmic patients compared to those without arrhythmia (2.25 vs. 2.14 mg/dl, both values were within the normal range and there was no significant difference between the two groups. Serum creatinine levels

Classification of ECG signal with Support Vector Machine Method for Arrhythmia Detection

Science.gov (United States)

Turnip, Arjon; Ilham Rizqywan, M.; Kusumandari, Dwi E.; Turnip, Mardi; Sihombing, Poltak

2018-03-01

An electrocardiogram is a potential bioelectric record that occurs as a result of cardiac activity. QRS Detection with zero crossing calculation is one method that can precisely determine peak R of QRS wave as part of arrhythmia detection. In this paper, two experimental scheme (2 minutes duration with different activities: relaxed and, typing) were conducted. From the two experiments it were obtained: accuracy, sensitivity, and positive predictivity about 100% each for the first experiment and about 79%, 93%, 83% for the second experiment, respectively. Furthermore, the feature set of MIT-BIH arrhythmia using the support vector machine (SVM) method on the WEKA software is evaluated. By combining the available attributes on the WEKA algorithm, the result is constant since all classes of SVM goes to the normal class with average 88.49% accuracy.

The effect of intermittent fasting and water restriction on myocardial ischemia/reperfusion-induced arrhythmia in rats

OpenAIRE

KAYA, Salih Tunç; BOZDOĞAN, Ömer

2011-01-01

To investigate the effect of intermittent fasting and water restriction on ischemia/reperfusion-induced arrhythmias. Materials and methods: Six minutes of ischemia followed by 6 min of reperfusion was produced by the ligation and then releasing of the left coronary artery. Intermittent fasting and water restriction were applied during 1 month for 12 h/day. The duration, type, and incidence of arrhythmias during reperfusion and the survival rate at the end of reperfusion were determined and c...

LiteNet: Lightweight Neural Network for Detecting Arrhythmias at Resource-Constrained Mobile Devices

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Ziyang He

2018-04-01

Full Text Available By running applications and services closer to the user, edge processing provides many advantages, such as short response time and reduced network traffic. Deep-learning based algorithms provide significantly better performances than traditional algorithms in many fields but demand more resources, such as higher computational power and more memory. Hence, designing deep learning algorithms that are more suitable for resource-constrained mobile devices is vital. In this paper, we build a lightweight neural network, termed LiteNet which uses a deep learning algorithm design to diagnose arrhythmias, as an example to show how we design deep learning schemes for resource-constrained mobile devices. Compare to other deep learning models with an equivalent accuracy, LiteNet has several advantages. It requires less memory, incurs lower computational cost, and is more feasible for deployment on resource-constrained mobile devices. It can be trained faster than other neural network algorithms and requires less communication across different processing units during distributed training. It uses filters of heterogeneous size in a convolutional layer, which contributes to the generation of various feature maps. The algorithm was tested using the MIT-BIH electrocardiogram (ECG arrhythmia database; the results showed that LiteNet outperforms comparable schemes in diagnosing arrhythmias, and in its feasibility for use at the mobile devices.

Obesity and exercise-induced ectopic ventricular arrhythmias in apparently healthy middle aged adults.

Science.gov (United States)

Sabbag, Avi; Sidi, Yechezkel; Kivity, Shaye; Beinart, Roy; Glikson, Michael; Segev, Shlomo; Goldenberg, Ilan; Maor, Elad

2016-03-01

Obesity and overweight are strongly associated with cardiovascular morbidity and mortality. However, there are limited data on the association between excess weight and the risk of ectopic ventricular activity. We investigated the association between body mass index (BMI) and the risk for ectopic ventricular activity (defined as multiple ventricular premature beats (≥3), ventricular bigeminy, nonsustained ventricular tachycardia or sustained ventricular tachycardia) during exercise stress testing among 22,516 apparently healthy men and women who attended periodic health screening examinations between the years 2000 and 2014. All subjects had completed maximal exercise stress testing annually according to the Bruce protocol. Subjects were divided at baseline into three groups: normal weight (BMI ≥ 18.5 kg/m(2) andexercise-induced ectopic ventricular activity arrhythmias was highest among obese subjects, intermediate among overweight subjects and lowest among subjects with normal weight (3.4%, 2.7% and 2.2% respectively; p exercise compared with subjects with normal weight (p = 0.005), and that each 1 kg/m(2) increase in BMI was associated with a significant 4% (p = 0.002) increased adjusted risk for exercise-induced ventricular arrhythmias. Obesity is independently associated with increased likelihood of ectopic ventricular arrhythmia during exercise. © The European Society of Cardiology 2015.

LiteNet: Lightweight Neural Network for Detecting Arrhythmias at Resource-Constrained Mobile Devices.

Science.gov (United States)

He, Ziyang; Zhang, Xiaoqing; Cao, Yangjie; Liu, Zhi; Zhang, Bo; Wang, Xiaoyan

2018-04-17

By running applications and services closer to the user, edge processing provides many advantages, such as short response time and reduced network traffic. Deep-learning based algorithms provide significantly better performances than traditional algorithms in many fields but demand more resources, such as higher computational power and more memory. Hence, designing deep learning algorithms that are more suitable for resource-constrained mobile devices is vital. In this paper, we build a lightweight neural network, termed LiteNet which uses a deep learning algorithm design to diagnose arrhythmias, as an example to show how we design deep learning schemes for resource-constrained mobile devices. Compare to other deep learning models with an equivalent accuracy, LiteNet has several advantages. It requires less memory, incurs lower computational cost, and is more feasible for deployment on resource-constrained mobile devices. It can be trained faster than other neural network algorithms and requires less communication across different processing units during distributed training. It uses filters of heterogeneous size in a convolutional layer, which contributes to the generation of various feature maps. The algorithm was tested using the MIT-BIH electrocardiogram (ECG) arrhythmia database; the results showed that LiteNet outperforms comparable schemes in diagnosing arrhythmias, and in its feasibility for use at the mobile devices.

Dispersion of repolarization and refractoriness are determinants of arrhythmia phenotype in transgenic mice with long QT.

Science.gov (United States)

London, Barry; Baker, Linda C; Petkova-Kirova, Polina; Nerbonne, Jeanne M; Choi, Bum-Rak; Salama, Guy

2007-01-01

Enhanced dispersion of repolarization (DR) and refractoriness may be a unifying mechanism central to arrhythmia genesis in the long QT (LQT) syndrome. The role of DR in promoting arrhythmias was investigated in several strains of molecularly engineered mice: (a) Kv4.2 dominant negative transgenic (Kv4.2DN) that lacks the fast component of the transient outward current, I(to,f), have action potential (AP) and QT prolongation, but no spontaneous arrhythmias, (b) Kv1.4 targeted mice (Kv1.4-/-) that lack the slow component of I(to) (I(to,s)), have no QT prolongation and no spontaneous arrhythmias, and (c) double transgenic (Kv4.2DN x Kv1.4-/-) mice that lack both I(to,f) and I(to,s), have AP and QT prolongation, and spontaneous ventricular tachyarrhythmias. Hearts were perfused, stained with di-4-ANEPPS and optically mapped. Activation patterns and conduction velocities were similar between the strains but AP duration at 75% recovery (APD75) was longer in Kv4.2DN (28.0 +/- 2.5 ms, P mice than controls (20.3 +/- 1.0 ms, n = 5). Dispersion of refractoriness between apex and base was markedly reduced in Kv4.2DN (0.3 +/- 0.5 ms, n = 6, P mice compared with controls (10 +/- 2 ms, n = 5). A premature pulse elicited ventricular tachycardia (VT) in Kv1.4-/- (n = 4/5) and Kv4.2DN x Kv1.4-/- hearts (n = 5/5) but not Kv4.2DN hearts (n = 0/6). Voltage-clamp recordings showed that I(to,f) was 30% greater in myocytes from the apex than base which may account for the absence of DR in Kv4.2DN mice. Thus, dispersion of repolarization (DR) appears to be an important determinant of arrhythmia vulnerability.

An extended family suddenly confronted with a life-threatening hereditary arrhythmia

NARCIS (Netherlands)

Hendriks, K.S.W.H.; Van Langen, I.M.; Van Tintelen, J.P.; Grosfeld, F.J.M.; Wilde, A.A.M.; Ten Kroode, H.F.J.

2005-01-01

Objective. This exploratory study serves to illustrate the psychological impact on an extended family in the process of genetic counselling and testing for a potentially life-threatening arrhythmia, the long-QT syndrome (LQTS). Method. All members of the third generation and their partners (n=11)

Cardiovascular exercise and burden of arrhythmia in patients with atrial fibrillation

DEFF Research Database (Denmark)

Skielboe, Ane Katrine; Bandholm, Thomas Quaade; Hakmann, Stine

2017-01-01

BACKGROUND: Physical activity at moderate-high intensity is recommended to prevent lifestyle diseases. Patients with atrial fibrillation are at risk of a sedentary lifestyle due to fear of exercise-induced episodes of atrial fibrillation. The burden of arrhythmia can be reduced by physical exercise...

Arrhythmias and hemodialysis: role of potassium and new diagnostic tools.

Science.gov (United States)

Buemi, Michele; Coppolino, Giuseppe; Bolignano, Davide; Sturiale, Alessio; Campo, Susanna; Buemi, Antoine; Crascì, Eleonora; Romeo, Adolfo

2009-01-01

Cardiovascular diseases represent the main causes of death in patients affected by renal failure, and arrhythmias are frequently observed in patients undergoing hemodialysis. Dialytic treatment per se can be considered as an arrhythmogenic stimulus; moreover, uraemic patients are characterized by a "pro-arrhythmic substrate" because of the high prevalence of ischaemic heart disease, left ventricular hypertrophy and autonomic neuropathy. One of the most important pathogenetic element involved in the onset of intra-dialytic arrhythmias is the alteration in electrolytes concentration, particularly calcium and potassium. It may be very useful to monitor the patient's cardiac activity during the whole hemodilaytic session. Nevertheless, the application of an extended intradialytic electrocardiographic monitoring is not simple because of several technical and structural impairments. We tried to overcome these difficulties using Whealthy, a wearable system consisting in a t-shirt composed of conductors and piezoresistive materials, integrated to form fibers and threads connected to tissutal sensors, electrodes, and connectors. ECG and pneumographic impedance signals are acquired by the electrodes in the tissue, and the data are registered by a small computer and transmitted via GPRS or Bluetooth.

An extended family suddenly confronted with a life-threatening hereditary arrhythmia

NARCIS (Netherlands)

Hendriks, K. S. W. H.; van Langen, I. M.; van Tintelen, J. P.; Grosfeld, F. J. M.; Wilde, A. A. M.; ten Kroode, H. F. J.

2005-01-01

This exploratory study serves to illustrate the psychological impact on an extended family in the process of genetic counselling and testing for a potentially life-threatening arrhythmia, the long-QT syndrome (LQTS). All members of the third generation and their partners (n=11) were interviewed, the

N-3 fatty acids from fish and markers of cardiac arrhythmia

NARCIS (Netherlands)

Geelen, A.

2004-01-01

N‑3 fatty acids from fish may protect against heart disease mortality by preventing fatal arrhythmias. The objective of this thesis was to investigate whether this possible antiarrhythmic effect of n-3 fatty acids is supported by short-term effects on electrophysiological markers. We performed two

The Role of Biologically Active Ingredients from Natural Drug Treatments for Arrhythmias in Different Mechanisms.

Science.gov (United States)

Li, Jie; Hu, Dan; Song, Xiaoli; Han, Tao; Gao, Yonghong; Xing, Yanwei

2017-01-01

Arrhythmia is a disease that is caused by abnormal electrical activity in the heart rate or rhythm. It is the major cause of cardiovascular morbidity and mortality. Although several antiarrhythmic drugs have been used in clinic for decades, their application is often limited by their adverse effects. As a result, natural drugs, which have fewer side effects, are now being used to treat arrhythmias. We searched for all articles on the role of biologically active ingredients from natural drug treatments for arrhythmias in different mechanisms in PubMed. This study reviews 19 natural drug therapies, with 18 active ingredient therapies, such as alkaloids, flavonoids, saponins, quinones, and terpenes, and two kinds of traditional Chinese medicine compound (Wenxin-Keli and Shensongyangxin), all of which have been studied and reported as having antiarrhythmic effects. The primary focus is the proposed antiarrhythmic mechanism of each natural drug agent. Conclusion . We stress persistent vigilance on the part of the provider in discussing the use of natural drug agents to provide a solid theoretical foundation for further research on antiarrhythmia drugs.

Ion Channel Trafficking: Control of Ion Channel Density as a Target for Arrhythmias?

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Elise Balse

2017-10-01

Full Text Available The shape of the cardiac action potential (AP is determined by the contributions of numerous ion channels. Any dysfunction in the proper function or expression of these ion channels can result in a change in effective refractory period (ERP and lead to arrhythmia. The processes underlying the correct targeting of ion channels to the plasma membrane are complex, and have not been fully characterized in cardiac myocytes. Emerging evidence highlights ion channel trafficking as a potential causative factor in certain acquired and inherited arrhythmias, and therapies which target trafficking as opposed to pore block are starting to receive attention. In this review we present the current evidence for the mechanisms which underlie precise control of cardiac ion channel trafficking and targeting.

Recommendations regarding dietary intake and caffeine and alcohol consumption in patients with cardiac arrhythmias: what do you tell your patients to do or not to do?

Science.gov (United States)

Glatter, Kathryn A; Myers, Richard; Chiamvimonvat, Nipavan

2012-10-01

The etiology of arrhythmias including atrial fibrillation is multifactorial. Most arrhythmias are associated with comorbid illnesses like hypertension, diabetes, thyroid disease, or advanced age. Although it is tempting to blame a stimulant like caffeine as a trigger for arrhythmias, the literature does not support this idea. There is no real benefit to having patients with arrhythmias limit their caffeine intake. Caffeine is a vasoactive substance that also may promote the release of norepinephrine and epinephrine. However, acute ingestion of caffeine (as coffee or tea) does not cause atrial fibrillation. Even patients suffering a myocardial infarction do not have an increased incidence of ventricular or other arrhythmias after ingesting several cups of coffee. Large epidemiologic studies have also failed to find a connection between the amount of coffee/caffeine used and the development of arrhythmias. As such, it does not make sense to suggest that patients with palpitations, paroxysmal atrial fibrillation, or supraventricular tachycardia, abstain from caffeine use. Energy drinks are a new phenomenon on the beverage market, with 30-50 % of young adults and teens using them regularly. Energy drinks are loaded with caffeine, sugar, and other chemicals that can stimulate the cardiac system. There is an increasing body of mainly anecdotal case reports describing arrhythmias or even sudden death triggered by exercise plus using energy drinks. Clearly, there must be more study in this area, but it is wise to either limit or avoid their use in patients with arrhythmias. Moderate to heavy alcohol use seems to be associated with the development of atrial fibrillation. The term "holiday heart" was coined back in 1978, to describe patients who had atrial fibrillation following binge alcohol use. Thus, it is reasonable to recommend to patients with arrhythmias that they limit their alcohol use, although unfortunately this treatment will likely not completely resolve their

Family and population strategies for screening and counselling of inherited cardiac arrhythmias

NARCIS (Netherlands)

Van Langen, I.M.; Hofman, N.; Tan, H.L.; Wilde, A.A.M.

2004-01-01

Family screening in inherited cardiac arrhythmias has been performed in The Netherlands since 1996, when diagnostic DNA testing in long QT syndrome (LOTS) and hypertrophic cardiomyopathy (HCM) became technically possible. In multidisciplinary outpatient academic clinics, an adjusted protocol for

AV-block and conduction slowing prevail over TdP arrhythmias in the methoxamine-sensitized pro-arrhythmic rabbit model.

Science.gov (United States)

Varkevisser, Rosanne; Vos, Marc A; Beekman, Jet D; Tieland, Ralph G; Van Der Heyden, Marcel A

2015-01-01

The methoxamine-sensitized rabbit model is widely used to screen drugs for proarrhythmic properties, especially repolarization-dependent TdP arrhythmias. With the change of anesthesia and/or sensitizing agent, conduction disturbances have been reported as well. Therefore, we compared currently available in-house anesthetics in order to preserve arrhythmia sensitivity and preclude conduction disturbances. Rabbits were randomly assigned to 3 groups: (1) 35 mg/kg ketamine + 5 mg/kg xylazine; (2) 0.5 mL/kg hypnorm + 3 mg/kg midazolam; (3) 35 mg/kg ketamine + 20 mg/kg propofol. Anesthesia was maintained by 1.5% isoflurane. Concomitant infusion of methoxamine (17 μg/kg/min for 40 minutes) and dofetilide (10 μg/kg/min for 30 minutes) was used to induce arrhythmias. Sole methoxamine infusion exclusively decreased HR in groups 1 and 3. Dofetilide lengthened repolarization, followed in time by PQ/QRS prolongation, second-degree AV block, and subsequently TdP arrhythmias. TdP was seen in 80%, 0%, and 33% of the rabbits in groups 1, 2, and 3, respectively. Decreasing the dose of dofetilide to 5 μg/kg/min in ketamine/xylazine anesthetized rabbits resulted in a drop in TdP incidence (25%) while conduction disturbances persisted. Flunarizine (n = 6) suppressed all TdP arrhythmias while conduction disturbances remained present. TdP incidence in the methoxamine-sensitized rabbit could be dramatically influenced by anesthesia, drug dose, and flunarizine, while conduction slowing remained present. Thus, conduction slowing seems to be the integral outcome in this model. © 2014 Wiley Periodicals, Inc.

Prevalence of Fibromyalgia Syndrome and Its Correlations with Arrhythmia in Patients with Palpitations

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Ayhan Aşkın

2018-04-01

Full Text Available Objective: It is aimed to determine the prevalence of fibromyalgia syndrome (FMS and its correlations with arrhythmia in patients with palpitations. Material and Methods: Sixty-two patients who underwent electrophysiological study (EPS due to palpitation complaints in Cardiology department and 40 healthy controls were included in the study. The precise diagnosis of arrhythmia was established using EPS. All participants were screened for FMS using American College of Rheumatology 2010 Fibromyalgia diagnostic criteria. Clinical assessments included measurement of severity of pain, fatigue and morning fatigue with visual analog scale (VAS, functional status with Fibromyalgia Impact Questionnaire (FIQ, and anxiety/depression with Hospital Anxiety and Depression Scale (HAD. Results: FMS was diagnosed in 22 of the 62 patients (36%, and 4 of the 40 healthy controls (10% (p 0.05. EPS+ patients with FMS had higher fatigue levels, HAD and FIQ scores than EPS− patients, although statistically insignificant. HV durations were statistically longer in the EPS− subgroup (p < 0.05 but other EPS data were similar. Conclusion: FMS frequency and HAD anxiety scores were found to be higher in patients with palpitation complaints. However, we found no association between arrhythmia, EPS parameters and FMS. In our clinical practice we should keep in mind to carry out assessments in terms of FMS in patients with palpitation.

Cardiac Arrhythmia: In vivo screening in the zebrafish to overcome complexity in drug discovery.

Science.gov (United States)

Macrae, Calum A

2010-07-01

IMPORTANCE OF THE FIELD: Cardiac arrhythmias remain a major challenge for modern drug discovery. Clinical events are paroxysmal, often rare and may be asymptomatic until a highly morbid complication. Target selection is often based on limited information and though highly specific agents are identified in screening, the final efficacy is often compromised by unanticipated systemic responses, a narrow therapeutic index and substantial toxicities. AREAS COVERED IN THIS REVIEW: Our understanding of complexity of arrhythmogenesis has grown dramatically over the last two decades, and the range of potential disease mechanisms now includes pathways previously thought only tangentially involved in arrhythmia. This review surveys the literature on arrhythmia mechanisms from 1965 to the present day, outlines the complex biology underlying potentially each and every rhythm disturbance, and highlights the problems for rational target identification. The rationale for in vivo screening is described and the utility of the zebrafish for this approach and for complementary work in functional genomics is discussed. Current limitations of the model in this setting and the need for careful validation in new disease areas are also described. WHAT THE READER WILL GAIN: An overview of the complex mechanisms underlying most clinical arrhythmias, and insight into the limits of ion channel conductances as drug targets. An introduction to the zebrafish as a model organism, in particular for cardiovascular biology. Potential approaches to overcoming the hurdles to drug discovery in the face of complex biology including in vivo screening of zebrafish genetic disease models. TAKE HOME MESSAGE: In vivo screening in faithful disease models allows the effects of drugs on integrative physiology and disease biology to be captured during the screening process, in a manner agnostic to potential drug target or targets. This systematic strategy bypasses current gaps in our understanding of disease

Reduction of false arrhythmia alarms using signal selection and machine learning

NARCIS (Netherlands)

Eerikäinen, L.M.; Vanschoren, J.; Rooijakkers, M.J.; Vullings, R.; Aarts, R.M.

2016-01-01

In this paper, we propose an algorithm that classifies whether a generated cardiac arrhythmia alarm is true or false. The large number of false alarms in intensive care is a severe issue. The noise peaks caused by alarms can be high and in a noisy environment nurses can experience stress and

Transcatheter radiofrequency ablation under the guidance of three-dimensional mapping for the treatment of complex cardiac arrhythmias

International Nuclear Information System (INIS)

Hong Lang; Wang Hong; Lai Hengli; Ying Qiulin; Chen Zhangqiang; Lu Linxiang; Qiu Yun; Xiao Chengwei

2010-01-01

Objective: To investigate the effectiveness and safety of transcatheter radiofrequency ablation guided by a three-dimensional mapping system (Ensite or Carto) for the treatment of complex cardiac arrhythmias. Methods: A cohort of 123 consecutive hospitalized inpatients during the period from February 2006 to December 2008 were selected for this study. These patients suffered from various arrhythmias, including paroxysmal atrial fibrillation (n = 58), persistent or permanent atrial fibrillation (n = 10), atrial flutter (n = 13), atrial tachycardia (n = 12) and ventricular tachycardia or frequent ventricular premature beats (n = 30). Transcatheter radiofrequency ablation for arrhythmias was performed under the guidance of an EnSite3000 / NavX or Array mapping system in 80 cases, and under the guidance of a CARTO mapping system in the remaining 43 cases. Results: Successful ablation of arrhythmias was obtained by single operation in 106 cases (86.18%), including 59 cases with atrial fibrillation, 11 cases with atrial flutter, 10 cases with atrial tachycardia, and 26 cases with ventricular tachycardia or premature ventricular beat.Ablation procedure was carried out and was successful in 10 cases with a successful rate of 94.31%, including 5 cases with atrial fibrillation, 1 case with recurred atrial flutter, 1 case with recurrent atrial tachycardia, and 3 cases with ventricular tachycardia or premature ventricular beat.After operation, complications occurred in 6 cases, including cardiac tamponade in 4 cases, distal embolism of the left anterior descending coronary artery in 1 case, and pulmonary embolism in 1 case. Conclusion: Three-dimensional mapping system can clearly and stereoscopically display the cardiac structures. Therefore, this technique is of great value in guiding the transcatheter radiofrequency ablation for complex arrhythmias, in improving the success rate of ablation and in increasing the safety of the procedure. (authors)

High level of oxygen treatment causes cardiotoxicity with arrhythmias and redox modulation

Energy Technology Data Exchange (ETDEWEB)

Chapalamadugu, Kalyan C.; Panguluri, Siva K. [Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL (United States); Bennett, Eric S. [Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL (United States); Kolliputi, Narasaiah [Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL (United States); Tipparaju, Srinivas M., E-mail: stippara@health.usf.edu [Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL (United States)

2015-01-01

Hyperoxia exposure in mice leads to cardiac hypertrophy and voltage-gated potassium (Kv) channel remodeling. Because redox balance of pyridine nucleotides affects Kv function and hyperoxia alters cellular redox potential, we hypothesized that hyperoxia exposure leads to cardiac ion channel disturbances and redox changes resulting in arrhythmias. In the present study, we investigated the electrical changes and redox abnormalities caused by 72 h hyperoxia treatment in mice. Cardiac repolarization changes were assessed by acquiring electrocardiogram (ECG) and cardiac action potentials (AP). Biochemical assays were employed to identify the pyridine nucleotide changes, Kv1.5 expression and myocardial injury. Hyperoxia treatment caused marked bradycardia, arrhythmia and significantly prolonged (ms) the, RR (186.2 ± 10.7 vs. 146.4 ± 6.2), PR (46.8 ± 3.1 vs. 39.3 ± 1.6), QRS (10.8 ± 0.6 vs. 8.5 ± 0.2), QTc (57.1 ± 3.5 vs. 40 ± 1.4) and JT (13.4 ± 2.1 vs. 7.0 ± 0.5) intervals, when compared with normoxia group. Hyperoxia treatment also induced significant increase in cardiac action potential duration (APD) (ex-APD{sub 90}; 73.8 ± 9.5 vs. 50.9 ± 3.1 ms) and elevated levels of serum markers of myocardial injury; cardiac troponin I (TnI) and lactate dehydrogenase (LDH). Hyperoxia exposure altered cardiac levels of mRNA/protein expression of; Kv1.5, Kvβ subunits and SiRT1, and increased ratios of reduced pyridine nucleotides (NADH/NAD and NADPH/NADP). Inhibition of SiRT1 in H9C2 cells using Splitomicin resulted in decreased SiRT1 and Kv1.5 expression, suggesting that SiRT1 may mediate Kv1.5 downregulation. In conclusion, the cardiotoxic effects of hyperoxia exposure involve ion channel disturbances and redox changes resulting in arrhythmias. - Highlights: • Hyperoxia treatment leads to arrhythmia with prolonged QTc and action potential duration. • Hyperoxia treatment alters cardiac pyridine nucleotide [NAD(P)H/NAD(P)] levels. • SiRT1 and Kv1.5 are co

High level of oxygen treatment causes cardiotoxicity with arrhythmias and redox modulation

International Nuclear Information System (INIS)

Chapalamadugu, Kalyan C.; Panguluri, Siva K.; Bennett, Eric S.; Kolliputi, Narasaiah; Tipparaju, Srinivas M.

2015-01-01

Hyperoxia exposure in mice leads to cardiac hypertrophy and voltage-gated potassium (Kv) channel remodeling. Because redox balance of pyridine nucleotides affects Kv function and hyperoxia alters cellular redox potential, we hypothesized that hyperoxia exposure leads to cardiac ion channel disturbances and redox changes resulting in arrhythmias. In the present study, we investigated the electrical changes and redox abnormalities caused by 72 h hyperoxia treatment in mice. Cardiac repolarization changes were assessed by acquiring electrocardiogram (ECG) and cardiac action potentials (AP). Biochemical assays were employed to identify the pyridine nucleotide changes, Kv1.5 expression and myocardial injury. Hyperoxia treatment caused marked bradycardia, arrhythmia and significantly prolonged (ms) the, RR (186.2 ± 10.7 vs. 146.4 ± 6.2), PR (46.8 ± 3.1 vs. 39.3 ± 1.6), QRS (10.8 ± 0.6 vs. 8.5 ± 0.2), QTc (57.1 ± 3.5 vs. 40 ± 1.4) and JT (13.4 ± 2.1 vs. 7.0 ± 0.5) intervals, when compared with normoxia group. Hyperoxia treatment also induced significant increase in cardiac action potential duration (APD) (ex-APD 90 ; 73.8 ± 9.5 vs. 50.9 ± 3.1 ms) and elevated levels of serum markers of myocardial injury; cardiac troponin I (TnI) and lactate dehydrogenase (LDH). Hyperoxia exposure altered cardiac levels of mRNA/protein expression of; Kv1.5, Kvβ subunits and SiRT1, and increased ratios of reduced pyridine nucleotides (NADH/NAD and NADPH/NADP). Inhibition of SiRT1 in H9C2 cells using Splitomicin resulted in decreased SiRT1 and Kv1.5 expression, suggesting that SiRT1 may mediate Kv1.5 downregulation. In conclusion, the cardiotoxic effects of hyperoxia exposure involve ion channel disturbances and redox changes resulting in arrhythmias. - Highlights: • Hyperoxia treatment leads to arrhythmia with prolonged QTc and action potential duration. • Hyperoxia treatment alters cardiac pyridine nucleotide [NAD(P)H/NAD(P)] levels. • SiRT1 and Kv1.5 are co-regulated in

A multicenter, long-term study on arrhythmias in children with Ebstein anomaly.

NARCIS (Netherlands)

Delhaas, T.; Sarvaas, G.J.; Rijlaarsdam, M.E.; Strengers, J.L.; Eveleigh, R.M.; Poulino, S.E.; Korte, C.L. de; Kapusta, L.

2010-01-01

To assess the prevalence, history, and treatment of arrhythmias, in particular preexcitation and Wolff-Parkinson-White (WPW) syndrome, in patients with Ebstein anomaly (EA) during childhood and adolescence, we performed a multicenter retrospective study of all consecutive live-born patients with EA,

A Multicenter, Long-Term Study on Arrhythmias in Children with Ebstein Anomaly

NARCIS (Netherlands)

Delhaas, Tammo; Sarvaas, Gideon J. du Marchie; Rijlaarsdam, Marry E.; Strengers, Jan L.; Eveleigh, Rhona M.; Poulino, Sumayah E.; de Korte, Chris L.; Kapusta, Livia

To assess the prevalence, history, and treatment of arrhythmias, in particular preexcitation and Wolff-Parkinson-White (WPW) syndrome, in patients with Ebstein anomaly (EA) during childhood and adolescence, we performed a multicenter retrospective study of all consecutive live-born patients with EA,

[Treatment of arrhythmia in coronary patients and hypertensives with beta blockers and Depasan retard].

Science.gov (United States)

Kandziora, J

1981-05-14

In the ambulatory of an internal specialist a number of patients suffering from angina pectoris or hypertonia together with arrhythmic troubles received an initial treatment with beta-blockers over a period of 21 days. In cases in which arrhythmia persisted after this initial period the treatment was continued for another 21 days with the addition of Depasan retard in function of a second medicament. This combined treatment in form of an open study was extended to a total number of 50 patients presenting ventricular extrasystolia in 45 cases and in 5 cases absolute arrhythmia in addition to the main disease. Treatment with Depasan retard showed good or satisfactory results in 39 out of 45 patients suffering from ventricular extrasystoles, whilst no effect could be obtained in the 5 cases with absolute arrhythmia. No signs of incompatibility or unwanted interactions were observed in the course of this open study. Based on these results it can be concluded that Depasan retard should be recommended in those cases where on account of persistent arrhythmical troubles and especially extrasystoles, during a treatment with beta-blockers in patients suffering from angina pectoris or hypertonia, and additional treatment with anti-arrhythmical medicaments appears to be indicated.

Automatic recognition of cardiac arrhythmias based on the geometric patterns of Poincaré plots

International Nuclear Information System (INIS)

Zhang, Lijuan; Guo, Tianci; Xi, Bin; Fan, Yang; Wang, Kun; Bi, Jiacheng; Wang, Ying

2015-01-01

The Poincaré plot emerges as an effective tool for assessing cardiovascular autonomic regulation. It displays nonlinear characteristics of heart rate variability (HRV) from electrocardiographic (ECG) recordings and gives a global view of the long range of ECG signals. In the telemedicine or computer-aided diagnosis system, it would offer significant auxiliary information for diagnosis if the patterns of the Poincaré plots can be automatically classified. Therefore, we developed an automatic classification system to distinguish five geometric patterns of the Poincaré plots from four types of cardiac arrhythmias. The statistics features are designed on measurements and an ensemble classifier of three types of neural networks is proposed. Aiming at the difficulty to set a proper threshold for classifying the multiple categories, the threshold selection strategy is analyzed. 24 h ECG monitoring recordings from 674 patients, which have four types of cardiac arrhythmias, are adopted for recognition. For comparison, Support Vector Machine (SVM) classifiers with linear and Gaussian kernels are also applied. The experiment results demonstrate the effectiveness of the extracted features and the better performance of the designed classifier. Our study can be applied to diagnose the corresponding sinus rhythm and arrhythmia substrates disease automatically in the telemedicine and computer-aided diagnosis system. (paper)

Risk of malignant arrhythmias in initially symptomatic patients with Wolff-Parkinson-White syndrome: results of a prospective long-term electrophysiological follow-up study.

Science.gov (United States)

Pappone, Carlo; Vicedomini, Gabriele; Manguso, Francesco; Baldi, Mario; Pappone, Alessia; Petretta, Andrea; Vitale, Raffaele; Saviano, Massimo; Ciaccio, Cristiano; Giannelli, Luigi; Calovic, Zarko; Tavazzi, Luigi; Santinelli, Vincenzo

2012-02-07

The available amount of detailed long-term data in patients with Wolff-Parkinson-White syndrome is limited, and no prospective electrophysiological studies looking at predictors of malignant arrhythmia are available. Among 8575 symptomatic Wolff-Parkinson-White patients with atrioventricular reentrant tachycardia referred for electrophysiological test, 369 (mean age, 23±12.5 years) declined catheter ablation and were followed up. The primary end point of the study was to evaluate over a 5-year follow-up the predictors and characteristics of patients who develop malignant arrhythmias. After a mean follow-up of 42.1±10 months, malignant arrhythmias developed in 29 patients (mean age, 13.9±5.6 years; 26 male), resulting in presyncope/syncope (25 patients), hemodynamic collapse (3 patients), or cardiac arrest caused by ventricular fibrillation (1 patient). Of the remaining 340 patients, 168 (mean age, 34.2±9.0 years) remained asymptomatic up to 5 years, and 172 (mean age, 13.6±5.1 years) had benign recurrence, including sustained atrioventricular reentrant tachycardia (132 patients) or atrial fibrillation (40 patients). Compared with the group with no malignant arrhythmias, the group with malignant arrhythmias showed shorter accessory-pathway effective refractory period (PWolff-Parkinson-White syndrome generally have a good outcome, and predictors of malignant arrhythmias are similar to those reported for asymptomatic patients with ventricular pre-excitation.

Induced pluripotent stem cell derived cardiomyocytes as models for cardiac arrhythmias

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Maaike eHoekstra

2012-08-01

Full Text Available Cardiac arrhythmias are a major cause of morbidity and mortality. In younger patients, the majority of sudden cardiac deaths have an underlying Mendelian genetic cause. Over the last 15 years, enormous progress has been made in identifying the distinct clinical phenotypes and in studying the basic cellular and genetic mechanisms associated with the primary Mendelian (monogenic arrhythmia syndromes. Investigation of the electrophysiological consequences of an ion channel mutation is ideally done in the native cardiomyocyte environment. However, the majority of such studies so far have relied on heterologous expression systems in which single ion channel genes are expressed in non-cardiac cells. In some cases, transgenic mouse models haven been generated, but these also have significant shortcomings, primarily related to species differences.The discovery that somatic cells can be reprogrammed to pluripotency as induced pluripotent stem cells (iPSC has generated much interest since it presents an opportunity to generate patient- and disease-specific cell lines from which normal and diseased human cardiomyocytes can be obtained These genetically diverse human model systems can be studied in vitro and used to decipher mechanisms of disease and identify strategies and reagents for new therapies. Here we review the present state of the art with respect to cardiac disease models already generated using IPSC technology and which have been (partially characterized.Human iPSC (hiPSC models have been described for the cardiac arrhythmia syndromes, including LQT1, LQT2, LQT3-Brugada Syndrome, LQT8/Timothy syndrome and catecholaminergic polymorphic ventricular tachycardia. In most cases, the hiPSC-derived cardiomyoctes recapitulate the disease phenotype and have already provided opportunities for novel insight into cardiac pathophysiology. It is expected that the lines will be useful in the development of pharmacological agents for the management of these

Predictors of the left ventricular dysfunction induced by ventricular arrhythmia

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А. І. Vytryhovskiy

2016-08-01

Full Text Available The most powerful predictor of life-threatening arrhythmia risk is a combination of low heart rate variability with low ejection fraction (EF of the left ventricle. Aim. To identify predictors of left ventricle dysfunction which is induced by ventricular arrhythmia. Materials and methods. To diagnose structural changes of left ventricular functional capacity and reserves in patients with previous myocardial infarction and patients with high and very high cardiovascular risk by SCORE scale and for establishment the relationship between morphological heart changes and pathological phenomenon of heart turbulence echocardiography and study of heart rate turbulence variability were performed. 603 patients were selected for the research. All patients were divided into groups: group 1 – patients with coronary heart disease, but without associated risk factors, such as smoking, obesity, metabolic syndrome; group 2 – patients who smoke tobacco more than 2 years (very high cardiovascular risk by scale SCORE; group 3 – patients with metabolic syndrome without coronary heart disease or arterial hypertension (very high cardiovascular risk by scale SCORE. The control group consisted of 149 persons. Results. The feature of structural changes in patients with myocardial infarction and in patients with a high cardiovascular risk by SCORE with heart rate turbulence compared with cases without НRT is considerably thickening of the left interventricular septum in systole. Based on this, it can be argued that the emergence of ventricular arrhythmia and accordingly phenomenon of heart rate turbulence in patients with existing cardiovascular diseases and risk factors has both morphological and functional character. Significant difference of echocardioscopy parameters in patients with postinfarction cardiosclerosis and risk factors by the SCORE system was established by index of intraventricular septum thickness in systole, and in persons with high risk – in

Sevoflurane causes less arrhythmias than desflurane after off-pump coronary artery bypass grafting: A pilot study

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Hemmerling Thomas

2010-01-01

Full Text Available Background: Volatile anesthetics provide myocardial protection during cardiac surgery. Sevoflurane and desflurane are both efficient agents that allow immediate extubation after off-pump coronary artery bypass grafting (OPCABG. This study compared the incidence of arrhythmias after OPCABG with the two agents. Materials and Methods: Forty patients undergoing OPCABG with immediate extubation and perioperative high thoracic analgesia were included in this controlled, double-blind study; anesthesia was either provided using 1 MAC of sevoflurane (SEVO-group or desflurane (DES-group. Monitoring of perioperative arrhythmias was provided by continuous monitoring of the EKG up to 72 hours after surgery, and routine EKG monitoring once every day, until time of discharge. Patient data, perioperative arrhythmias, and myocardial protection (troponin I, CK, CK-MB-ratio, and transesophageal echocardiography examinations were compared using t-test, Fisher′s exact test or two-way analysis of variance for repeated measurements; P < 0.05. Results: Patient data and surgery-related data were similar between the two groups; all the patients were successfully extubated immediately after surgery, with similar emergence times. Supraventricular tachycardia occurred only in the DES-group (5 of 20 patients, atrial fibrillation was significantly more frequent in the DES group versus SEVO-group, at five out of 20 versus one out of 20 patients, respectively. Myocardial protection was equally achieved in both groups. Discussion: Ultra-fast track anesthesia using sevoflurane seems more advantageous than desflurane for anesthesia, for OPCABG, as it is associated with significantly less atrial fibrillation or supraventricular arrhythmias after surgery.

Epicardial phrenic nerve displacement during catheter ablation of atrial and ventricular arrhythmias: procedural experience and outcomes.

Science.gov (United States)

Kumar, Saurabh; Barbhaiya, Chirag R; Baldinger, Samuel H; Koplan, Bruce A; Maytin, Melanie; Epstein, Laurence M; John, Roy M; Michaud, Gregory F; Tedrow, Usha B; Stevenson, William G

2015-08-01

Arrhythmia origin in close proximity to the phrenic nerve (PN) can hinder successful catheter ablation. We describe our approach with epicardial PN displacement in such instances. PN displacement via percutaneous pericardial access was attempted in 13 patients (age 49±16 years, 9 females) with either atrial tachycardia (6 patients) or atrial fibrillation triggered from a superior vena cava focus (1 patient) adjacent to the right PN or epicardial ventricular tachycardia origin adjacent to the left PN (6 patients). An epicardially placed steerable sheath/4 mm-catheter combination (5 patients) or a vascular or an esophageal balloon (8 patients) was ultimately successful. Balloon placement was often difficult requiring manipulation via a steerable sheath. In 2 ventricular tachycardia cases, absence of PN capture was achieved only once the balloon was directly over the ablation catheter. In 3 atrial tachycardia patients, PN displacement was not possible with a balloon; however, a steerable sheath/catheter combination was ultimately successful. PN displacement allowed acute abolishment of all targeted arrhythmias. No PN injury occurred acutely or in follow up. Two patients developed acute complications (pleuro-pericardial fistula 1 and pericardial bleeding 1). Survival free of target arrhythmia was achieved in all atrial tachycardia patients; however, a nontargeted ventricular tachycardia recurred in 1 patient at a median of 13 months' follow up. Arrhythmias originating in close proximity to the PN can be targeted successfully with PN displacement with an epicardially placed steerable sheath/catheter combination, or balloon, but this strategy can be difficult to implement. Better tools for phrenic nerve protection are desirable. © 2015 American Heart Association, Inc.

Anti-HERG activity and the risk of drug-induced arrhythmias and sudden death

DEFF Research Database (Denmark)

De Bruin, M L; Pettersson, M; Meyboom, R H B

2005-01-01

AIMS: Drug-induced QTc-prolongation, resulting from inhibition of HERG potassium channels may lead to serious ventricular arrhythmias and sudden death. We studied the quantitative anti-HERG activity of pro-arrhythmic drugs as a risk factor for this outcome in day-to-day practice. METHODS...... defined as reports of cardiac arrest, sudden death, torsade de pointes, ventricular fibrillation, and ventricular tachycardia (n = 5591), and compared with non-cases regarding the anti-HERG activity, defined as the effective therapeutic plasma concentration (ETCPunbound) divided by the HERG IC50 value......, of suspected drugs. We identified a significant association of 1.93 (95% CI: 1.89-1.98) between the anti-HERG activity of drugs, measured as log10 (ETCPunbound/IC50), and reporting of serious ventricular arrhythmias and sudden death to the WHO-UMC database. CONCLUSION: Anti-HERG activity is associated...

AANA Journal Course: update for nurse anesthetists. Arrhythmia management devices and electromagnetic interference.

Science.gov (United States)

Mattingly, Emily

2005-04-01

The technological complexity of implantable arrhythmia management devices, specifically pacemakers and defibrillators, has increased dramatically since their introduction only a few decades ago. Patients with such devices are encountered much more frequently in hospitals and surgery centers, yet anesthesia provider knowledge of safe and proper management is often incomplete. Anesthesia textbooks and references may provide only short paragraphs on arrhythmia management devices that do not address important perioperative management strategies for this ever-growing patient population. It is no longer satisfactory to simply place a magnet over an implanted device during surgery and assume that this action protects the patient from harm due to electromagnetic interference from inappropriate device function. This AANA Journal course serves as a concise review of basic device function, the sources and effects of electromagnetic interference in the operative setting, and patient management recommendations from current literature.

Scintigraphic assessment of cardiac sympathetic innervation with I-123-metaiodobenzylguanidine in cardiomyopathy. Special reference to cardiac arrhythmia

Energy Technology Data Exchange (ETDEWEB)

Asano, Takahisa; Otsuka, Nobuaki; Sone, Teruki; Mimura, Hiroaki; Yanagimoto, Shinichi; Tomomitsu, Tatsushi; Fukunaga, Masao [Kawasaki Medical School, Kurashiki, Okayama (Japan); Morita, Koichi

1999-07-01

Cardiac sympathetic imagings with I-123-metaiodobenzylguanidine (MIBG) were carried out in 5 cases with dilated cardiomyopathy (DCM), 26 cases with hypertrophic cardiomyopathy (HCM), and 4 cases without cardiac disease as a control to assess cardiac sympathetic innervation qualitatively and quantitatively, and to clarify the relation of MIBG accumulation to arrhythmia. MIBG scintigraphy was performed at 15 min. (early image) and 4 hr. (delayed image) after intravenous injection of MIBG 111 MBq. The MIBG uptake ratio of mediastinum (H/M) and the cardiac washout rate (WR) from early to delayed images were calculated. On both early and delayed SPECTs, MIBG uptake was assessed by defect scores (DSs). Regarding the cases with HCM, the MIBG uptake ratio, WR, and DS were also compared in cases with and without arrhythmia. In DCM, the MIBG uptake on delayed SPECT was markedly low, the H/M ratio was significantly lower, and the DS was significantly higher than in the control (all p<0.05). As for the WR, there was no significant difference between HCM, DCM and the control. In HCM, significantly reduced MIBG uptake was observed in cases with ventricular techycardia (VT) and in cases with atrial fibrillation (Af), as compared with cases without arrhythmia (all p<0.05). There results suggest that MIBG scintigraphy might be a useful tool in the assessment of cardiac sympathetic abnormalities in cardiomyopathy, especially in cases with arrhythmia. (author)

Late gadolinium enhancement by magnetic resonance explains adverse cardiac events in individuals with ventricular arrhythmia

International Nuclear Information System (INIS)

Courtis, J.; Vasallo, J.; Arabia, L.; Dimitroff, M.; Gonzalez, A.; Tibaldi, M.

2012-01-01

Objective: To determine whether the presence of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) predict adverse cardiac events in patients with ventricular arrhythmia. Methods: We selected 74 consecutive patients with symptomatic ventricular arrhythmia (premature ventricular contractions and ventricular tachycardia) and left ventricular ejection fraction (LVEF) >55% sent to CMR for evaluation of structural heart disease previously undetected by other complementary methods. LGE, systolic function and volumes of both ventricles were analyzed. At follow-up was assessed a combined end point: hospitalization for ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy and cardiac death. Results: During a median follow up of 575 days (interquartile range 24-1120 days) and by analyzing the population according to the presence (n=9, 12%) or not (n=65, 88%) LGE was observed that the group with positive Gd had lower LVEF (58% vs. 66% respectively, p=0.01) and larger volumes (EDV: 185 ml vs. 123 ml respectively, p=0.01 and ESV: 81 ml vs. 42 ml respectively, p=0.01) than the other group. Two (22%) patients in the LGE + group vs. one (4%) of those without LGE showed the combined endpoint (p=0.01) and when performing a logistic regression analysis it was found that the LGE is a predictor of adverse cardiac events analyzed (p=0.029). Conclusions: In this consecutive series of patients with ventricular arrhythmia we demonstrate a strong association between myocardial LGE and adverse cardiac events; this supports the hypothesis that myocardial fibrosis is an important arrhythmogenic substrate. In addition, almost all individuals without LGE were free of events during follow-up suggesting that it is possible to identify through the CMR low-risk individuals who can be treated conservatively. (authors) [es

Dental caries, periodontal disease, and cardiac arrhythmias in community-dwelling older persons aged 80 and older: is there a link?

DEFF Research Database (Denmark)

Holm-Pedersen, Poul; Avlund, Kirsten; Morse, Douglas E

2005-01-01

lesions had 2.8 times higher odds (95% confidence interval=1.1-7.0) of arrhythmia than persons without active coronal caries, but there was no greater risk for persons with three or more coronal caries lesions. There was no association between periodontal disease and arrhythmia. CONCLUSION: The findings......OBJECTIVES: To examine whether caries or periodontitis is associated with cardiac arrhythmias in community-dwelling people aged 80 and older. SETTING: Urban, community-based population in Stockholm, Sweden. DESIGN: Cross-sectional. PARTICIPANTS: Eligible persons were identified through...... by a physician or the Stockholm Inpatient Register. Active root caries, active coronal caries, and periodontitis were assessed using previously defined National Institute of Dental and Craniofacial Research diagnostic criteria. RESULTS: The primary finding of the multivariate logistic regression analysis...

Arrhythmia Mechanism and Scaling Effect on the Spectral Properties of Electroanatomical Maps With Manifold Harmonics.

Science.gov (United States)

Sanroman-Junquera, Margarita; Mora-Jimenez, Inmaculada; Garcia-Alberola, Arcadio; Caamano, Antonio J; Trenor, Beatriz; Rojo-Alvarez, Jose L

2018-04-01

Spatial and temporal processing of intracardiac electrograms provides relevant information to support the arrhythmia ablation during electrophysiological studies. Current cardiac navigation systems (CNS) and electrocardiographic imaging (ECGI) build detailed 3-D electroanatomical maps (EAM), which represent the spatial anatomical distribution of bioelectrical features, such as activation time or voltage. We present a principled methodology for spectral analysis of both EAM geometry and bioelectrical feature in CNS or ECGI, including their spectral representation, cutoff frequency, or spatial sampling rate (SSR). Existing manifold harmonic techniques for spectral mesh analysis are adapted to account for a fourth dimension, corresponding to the EAM bioelectrical feature. Appropriate scaling is required to address different magnitudes and units. With our approach, simulated and real EAM showed strong SSR dependence on both the arrhythmia mechanism and the cardiac anatomical shape. For instance, high frequencies increased significantly the SSR because of the "early-meets-late" in flutter EAM, compared with the sinus rhythm. Besides, higher frequency components were obtained for the left atrium (more complex anatomy) than for the right atrium in sinus rhythm. The proposed manifold harmonics methodology opens the field toward new signal processing tools for principled EAM spatiofeature analysis in CNS and ECGI, and to an improved knowledge on arrhythmia mechanisms.

hERG trafficking inhibition in drug-induced lethal cardiac arrhythmia.

Science.gov (United States)

Nogawa, Hisashi; Kawai, Tomoyuki

2014-10-15

Acquired long QT syndrome induced by non-cardiovascular drugs can cause lethal cardiac arrhythmia called torsades de points and is a significant problem in drug development. The prolongation of QT interval and cardiac action potential duration are mainly due to reduced physiological function of the rapidly activating voltage-dependent potassium channels encoded by human ether-a-go-go-related gene (hERG). Structurally diverse groups of drugs are known to directly inhibit hERG channel conductance. Therefore, the ability of acute hERG inhibition is routinely assessed at the preclinical stages in pharmaceutical testing. Recent findings indicated that chronic treatment with various drugs not only inhibits hERG channels but also decreases hERG channel expression in the plasma membrane of cardiomyocytes, which has become another concern in safety pharmacology. The mechanisms involve the disruption of hERG trafficking to the surface membrane or the acceleration of hERG protein degradation. From this perspective, we present a brief overview of mechanisms of drug-induced trafficking inhibition and pathological regulation. Understanding of drug-induced hERG trafficking inhibition may provide new strategies for predicting drug-induced QT prolongation and lethal cardiac arrhythmia in pharmaceutical drug development. Copyright © 2014 Elsevier B.V. All rights reserved.

Observational cohort study of ventricular arrhythmia in adults with Marfan syndrome caused by FBN1 mutations.

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Ali Aydin

Full Text Available Marfan syndrome is associated with ventricular arrhythmia but risk factors including FBN1 mutation characteristics require elucidation.We performed an observational cohort study of 80 consecutive adults (30 men, 50 women aged 42±15 years with Marfan syndrome caused by FBN1 mutations. We assessed ventricular arrhythmia on baseline ambulatory electrocardiography as >10 premature ventricular complexes per hour (>10 PVC/h, as ventricular couplets (Couplet, or as non-sustained ventricular tachycardia (nsVT, and during 31±18 months of follow-up as ventricular tachycardia (VT events (VTE such as sudden cardiac death (SCD, and sustained ventricular tachycardia (sVT. We identified >10 PVC/h in 28 (35%, Couplet/nsVT in 32 (40%, and VTE in 6 patients (8%, including 3 with SCD (4%. PVC>10/h, Couplet/nsVT, and VTE exhibited increased N-terminal pro-brain natriuretic peptide serum levels(P10/h and Couplet/nsVT also related to increased indexed end-systolic LV diameters (P = .024 and P = .020, to moderate mitral valve regurgitation (P = .018 and P = .003, and to prolonged QTc intervals (P = .001 and P = .006, respectively. Moreover, VTE related to mutations in exons 24-32 (P = .021. Kaplan-Meier analysis corroborated an association of VTE with increased NT-proBNP (P<.001 and with mutations in exons 24-32 (P<.001.Marfan syndrome with causative FBN1 mutations is associated with an increased risk for arrhythmia, and affected persons may require life-long monitoring. Ventricular arrhythmia on electrocardiography, signs of myocardial dysfunction and mutations in exons 24-32 may be risk factors of VTE.

Exercise-induced ventricular arrhythmias and vagal dysfunction in Chagas disease patients with no apparent cardiac involvement

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Henrique Silveira Costa

2015-04-01

Full Text Available INTRODUCTION : Exercise-induced ventricular arrhythmia (EIVA and autonomic imbalance are considered as early markers of heart disease in Chagas disease (ChD patients. The objective of the present study was to verify the differences in the occurrence of EIVA and autonomic maneuver indexes between healthy individuals and ChD patients with no apparent cardiac involvement. METHODS : A total of 75 ChD patients with no apparent cardiac involvement, aged 44.7 (8.5 years, and 38 healthy individuals, aged 44.0 (9.2 years, were evaluated using echocardiography, symptom-limited treadmill exercise testing and autonomic function tests. RESULTS : The occurrence of EIVA was higher in the chagasic group (48% than in the control group (23.7% during both the effort and the recovery phases. Frequent ventricular contractions occurred only in the patient group. Additionally, the respiratory sinus arrhythmia index was significantly lower in the chagasic individuals compared with the control group. CONCLUSIONS : ChD patients with no apparent cardiac involvement had a higher frequency of EIVA as well as more vagal dysfunction by respiratory sinus arrhythmia. These results suggest that even when asymptomatic, ChD patients possess important arrhythmogenic substrates and subclinical disease.

Arrhythmia-provoking factors and symptoms at the onset of paroxysmal atrial fibrillation: A study based on interviews with 100 patients seeking hospital assistance

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Madsen-Härdig Bjarne

2004-08-01

Full Text Available Abstract Background Surprisingly little information on symptoms of paroxysmal atrial fibrillation is available in scientific literature. Using questionnaires, we have analyzed the symptoms associated with arrhythmia attacks. Methods One hundred randomly-selected patients with idiopathic paroxysmal atrial fibrillation filled in a structured questionnaire. Results Psychic stress was the most common factor triggering arrhythmia (54%, followed by physical exertion (42%, tiredness (41% coffee (25% and infections (22%. Thirty-four patients cited alcohol, 26 in the form of red wine, 16 as white wine and 26 as spirits. Among these 34, red wine and spirits produced significantly more episodes of arrhythmia than white wine (p = 0.01 and 0.005 respectively. Symptoms during arrhythmia were palpitations while exerting (88%, reduced physical ability (87%, palpitations at rest (86%, shortage of breath during exertion (70% and anxiety (59%. Significant differences between sexes were noted regarding swollen legs (women 21%, men 6%, p = 0.027, nausea (women 36%, men 13%, p = 0.012 and anxiety (females 79%, males 51%, p = 0.014. Conclusion Psychic stress was the commonest triggering factor in hospitalized patients with paroxysmal atrial fibrillation. Red wine and spirits were more proarrhythmic than white wine. Symptoms in women in connection with attacks of arrhythmia vary somewhat from those in men.

Nonischemic Left Ventricular Scar as a Substrate of Life-Threatening Ventricular Arrhythmias and Sudden Cardiac Death in Competitive Athletes.

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Zorzi, Alessandro; Perazzolo Marra, Martina; Rigato, Ilaria; De Lazzari, Manuel; Susana, Angela; Niero, Alice; Pilichou, Kalliopi; Migliore, Federico; Rizzo, Stefania; Giorgi, Benedetta; De Conti, Giorgio; Sarto, Patrizio; Serratosa, Luis; Patrizi, Giampiero; De Maria, Elia; Pelliccia, Antonio; Basso, Cristina; Schiavon, Maurizio; Bauce, Barbara; Iliceto, Sabino; Thiene, Gaetano; Corrado, Domenico

2016-07-01

The clinical profile and arrhythmic outcome of competitive athletes with isolated nonischemic left ventricular (LV) scar as evidenced by contrast-enhanced cardiac magnetic resonance remain to be elucidated. We compared 35 athletes (80% men, age: 14-48 years) with ventricular arrhythmias and isolated LV subepicardial/midmyocardial late gadolinium enhancement (LGE) on contrast-enhanced cardiac magnetic resonance (group A) with 38 athletes with ventricular arrhythmias and no LGE (group B) and 40 healthy control athletes (group C). A stria LGE pattern with subepicardial/midmyocardial distribution, mostly involving the lateral LV wall, was found in 27 (77%) of group A versus 0 controls (group C; P<0.001), whereas a spotty pattern of LGE localized at the junction of the right ventricle to the septum was respectively observed in 11 (31%) versus 10 (25%; P=0.52). All athletes with stria pattern showed ventricular arrhythmias with a predominant right bundle branch block morphology, 13 of 27 (48%) showed ECG repolarization abnormalities, and 5 of 27 (19%) showed echocardiographic hypokinesis of the lateral LV wall. The majority of athletes with no or spotty LGE pattern had ventricular arrhythmias with a predominant left bundle branch block morphology and no ECG or echocardiographic abnormalities. During a follow-up of 38±25 months, 6 of 27 (22%) athletes with stria pattern experienced malignant arrhythmic events such as appropriate implantable cardiac defibrillator shock (n=4), sustained ventricular tachycardia (n=1), or sudden death (n=1), compared with none of athletes with no or LGE spotty pattern and controls. Isolated nonischemic LV LGE with a stria pattern may be associated with life-threatening arrhythmias and sudden death in the athlete. Because of its subepicardial/midmyocardial location, LV scar is often not detected by echocardiography. © 2016 The Authors.

Arrhythmia causes lipid accumulation and reduced glucose uptake.

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Lenski, Matthias; Schleider, Gregor; Kohlhaas, Michael; Adrian, Lucas; Adam, Oliver; Tian, Qinghai; Kaestner, Lars; Lipp, Peter; Lehrke, Michael; Maack, Christoph; Böhm, Michael; Laufs, Ulrich

2015-01-01

Atrial fibrillation (AF) is characterized by irregular contractions of atrial cardiomyocytes and increased energy demand. The aim of this study was to characterize the influence of arrhythmia on glucose and fatty acid (FA) metabolism in cardiomyocytes, mice and human left atrial myocardium. Compared to regular pacing, irregular (pseudo-random variation at the same number of contractions/min) pacing of neonatal rat cardiomyocytes induced shorter action potential durations and effective refractory periods and increased diastolic [Ca(2+)]c. This was associated with the activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and AMP-activated protein kinase (AMPK). Membrane expression of fatty acid translocase (FAT/CD36) and (14)C-palmitic acid uptake were augmented while membrane expression of glucose transporter subtype 4 (GLUT-4) as well as (3)H-glucose uptake were reduced. Inhibition of AMPK and CaMKII prevented these arrhythmia-induced metabolic changes. Similar alterations of FA metabolism were observed in a transgenic mouse model (RacET) for spontaneous AF. Consistent with these findings samples of left atrial myocardium of patients with AF compared to matched samples of patients with sinus rhythm showed up-regulation of CaMKII and AMPK and increased membrane expression of FAT/CD36, resulting in lipid accumulation. These changes of FA metabolism were accompanied by decreased membrane expression of GLUT-4, increased glycogen content and increased expression of the pro-apoptotic protein bax. Irregular pacing of cardiomyocytes increases diastolic [Ca(2+)]c and activation of CaMKII and AMPK resulting in lipid accumulation, reduced glucose uptake and increased glycogen synthesis. These metabolic changes are accompanied by an activation of pro-apoptotic signalling pathways.

Flecainide Therapy Reduces Exercise-Induced Ventricular Arrhythmias in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia

NARCIS (Netherlands)

van der Werf, Christian; Kannankeril, Prince J.; Sacher, Frederic; Krahn, Andrew D.; Viskin, Sami; Leenhardt, Antoine; Shimizu, Wataru; Sumitomo, Naokata; Fish, Frank A.; Bhuiyan, Zahurul A.; Willems, Albert R.; van der Veen, Maurits J.; Watanabe, Hiroshi; Laborderie, Julien; Haïssaguerre, Michel; Knollmann, Björn C.; Wilde, Arthur A. M.

2011-01-01

Objectives This study evaluated the efficacy and safety of flecainide in addition to conventional drug therapy in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Background CPVT is an inherited arrhythmia syndrome caused by gene mutations that destabilize cardiac

A real time ECG signal processing application for arrhythmia detection on portable devices

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Georganis, A.; Doulgeraki, N.; Asvestas, P.

2017-11-01

Arrhythmia describes the disorders of normal heart rate, which, depending on the case, can even be fatal for a patient with severe history of heart disease. The purpose of this work is to develop an application for heart signal visualization, processing and analysis in Android portable devices e.g. Mobile phones, tablets, etc. The application is able to retrieve the signal initially from a file and at a later stage this signal is processed and analysed within the device so that it can be classified according to the features of the arrhythmia. In the processing and analysing stage, different algorithms are included among them the Moving Average and Pan Tompkins algorithm as well as the use of wavelets, in order to extract features and characteristics. At the final stage, testing is performed by simulating our application in real-time records, using the TCP network protocol for communicating the mobile with a simulated signal source. The classification of ECG beat to be processed is performed by neural networks.

Ambulatory cardiac arrhythmias in relation to mild hypokalaemia and prognosis in community dwelling middle-aged and elderly subjects

DEFF Research Database (Denmark)

Mattsson, Nick; Sadjadieh, Golnaz; Kumarathurai, Preman

2016-01-01

with frequency of premature ventricular complexes (PVCs) especially in combination with diuretic treatment (r = -0.22, P = 0.015). Hypokalaemia was not associated with supraventricular arrhythmias. Subjects at lowest quintile of p-potassium (mean 3.42, range 2.7-3.6 mmol/L) were defined as hypokalaemic......, 10 and 15 per 1000 patient-year in those with one abnormality, and 3 per 1000 patient-year in subjects with no abnormality. One variable combining hypokalaemia with excessive supraventricular arrhythmias gave similar results in univariate analysis, but not after multivariate adjustments. CONCLUSION...

Prevention of fatal arrhythmias in high-risk subjects by fish oil n-3 fatty acid intake.

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Leaf, Alexander; Albert, Christine M; Josephson, Mark; Steinhaus, David; Kluger, Jeffrey; Kang, Jing X; Cox, Benjamin; Zhang, Hui; Schoenfeld, David

2005-11-01

The long-chain n-3 fatty acids in fish have been demonstrated to have antiarrhythmic properties in experimental models and to prevent sudden cardiac death in a randomized trial of post-myocardial infarction patients. Therefore, we hypothesized that these n-3 fatty acids might prevent potentially fatal ventricular arrhythmias in high-risk patients. Four hundred two patients with implanted cardioverter/defibrillators (ICDs) were randomly assigned to double-blind treatment with either a fish oil or an olive oil daily supplement for 12 months. The primary end point, time to first ICD event for ventricular tachycardia or fibrillation (VT or VF) confirmed by stored electrograms or death from any cause, was analyzed by intention to treat. Secondary analyses were performed for "probable" ventricular arrhythmias, "on-treatment" analyses for all subjects who had taken any of their oil supplements, and "on-treatment" analyses only of those subjects who were on treatment for at least 11 months. Compliance with double-blind treatment was similar in the 2 groups; however, the noncompliance rate was high (35% of all enrollees). In the primary analysis, assignment to treatment with the fish oil supplement showed a trend toward a prolonged time to the first ICD event (VT or VF) or of death from any cause (risk reduction of 28%; P=0.057). When therapies for probable episodes of VT or VF were included, the risk reduction became significant at 31%; P=0.033. For those who stayed on protocol for at least 11 months, the antiarrhythmic benefit of fish oil was improved for those with confirmed events (risk reduction of 38%; P=0.034). Although significance was not achieved for the primary end point, this study provides evidence that for individuals at high risk of fatal ventricular arrhythmias, regular daily ingestion of fish oil fatty acids may significantly reduce potentially fatal ventricular arrhythmias.

Risk Prediction of One-Year Mortality in Patients with Cardiac Arrhythmias Using Random Survival Forest

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Fen Miao

2015-01-01

Full Text Available Existing models for predicting mortality based on traditional Cox proportional hazard approach (CPH often have low prediction accuracy. This paper aims to develop a clinical risk model with good accuracy for predicting 1-year mortality in cardiac arrhythmias patients using random survival forest (RSF, a robust approach for survival analysis. 10,488 cardiac arrhythmias patients available in the public MIMIC II clinical database were investigated, with 3,452 deaths occurring within 1-year followups. Forty risk factors including demographics and clinical and laboratory information and antiarrhythmic agents were analyzed as potential predictors of all-cause mortality. RSF was adopted to build a comprehensive survival model and a simplified risk model composed of 14 top risk factors. The built comprehensive model achieved a prediction accuracy of 0.81 measured by c-statistic with 10-fold cross validation. The simplified risk model also achieved a good accuracy of 0.799. Both results outperformed traditional CPH (which achieved a c-statistic of 0.733 for the comprehensive model and 0.718 for the simplified model. Moreover, various factors are observed to have nonlinear impact on cardiac arrhythmias prognosis. As a result, RSF based model which took nonlinearity into account significantly outperformed traditional Cox proportional hazard model and has great potential to be a more effective approach for survival analysis.

Heart rate turbulence and variability in patients with ventricular arrhythmias

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Diego Tarricone

2009-08-01

Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

Geometric patterns of time-delay plots from different cardiac rhythms and arrhythmias using short-term EKG signals.

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Borracci, Raúl A; Montoya Pulvet, José D; Ingino, Carlos A; Fitz Maurice, Mario; Hirschon Prado, Alfredo; Dominé, Enrique

2017-12-27

To date, no systematic work has been intended to describe spatio-temporal patterns of cardiac rhythms using only short series of RR intervals, to facilitate visual or computerized-aided identification of EKG motifs for use in clinical practice. The aim of this study was to detect and classify eye-catching geometric patterns of Poincaré time-delay plots from different types of cardiac rhythms and arrhythmias using short-term EKG signals. Approximately 150-300 representative, consecutive beats were retrieved from 24-h Holter registers of 100 patients with different heart rhythms. Two-dimensional Poincaré charts were created, and the resulting geometric patterns were transformed into representative familiar eye-catching drawings to interpret different arrhythmias. Poincaré plot representation of RR interval data revealed a wide variety of visual patterns: (i) comet-shaped for sinus rhythm; (ii) torpedo-shaped for sinus bradycardia; (iii) cigarette-shaped for sinus tachycardia; (iv) butterfly-shaped for sinus tachycardia and isolated atrial premature complexes; (v) arrow-shaped for isolated premature complexes and inappropriate sinus tachycardia; (vi) inverted fan-shaped for sinus rhythm with frequent atrial premature complexes; (vii) tornado-shaped for atrial flutter and atrial tachycardia; and (viii) fan-shaped for atrial fibrillation. Modified Poincaré plots with smoothed lines connecting successive points could accurately classify different types of arrhythmias based on short RR interval sequence variability. Characteristic emergent patterns can be visually identified and eventually could be distinguished by an automatic classification system able to discern between arrhythmias. This work provides an alternative method to interpret time-delay plots obtained from short-term EKG signal recordings. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Associations between arrhythmia episodes and temporally and spatially resolved black carbon and particulate matter in elderly patients

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Zanobetti, Antonella; Coull, Brent A.; Gryparis, Alexandros; Kloog, Itai; Sparrow, David; Vokonas, Pantel S; Wright, Robert O.; Gold, Diane R; Schwartz, Joel

2015-01-01

Objectives Ambient air pollution has been associated with sudden deaths, some of which are likely due to ventricular arrhythmias. Defibrillator discharge studies have examined the association of air pollution with arrhythmias in sensitive populations. No studies have assessed this association using residence-specific estimates of air pollution exposure. Methods In the Normative Aging Study, we investigated the association between temporally-and spatially-resolved black carbon (BC) and PM2.5 and arrhythmia episodes (bigeminy, trigeminy or couplets episodes) measured as ventricular ectopy (VE) by 4-min electrocardiogram (ECG) monitoring in repeated measures of 701 subjects, during the years 2000 to 2010. We used a binomial distribution (having or not a VE episode) in a mixed effect model with a random intercept for subject, controlling for seasonality, temperature, day of the week, medication use, smoking, having diabetes, BMI and age. We also examined whether these associations were modified by genotype or phenotype. Results We found significant increases in VE with both pollutants and lags; for the estimated concentration averaged over the three days prior to the health assessment we found increases in the odds of having VE with an OR of 1.52 (95% CI: 1.19–1.94) for an IQR (0.30 μg/m3) increase in BC and an OR of 1.39 (95% CI: 1.12–1.71) for an IQR (5.63 μg/m3) increase in PM2.5. We also found higher effects in subjects with the GSTT1 and GSTM1 variants and in obese (P-valuespollutants may increase the risk of ventricular arrhythmia in elderly subjects. PMID:24142987

Particulate air pollution induces arrhythmia via oxidative stress and calcium calmodulin kinase II activation

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin-Bae [The Division of Cardiology, Kyung Hee University College of Medicine, 1 Hoegi-dong, Dongdaemun-Gu, Seoul (Korea, Republic of); Kim, Changsoo [The Department of Preventive Medicine, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Choi, Eunmi [Cardiovascular Research Institute and Severance Biomedical Science Institute, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Park, Sanghoon; Park, Hyelim; Pak, Hui-Nam; Lee, Moon-Hyoung [The Division of Cardiology, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Shin, Dong Chun [The Department of Preventive Medicine, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Hwang, Ki-Chul [Cardiovascular Research Institute and Severance Biomedical Science Institute, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); The Division of Cardiology, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of); Joung, Boyoung, E-mail: cby6908@yuhs.ac [The Division of Cardiology, Yonsei University College of Medicine, 250 Seungsanno, Seodaemun-gu, Seoul (Korea, Republic of)

2012-02-15

Ambient particulate matter (PM) can increase the incidence of arrhythmia. However, the arrhythmogenic mechanism of PM is poorly understood. This study investigated the arrhythmogenic mechanism of PM. In Sprague–Dawley rats, QT interval was increased from 115.0 ± 14.0 to 142.1 ± 18.4 ms (p = 0.02) after endotracheal exposure of DEP (200 μg/ml for 30 min, n = 5). Ventricular premature contractions were more frequently observed after DEP exposure (100%) than baseline (20%, p = 0.04). These effects were prevented by pretreatment of N-acetylcysteine (NAC, 5 mmol/L, n = 3). In 12 Langendorff-perfused rat hearts, DEP infusion of 12.5 μg/ml for 20 min prolonged action potential duration (APD) at only left ventricular base increasing apicobasal repolarization gradients. Spontaneous early afterdepolarization (EAD) and ventricular tachycardia (VT) were observed in 8 (67%) and 6 (50%) hearts, respectively, versus no spontaneous triggered activity or VT in any hearts before DEP infusion. DEP-induced APD prolongation, EAD and VT were successfully prevented with NAC (5 mmol/L, n = 5), nifedipine (10 μmol/L, n = 5), and active Ca{sup 2+}/calmodulin-dependent protein kinase II (CaMKII) blockade, KN 93 (1 μmol/L, n = 5), but not by thapsigargin (200 nmol/L) plus ryanodine (10 μmol/L, n = 5) and inactive CaMKII blockade, KN 92 (1 μmol/L, n = 5). In neonatal rat cardiomyocytes, DEP provoked ROS generation in dose dependant manner. DEP (12.5 μg/ml) induced apoptosis, and this effect was prevented by NAC and KN 93. Thus, this study shows that in vivo and vitro exposure of PM induced APD prolongation, EAD and ventricular arrhythmia. These effects might be caused by oxidative stress and CaMKII activation. -- Highlights: ► The ambient PM consistently prolonged repolarization. ► The ambient PM induced triggered activity and ventricular arrhythmia. ► These effects were prevented by antioxidants, I{sub CaL} blockade and CaMKII blockade. ► The ambient PM can induce

Respiratory sinus arrhythmia responses to cognitive tasks : effects of task factors and RSA indices

NARCIS (Netherlands)

Overbeek, T.; Boxtel, van Anton; Westerink, J.H.D.M.

2014-01-01

Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable

Respiratory sinus arrhythmia responses to cognitive tasks: Effects of task factors and RSA indices

NARCIS (Netherlands)

Overbeek, T.J.M.; van Boxtel, A.; Westerink, J.H.D.M.

2014-01-01

Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable

Mechanisms and Clinical Management of Ventricular Arrhythmias following Blunt Chest Trauma

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Daniel H. Wolbrom

2016-01-01

Full Text Available Nonpenetrating, blunt chest trauma is a serious medical condition with varied clinical presentations and implications. This can be the result of a dense projectile during competitive and recreational sports but may also include other etiologies such as motor vehicle accidents or traumatic falls. In this setting, the manifestation of ventricular arrhythmias has been observed both acutely and chronically. This is based on two entirely separate mechanisms and etiologies requiring different treatments. Ventricular fibrillation can occur immediately after chest wall injury (commotio cordis and requires rapid defibrillation. Monomorphic ventricular tachycardia can develop in the chronic stage due to underlying structural heart disease long after blunt chest injury. The associated arrhythmogenic tissue may be complex and provides the necessary substrate to form a reentrant VT circuit. Ventricular tachycardia in the absence of overt structural heart disease appears to be focal in nature with rapid termination during ablation. Regardless of the VT mechanism, patients with recurrent episodes, despite antiarrhythmic medication in the chronic stage following blunt chest injury, are likely to require ablation to achieve VT control. This review article will describe the mechanisms, pathophysiology, and treatment of ventricular arrhythmias that occur in both the acute and chronic stages following blunt chest trauma.

Oxidized CaMKII (Ca2+/Calmodulin-Dependent Protein Kinase II) Is Essential for Ventricular Arrhythmia in a Mouse Model of Duchenne Muscular Dystrophy.

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Wang, Qiongling; Quick, Ann P; Cao, Shuyi; Reynolds, Julia; Chiang, David Y; Beavers, David; Li, Na; Wang, Guoliang; Rodney, George G; Anderson, Mark E; Wehrens, Xander H T

2018-04-01

Duchenne muscular dystrophy patients are prone to ventricular arrhythmias, which may be caused by abnormal calcium (Ca 2+ ) homeostasis and elevated reactive oxygen species. CaMKII (Ca 2+ /calmodulin-dependent protein kinase II) is vital for normal Ca 2+ homeostasis, but excessive CaMKII activity contributes to abnormal Ca 2+ homeostasis and arrhythmias in cardiomyocytes. Reactive oxygen species induce CaMKII to become autonomously active. We hypothesized that genetic inhibition of CaMKII oxidation (ox-CaMKII) in a mouse model of Duchenne muscular dystrophy can alleviate abnormal Ca 2+ homeostasis, thus, preventing ventricular arrhythmia. The objective of this study was to test if selective loss of ox-CaMKII affects ventricular arrhythmias in the mdx mouse model of Duchenne muscular dystrophy. 5-(6)-Chloromethyl-2,7-dichlorodihydrofluorescein diacetate staining revealed increased reactive oxygen species production in ventricular myocytes isolated from mdx mice, which coincides with elevated ventricular ox-CaMKII demonstrated by Western blotting. Genetic inhibition of ox-CaMKII by knockin replacement of the regulatory domain methionines with valines (MM-VV [CaMKII M281/282V]) prevented ventricular tachycardia in mdx mice. Confocal calcium imaging of ventricular myocytes isolated from mdx :MM-VV mice revealed normalization of intracellular Ca 2+ release events compared with cardiomyocytes from mdx mice. Abnormal action potentials assessed by optical mapping in mdx mice were also alleviated by genetic inhibition of ox-CaMKII. Knockout of the NADPH oxidase regulatory subunit p47 phox normalized elevated ox-CaMKII, repaired intracellular Ca 2+ homeostasis, and rescued inducible ventricular arrhythmias in mdx mice. Inhibition of reactive oxygen species or ox-CaMKII protects against proarrhythmic intracellular Ca 2+ handling and prevents ventricular arrhythmia in a mouse model of Duchenne muscular dystrophy. © 2018 American Heart Association, Inc.

Arrhythmias After Tetralogy of Fallot Repair

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Folino, Antonio Franco; Daliento, Luciano

2005-01-01

Tetralogy of Fallot is the most common cyanotic congenital heart disease, with a good outcome after total surgical correction. In spite of a low perioperative mortality and a good quality of life, late sudden death remains a significant clinical problem, mainly related to episodes of sustained ventricular tachycardia and ventricular fibrillation. Fibro-fatty substitution around infundibular resection, intraventricular septal scar, and patchy myocardial fibrosis, may provide anatomical substrates of abnormal depolarization and repolarization causing reentrant ventricular arrhythmias. Several non-invasive indices based on classical examination such as ECG, signal-averaging ECG, and echocardiography have been proposed to identify patients at high risk of sudden death, with hopeful results. In the last years other more sophisticated invasive and non-invasive tools, such as heart rate variability, electroanatomic mapping and cardiac magnetic resonance added a relevant contribution to risk stratification. Even if each method per se is affected by some limitations, a comprehensive multifactorial clinical and investigative examination can provide an accurate risk evaluation for every patient. PMID:16943881

Brief Report: Social Skills, Internalizing and Externalizing Symptoms, and Respiratory Sinus Arrhythmia in Autism

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Neuhaus, Emily; Bernier, Raphael; Beauchaine, Theodore P.

2014-01-01

Theoretical and empirical models describe respiratory sinus arrhythmia (RSA) as a peripheral biomarker of emotion regulation and social competence. Recent findings also link RSA to individual differences in social functioning within autism spectrum disorder (ASD). However, associations between RSA and symptoms of internalizing/externalizing…

Low frequency of cardniac arrhythmias and lack of structural heart disease in medically-naïve acromegaly patients: a prospective study at baseline and after 1 year of somatostatin analogs treatment.

Science.gov (United States)

Warszawski, Leila; Kasuki, Leandro; Sá, Rodrigo; Dos Santos Silva, Cintia Marques; Volschan, Isabela; Gottlieb, Ilan; Pedrosa, Roberto Coury; Gadelha, Mônica R

2016-12-01

The incidence of arrhythmias may be increased in acromegaly, but the pathophysiologic mechanisms involved are still unclear, and it has never been correlated with structural heart changes analyzed by the gold-standard method cardiac magnetic resonance (CMR). Evaluate the frequency of arrhythmias in drug-naïve acromegaly patients at baseline and after 1 year of somatostatin analogs (SA) treatment and to correlate the occurrence of arrhythmias with the presence of structural heart changes. Consecutive drug-naïve acromegaly patients were recruited. The occurrence of arrhythmias and structural heart changes were studied through 24-h Holter and CMR, respectively, at baseline and after 1-year SA treatment. Thirty-six patients were studied at baseline and 28 were re-evaluated after 1 year of SA treatment. There were 13 females and median age was 48 years (20-73 years). Nine patients (32 %) were controlled after treatment. No sustained arrhythmias were reported in the 24-h Holter. No arrhythmia-related symptoms were observed. Only two patients presented left ventricular hypertrophy and three patients presented fibrosis at baseline. There was no correlation of the left ventricular mass with the number of episodes of arrhythmias and they were not more prevalent in the patients presenting cardiac fibrosis. We found no sustained arrhythmias and a lack of arrhythmia-related symptoms at baseline and after 1 year of SA treatment in a contemporary cohort of acromegaly patients that also present a low frequency of structural heart changes, indicating that these patients may have a lower frequency of heart disease than previously reported.

[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

Science.gov (United States)

Iwane, M; Shibe, Y; Itoh, K; Kinoshita, F; Kanagawa, Y; Kobayashi, M; Mugitani, K; Ohta, M; Ohata, H; Yoshikawa, A; Ikuta, Z; Nakamura, Y; Mohara, O

2001-03-01

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

Facilitating arrhythmia simulation: the method of quantitative cellular automata modeling and parallel running

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Mondry Adrian

2004-08-01

Full Text Available Abstract Background Many arrhythmias are triggered by abnormal electrical activity at the ionic channel and cell level, and then evolve spatio-temporally within the heart. To understand arrhythmias better and to diagnose them more precisely by their ECG waveforms, a whole-heart model is required to explore the association between the massively parallel activities at the channel/cell level and the integrative electrophysiological phenomena at organ level. Methods We have developed a method to build large-scale electrophysiological models by using extended cellular automata, and to run such models on a cluster of shared memory machines. We describe here the method, including the extension of a language-based cellular automaton to implement quantitative computing, the building of a whole-heart model with Visible Human Project data, the parallelization of the model on a cluster of shared memory computers with OpenMP and MPI hybrid programming, and a simulation algorithm that links cellular activity with the ECG. Results We demonstrate that electrical activities at channel, cell, and organ levels can be traced and captured conveniently in our extended cellular automaton system. Examples of some ECG waveforms simulated with a 2-D slice are given to support the ECG simulation algorithm. A performance evaluation of the 3-D model on a four-node cluster is also given. Conclusions Quantitative multicellular modeling with extended cellular automata is a highly efficient and widely applicable method to weave experimental data at different levels into computational models. This process can be used to investigate complex and collective biological activities that can be described neither by their governing differentiation equations nor by discrete parallel computation. Transparent cluster computing is a convenient and effective method to make time-consuming simulation feasible. Arrhythmias, as a typical case, can be effectively simulated with the methods

Outcome for Fetuses with Prenatally Detected Congenital Heart Disease and Cardiac Arrhythmias in Taiwan

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Sheng-Mou Hsiao

2007-01-01

Conclusion: Outcome for fetuses with prenatally detected CHD remains poor, with the prognosis negatively influenced by the presence of complex heart defects as well as extracardiac and chromosomal anomalies. However, prognosis is good for fetuses with cardiac arrhythmia, except with long QT syndrome or hydrops fetalis.

Atrial Arrhythmias in Obstructive Sleep Apnea: Underlying Mechanisms and Implications in the Clinical Setting

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David Filgueiras-Rama

2013-01-01

Full Text Available Obstructive sleep apnea (OSA is a common disorder characterized by repetitive interruption of ventilation during sleep caused by recurrent upper airway collapse, which leads to intermittent hypoxia. The disorder is commonly undiagnosed despite its relationship with substantial cardiovascular morbidity and mortality. Moreover, the effects of the disorder appear to be particularly dangerous in young subjects. In the last decade, substantial clinical evidence has identified OSA as independent risk factor for both bradyarrhythmias and tachyarrhythmias. To date the mechanisms leading to such arrhythmias have not been completely understood. However, recent data from animal models and new molecular analyses have increased our knowledge of the field, which might lead to future improvement in current therapeutic strategies mainly based on continuous positive airway pressure. This paper aims at providing readers a brief and specific revision of current knowledge about the mechanisms underlying atrial arrhythmias in OSA and their clinical and therapeutic implications.

Anxiety and risk of ventricular arrhythmias or mortality in patients with an implantable cardioverter defibrillator

DEFF Research Database (Denmark)

Habibović, Mirela; Pedersen, Susanne S.; van den Broek, Krista C

2013-01-01

A subgroup of patients with an implantable cardioverter defibrillator (ICD) experiences anxiety after device implantation. The purpose of the present study was to evaluate whether anxiety is predictive of ventricular arrhythmias and all-cause mortality 1 year post ICD implantation....

Catheter radiofrequency ablation for arrhythmias under the guidance of the Carto 3 three-dimensional mapping system in an operating room without digital subtraction angiography.

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Huang, Xingfu; Chen, Yanjia; Huang, Zheng; He, Liwei; Liu, Shenrong; Deng, Xiaojiang; Wang, Yongsheng; Li, Rucheng; Xu, Dingli; Peng, Jian

2018-06-01

Several studies have reported the efficacy of a zero-fluoroscopy approach for catheter radiofrequency ablation of arrhythmias in a digital subtraction angiography (DSA) room. However, no reports are available on the ablation of arrhythmias in the absence of DSA in the operating room. To investigate the efficacy and safety of catheter radiofrequency ablation for arrhythmias under the guidance of a Carto 3 three-dimensional (3D) mapping system in an operating room without DSA. Patients were enrolled according to the type of arrhythmia. The Carto 3 mapping system was used to reconstruct heart models and guide the electrophysiologic examination, mapping, and ablation. The total procedure, reconstruction, electrophysiologic examination, and mapping times were recorded. Furthermore, immediate success rates and complications were also recorded. A total of 20 patients were enrolled, including 12 males. The average age was 51.3 ± 17.2 (19-76) years. Nine cases of atrioventricular nodal re-entrant tachycardia, 7 cases of frequent ventricular premature contractions, 3 cases of Wolff-Parkinson-White syndrome, and 1 case of typical atrial flutter were included. All arrhythmias were successfully ablated. The procedure time was 127.0 ± 21.0 (99-177) minutes, the reconstruction time was 6.5 ± 2.9 (3-14) minutes, the electrophysiologic study time was 10.4 ± 3.4 (6-20) minutes, and the mapping time was 11.7 ± 8.3 (3-36) minutes. No complications occurred. Radiofrequency ablation of arrhythmias without DSA is effective and feasible under the guidance of the Carto 3 mapping system. However, the electrophysiology physician must have sufficient experience, and related emergency measures must be present to ensure safety.

A multiprocessor system for the analysis of cardiac arrhythmias

International Nuclear Information System (INIS)

Jugo, G. Diego J.

1983-01-01

The study presented here forms part of a real-time electrocardiographic signal analysis system project. The medical data analysis system consists of eight independent analyser units, all of which are connected to a controller unit by the standard IEEE-488 bus. Each bed is monitored by an arrhythmias analyser which has the facilities for analysing a patient's electrocardiogram automatically in real time. The measurements may be made in the presence of a pacemaker. The system described presents the technique of a separate and a simultaneous data analysis on two different ECG channels. This permit: a better diagnosis and an optimum use of the bus. (author) [fr

Delayed-enhancement MRI of apical hypertrophic cardiomyopathy: assessment of the intramural distribution and comparison with clinical symptoms, ventricular arrhythmias, and cine MRI

International Nuclear Information System (INIS)

Amano, Yasuo; Fukushima, Yoshimitsu; Kumita, Shinichiro; Takayama, Morimasa; Kitamura, Mitsunobu

2011-01-01

Background: Hypertrophic cardiomyopathy (HCM) is reported to show patchy midwall myocardial hyper enhancement on delayed-enhancement magnetic resonance imaging (DE-MRI). The intramural distribution of myocardial hyper enhancement and its correlation with clinical symptoms, ventricular arrhythmias, and cardiac function have not been described for symptomatic apical HCM. Purpose: To evaluate the features and significance of myocardial hyper enhancement on DE-MRI in symptomatic apical HCM. Material and Methods: Thirteen patients with symptomatic apical HCM and their 65 apical segments were investigated. Myocardial hyper enhancement and regional and global functional parameters were determined with MRI. We investigated the intramural distribution and frequencies of this myocardial hyper enhancement and compared them with the patients' clinical symptoms, the presence of ventricular arrhythmias, and cine MRI. Results: Eight (61.5%) patients with symptomatic apical HCM displayed apical myocardial hyper enhancement, and 22 (33.8%) of the 65 apical segments examined showed myocardial hyper enhancement. Of the myocardial hyper enhancement observed, 81.8% showed a subendocardial pattern.The Hyperenhanced apical myocardium had a lower percentage of systolic myocardial thickening, and was associated with serious symptoms (e.g. syncope) and ventricular arrhythmias. Conclusion: Patients with symptomatic apical HCM showed myocardial hyper enhancement involving the subendocardial layer, which might be related to regional systolic dysfunction, serious clinical symptoms, and ventricular arrhythmias

The relationship between ECG signs of atrial infarction and the development of supraventricular arrhythmias in patients with acute myocardial infarction

DEFF Research Database (Denmark)

Nielsen, F E; Andersen, H H; Gram-Hansen, P

1992-01-01

ECGs obtained on arrival at the hospital from 277 patients with acute myocardial infarction were analyzed retrospectively for PR displacements, which were classified as major or minor criteria for atrial infarction and related to the later occurrence of supraventricular arrhythmia in the hospital...... arrhythmias, giving odds ratios of 9.9 and 3.7, respectively. Enzyme-estimated infarct size, the occurrence of heart failure, and mortality rates did not differ in patients with or without major criteria for atrial infarction. We conclude that the occurrence of PR segment displacements on the admission ECG...

Effects of exogenous oxygen derived free radicals on myocardial capillary permeability, vascular tone, and incidence of ventricular arrhythmias in the canine heart

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Svendsen, Jesper Hastrup; Bjerrum, P J

1992-01-01

The aim was to examine the effects of exogenous oxygen derived free radicals on myocardial capillary permeability for a small hydrophilic indicator, postischaemic vascular tone, and the occurrence of arrhythmias in the canine heart in vivo.......The aim was to examine the effects of exogenous oxygen derived free radicals on myocardial capillary permeability for a small hydrophilic indicator, postischaemic vascular tone, and the occurrence of arrhythmias in the canine heart in vivo....

Cardiac cell therapy: overexpression of connexin43 in skeletal myoblasts and prevention of ventricular arrhythmias

NARCIS (Netherlands)

Fernandes, Sarah; van Rijen, Harold V. M.; Forest, Virginie; Evain, Stéphane; Leblond, Anne-Laure; Mérot, Jean; Charpentier, Flavien; de Bakker, Jacques M. T.; Lemarchand, Patricia

2009-01-01

Cell-based therapies have great potential for the treatment of cardiovascular diseases. Recently, using a transgenic mouse model Roell et al. reported that cardiac engraftment of connexin43 (Cx43)-overexpressing myoblasts in vivo prevents post-infarct arrhythmia, a common cause of death in patients

Cost-effectiveness of genotyping in inherited arrhythmia syndromes: are we getting value for the money?

NARCIS (Netherlands)

Wilde, Arthur A. M.; Pinto, Yigal M.

2009-01-01

Over the last decade, the identification of the diverse genetic basis of most important inherited arrhythmia syndromes has remarkably changed our attitude toward these life-threatening diseases. Just over 10 years ago, long-QT syndrome (LQTS) was considered one disease entity, Brugada -QT syndrome

Particulate Air Pollution, Ambulatory Heart Rate Variability, and Cardiac Arrhythmia in Retirement Community Residents with Coronary Artery Disease

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Longhurst, John; Tjoa, Thomas; Sioutas, Constantinos; Delfino, Ralph J.

2013-01-01

Background: Decreased heart rate variability (HRV) has been associated with future cardiac morbidity and mortality and is often used as a marker of altered cardiac autonomic balance in studies of health effects of airborne particulate matter. Fewer studies have evaluated associations between air pollutants and cardiac arrhythmia. Objectives: We examined relationships between cardiac arrhythmias, HRV, and exposures to airborne particulate matter. Methods: We measured HRV and arrhythmia with ambulatory electrocardiograms in a cohort panel study for up to 235 hr per participant among 50 nonsmokers with coronary artery disease who were ≥ 71 years of age and living in four retirement communities in the Los Angeles, California, Air Basin. Exposures included hourly outdoor gases, hourly traffic-related and secondary organic aerosol markers, and daily size-fractionated particle mass. We used repeated measures analyses, adjusting for actigraph-derived physical activity and heart rate, temperature, day of week, season, and community location. Results: Ventricular tachycardia was significantly increased in association with increases in markers of traffic-related particles, secondary organic carbon, and ozone. Few consistent associations were observed for supraventricular tachycardia. Particulates were significantly associated with decreased ambulatory HRV only in the 20 participants using ACE (angiotensin I–converting enzyme) inhibitors. Conclusions: Although these data support the hypothesis that particulate exposures may increase the risk of ventricular tachycardia for elderly people with coronary artery disease, HRV was not associated with exposure in most of our participants. These results are consistent with previous findings in this cohort for systemic inflammation, blood pressure, and ST segment depression. Citation: Bartell SM, Longhurst J, Tjoa T, Sioutas C, Delfino RJ. 2013. Particulate air pollution, ambulatory heart rate variability, and cardiac arrhythmia in

Effect of sodium nitrite on ischaemia and reperfusion-induced arrhythmias in anaesthetized dogs: is protein S-nitrosylation involved?

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Mária Kovács

Full Text Available To provide evidence for the protective role of inorganic nitrite against acute ischaemia and reperfusion-induced ventricular arrhythmias in a large animal model.Dogs, anaesthetized with chloralose and urethane, were administered intravenously with sodium nitrite (0.2 µmol kg(-1 min(-1 in two protocols. In protocol 1 nitrite was infused 10 min prior to and during a 25 min occlusion of the left anterior descending (LAD coronary artery (NaNO2-PO; n = 14, whereas in protocol 2 the infusion was started 10 min prior to reperfusion of the occluded vessel (NaNO2-PR; n = 12. Control dogs (n = 15 were infused with saline and subjected to the same period of ischaemia and reperfusion. Severities of ischaemia and ventricular arrhythmias, as well as changes in plasma nitrate/nitrite (NOx levels in the coronary sinus blood, were assessed throughout the experiment. Myocardial superoxide and nitrotyrosine (NT levels were determined during reperfusion. Changes in protein S-nitrosylation (SNO and S-glutathionylation were also examined.Compared with controls, sodium nitrite administered either pre-occlusion or pre-reperfusion markedly suppressed the number and severity of ventricular arrhythmias during occlusion and increased survival (0% vs. 50 and 92% upon reperfusion. There were also significant decreases in superoxide and NT levels in the nitrite treated dogs. Compared with controls, increased SNO was found only in NaNO2-PR dogs, whereas S-glutathionylation occurred primarily in NaNO2-PO dogs.Intravenous infusion of nitrite profoundly reduced the severity of ventricular arrhythmias resulting from acute ischaemia and reperfusion in anaesthetized dogs. This effect, among several others, may result from an NO-mediated reduction in oxidative stress, perhaps through protein SNO and/or S-glutathionylation.

Differential roles of two delayed rectifier potassium currents in regulation of ventricular action potential duration and arrhythmia susceptibility.

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Devenyi, Ryan A; Ortega, Francis A; Groenendaal, Willemijn; Krogh-Madsen, Trine; Christini, David J; Sobie, Eric A

2017-04-01

Arrhythmias result from disruptions to cardiac electrical activity, although the factors that control cellular action potentials are incompletely understood. We combined mathematical modelling with experiments in heart cells from guinea pigs to determine how cellular electrical activity is regulated. A mismatch between modelling predictions and the experimental results allowed us to construct an improved, more predictive mathematical model. The balance between two particular potassium currents dictates how heart cells respond to perturbations and their susceptibility to arrhythmias. Imbalances of ionic currents can destabilize the cardiac action potential and potentially trigger lethal cardiac arrhythmias. In the present study, we combined mathematical modelling with information-rich dynamic clamp experiments to determine the regulation of action potential morphology in guinea pig ventricular myocytes. Parameter sensitivity analysis was used to predict how changes in ionic currents alter action potential duration, and these were tested experimentally using dynamic clamp, a technique that allows for multiple perturbations to be tested in each cell. Surprisingly, we found that a leading mathematical model, developed with traditional approaches, systematically underestimated experimental responses to dynamic clamp perturbations. We then re-parameterized the model using a genetic algorithm, which allowed us to estimate ionic current levels in each of the cells studied. This unbiased model adjustment consistently predicted an increase in the rapid delayed rectifier K + current and a drastic decrease in the slow delayed rectifier K + current, and this prediction was validated experimentally. Subsequent simulations with the adjusted model generated the clinically relevant prediction that the slow delayed rectifier is better able to stabilize the action potential and suppress pro-arrhythmic events than the rapid delayed rectifier. In summary, iterative coupling of

Excessive exercise habits of runners as new signs of hypertension and arrhythmia.

Science.gov (United States)

Kim, Young-Joo; Kim, Chul-Hyun; Park, Kyoung-Min

2016-08-15

Excessive exercise may induce arrhythmia, and this risk is higher in middle-aged people. The study aim was to compare the exercise characteristics of middle-aged runners participating in excessive endurance exercise. The subjects of this study were 552 runners (mean age; 49.0±7.4years) without structural heart disease who performed exercise at least twice per week, had consistently exercised for at least three years, and had finished at least five marathons. The arrhythmia runner group (ARG, n=14) and normal runner group (NRG, n=538) were compared with regard to hemodynamic response, cardiorespiratory fitness level, training history, number of finished races, finishing times, and exercise habits. The mean resting systolic (134.0±15.8mmHg) and diastolic (85.8±10.9mmHg) blood pressure values indicated pre-hypertension, while the mean maximal SBP (213.7±27.4mmHg) values indicated exercise-induced hypertension. The VO2max was significantly higher and the maximal DBP was significantly lower in the ARG than in the NRG (phypertension and exercise-induced hypertension, and the ARG had higher VO2max values, greater exercise intensities, and longer training histories than the NRG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Arrhythmias After Tetralogy of Fallot Repair

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Antonio Franco Folino

2005-10-01

Full Text Available Tetralogy of Fallot is the most common cyanotic congenital heart disease, with a good outcome after total surgical correction. In spite of a low perioperative mortality and a good quality of life, late sudden death remains a significant clinical problem, mainly related to episodes of sustained ventricular tachycardia and ventricular fibrillation. Fibro-fatty substitution around infundibular resection, intraventricular septal scar, and patchy myocardial fibrosis, may provide anatomical substrates of abnormal depolarization and repolarization causing reentrant ventricular arrhythmias. Several non-invasive indices based on classical examination such as ECG, signal-averaging ECG, and echocardiography have been proposed to identify patients at high risk of sudden death, with hopeful results. In the last years other more sophisticated invasive and non-invasive tools, such as heart rate variability, electroanatomic mapping and cardiac magnetic resonance added a relevant contribution to risk stratification. Even if each method per se is affected by some limitations, a comprehensive multifactorial clinical and investigative examination can provide an accurate risk evaluation for every patient.

10-year follow-up after radiofrequency ablation of idiopathic ventricular arrhythmias from right ventricular outflow tract

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Synne Dragesund Rørvik

2016-05-01

Conclusions: A reduction of symptoms and use of antiarrhythmic medication, as well as an improvement in the general health perception and fitness to work after RFA of idiopathic ventricular arrhythmias can be demonstrated at ten-year follow-up.

Identifying potential functional impact of mutations and polymorphisms: Linking heart failure, increased risk of arrhythmias and sudden cardiac death.

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BENOIT eJAGU

2013-09-01

Full Text Available Researchers and clinicians have discovered several important concepts regarding the mechanisms responsible for increased risk of arrhythmias, heart failure and sudden cardiac death. One major step in defining the molecular basis of normal and abnormal cardiac electrical behaviour has been the identification of single mutations that greatly increase the risk for arrhythmias and sudden cardiac death by changing channel-gating characteristics. Indeed, mutations in several genes encoding ion channels, such as SCN5A, which encodes the major cardiac Na+ channel, have emerged as the basis for a variety of inherited cardiac arrhythmias such as long QT syndrome, Brugada syndrome, progressive cardiac conduction disorder, sinus node dysfunction or sudden infant death syndrome. In addition, genes encoding ion channel accessory proteins, like anchoring or chaperone proteins, which modify the expression, the regulation of endocytosis and the degradation of ion channel α-subunits have also been reported as susceptibility genes for arrhythmic syndromes. The regulation of ion channel protein expression also depends on a fine-tuned balance among different other mechanisms, such as gene transcription, RNA processing, post-transcriptional control of gene expression by miRNA, protein synthesis, assembly and post-translational modification and trafficking.

Atrial arrhythmia in ageing spontaneously hypertensive rats: unraveling the substrate in hypertension and ageing.

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Dennis H Lau

Full Text Available BACKGROUND: Both ageing and hypertension are known risk factors for atrial fibrillation (AF although the pathophysiological contribution or interaction of the individual factors remains poorly understood. Here we aim to delineate the arrhythmogenic atrial substrate in mature spontaneously hypertensive rats (SHR. METHODS: SHR were studied at 12 and 15 months of age (n = 8 per group together with equal numbers of age-matched normotensive Wistar-Kyoto control rats (WKY. Electrophysiologic study was performed on superfused isolated right and left atrial preparations using a custom built high-density multiple-electrode array to determine effective refractory periods (ERP, atrial conduction and atrial arrhythmia inducibility. Tissue specimens were harvested for structural analysis. RESULTS: COMPARED TO WKY CONTROLS, THE SHR DEMONSTRATED: Higher systolic blood pressure (p<0.0001, bi-atrial enlargement (p<0.05, bi-ventricular hypertrophy (p<0.05, lower atrial ERP (p = 0.008, increased atrial conduction heterogeneity (p = 0.001 and increased atrial interstitial fibrosis (p = 0.006 & CD68-positive macrophages infiltration (p<0.0001. These changes resulted in higher atrial arrhythmia inducibility (p = 0.01 and longer induced AF episodes (p = 0.02 in 15-month old SHR. Ageing contributed to incremental bi-atrial hypertrophy (p<0.01 and atrial conduction heterogeneity (p<0.01 without affecting atrial ERP, fibrosis and arrhythmia inducibility. The limited effect of ageing on the atrial substrate may be secondary to the reduction in CD68-positive macrophages. CONCLUSIONS: Significant atrial electrical and structural remodeling is evident in the ageing spontaneously hypertensive rat atria. Concomitant hypertension appears to play a greater pathophysiological role than ageing despite their compounding effect on the atrial substrate. Inflammation is pathophysiologically linked to the pro-fibrotic changes in the hypertensive atria.

Bile acids induce arrhythmias in human atrial myocardium--implications for altered serum bile acid composition in patients with atrial fibrillation.

Science.gov (United States)

Rainer, Peter P; Primessnig, Uwe; Harenkamp, Sandra; Doleschal, Bernhard; Wallner, Markus; Fauler, Guenter; Stojakovic, Tatjana; Wachter, Rolf; Yates, Ameli; Groschner, Klaus; Trauner, Michael; Pieske, Burkert M; von Lewinski, Dirk

2013-11-01

High bile acid serum concentrations have been implicated in cardiac disease, particularly in arrhythmias. Most data originate from in vitro studies and animal models. We tested the hypotheses that (1) high bile acid concentrations are arrhythmogenic in adult human myocardium, (2) serum bile acid concentrations and composition are altered in patients with atrial fibrillation (AF) and (3) the therapeutically used ursodeoxycholic acid has different effects than other potentially toxic bile acids. Multicellular human atrial preparations ('trabeculae') were exposed to primary bile acids and the incidence of arrhythmic events was assessed. Bile acid concentrations were measured in serum samples from 250 patients and their association with AF and ECG parameters analysed. Additionally, we conducted electrophysiological studies in murine myocytes. Taurocholic acid (TCA) concentration-dependently induced arrhythmias in atrial trabeculae (14/28 at 300 µM TCA, pursodeoxycholic acid did not. Patients with AF had significantly decreased serum levels of ursodeoxycholic acid conjugates and increased levels of non-ursodeoxycholic bile acids. In isolated myocytes, TCA depolarised the resting membrane potential, enhanced Na(+)/Ca(2+) exchanger (NCX) tail current density and induced afterdepolarisations. Inhibition of NCX prevented arrhythmias in atrial trabeculae. High TCA concentrations induce arrhythmias in adult human atria while ursodeoxycholic acid does not. AF is associated with higher serum levels of non-ursodeoxycholic bile acid conjugates and low levels of ursodeoxycholic acid conjugates. These data suggest that higher levels of toxic (arrhythmogenic) and low levels of protective bile acids create a milieu with a decreased arrhythmic threshold and thus may facilitate arrhythmic events.

Effects of dexmedetomidine on heart arrhythmia prevention in off-pump coronary artery bypass surgery: A randomized clinical trial.

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Soltani, Ghasem; Jahanbakhsh, Saeed; Tashnizi, Mohammad Abbasi; Fathi, Mehdi; Amini, Shahram; Zirak, Nahid; Sheybani, Shima

2017-10-01

Arrhythmia occurring during and after surgery is one of the major complications in open-heart surgery. Dexmedetomidine is an intravenous alpha-2 agonist and very specific short-acting drug to protect the various organs against ischemic injuries and blood reflow. However, the effect of dexmedetomidine for preventing intraoperative heart arrhythmias has not been recognized. This study aimed to determine the effect of dexmedetomidine on the incidence rate of heart arrhythmias and anesthetic required in off-pump coronary artery bypass surgery. This randomized clinical trial was conducted on patients who were candidates for off-pump coronary artery bypass referring to Imam Reza Hospital of Mashhad, Iran, from July 2016 through January 2017. The patients were randomly assigned to two groups of intervention (infusion of 0.5 mcg/kg/h dexmedetomidine together with induction followed by infusion of 0.5 mcg/kg/h by the end of the surgery) or control (saline infusion). Mean arterial pressure (MAP) and heart rate (HR) were measured before induction, during surgery operation and ICU admission. Data were analyzed by SPSS version 18 using Chi Square and independent-samples t-test. A total of 76 patients with a mean age of 59.8 ± 8.2 years (in two groups of 38) were studied. The two groups had no statistically significant difference in terms of background variables. The MAP and HR values before induction, during surgery and ICU admission were significantly higher in the control group than in the intervention group (p=0.001). Out of the studied arrhythmias, the values of PAC (55.2% vs. 15.7%), PVC (81.5% vs. 21.0%), AF (26.3% vs. 7.8%), VTAC (21.0% vs. 2.6%) were significantly lower in dexmedetomidine group (p=0.001). It seems that dexmedetomidine administration during induction and surgery can cause significant reduction in most of the common arrhythmias in off-pump coronary bypass surgery. The use of dexmedetomidine maintains MAP and HR at significantly lower values, and changes

High-throughput cardiac safety evaluation and multi-parameter arrhythmia profiling of cardiomyocytes using microelectrode arrays

Energy Technology Data Exchange (ETDEWEB)

Gilchrist, Kristin H., E-mail: kgilchrist@rti.org; Lewis, Gregory F.; Gay, Elaine A.; Sellgren, Katelyn L.; Grego, Sonia

2015-10-15

Microelectrode arrays (MEAs) recording extracellular field potentials of human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) provide a rich data set for functional assessment of drug response. The aim of this work is the development of a method for a systematic analysis of arrhythmia using MEAs, with emphasis on the development of six parameters accounting for different types of cardiomyocyte signal irregularities. We describe a software approach to carry out such analysis automatically including generation of a heat map that enables quick visualization of arrhythmic liability of compounds. We also implemented signal processing techniques for reliable extraction of the repolarization peak for field potential duration (FPD) measurement even from recordings with low signal to noise ratios. We measured hiPS-CM's on a 48 well MEA system with 5 minute recordings at multiple time points (0.5, 1, 2 and 4 h) after drug exposure. We evaluated concentration responses for seven compounds with a combination of hERG, QT and clinical proarrhythmia properties: Verapamil, Ranolazine, Flecainide, Amiodarone, Ouabain, Cisapride, and Terfenadine. The predictive utility of MEA parameters as surrogates of these clinical effects were examined. The beat rate and FPD results exhibited good correlations with previous MEA studies in stem cell derived cardiomyocytes and clinical data. The six-parameter arrhythmia assessment exhibited excellent predictive agreement with the known arrhythmogenic potential of the tested compounds, and holds promise as a new method to predict arrhythmic liability. - Highlights: • Six parameters describing arrhythmia were defined and measured for known compounds. • Software for efficient parameter extraction from large MEA data sets was developed. • The proposed cellular parameter set is predictive of clinical drug proarrhythmia.

Ventricular arrhythmias and sudden cardiac arrest in Takotsubo cardiomyopathy: Incidence, predictive factors, and clinical implications.

Science.gov (United States)

Jesel, Laurence; Berthon, Charlotte; Messas, Nathan; Lim, Han S; Girardey, Mélanie; Marzak, Halim; Marchandot, Benjamin; Trinh, Annie; Ohlmann, Patrick; Morel, Olivier

2018-04-06

Takotsubo cardiomyopathy (TTC) is a stress-related transient cardiomyopathy. Life-threatening arrhythmias (LTA) can occur and worsen prognosis. The purpose of this study was to assess the incidence and outcome of LTA in TTC, as well as its predictive factors and clinical implications. We studied 214 consecutive cases of TTC over 8 years. The study cohort was divided into 2 groups: those with LTA (LTA group) and those without (non-LTA group). LTA was defined as ventricular tachycardia, ventricular fibrillation, or cardiac arrest. LTA occurred in 10.7% of patients mainly in the first 24 hours of hospitalization: ventricular tachycardia (n = 2), ventricular fibrillation (n = 11), cardiac arrest (n = 10: 5 asystole, 3 complete heart block, and 2 sinoatrial block). LTA were associated with lower left ventricular ejection fraction (LVEF) and a high rate of conduction disturbances. In-hospital (39.1% vs 8.9%; P 105 ms were independent predictors of LTA. In cases where a device was implanted, conduction disturbances persisted after the index event despite complete recovery of LVEF. There was no ventricular arrhythmia recurrence during follow-up. LTA occur early in patients presenting with TTC and is associated with significantly worse short- and long-term prognosis. Left ventricular impairment and QRS duration >105 ms are independent predictors of LTA. Ventricular arrhythmias occurred in the acute phase without further recurrence recorded in hospital survivors, whereas severe conduction disorders persisted during long-term follow-up. These findings may have implications on the choice of device therapy for this specific patient subgroup. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Cardiac arrhythmias during aerobatic flight and its simulation on a centrifuge.

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Zawadzka-Bartczak, Ewelina K; Kopka, Lech H

2011-06-01

It is well known that accelerations during centrifuge training and during flight can provoke cardiac arrhythmias. Our study was designed to investigate both the similarities and differences between heart rhythm disturbances during flights and centrifuge tests. There were 40 asymptomatic, healthy pilots who performed two training flights and were also tested in a human centrifuge according to a program of rapid onset rate acceleration (ROR) and of centrifuge simulation of the actual acceleration experienced in flight (Simulation). During the flight and centrifuge tests ECG was monitored with the Holter method. ECG was examined for heart rhythm changes and disturbances. During flights, premature ventricular contractions (PVCs) were found in 25% of the subjects, premature supraventricular contractions (PSVCs) and PVCs with bigeminy in 5%, and pairs of PVCs in 2.5% of subjects. During the centrifuge tests, PVCs were experienced by 45% of the subjects, PSVCs and pairs of PVCs by 7.5%, and PVCs with bigeminy by 2.5%. Sinus bradycardia was observed during flights and centrifuge tests in 7.5% of subjects. Comparative evaluation of electrocardiographic records in military pilots during flights and centrifuge tests demonstrated that: 1) there were no clinically significant arrhythmias recorded; and 2) the frequency and kind of heart rhythm disturbances during aerobatic flight and its simulation on a centrifuge were not identical and did not occur repetitively in the same persons during equal phases of the tests.

Remote ischemic preconditioning differentially attenuates post-ischemic cardiac arrhythmia in streptozotocin-induced diabetic versus nondiabetic rats.

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Hu, Zhaoyang; Chen, Mou; Zhang, Ping; Liu, Jin; Abbott, Geoffrey W

2017-04-26

Sudden cardiac death (SCD), a leading cause of global mortality, most commonly arises from a substrate of cardiac ischemia, but requires an additional trigger. Diabetes mellitus (DM) predisposes to SCD even after adjusting for other DM-linked cardiovascular pathology such as coronary artery disease. We previously showed that remote liver ischemia preconditioning (RLIPC) is highly protective against cardiac ischemia reperfusion injury (IRI) linked ventricular arrhythmias and myocardial infarction, via induction of the cardioprotective RISK pathway, and specifically, inhibitory phosphorylation of GSK-3β (Ser 9). We evaluated the impact of acute streptozotocin-induced DM on coronary artery ligation IRI-linked ventricular arrhythmogenesis and RLIPC therapy in rats. Post-IRI arrhythmia induction was similar in nondiabetic and DM rats, but, unexpectedly, DM rats exhibited lower incidence of SCD during reperfusion (41 vs. 100%), suggesting uncontrolled hyperglycemia does not acutely predispose to SCD. RLIPC was highly effective in both nondiabetic and DM rats at reducing incidence and duration of, and increasing latency to, all classes of ventricular tachyarrhythmias. In contrast, atrioventricular block (AVB) was highly responsive to RLIPC in nondiabetic rats (incidence reduced from 72 to 18%) but unresponsive in DM rats. RISK pathway induction was similar in nondiabetic and DM rats, thus not explaining the DM-specific resistance of AVB to therapy. Our findings uncover important acute DM-specific differences in responsiveness to remote preconditioning for ventricular tachyarrhythmias versus AVB, which may have clinical significance given that AVB is a malignant arrhythmia twofold more common in human diabetics than nondiabetics, and correlated to plasma glucose levels >10 mmol/L.

Effect of low oral doses of disopyramide and amiodarone on ventricular and atrial arrhythmias of chagasic patients with advanced myocardial damage.

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Carrasco, H A; Vicuña, A V; Molina, C; Landaeta, A; Reynosa, J; Vicuña, N; Fuenmayor, A; López, F

1985-12-01

Low-dose (7 mg/kg per day) disopyramide administration to arrhythmic chagasic patients decreased the frequency of ventricular extrasystoles in 4 of 17 patients (24%) and suppressed most complex ventricular arrhythmias in 12 of 15 patients (80%). This assessment was made from 72-h continuous Holter monitoring recorded during the course of this double blind, placebo-controlled randomized crossover study. Seven patients (41%) complained of anticholinergic side effects, but no contractile or conduction system depression was seen. Amiodarone (200 mg) given on a single blind, placebo-controlled basis to 9 of these patients reduced the frequency of ventricular extrasystoles in 6 of 9 patients (67%) and suppressed complex ventricular ectopy in 6 of 7 patients (85%). One patient was unable to tolerate this drug (11%). Both drugs seemed less effective in controlling supraventricular arrhythmias, although disopyramide eliminated paroxysms of supraventricular tachycardia in 9 of 13 (69%) and amiodarone in all 6 patients with this arrhythmia. Amiodarone appears to be a better antiarrhythmic drug for chagasic patients, due to its greater effectiveness and lower incidence of side effects.

Automated system for ST segment and arrhythmia analysis in exercise radionuclide ventriculography

International Nuclear Information System (INIS)

Hsia, P.W.; Jenkins, J.M.; Shimoni, Y.; Gage, K.P.; Santinga, J.T.; Pitt, B.

1986-01-01

A computer-based system for interpretation of the electrocardiogram (ECG) in the diagnosis of arrhythmia and ST segment abnormality in an exercise system is presented. The system was designed for inclusion in a gamma camera so the ECG diagnosis could be combined with the diagnostic capability of radionuclide ventriculography. Digitized data are analyzed in a beat-by-beat mode and a contextual diagnosis of underlying rhythm is provided. Each beat is assigned a beat code based on a combination of waveform analysis and RR interval measurement. The waveform analysis employs a new correlation coefficient formula which corrects for baseline wander. Selective signal averaging, in which only normal beats are included, is done for an improved signal-to-noise ratio prior to ST segment analysis. Template generation, R wave detection, QRS window size, baseline correction, and continuous updating of heart rate have all been automated. ST level and slope measurements are computed on signal-averaged data. Arrhythmia analysis of 13 passages of abnormal rhythm by computer was found to be correct in 98.4 percent of all beats. 25 passages of exercise data, 1-5 min in length, were evaluated by the cardiologist and found to be in agreement in 95.8 percent in measurements of ST level and 91.7 percent in measurements of ST slope

Intracardiac echo-facilitated 3D electroanatomical mapping of ventricular arrhythmias from the papillary muscles: assessing the 'fourth dimension' during ablation.

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Proietti, Riccardo; Rivera, Santiago; Dussault, Charles; Essebag, Vidal; Bernier, Martin L; Ayala-Paredes, Felix; Badra-Verdu, Mariano; Roux, Jean-François

2017-01-01

Ventricular arrhythmias (VA) originating from a papillary muscle (PM) have recently been described as a distinct clinical entity with peculiar features that make its treatment with catheter ablation challenging. Here, we report our experience using an intracardiac echo-facilitated 3D electroanatomical mapping approach in a case series of patients undergoing ablation for PM VA. Sixteen patients who underwent catheter ablation for ventricular tachycardia (VT) or symptomatic premature ventricular contractions originating from left ventricular PMs were included in the study. A total of 24 procedures (mean 1.5 per patient) were performed: 15 using a retrograde aortic approach and 9 using a transseptal approach. Integrated intracardiac ultrasound for 3D electroanatomical mapping was used in 15 of the 24 procedures. The posteromedial PM was the most frequent culprit for the clinical arrhythmia, and the body was the part of the PM most likely to be the successful site for ablation. The site of ablation was identified based on the best pace map matching the clinical arrhythmia and the site of earliest the activation. At a mean follow-up of 10.5 ± 7 months, only two patients had recurrent arrhythmias following a repeat ablation procedure. An echo-facilitated 3D electroanatomical mapping allows for real-time creation of precise geometries of cardiac chambers and endocavitary structures. This is useful during procedures such as catheter ablation of VAs originating from PMs, which require detailed representation of anatomical landmarks. Routine adoption of this technique should be considered to improve outcomes of PM VA ablation. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Serious arrhythmias in patients with apical hypertrophic cardiomyopathy

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Okishige, Kaoru; Sasano, Tetsuo; Yano, Kei; Azegami, Kouji; Suzuki, Kou; Itoh, Kuniyasu [Yokohama Red Cross Hospital (Japan)

2001-05-01

We report cases of serious arrhythmias associated with apical hypertrophic cardiomyopathy (AHCM). Thirty-one patients were referred to our institute to undergo further assessment of their AHCM from 1988 to 1999. Three patients with nonsustained ventricular tachycardia demonstrated an {sup 123}I-MIBG regional reduction in the tracer uptake. In two patients with ventricular fibrillation (VF), the findings from {sup 123}I-MIBG imaging revealed regional sympathetic denervation in the inferior and lateral regions. Electrophysiologic study demonstrated reproducible induction of VF in aborted sudden death and presyncopal patients, resulting in the need for an implantable defibrillator device and amiodarone in each patient. Patients with refractory atrial fibrillation with a rapid ventricular response suffered from serious congestive heart failure. A prudent assessment and strategy in patients with this disease would be indispensable in avoiding a disastrous outcome. (author)

Nonpharmacologic control of postoperative supraventricular arrhythmias using AV nodal fat pad stimulation in a young animal open heart surgical model.

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Moak, Jeffrey P; Mercader, Marco A; He, Dingchao; Trachiotis, Gregory; Langert, Joshua; Blicharz, Andy; Montaque, Erin; Li, Xiyan; Cheng, Yao I; McCarter, Robert; Bornzin, Gene A; Martin, Gerard R; Jonas, Richard A

2013-06-01

Supraventricular arrhythmias (junctional ectopic tachycardia [JET] and atrial tachyarrhythmias) frequently complicate recovery from open heart surgery in children and can be difficult to manage. Medical treatment of JET can result in significant morbidity. Our goal was to develop a nonpharmacological approach using autonomic stimulation of selective fat pad (FP) regions of the heart in a young canine model of open heart surgery to control 2 common postoperative supraventricular arrhythmias. Eight mongrel dogs, varying in age from 5 to 8 months and weighting 22±4 kg, underwent open heart surgery replicating a nontransannular approach to tetralogy of Fallot repair. Neural stimulation of the right inferior FP was used to control the ventricular response to supraventricular arrhythmias. Right inferior FP stimulation decreased baseline AV nodal conduction without altering sinus cycle length. AV node Wenckebach cycle length prolonged from 270±33 to 352±89 ms, P=0.02. Atrial fibrillation occurred in 7 animals, simulating a rapid atrial tachyarrhythmias. FP stimulation slowed the ventricular response rate from 166±58 to 63±29 beats per minute, Popen heart surgery model. FP stimulation may be a useful new technique for managing children with JET and atrial tachyarrhythmias.

European Heart Rhythm Association (EHRA) position paper on arrhythmia management and device therapies in endocrine disorders, endorsed by Asia Pacific Heart Rhythm Society (APHRS) and Latin American Heart Rhythm Society (LAHRS).

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Gorenek, Bulent; Boriani, Giuseppe; Dan, Gheorge-Andrei; Fauchier, Laurent; Fenelon, Guilherme; Huang, He; Kudaiberdieva, Gulmira; Lip, Gregory Y H; Mahajan, Rajiv; Potpara, Tatjana; Ramirez, Juan David; Vos, Marc A; Marin, Francisco

2018-03-16

Endocrine disorders are associated with various tachyarrhythmias, including atrial fibrillation (AF), ventricular tachycardia (VT), ventricular fibrillation (VF), and bradyarrhythmias. Along with underlying arrhythmia substrate, electrolyte disturbances, glucose, and hormone levels, accompanying endocrine disorders contribute to development of arrhythmia. Arrhythmias may be life-threatening, facilitate cardiogenic shock development and increase mortality. The knowledge on the incidence of tachy- and bradyarrhythmias, clinical and prognostic significance as well as their management is limited; it is represented in observational studies and mostly in case reports on management of challenging cases. It should be also emphasized, that the topic is not covered in detail in current guidelines. Therefore, cardiologists and multidisciplinary teams participating in care of such patients do need the evidence-based, or in case of limited evidence expert-opinion based recommendations, how to treat arrhythmias using contemporary approaches, prevent their complications and recurrence in patients with endocrine disorders. In recognizing this close relationship between endocrine disorders and arrhythmias, the European Heart Rhythm Association (EHRA) convened a Task Force, with representation from Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLAECE), with the remit of comprehensively reviewing the available evidence and publishing a joint consensus document on endocrine disorders and cardiac arrhythmias, and providing up-to-date consensus recommendations for use in clinical practice.

Remodeling of repolarization and arrhythmia susceptibility in a myosin-binding protein C knockout mouse model.

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Toib, Amir; Zhang, Chen; Borghetti, Giulia; Zhang, Xiaoxiao; Wallner, Markus; Yang, Yijun; Troupes, Constantine D; Kubo, Hajime; Sharp, Thomas E; Feldsott, Eric; Berretta, Remus M; Zalavadia, Neil; Trappanese, Danielle M; Harper, Shavonn; Gross, Polina; Chen, Xiongwen; Mohsin, Sadia; Houser, Steven R

2017-09-01

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac diseases and among the leading causes of sudden cardiac death (SCD) in the young. The cellular mechanisms leading to SCD in HCM are not well known. Prolongation of the action potential (AP) duration (APD) is a common feature predisposing hypertrophied hearts to SCD. Previous studies have explored the roles of inward Na + and Ca 2+ in the development of HCM, but the role of repolarizing K + currents has not been defined. The objective of this study was to characterize the arrhythmogenic phenotype and cellular electrophysiological properties of mice with HCM, induced by myosin-binding protein C (MyBPC) knockout (KO), and to test the hypothesis that remodeling of repolarizing K + currents causes APD prolongation in MyBPC KO myocytes. We demonstrated that MyBPC KO mice developed severe hypertrophy and cardiac dysfunction compared with wild-type (WT) control mice. Telemetric electrocardiographic recordings of awake mice revealed prolongation of the corrected QT interval in the KO compared with WT control mice, with overt ventricular arrhythmias. Whole cell current- and voltage-clamp experiments comparing KO with WT mice demonstrated ventricular myocyte hypertrophy, AP prolongation, and decreased repolarizing K + currents. Quantitative RT-PCR analysis revealed decreased mRNA levels of several key K + channel subunits. In conclusion, decrease in repolarizing K + currents in MyBPC KO ventricular myocytes contributes to AP and corrected QT interval prolongation and could account for the arrhythmia susceptibility. NEW & NOTEWORTHY Ventricular myocytes isolated from the myosin-binding protein C knockout hypertrophic cardiomyopathy mouse model demonstrate decreased repolarizing K + currents and action potential and QT interval prolongation, linking cellular repolarization abnormalities with arrhythmia susceptibility and the risk for sudden cardiac death in hypertrophic cardiomyopathy. Copyright © 2017

Feasibility and accuracy of a new mobile electrocardiography device, ER-2000®, in the diagnosis of arrhythmia

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Yae Min Park

2015-08-01

Conclusions: A rhythm strip obtained using ER-2000® is accurate in diagnosing arrhythmia, despite some differences in the detailed morphology of the QRS and T-wave, and the pacing spike compared to those obtained by the 12-lead ECG.

Ventricular arrhythmia burst is an independent indicator of larger infarct size even in optimal reperfusion in STEMI

NARCIS (Netherlands)

van der Weg, Kirian; Majidi, Mohamed; Haeck, Joost D. E.; Tijssen, Jan G. P.; Green, Cynthia L.; Koch, Karel T.; Kuijt, Wichert J.; Krucoff, Mitchell W.; Gorgels, Anton P. M.; de Winter, Robbert J.

2016-01-01

We hypothesized that ventricular arrhythmia (VA) bursts during reperfusion phase are a marker of larger infarct size despite optimal epicardial and microvascular perfusion. 126 STEMI patients were studied with 24h continuous, 12-lead Holter monitoring. Myocardial blush grade (MBG) was determined and

Integrative computational models of cardiac arrhythmias -- simulating the structurally realistic heart

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Trayanova, Natalia A; Tice, Brock M

2009-01-01

Simulation of cardiac electrical function, and specifically, simulation aimed at understanding the mechanisms of cardiac rhythm disorders, represents an example of a successful integrative multiscale modeling approach, uncovering emergent behavior at the successive scales in the hierarchy of structural complexity. The goal of this article is to present a review of the integrative multiscale models of realistic ventricular structure used in the quest to understand and treat ventricular arrhythmias. It concludes with the new advances in image-based modeling of the heart and the promise it holds for the development of individualized models of ventricular function in health and disease. PMID:20628585

Inhibition of N-type Ca2+ channels ameliorates an imbalance in cardiac autonomic nerve activity and prevents lethal arrhythmias in mice with heart failure.

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Yamada, Yuko; Kinoshita, Hideyuki; Kuwahara, Koichiro; Nakagawa, Yasuaki; Kuwabara, Yoshihiro; Minami, Takeya; Yamada, Chinatsu; Shibata, Junko; Nakao, Kazuhiro; Cho, Kosai; Arai, Yuji; Yasuno, Shinji; Nishikimi, Toshio; Ueshima, Kenji; Kamakura, Shiro; Nishida, Motohiro; Kiyonaka, Shigeki; Mori, Yasuo; Kimura, Takeshi; Kangawa, Kenji; Nakao, Kazuwa

2014-10-01

Dysregulation of autonomic nervous system activity can trigger ventricular arrhythmias and sudden death in patients with heart failure. N-type Ca(2+) channels (NCCs) play an important role in sympathetic nervous system activation by regulating the calcium entry that triggers release of neurotransmitters from peripheral sympathetic nerve terminals. We have investigated the ability of NCC blockade to prevent lethal arrhythmias associated with heart failure. We compared the effects of cilnidipine, a dual N- and L-type Ca(2+) channel blocker, with those of nitrendipine, a selective L-type Ca(2+) channel blocker, in transgenic mice expressing a cardiac-specific, dominant-negative form of neuron-restrictive silencer factor (dnNRSF-Tg). In this mouse model of dilated cardiomyopathy leading to sudden arrhythmic death, cardiac structure and function did not significantly differ among the control, cilnidipine, and nitrendipine groups. However, cilnidipine dramatically reduced arrhythmias in dnNRSF-Tg mice, significantly improving their survival rate and correcting the imbalance between cardiac sympathetic and parasympathetic nervous system activity. A β-blocker, bisoprolol, showed similar effects in these mice. Genetic titration of NCCs, achieved by crossing dnNRSF-Tg mice with mice lacking CACNA1B, which encodes the α1 subunit of NCCs, improved the survival rate. With restoration of cardiac autonomic balance, dnNRSF-Tg;CACNA1B(+/-) mice showed fewer malignant arrhythmias than dnNRSF-Tg;CACNA1B(+/+) mice. Both pharmacological blockade of NCCs and their genetic titration improved cardiac autonomic balance and prevented lethal arrhythmias in a mouse model of dilated cardiomyopathy and sudden arrhythmic death. Our findings suggest that NCC blockade is a potentially useful approach to preventing sudden death in patients with heart failure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Novel Calmodulin (CALM2) Mutations Associated with Congenital Arrhythmia Susceptibility

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Makita, Naomasa; Yagihara, Nobue; Crotti, Lia; Johnson, Christopher N.; Beckmann, Britt-Maria; Roh, Michelle S.; Shigemizu, Daichi; Lichtner, Peter; Ishikawa, Taisuke; Aiba, Takeshi; Homfray, Tessa; Behr, Elijah R.; Klug, Didier; Denjoy, Isabelle; Mastantuono, Elisa; Theisen, Daniel; Tsunoda, Tatsuhiko; Satake, Wataru; Toda, Tatsushi; Nakagawa, Hidewaki; Tsuji, Yukiomi; Tsuchiya, Takeshi; Yamamoto, Hirokazu; Miyamoto, Yoshihiro; Endo, Naoto; Kimura, Akinori; Ozaki, Kouichi; Motomura, Hideki; Suda, Kenji; Tanaka, Toshihiro; Schwartz, Peter J.; Meitinger, Thomas; Kääb, Stefan; Guicheney, Pascale; Shimizu, Wataru; Bhuiyan, Zahurul A.; Watanabe, Hiroshi; Chazin, Walter J.; George, Alfred L.

2014-01-01

Background Genetic predisposition to life-threatening cardiac arrhythmias such as in congenital long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) represent treatable causes of sudden cardiac death in young adults and children. Recently, mutations in calmodulin (CALM1, CALM2) have been associated with severe forms of LQTS and CPVT, with life-threatening arrhythmias occurring very early in life. Additional mutation-positive cases are needed to discern genotype-phenotype correlations associated with calmodulin mutations. Methods and Results We employed conventional and next-generation sequencing approaches including exome analysis in genotype-negative LQTS probands. We identified five novel de novo missense mutations in CALM2 in three subjects with LQTS (p.N98S, p.N98I, p.D134H) and two subjects with clinical features of both LQTS and CPVT (p.D132E, p.Q136P). Age of onset of major symptoms (syncope or cardiac arrest) ranged from 1–9 years. Three of five probands had cardiac arrest and one of these subjects did not survive. Although all probands had LQTS, two subjects also exhibited electrocardiographic features consistent with CPVT. The clinical severity among subjects in this series was generally less than that originally reported for CALM1 and CALM2 associated with recurrent cardiac arrest during infancy. Four of five probands responded to β-blocker therapy whereas one subject with mutation p.Q136P died suddenly during exertion despite this treatment. Mutations affect conserved residues located within calcium binding loops III (p.N98S, p.N98I) or IV (p.D132E, p.D134H, p.Q136P) and caused reduced calcium binding affinity. Conclusions CALM2 mutations can be associated with LQTS and with overlapping features of LQTS and CPVT. PMID:24917665

Carbon monoxide exposure enhances arrhythmia after cardiac stress: involvement of oxidative stress.

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André, Lucas; Gouzi, Fares; Thireau, Jérôme; Meyer, Gregory; Boissiere, Julien; Delage, Martine; Abdellaoui, Aldja; Feillet-Coudray, Christine; Fouret, Gilles; Cristol, Jean-Paul; Lacampagne, Alain; Obert, Philippe; Reboul, Cyril; Fauconnier, Jérémy; Hayot, Maurice; Richard, Sylvain; Cazorla, Olivier

2011-11-01

Arrhythmias following cardiac stress are a key predictor of death in healthy population. Carbon monoxide (CO) is a ubiquitous pollutant promoting oxidative stress and associated with hospitalization for cardiovascular disease and cardiac mortality. We investigated the effect of chronic CO exposure on the occurrence of arrhythmic events after a cardiac stress test and the possible involvement of related oxidative stress. Wistar rats exposed chronically (4 weeks) to sustained urban CO pollution presented more arrhythmic events than controls during recovery after cardiac challenge with isoprenaline in vivo. Sudden death occurred in 22% of CO-exposed rats versus 0% for controls. Malondialdehyde (MDA), an end-product of lipid peroxidation, was increased in left ventricular tissue of CO-exposed rats. Cardiomyocytes isolated from CO-exposed rats showed higher reactive oxygen species (ROS) production (measured with MitoSox Red dye), higher diastolic Ca(2+) resulting from SR calcium leak and an higher occurrence of irregular Ca(2+) transients (measured with Indo-1) in comparison to control cells after a high pacing sequence. Acute treatment with a ROS scavenger (N-acetylcysteine, 20 mmol/L, 1 h) prevented this sequence of alterations and decreased the number of arrhythmic cells following high pacing. Chronic CO exposure promotes oxidative stress that alters Ca(2+) homeostasis (through RYR2 and SERCA defects) and thereby mediates the triggering of ventricular arrhythmia after cardiac stress that can lead to sudden death.

Chaos for cardiac arrhythmias through a one-dimensional modulation equation for alternans

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Dai, Shu; Schaeffer, David G.

2010-01-01

Instabilities in cardiac dynamics have been widely investigated in recent years. One facet of this work has studied chaotic behavior, especially possible correlations with fatal arrhythmias. Previously chaotic behavior was observed in various models, specifically in the breakup of spiral and scroll waves. In this paper we study cardiac dynamics and find spatiotemporal chaotic behavior through the Echebarria–Karma modulation equation for alternans in one dimension. Although extreme parameter values are required to produce chaos in this model, it seems significant mathematically that chaos may occur by a different mechanism from previous observations. PMID:20590327

Adrenal and extra-adrenal pheochromocytomas presenting as life-threatening ventricular arrhythmias: Report of three cases

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Sai Satish Oruganti

2016-05-01

Full Text Available Pheochromocytoma patients can rarely have prolonged QT interval in the ECG. We report three cases of pheochromocytoma in females presenting with ventricular arrhythmia; two had torsades de pointes and a third patient had frequent VPCs and nonsustained ventricular tachycardia. All the patients were treated with surgical removal of the tumor with complete relief of symptoms and normalization of QT interval.

The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress

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Ulyaninskiy, L. S.; Urmancheyeva, T. G.; Stepanyan, Y. P.; Fufacheva, A. A.; Gritsak, A. V.; Kuznetsova, B. A.; Kvitka, A. A.

1982-01-01

Experimental emotional stress which can produce various disorders of cardiac rhythm: sinus tachycardia, atrial fibrillation, ventricular, extrasystoles and paroxysmal ventricular tachysystoles was studied. In these conditions the adrenalin content in the blood and myocardium is increased 3 to 4 times. It is found that moderate motor activity leads to a relative decrease of adrenalin in the myocardium and arrest of cardiac arrhythmias.

AV-block and conduction slowing prevail over TdP arrhythmias in the methoxamine-sensitized pro-arrhythmic rabbit model

NARCIS (Netherlands)

Varkevisser, Rosanne; Vos, Marc A; Beekman, Jet; Tieland, Ralph G; Van Der Heyden, Marcel A

INTRODUCTION: The methoxamine-sensitized rabbit model is widely used to screen drugs for proarrhythmic properties, especially repolarization-dependent TdP arrhythmias. With the change of anesthesia and/or sensitizing agent, conduction disturbances have been reported as well. Therefore, we compared

Atypical dengue meningitis in Makkah, Saudi Arabia with slow resolving, prominent migraine like headache, phobia, and arrhythmia

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Kalakatawi H Mamdouh

2013-01-01

Full Text Available Although dengue meningitis is a rare presentation of dengue infection, our aim is to focus on atypical presentation of dengue meningitis that may appear in dengue endemic area like the Makkah region. We report two cases of clinical meningitis with positive dengue virus (DENV IgM in cerebrospinal fluid, followed for minimal 3 months for their prominent attacks of migraine like headache, phobia, and arrhythmia. With special consideration to attack time, type, severity, and respond to classical therapy, using regular ECG monitoring, visual analog pain score and neuropsychological assessments were done. Both cases showed resistant migraine like headaches to classic anti-migraine therapy except for strong NSAID and narcotics with tendency to have severe to extreme severe daily migraine like headache on early to late afternoon time, associated with non-fatal arrhythmias and extreme death phobia, that resolve slowly in a minimal 3 month period. In conclusion, dengue meningitis in the endemic area may present atypically.

From Incidental, Mechanically-Induced Arrhythmias to Reflex-Defined Arrhythmogenicity: On The Track of The Ternary Reflex System Resemblance to The "Infancy" of New Era or Rediscovery.

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Stirbys, Petras

2016-01-01

The underlying pathophysiology of supraventricular and ventricular arrhythmias remains a matter of intense investigation. Though evolving, the contemporary explanations do not encompass all aspects of arrhythmogenicity. An improved understanding of arrhythmia substrate is needed to augment therapeutic capabilities. Our observation and literature sources demonstrate relatively high incidence of transitory arrhythmias which are non-intentionally generated by the endocardial lead/catheter manipulation. These findings are interesting and potentially may crystallize the reflex-dependent proarrhythmic cardiac activity. Herein we suggest the "reflexogenic arrhythmogenicity" concept extending an overall spectrum of known hypotheses. Cardiovascular reflex action can be categorized into three-tiered levels - intra-cellular, inter-cellular and inter-organic. The first two levels of the triplicate system reside within the cardiac anatomical landmarks (in fact intramurally, intra-organically), however the third one implicates central (cerebral) activity which boomerangs back via centripetal and centrifugal connections. These levels likely compose synoptic ternary reflex set system which may be validated in future studies. To hypothesize, coordinated mutual reciprocity of reflex activity results in stabilization of heart rhythm in robust heart. Any stressful cardiac event may lead to the shift of the rhythm toward unfavorable clinical entity probably via the loss of the influence of dominant reflex. Overall, an interaction and likely intrinsic inter-tiered competition along with possible interplay between physiological and pathological reflexes may be treated as contributing factors for the inception and maintaining of arrhythmias and cardiac performance as well. These assumptions await further documentation. If such a tenet were recognized, the changes in the clinical approach to arrhythmia management might be anticipated, preferably by selective reflex suppression or

Inflammation markers are associated with metabolic syndrome and ventricular arrhythmia in patients with coronary artery disease

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Krzysztof Safranow

2016-02-01

Full Text Available Background: Inflammation plays a major role in the development and progression of atherosclerosis and coronary artery disease (CAD. Inflammation markers, including white blood cell (WBC count, C-reactive protein (CRP and interleukin-6 (IL-6, are widely used for cardiovascular risk prediction. The aim of the study was to establish factors associated with WBC, CRP and IL-6 in patients with CAD. Two functional polymorphisms in genes encoding enzymes participating in adenosine metabolism were analyzed (C34T AMPD1, G22A ADA. Methods: Plasma concentrations of IL-6 were measured using high-sensitivity ELISA kits, and the nephelometric method was used for high-sensitivity CRP (hs-CRP measurement in 167 CAD patients. Results: Presence of metabolic syndrome (MS and its components, presence of heart failure, severity of CAD symptoms, severe past ventricular arrhythmia (sustained ventricular tachycardia [sVT] or ventricular fibrillation [VF], lower left ventricle ejection fraction, higher left ventricle mass index, higher end-diastolic volume and higher number of smoking pack-years were significantly associated with higher WBC, CRP and IL-6. Strong associations with arrhythmia were observed for IL-6 (median 3.90 vs 1.89 pg/mL, p<0.00001 and CRP concentration (6.32 vs 1.47 mg/L, p=0.00009, while MS was associated most strongly with IL-6. CRP and IL-6 were independent markers discriminating patients with sVT or VF. There were no associations between AMPD1 or ADA genotypes and inflammation markers. Conclusions: WBC, CRP and IL-6 are strongly associated with components of the metabolic syndrome. Their strong association with life-threatening ventricular arrhythmia emphasizes the proarrhythmic role of inflammation in the increased cardiovascular risk of CAD patients.

Salade malade: malignant ventricular arrhythmias due to an accidental intoxication with Aconitum napellus.

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Weijters, B J; Verbunt, R J A M; Hoogsteen, J; Visser, R F

2008-01-01

Intoxication with Aconitum napellus is rare in our regions. Aconite alkaloids can cause ventricular arrhythmia by a prolonged activation of sodium channels. Because the margin of safety is low between the analgesic and toxic dose, intoxication is not rare when Aconite is used in herbal medicine. We present a case in which a 39-year-old male was accidentally intoxicated with Aconite. Even though no antidote or adequate therapy is available he was successfully resuscitated. (Neth Heart J 2008;16:96-9.).

Particles Alter Diesel Exhaust Gases-Induced Hypotension, Cardiac Arrhythmia,Conduction Disturbance, and Autonomic Imbalance in Heart Failure-Prone Rats

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Epidemiologic studies indicate that acute exposures to vehicular traffic and particulate matter (PM) air pollution are key causes of fatal cardiac arrhythmia, especially in those with preexisting cardiovascular disease. Researchers point to electrophysiologic dysfunction and auto...

Cardiac arrhythmia with premature ventricular contractures induced by interferon beta in a patient with multiple sclerosis

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Igor Sobol

2015-03-01

Full Text Available Multiple sclerosis (MS is an immune-mediated inflammatory and neurodegenerative disease of the central nervous system. Interferon (IFN beta is an active ingredient of five out of twelve disease modifying treatments approved for MS. We report a case of IFN-beta-induced cardiac arrhythmia with premature ventricular contractures in a patient recently diagnosed with MS.

THE USE OF OMEGA-3 FATTY ACIDS FOR THE TREATMENT OF PATIENTS WITH CARDIAC ARRHYTHMIAS

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A. O. Malygin

2015-09-01

Full Text Available Antiarrhythmic effect of omega-3 polyunsaturated fatty acids (ω-3 PUFA, eicosapentaenoic and docosahexaenoic acids in patients with recurrent atrial fibrillation and ventricular arrhythmias had been proven. The positive effect of the ω-3 PUFA on the risk of sudden arrhythmic death and overall mortality in the patients after myocardial infarction and patients with chronic heart failure had been also proven.

Differential Susceptibility and the Early Development of Aggression: Interactive Effects of Respiratory Sinus Arrhythmia and Environmental Quality

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Eisenberg, Nancy; Sulik, Michael J.; Spinrad, Tracy L.; Edwards, Alison; Eggum, Natalie D.; Liew, Jeffrey; Sallquist, Julie; Popp, Tierney K.; Smith, Cynthia L.; Hart, Daniel

2012-01-01

The purpose of the current study was to predict the development of aggressive behavior from young children's respiratory sinus arrhythmia (RSA) and environmental quality. In a longitudinal sample of 213 children, baseline RSA, RSA suppression in response to a film of crying babies, and a composite measure of environmental quality (incorporating…

A comparison of heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major.

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Amoozgar, Hamid; Zeighami, Samaneh; Haghpanah, Sezaneh; Karimi, Mehran

2017-01-01

The goal of this study was to compare heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major. In this cross-sectional study, 60 patients with beta thalassemia major and 60 patients with beta thalassemia intermedia who had clinically no symptoms of arrhythmia and clinically normal heart function were evaluated using 24-hour ambulatory electrocardiogram monitoring and echocardiography. For data analysis SPSS ver.20 software was used. A P-value of less than 0.05 was considered statistically significant. The mean age of the beta thalassemia intermedia patients was 24.18 ± 7.9 years and the mean age in beta thalassemia major was 24.38 ± 7.7 years (P>0.05). Premature atrial contractions (PACs) were observed in 14 (23.3%) patients with beta thalassemia intermedia and in 22 (36.6%) beta thalassemia major patients. Premature ventricular contractions (PVCs) were detected in 8 (13.3%) patients in the beta thalassemia intermediate group and 16 (26.6) patients in the beta thalassemia major group, respectively. The left ventricular diastolic dimension, end-diastolic volume, and stroke volume were significantly higher in beta thalassemia intermedia group (Pintermedia group. Both atrial and ventricular arrhythmias were more common in the beta thalassemia major group. Higher end-diastolic volume and stroke volume were detected in the beta thalassemia intermedia group. Pulmonary acceleration time was lower in the beta thalassemia intermedia group, which can be an indicator of higher pulmonary pressure.

An Adaptive Particle Weighting Strategy for ECG Denoising Using Marginalized Particle Extended Kalman Filter: An Evaluation in Arrhythmia Contexts.

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Hesar, Hamed Danandeh; Mohebbi, Maryam

2017-11-01

Model-based Bayesian frameworks have a common problem in processing electrocardiogram (ECG) signals with sudden morphological changes. This situation often happens in the case of arrhythmias where ECGs do not obey the predefined state models. To solve this problem, in this paper, a model-based Bayesian denoising framework is proposed using marginalized particle-extended Kalman filter (MP-EKF), variational mode decomposition, and a novel fuzzy-based adaptive particle weighting strategy. This strategy helps MP-EKF to perform well even when the morphology of signal does not comply with the predefined dynamic model. In addition, this strategy adapts MP-EKF's behavior to the acquired measurements in different input signal to noise ratios (SNRs). At low input SNRs, this strategy decreases the particles' trust level to the measurements while increasing their trust level to a synthetic ECG constructed with the feature parameters of ECG dynamic model. At high input SNRs, the particles' trust level to the measurements is increased and the trust level to synthetic ECG is decreased. The proposed method was evaluated on MIT-BIH normal sinus rhythm database and compared with EKF/EKS frameworks and previously proposed MP-EKF. It was also evaluated on ECG segments extracted from MIT-BIH arrhythmia database, which contained ventricular and atrial arrhythmia. The results showed that the proposed algorithm had a noticeable superiority over benchmark methods from both SNR improvement and multiscale entropy based weighted distortion (MSEWPRD) viewpoints at low input SNRs.

Arrhythmias and sudden death among older children and young adults following tetralogy of Fallot repair in the current era: are previously reported risk factors still applicable?

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Arya, Swati; Kovach, Julie; Singh, Harinder; Karpawich, Peter P

2014-01-01

Young adult patients (pts) with repaired tetralogy of Fallot (TOF) remain at risk for arrhythmias (Ar) and sudden cardiac death (SCD). Based on past studies with earlier pt subsets, Ar/SCD events were associated with right ventricular (RV) systolic pressures >60 mm Hg, outflow tract gradients >20 mm Hg, and QRS duration >180 ms. However, there are limited recent studies to evaluate these risk factors in the current patient generation. Patients with TOF followed over the past 50 years were grouped by presence of any arrhythmias (group 1), absence of arrhythmias (group 2), and presence of SCD or significant ventricular arrhythmias (group 3) and correlated with current pt age, gender, age at repair, repair types, echocardiogram, cardiac magnetic resonance imaging, electrocardiogram/Holter, hemodynamics, and electrophysiology findings. Of 109 pts, 52 were male aged 17-58 years. Of these, 59 (54%) had Ar, two of whom had SCD. These 59 pts were chronologically older at the time of analysis, with repair at an older age and wider QRS duration (78-240, mean 158 ms) when compared with those without Ar. However, there was no correlation with surgical era, surgical repair, gender, RV pressure >60 mm Hg, right ventricular outflow tract gradient >20 mm Hg, or RV end-diastolic volume on CMRI. Ar/SCD risk continues to correlate with repair age and advancing pt age. QRS duration is longer in these patients but at a shorter interval (mean 158 ms) and less RV pressure (mean 43 mm Hg) than previously reported. In the current TOF patient generation, neither surgical era, type of repair, RV outflow gradient nor RV volume correlate with Ar/SCD. Electrophysiologic testing to verify and identify arrhythmias remains clinically effective. © 2013 Wiley Periodicals, Inc.

Use of the Surface Electrocardiogram to Define the Nature of Challenging Arrhythmias.

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Singh, David K; Peter, C Thomas

2016-03-01

Despite unprecedented advances in technology, the electrocardiogram (ECG) remains essential to the practice of modern electrophysiology. Since its emergence at the turn of the nineteenth century, the form of the ECG has changed little. What has changed is our ability to understand the complex mechanisms that underlie various arrhythmias. In this article, the authors review several important principles of ECG interpretation by providing illustrative tracings. The authors also highlight several important concepts that be can used in ECG analysis. There are several fundamental principles that should be considered in ECG interpretation. Copyright © 2016 Elsevier Inc. All rights reserved.

[Surgery of refractory ischemic arrhythmia].

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Viganò, M; Graffigna, A; Salerno, G

1992-03-01

Since June 1980, 138 patients have undergone surgical treatment for refractory ventricular tachycardia due to ischemic heart disease. Electrically guided surgical ablation (EGSA) of the focus was performed in 117 patients, while 14 patients underwent application of automatic implantable cardioverter-defibrillator (AICD), and 8 patients underwent heart transplantation. During the whole period considered, among the EGSA patients an operative mortality of 13 patients was observed (11.4%), with a late mortality of another 14 patients (13.4%). Two early and six late recurrences were described, and 4 cases of sudden or unexplained death, with 2 cases clearly due to an arrhythmic event. Multivariate analysis showed preoperative ejection fraction lower than 25% as a powerful predictor of early mortality (32% vs 0%). Actuarial survival rate of patients with LVEF lower than 25% was 67 +/- 12% vs 95 +/- 2% at one year and 37 +/- 25% vs 94 +/- 8% at 8 years. A high operative mortality was then observed in patients who underwent aneurysmectomy alone or visually guided procedures as compared to electrically guided procedures (75% or 3 deaths out of 4 patients vs 8.5% or 10 out of 113 patients, respectively). Patients who received an AICD with or without associated procedures showed 1 case of in-hospital mortality and no late mortality; in 6 patients at least one shock was delivered; in two patients the AICD was implanted during an EGSA procedure, due to multiple or difficult origins of the arrhythmias. Of patients who underwent heart transplantation one case of later mortality was observed due to malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term fasting reduces the extent of myocardial infarction and incidence of reperfusion arrhythmias in rats

Czech Academy of Sciences Publication Activity Database

Šnorek, M.; Hodyc, D.; Šedivý, V.; Ďurišová, J.; Skoumalová, A.; Wilhelm, J.; Neckář, Jan; Kolář, František; Herget, J.

2012-01-01

Roč. 61, č. 6 (2012), s. 567-574 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/08/0108 Institutional research plan: CEZ:AV0Z5011922 Keywords : myocardial ischemia/reperfusion * arrhythmias * infarction * fasting * ketone bodies Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.531, year: 2012

Short-term Effects of High-Dose Caffeine on Cardiac Arrhythmias in Patients With Heart Failure: A Randomized Clinical Trial.

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Zuchinali, Priccila; Souza, Gabriela C; Pimentel, Maurício; Chemello, Diego; Zimerman, André; Giaretta, Vanessa; Salamoni, Joyce; Fracasso, Bianca; Zimerman, Leandro I; Rohde, Luis E

2016-12-01

The presumed proarrhythmic action of caffeine is controversial. Few studies have assessed the effect of high doses of caffeine in patients with heart failure due to left ventricular systolic dysfunction at high risk for ventricular arrhythmias. To compare the effect of high-dose caffeine or placebo on the frequency of supraventricular and ventricular arrhythmias, both at rest and during a symptom-limited exercise test. Double-blinded randomized clinical trial with a crossover design conducted at the heart failure and cardiac transplant clinic of a tertiary-care university hospital. The trial included patients with chronic heart failure with moderate-to-severe systolic dysfunction (left ventricular ejection fraction capsules, in addition to 5 doses of 100 mL decaffeinated coffee at 1-hour intervals, for a total of 500 mg of caffeine or placebo during a 5-hour protocol. After a 1-week washout period, the protocol was repeated. Number and percentage of ventricular and supraventricular premature beats assessed by continuous electrocardiographic monitoring. We enrolled 51 patients (37 [74%] male; mean [SD] age, 60.6 [10.9] years) with predominantly moderate-to-severe left ventricular systolic dysfunction (mean [SD] left ventricular ejection fraction, 29% [7%]); 31 [61%] had an implantable cardioverter-defibrillator device. No significant differences between the caffeine and placebo groups were observed in the number of ventricular (185 vs 239 beats, respectively; P = .47) and supraventricular premature beats (6 vs 6 beats, respectively; P = .44), as well as in couplets, bigeminal cycles, or nonsustained tachycardia during continuous electrocardiographic monitoring. Exercise test-derived variables, such as ventricular and supraventricular premature beats, duration of exercise, estimated peak oxygen consumption, and heart rate, were not influenced by caffeine ingestion. We observed no increases in ventricular premature beats (91 vs 223 vs 207 beats, respectively

Pit-a-Pat: A Smart Electrocardiogram System for Detecting Arrhythmia.

Science.gov (United States)

Park, Juyoung; Lee, Kuyeon; Kang, Kyungtae

2015-10-01

Electrocardiogram (ECG) telemonitoring is one of the most promising applications of medical telemetry. However, previous approaches to ECG telemonitoring have largely relied on public databases of ECG results. In this article we propose a smart ECG system called Pit-a-Pat, which extracts features from ECG signals and detects arrhythmia. It is designed to run on an Android™ (Google, Mountain View, CA) device, without requiring modifications to other software. We implemented the Pit-a-Pat system using a commercial ECG device, and the experimental results demonstrate the effectiveness and accuracy of Pit-a-Pat for monitoring the ECG signal and analyzing the cardiac activity of a mobile patient. The proposed system allows monitoring of cardiac activity with automatic analysis, thereby providing a convenient, inexpensive, and ubiquitous adjunct to personal healthcare.

Resting respiratory sinus arrhythmia is associated with tonic positive emotionality.

Science.gov (United States)

Oveis, Christopher; Cohen, Adam B; Gruber, June; Shiota, Michelle N; Haidt, Jonathan; Keltner, Dacher

2009-04-01

Resting respiratory sinus arrhythmia (RSAREST) indexes important aspects of individual differences in emotionality. In the present investigation, the authors address whether RSAREST is associated with tonic positive or negative emotionality, and whether RSAREST relates to phasic emotional responding to discrete positive emotion-eliciting stimuli. Across an 8-month, multiassessment study of first-year university students (n = 80), individual differences in RSAREST were associated with positive but not negative tonic emotionality, assessed at the level of personality traits, long-term moods, the disposition toward optimism, and baseline reports of current emotional states. RSAREST was not related to increased positive emotion, or stimulus-specific emotion, in response to compassion-, awe-, or pride-inducing stimuli. These findings suggest that resting RSA indexes aspects of a person's tonic positive emotionality. (c) 2009 APA, all rights reserved.

Flecainide reduces ventricular arrhythmias via a mechanism that differs from that of β-blockers in catecholaminergic polymorphic ventricular tachycardia

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Kenichi Dochi

2013-10-01

Conclusion: Flecainide effectively reduced ventricular arrhythmias via a mechanism that differs from that of β-blockers in genotype-positive patients with CPVT. The specific effects of flecainide may be critical in the improvement noted in the patients' ability to perform daily activities.

Electron-beam CT coronary angiography in the patients with high heart rate arrhythmia or pacemaker

International Nuclear Information System (INIS)

Dong Zhi; Zhu Jiemin; Liu Zhe; Liu Junbo; Li Youjie; Qi Ji

2006-01-01

Objective: To report the clinical applicability of coronary angiography for patients with high heart rate, arrhythmia or cardiac pacing using the new-generation of electron-beam CT (e-Speed). Methods: EBCT (GE e-Speed) coronary angiography was performed in 36 eases (male 27, female 9, mean age 58), including the heart rate more than 90 bpm in 20 patients, frequent ectopic beats in 11 cases, implantation of cardiac pacemaker in 4 patients and the unacceptable MSCT image quality due to variability of interscan heart rate (from 82 bpm to 104 bpm) in 1 case. After volume data set was acquired using spiral mode with prospective ECG-gating, the reconstructions of MIP, CPR, VR and Cine were performed. The VR quality was evaluated using a five-point scale. Results: The quality of coronary imaging in all of 36 cases were acceptable. The total visualization rate of coronary artery branches was 80.0%. Left main, left anterior artery and right coronary artery were visualized in all patients and in 94.3% of all cases circumflex artery were visible. Conclusion: EBCT (e-Speed) is applicable in noninvasive coronary angiography for patients with high heart rate, arrhythmia or implanted cardiac pacemaker', and this examination can obtain satisfied diagnosis. (authors)

Growth factor-induced mobilization of cardiac progenitor cells reduces the risk of arrhythmias, in a rat model of chronic myocardial infarction.

Directory of Open Access Journals (Sweden)

Leonardo Bocchi

Full Text Available Heart repair by stem cell treatment may involve life-threatening arrhythmias. Cardiac progenitor cells (CPCs appear best suited for reconstituting lost myocardium without posing arrhythmic risks, being commissioned towards cardiac phenotype. In this study we tested the hypothesis that mobilization of CPCs through locally delivered Hepatocyte Growth Factor and Insulin-Like Growth Factor-1 to heal chronic myocardial infarction (MI, lowers the proneness to arrhythmias. We used 133 adult male Wistar rats either with one-month old MI and treated with growth factors (GFs, n = 60 or vehicle (V, n = 55, or sham operated (n = 18. In selected groups of animals, prior to and two weeks after GF/V delivery, we evaluated stress-induced ventricular arrhythmias by telemetry-ECG, cardiac mechanics by echocardiography, and ventricular excitability, conduction velocity and refractoriness by epicardial multiple-lead recording. Invasive hemodynamic measurements were performed before sacrifice and eventually the hearts were subjected to anatomical, morphometric, immunohistochemical, and molecular biology analyses. When compared with untreated MI, GFs decreased stress-induced arrhythmias and concurrently prolonged the effective refractory period (ERP without affecting neither the duration of ventricular repolarization, as suggested by measurements of QTc interval and mRNA levels for K-channel α-subunits Kv4.2 and Kv4.3, nor the dispersion of refractoriness. Further, markers of cardiomyocyte reactive hypertrophy, including mRNA levels for K-channel α-subunit Kv1.4 and β-subunit KChIP2, interstitial fibrosis and negative structural remodeling were significantly reduced in peri-infarcted/remote ventricular myocardium. Finally, analyses of BrdU incorporation and distribution of connexin43 and N-cadherin indicated that cytokines generated new vessels and electromechanically-connected myocytes and abolished the correlation of infarct size with deterioration

Inflammation markers are associated with metabolic syndrome and ventricular arrhythmia in patients with coronary artery disease

Directory of Open Access Journals (Sweden)

Krzysztof Safranow

2016-02-01

Full Text Available In this study we examined the association between WBC, CRP and IL-6 plasma concentrations and clinical and biochemical parameters in patients with CAD. Many reports have been published on associations between inflammation markers and cardiovascular diseases. Therefore we did not aim to confirm that inflammation is a significant risk factor of CAD, but to explore associations between inflammation and other features (including metabolic syndrome and arrhythmia in patients already diagnosed with CAD. IL-1beta plasma concentrations were too low for reliable measurement in our patients. Increased levels of WBC, CRP and IL-6 were associated with heart failure, severity of CAD symptoms, severe past ventricular arrhythmia, lower left ventricle ejection fraction, higher left ventricle mass index or end-diastolic volume, metabolic syndrome components and higher number of smoking pack-years. In multivariate analyses the common independent predictors of higher WBC, CRP and IL-6 were: symptoms of advanced CAD, ventricular arrhythmia, obesity and dyslipidaemia. The relatively high proportion of patients with heart failure or an implanted ICD and severe ventricular arrhythmias in the study group reflects the profile of the Department of Cardiology, which is an academic tertiary referral centre. Advanced CAD symptoms (reflected by higher CCS class and presence of heart failure, as a result of functional heart damage related to ischemia, were independent predictors of higher levels of inflammation markers. Interestingly, echocardiography parameters were not significant predictors of inflammation markers in multivariate models including clinical symptoms. This association may indicate that the markers reflect the increasing intensity of inflammation during the natural clinical course of progressing CAD. It would be very interesting to investigate in prospective studies whether coronary revascularization, which alleviates CAD symptoms and improves cardiovascular

Respiratory sinus arrhythmia as a measure of cognitive workload.

Science.gov (United States)

Muth, Eric R; Moss, Jason D; Rosopa, Patrick J; Salley, James N; Walker, Alexander D

2012-01-01

The current standard for measuring cognitive workload is the NASA Task-load Index (TLX) questionnaire. Although this measure has a high degree of reliability, diagnosticity, and sensitivity, a reliable physiological measure of cognitive workload could provide a non-invasive, objective measure of workload that could be tracked in real or near real-time without interrupting the task. This study investigated changes in respiratory sinus arrhythmia (RSA) during seven different sub-sections of a proposed selection test for Navy aviation and compared them to changes reported on the NASA-TLX. 201 healthy participants performed the seven tasks of the Navy's Performance Based Measure. RSA was measured during each task and the NASA-TLX was administered after each task. Multi-level modeling revealed that RSA significantly predicted NASA-TLX scores. A moderate within-subject correlation was also found between RSA and NASA TLX scores. The findings support the potential development of RSA as a real-time measure of cognitive workload. Copyright © 2011. Published by Elsevier B.V.

Arrhythmia and conduction disorders in acute inferior myocardial infarction with right ventricular involvement

International Nuclear Information System (INIS)

Samadikhah, J.; Hakim, S.H.; Azarfarin, R.; Ghaffari, S.

2007-01-01

To assess the prognostic impact of Right Ventricular (RV) myocardial involvement in patients with inferior MI. One hundred seventy patients who were admitted to cardiac care unit of Madani Heart Hospital, Tabriz, Iran with the diagnosis of inferior MI with (group 1) or without (group 2) simultaneous involvement of RV were studied from 2005 to 2006. Patients presenting within 12 hours of symptom onset were eligible for inclusion. Those with simultaneous Anterior wall MI, patients undergoing primary percutaneous transluminal coronary angioplasty and those with renal impairment (creatinine >2 mg/dl) were excluded. Eighty eight percent of the patients with RVMI and 75% with isolated inferior MI had some type of arrhythmia. AV block occurred in 42% of the infarctions with RV involvement and only in 29% of the control group. Intra ventricular conduction disturbance (IVCD) also were more frequent in RVMI (29.4% VS 13.1%, p=0.021), especially the RBBB (20% VS 7.4%, P=0.003). Ventricular fibrillation (VF) was observed in 5.2% and 1.2% and ventricular tachycardia in 26% and 12.2% respectively. In 27% of patients with RVMI it was necessary to implant a pacemaker as compared to 10% in control group. Mortality was higher in the patients with inferior infarction extended to the RV (15.3% vs 3.5%., P=0.0001). There was not a meaningful difference in incidence of LBBB between group 1 and 2 (3.1% vs 2.9% P=0.9). Patients with inferior MI who also have RV myocardial involvement are at increased risk of death and arrhythmias. (author)

Effect of acute alloxan diabetes on ischemic and reperfusion arrhythmias in rats with different activity of nitric oxide system.

Science.gov (United States)

Belkina, L M; Terekhina, O L; Smirnova, E A; Usacheva, M A; Kruglov, S V; Saltykova, V A

2011-01-01

Similar degree of glycemia (28-31 mmol/liter) and similar mortality (37-42%) were revealed in August rats exhibiting enhanced activity of NO system and in Wistar rats 3 weeks after alloxan treatment. Under conditions of myocardial ischemia caused by 10-min coronary artery ligation, the intensity of arrhythmias did not differ from the control in Wistar rats with diabetes mellitus and increased in August rats. Under conditions of reperfusion, diabetes produced an antiarrhythmic effect in Wistar rats and did not affect arrhythmia in August rats. Plasma concentrations of nitrates and nitrites in Wistar and August rats increased by 82 and 143%, respectively, compared to the control. The level of hemoxygenase-1 (hsp32) in the myocardium remained unchanged in Wistar rats and decreased by 26% in August rats. Thus, the absence of antiarrhythmic effect of acute diabetes in August rats is probably related to elevated NO content and reduced antioxidant activity.

Arrhythmia-free survival and pulmonary vein reconnection patterns after second-generation cryoballoon and contact-force radiofrequency pulmonary vein isolation.

Science.gov (United States)

Buist, Thomas J; Adiyaman, Ahmet; Smit, Jaap Jan J; Ramdat Misier, Anand R; Elvan, Arif

2018-06-01

The aim of this study was to compare second-generation cryoballoon and contact-force radiofrequency point-by-point pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients with regard to pulmonary vein reconnection and arrhythmia-free survival. Altogether, 269 consecutive patients with drug-refractory AF undergoing PVI were included and randomly allocated to second-generation cryoballoon or contact-force point-by-point radiofrequency ablation. Median follow-up duration was 389 days (interquartile range 219-599). Mean age was 59 years (71% male); 136 patients underwent cryoballoon and 133 patients underwent radiofrequency ablation. Acute electrical PVI was 100% for both techniques. Procedure duration was significantly shorter in cryoballoon vs radiofrequency (166.5 vs 184.13 min P = 0.016). Complication rates were similar (6.0 vs 6.7%, P = 1.00). Single procedure freedom of atrial arrhythmias was significantly higher in cryoballoon as compared to radiofrequency (75.2 vs 57.4%, P = 0.013). In multivariate analysis, persistent AF, AF duration, and cryoballoon ablation were associated with freedom of atrial tachyarrhythmias. The number of repeat ablation procedures was significantly lower in the cryoballoon compared to radiofrequency (15.0 vs 24.3%, P = 0.045). At repeat ablation, pulmonary vein reconnection rate was significantly lower after cryoballoon as compared to radiofrequency ablation (36.8 vs 58.1%, P = 0.003). Improved arrhythmia-free survival and more durable pulmonary vein isolation is seen after PVI using second-generation cryoballoon as compared to contact-force radiofrequency, in patients with drug-refractory paroxysmal AF. Complication rates for both ablation techniques are low.

An international multicenter study comparing arrhythmia prevalence between the intracardiac lateral tunnel and the extracardiac conduit type of Fontan operations.

Science.gov (United States)

Balaji, Seshadri; Daga, Ankana; Bradley, David J; Etheridge, Susan P; Law, Ian H; Batra, Anjan S; Sanatani, Shubayan; Singh, Anoop K; Gajewski, Kelly K; Tsao, Sabrina; Singh, Harinder R; Tisma-Dupanovic, Svjetlana; Tateno, Shigeru; Takamuro, Motoki; Nakajima, Hiromichi; Roos-Hesselink, Jolien W; Shah, Maully

2014-08-01

The study objective was to determine whether the extracardiac conduit Fontan confers an arrhythmia advantage over the intracardiac lateral tunnel Fontan. This multicenter study of 1271 patients compared bradyarrhythmia (defined as need for pacing) and tachyarrhythmia (defined as needing antiarrhythmic therapy) between 602 patients undergoing the intracardiac Fontan and 669 patients undergoing the extracardiac Fontan. The median age at the time of the Fontan procedure was 2.1 years (interquartile range, 1.6-3.2 years) for the intracardiac group and 3.0 years (interquartile range, 2.4-3.9) for the extracardiac group (P 30 days) bradyarrhythmia occurred in 105 patients (18%) in the intracardiac group and 63 patients (9%) in the extracardiac group (P 30 days) tachyarrhythmia occurred in 58 patients (10%) in the intracardiac group and 23 patients (3%) in the extracardiac group (P factoring time since surgery, more patients in the extracardiac group had early bradycardia (odds ratio, 2.9; 95% confidence interval, 1.8-4.6), with no difference in early tachycardia, late bradycardia, or late tachycardia. Overall arrhythmia burden is similar between the 2 groups, but the extracardiac Fontan group had a higher incidence of early bradyarrhythmias. There was no difference in the incidence of late tachyarrhythmias over time between the 2 operations. Therefore, the type of Fontan performed should be based on factors other than an anticipated reduction in arrhythmia burden from the extracardiac conduit. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Effects of Statin on Arrhythmia and Heart Rate Variability in Healthy Persons With 48-Hour Sleep Deprivation.

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Chen, Wei Ren; Liu, Hong Bin; Sha, Yuan; Shi, Yang; Wang, Hao; Yin, Da Wei; Chen, Yun Dai; Shi, Xiang Min

2016-10-31

It has been reported that sleep deprivation is associated with cardiac autonomic disorder, inflammation, and oxidative stress. Statins have significant cardiovascular protective effects in patients with cardiovascular disease. This study aimed to investigate the protective effect of statins on arrhythmia and heart rate variability in young healthy persons after 48-hour sleep deprivation. This study enrolled 72 young healthy participants aged 26.5±3.5 years. All participants received 48-hour continuous ambulatory electrocardiogram monitoring. Arrhythmia, time, and frequency domain parameters were analyzed for all participants. The primary end point, low/high frequency ratio, was significantly lower in the statin group than in the control group (2.48±1.12 versus 3.02±1.23, Psleep deprivation, low frequency-the frequency of premature atrial complexes and premature ventricular complexes-was significantly decreased in the statin group compared with the control group (Psleep deprivation in the statin group compared with the control group (Psleep deprivation. This finding should be confirmed by larger scale trials. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02496962. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

O-GlcNAcylation of cardiac Nav1.5 contributes to the development of arrhythmias in diabetic hearts.

Science.gov (United States)

Yu, Peng; Hu, Lili; Xie, Jinyan; Chen, Sisi; Huang, Lin; Xu, Zixuan; Liu, Xiao; Zhou, Qiongqiong; Yuan, Ping; Yan, Xia; Jin, Jiejin; Shen, Yang; Zhu, Wengen; Fu, Linghua; Chen, Qi; Yu, Jianhua; Hu, Jianxin; Cao, Qing; Wan, Rong; Hong, Kui

2018-06-01

Cardiovascular complications are major causes of mortality and morbidity in diabetic patients. The mechanisms underlying the progression of diabetic heart (DH) to ventricular arrhythmias are unclear. O-linked GlcNAcylation (O-GlcNAc) is a reversible post-translational modification for the regulation of diverse cellular processes. The purpose of this study was to assess whether the cardiac voltage-gated sodium channel (Nav1.5) is subjected to O-linked GlcNAcylation (O-GlcNAc), which plays an essential role in DH-induced arrhythmias. In this study, Sprague-Dawley rats (male, 200-230 g) were treated with a single high-dose of streptozotocin (STZ, 80 mg/kg) to generate a rat model of diabetes. STZ-induced 3-month diabetic rats displayed increased susceptibility to ventricular arrhythmias. The elevated O-GlcNAc modification was correlated with decreases in both total and cytoplasmic Nav1.5 expression in vivo and in vitro. In addition, both co-immunoprecipitation and immunostaining assays demonstrated that hyperglycemia could increase the O-GlcNAc-modified Nav1.5 levels and decrease the interaction between Nav1.5 and Nav1.5-binding proteins Nedd4-2/SAP-97. Furthermore, patch-clamp measurements in HEK-293 T cells showed that Nav1.5 current densities decreased by 30% after high-glucose treatment, and the sodium currents increased via O-GlcNAc inhibition. Our data suggested that hyperglycemia increased the O-GlcNAc modification of Nav1.5 expression and decreased the interaction between Nav1.5 and Nedd4-2/SAP-97, which led to the abnormal expression and distribution of Nav1.5, loss of function of the sodium channel, and prolongation of the PR/QT interval. Excessive O-GlcNAc modification of Nav1.5 is a novel signaling event, which may be an underlying contributing factor for the development of the arrhythmogenesis in DH. Copyright © 2017. Published by Elsevier B.V.

Real-Time Analytics for the Healthcare Industry: Arrhythmia Detection.

Science.gov (United States)

Agneeswaran, Vijay Srinivas; Mukherjee, Joydeb; Gupta, Ashutosh; Tonpay, Pranay; Tiwari, Jayati; Agarwal, Nitin

2013-09-01

It is time for the healthcare industry to move from the era of "analyzing our health history" to the age of "managing the future of our health." In this article, we illustrate the importance of real-time analytics across the healthcare industry by providing a generic mechanism to reengineer traditional analytics expressed in the R programming language into Storm-based real-time analytics code. This is a powerful abstraction, since most data scientists use R to write the analytics and are not clear on how to make the data work in real-time and on high-velocity data. Our paper focuses on the applications necessary to a healthcare analytics scenario, specifically focusing on the importance of electrocardiogram (ECG) monitoring. A physician can use our framework to compare ECG reports by categorization and consequently detect Arrhythmia. The framework can read the ECG signals and uses a machine learning-based categorizer that runs within a Storm environment to compare different ECG signals. The paper also presents some performance studies of the framework to illustrate the throughput and accuracy trade-off in real-time analytics.

POPDC1S201F causes muscular dystrophy and arrhythmia by affecting protein trafficking

Science.gov (United States)

Schindler, Roland F.R.; Scotton, Chiara; Zhang, Jianguo; Passarelli, Chiara; Ortiz-Bonnin, Beatriz; Simrick, Subreena; Schwerte, Thorsten; Poon, Kar-Lai; Fang, Mingyan; Rinné, Susanne; Froese, Alexander; Nikolaev, Viacheslav O.; Grunert, Christiane; Müller, Thomas; Tasca, Giorgio; Sarathchandra, Padmini; Drago, Fabrizio; Dallapiccola, Bruno; Rapezzi, Claudio; Arbustini, Eloisa; Di Raimo, Francesca Romana; Neri, Marcella; Selvatici, Rita; Gualandi, Francesca; Fattori, Fabiana; Pietrangelo, Antonello; Li, Wenyan; Jiang, Hui; Xu, Xun; Bertini, Enrico; Decher, Niels; Wang, Jun; Brand, Thomas; Ferlini, Alessandra

2015-01-01

The Popeye domain–containing 1 (POPDC1) gene encodes a plasma membrane–localized cAMP-binding protein that is abundantly expressed in striated muscle. In animal models, POPDC1 is an essential regulator of structure and function of cardiac and skeletal muscle; however, POPDC1 mutations have not been associated with human cardiac and muscular diseases. Here, we have described a homozygous missense variant (c.602C>T, p.S201F) in POPDC1, identified by whole-exome sequencing, in a family of 4 with cardiac arrhythmia and limb-girdle muscular dystrophy (LGMD). This allele was absent in known databases and segregated with the pathological phenotype in this family. We did not find the allele in a further screen of 104 patients with a similar phenotype, suggesting this mutation to be family specific. Compared with WT protein, POPDC1S201F displayed a 50% reduction in cAMP affinity, and in skeletal muscle from patients, both POPDC1S201F and WT POPDC2 displayed impaired membrane trafficking. Forced expression of POPDC1S201F in a murine cardiac muscle cell line (HL-1) increased hyperpolarization and upstroke velocity of the action potential. In zebrafish, expression of the homologous mutation (popdc1S191F) caused heart and skeletal muscle phenotypes that resembled those observed in patients. Our study therefore identifies POPDC1 as a disease gene causing a very rare autosomal recessive cardiac arrhythmia and LGMD, expanding the genetic causes of this heterogeneous group of inherited rare diseases. PMID:26642364

Pharmacological delayed preconditioning against ischaemia-induced ventricular arrhythmias: effect of an adenosine A1-receptor agonist

OpenAIRE

Tissier, Renaud; Souktani, Rachid; Parent de Curzon, Olivier; Lellouche, Nicolas; Henry, Patrick; Giudicelli, Jean-François; Berdeaux, Alain; Ghaleh, Bijan

2001-01-01

The goal of this study was to investigate the effects of the delayed pharmacological preconditioning produced by an adenosine A1-receptor agonist (A1-DPC) against ventricular arrhythmias induced by ischaemia and reperfusion, compared to those of ischaemia-induced delayed preconditioning (I-DPC).Eighty-nine instrumented conscious rabbits underwent a 2 consecutive days protocol. On day 1, rabbits were randomly divided into four groups: ‘Control' (saline, i.v.), ‘I-DPC' (six 4-min coronary arter...

Is exposure to ionising radiation associated with childhood cardiac arrhythmia in the Russian territories contaminated by the Chernobyl fallout? A cross-sectional population-based study.

Science.gov (United States)

Jourdain, Jean-Rene; Landon, Geraldine; Clero, Enora; Doroshchenko, Vladimir; Silenok, Aleksandr; Kurnosova, Irina; Butsenin, Andrei; Denjoy, Isabelle; Franck, Didier; Heuze, Jean-Pierre; Gourmelon, Patrick

2018-03-25

To investigate childhood cardiac arrhythmia and chronic exposure to caesium-137 ( 137 Cs) resulting from the Chernobyl accident. Prospective cross-sectional study using exposed/unexposed design conducted in the Bryansk region from May 2009 to May 2013 on children selected on the basis of 137 Cs soil deposition: control territories ([ 137 Cs]555 kBq per square metre, where children were considered as exposed). Russian territories affected by the Chernobyl fallout (Bryansk region). This cross-sectional study included 18 152 children aged 2-18 years and living in the Bryansk region (Russia). All children received three medical examinations (ECG, echocardiography and 137 Cs whole-body activity measurement) and some of them were given with a 24-hour Holter monitoring and blood tests. Cardiac arrhythmia was diagnosed in 1172 children living in contaminated territories and 1354 children living in control territories. The crude prevalence estimated to 13.3% in contaminated territories was significantly lower than in control territories with 15.2% over the period 2009-2013 (PChernobyl fallout. The suspected increase of cardiac arrhythmia in children exposed to Chernobyl fallout is not confirmed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Conventional versus 3-D Echocardiography to Predict Arrhythmia Recurrence After Atrial Fibrillation Ablation.

Science.gov (United States)

Bossard, Matthias; Knecht, Sven; Aeschbacher, Stefanie; Buechel, Ronny R; Hochgruber, Thomas; Zimmermann, Andreas J; Kessel-Schaefer, Arnheid; Stephan, Frank-Peter; Völlmin, Gian; Pradella, Maurice; Sticherling, Christian; Osswald, Stefan; Kaufmann, Beat A; Conen, David; Kühne, Michael

2017-06-01

Arrhythmia recurrence after atrial fibrillation (AF) ablation remains high and requires repeat interventions in a substantial number of patients. We assessed the value of conventional and 3-D echocardiography to predict AF recurrence. Consecutive patients undergoing AF ablation by means of pulmonary vein isolation were included in a prospective registry. Echocardiograms were obtained prior to the ablation procedure, and analyzed offline in a standardized manner, including 3-D left atrial (LA) volumetry and determination of LA function and sphericity. The primary endpoint, AF recurrence (>30 seconds) between 3 to 12 months after AF ablation, was independently adjudicated. We included 276 patients (73% male, mean age 59.9 ± 9.9 years). Paroxysmal and persistent AF were present in 178 (64%) and 98 (36%) patients, respectively. Mean left ventricular ejection fraction and indexed LA volume in 3-D (LAVI) were 52 ± 12% and 42 ± 13 mL/m 2 , respectively. AF recurrence was observed in 110 (40%) patients after a single procedure. Median (interquartile range) time to AF recurrence was 123 (92; 236) days. In multivariable Cox regression models, the only predictors for AF recurrence were the minimal, maximal, and indexed 3-D LA volumes, P = 0.024, P = 0.016, and P = 0.014, respectively. Quartile specific analysis of 3-D LAVI showed an HR of 1.885 (95%CI 1.066-3.334; P for trend = 0.015) for the highest compared to the lowest quartile. Our results show the important role of LA volume for the long-term freedom from arrhythmia after AF ablation. These data also highlight the potential of 3-D echocardiography in this context and may facilitate patient selection for AF ablation. © 2017 Wiley Periodicals, Inc.

The impact of exercise on ventricular arrhythmias in adults with tetralogy of Fallot.

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Ávila, Pablo; Marcotte, François; Dore, Annie; Mercier, Lise-Andrée; Shohoudi, Azadeh; Mongeon, François-Pierre; Mondésert, Blandine; Proietti, Anna; Ibrahim, Reda; Asgar, Anita; Poirier, Nancy; Khairy, Paul

2016-09-15

Sudden death of presumed arrhythmic etiology is the leading cause of mortality in adults with tetralogy of Fallot. To assess the impact of exercise on ventricular arrhythmias in adults with tetralogy of Fallot. Adults with repaired tetralogy of Fallot were randomized in a 2:1 ratio to an open-label trial of standard care versus 12weeks of supervised combined aerobic/resistance training with continuous Holter monitoring. Proportion of premature ventricular complexes (PVC) and runs of non-sustained ventricular tachycardia (NSVT) were assessed by mixed and Poisson regression models with generalized estimating equations for repeated measures. A total of 152 Holters were performed in 17 patients, median age 35 (interquartile range [IQR] 28, 42) years, 65% male, 13 of whom were randomized to exercise training. Baseline characteristics were similar between groups. Exercise training resulted in significant increases in peak oxygen uptake (11±19%, p=0.028), metabolic equivalents (11±18%, p=0.027), and exercise duration (8±10%, p=0.009) compared to no changes in controls. Frequent (≥30 per hour) PVCs were present in 46% of patients, couplets in 62%, and 3 to 7 beat runs of NSVT in 31%. The median proportion of PVCs was 1.93‰ (IQR 0.41, 5.89) at baseline and 1.45‰ (IQR 0.08, 2.76) during the initial exercise session (p=0.722), and remained stable over time (ß coefficient=-0.031, p=0.408). Runs of NSVT decreased significantly over time (ß coefficient=-0.032, p=0.018). In adults with repaired tetralogy of Fallot, exercise training is safe, improves exercise capacity, and appears to confer a beneficial effect on ventricular arrhythmias. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

International Nuclear Information System (INIS)

Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-bo; Sun, Xiao-bo

2014-01-01

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na + channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca 2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca 2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca 2+ overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca 2+ handling proteins demonstrated that aconitine promoted Ca 2+ overload through the expression regulation of Ca 2+ handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca 2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca 2+ overload causes arrhythmia in rats

Fractal ventilation enhances respiratory sinus arrhythmia

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Girling Linda G

2005-05-01

Full Text Available Abstract Background Programming a mechanical ventilator with a biologically variable or fractal breathing pattern (an example of 1/f noise improves gas exchange and respiratory mechanics. Here we show that fractal ventilation increases respiratory sinus arrhythmia (RSA – a mechanism known to improve ventilation/perfusion matching. Methods Pigs were anaesthetised with propofol/ketamine, paralysed with doxacurium, and ventilated in either control mode (CV or in fractal mode (FV at baseline and then following infusion of oleic acid to result in lung injury. Results Mean RSA and mean positive RSA were nearly double with FV, both at baseline and following oleic acid. At baseline, mean RSA = 18.6 msec with CV and 36.8 msec with FV (n = 10; p = 0.043; post oleic acid, mean RSA = 11.1 msec with CV and 21.8 msec with FV (n = 9, p = 0.028; at baseline, mean positive RSA = 20.8 msec with CV and 38.1 msec with FV (p = 0.047; post oleic acid, mean positive RSA = 13.2 msec with CV and 24.4 msec with FV (p = 0.026. Heart rate variability was also greater with FV. At baseline the coefficient of variation for heart rate was 2.2% during CV and 4.0% during FV. Following oleic acid the variation was 2.1 vs. 5.6% respectively. Conclusion These findings suggest FV enhances physiological entrainment between respiratory, brain stem and cardiac nonlinear oscillators, further supporting the concept that RSA itself reflects cardiorespiratory interaction. In addition, these results provide another mechanism whereby FV may be superior to conventional CV.

Inhalation of diluted diesel engine emission impacts heart rate variability and arrhythmia occurrence in a rat model of chronic ischemic heart failure

Energy Technology Data Exchange (ETDEWEB)

Anselme, Frederic [Rouen University Hospital, Service de Cardiologie, Rouen (France); Loriot, Stephane; Henry, Jean-Paul; Thuillez, Christian; Morin, Jean-Paul [University of Rouen France, INSERM U644, School of Medicine-Pharmacy, Rouen, Cedex (France); Dionnet, Frederic [Centre d' Etudes et de Recherches Technologiques en Aerothermique et Moteurs, Saint Etienne du Rouvray (France); Napoleoni, Jean-Gerard [EMKA Technologies, Paris (France)

2007-04-15

Both increase in cardiac arrhythmia incidence and decrease in heart rate variability (HRV) have been described following human and experimental animal exposures to air pollutants. However, the potential causal relationship between these two factors remains unclear. Incidence of ventricular arrhythmia and HRV were evaluated during and after a 3 h period of Diesel engine exhaust exposure in ten healthy and ten chronic ischemic heart failure (CHF, 3 months after coronary ligation) Wistar rats using implantable ECG telemetry. Air pollutants were delivered to specifically designed whole body individual exposure chambers at particulate matter concentrations similar to those measured inside cabins of cars inserted in congested urban traffic. Recordings were obtained from unrestraint and unsedated vigil rats. Immediate decrease in RMSSD was observed in both healthy (6.64 {+-} 2.62 vs. 4.89 {+-} 1.67 ms, P < 0.05) and CHF rats (8.01 {+-} 0.89 vs. 6.6 {+-} 1.37 ms, P < 0.05) following exposure. An immediate 200-500% increase in ventricular premature beats was observed in CHF rats only. Whereas HRV progressively returned to baseline values within 2.5 h after exposure start, the proarrhythmic effect persisted as late as 5 h after exposure termination in CHF rats. Persistence of ventricular proarrhythmic effects after HRV normalization suggests that HRV reduction is not the mechanism of cardiac arrhythmias in this model. Our methodological approach, closely reflecting the real clinical situations, appeared to be a unique tool to provide further insight into the pathophysiological mechanisms of traffic related airborne pollution health impact. (orig.)

Overexpression of Cx43 in cells of the myocardial scar: Correction of post-infarct arrhythmias through heterotypic cell-cell coupling.

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Roell, Wilhelm; Klein, Alexandra M; Breitbach, Martin; Becker, Torsten S; Parikh, Ashish; Lee, Jane; Zimmermann, Katrin; Reining, Shaun; Gabris, Beth; Ottersbach, Annika; Doran, Robert; Engelbrecht, Britta; Schiffer, Miriam; Kimura, Kenichi; Freitag, Patricia; Carls, Esther; Geisen, Caroline; Duerr, Georg D; Sasse, Philipp; Welz, Armin; Pfeifer, Alexander; Salama, Guy; Kotlikoff, Michael; Fleischmann, Bernd K

2018-05-08

Ventricular tachycardia (VT) is the most common and potentially lethal complication following myocardial infarction (MI). Biological correction of the conduction inhomogeneity that underlies re-entry could be a major advance in infarction therapy. As minimal increases in conduction of infarcted tissue markedly influence VT susceptibility, we reasoned that enhanced propagation of the electrical signal between non-excitable cells within a resolving infarct might comprise a simple means to decrease post-infarction arrhythmia risk. We therefore tested lentivirus-mediated delivery of the gap-junction protein Connexin 43 (Cx43) into acute myocardial lesions. Cx43 was expressed in (myo)fibroblasts and CD45 + cells within the scar and provided prominent and long lasting arrhythmia protection in vivo. Optical mapping of Cx43 injected hearts revealed enhanced conduction velocity within the scar, indicating Cx43-mediated electrical coupling between myocytes and (myo)fibroblasts. Thus, Cx43 gene therapy, by direct in vivo transduction of non-cardiomyocytes, comprises a simple and clinically applicable biological therapy that markedly reduces post-infarction VT.

Association of ventricular arrhythmia and in-hospital mortality in stroke patients in Florida: A nonconcurrent prospective study.

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Dahlin, Arielle A; Parsons, Chase C; Barengo, Noël C; Ruiz, Juan Gabriel; Ward-Peterson, Melissa; Zevallos, Juan Carlos

2017-07-01

Stroke remains one of the leading causes of death in the United States. Current evidence identified electrocardiographic abnormalities and cardiac arrhythmias in 50% of patients with an acute stroke. The purpose of this study was to assess whether the presence of ventricular arrhythmia (VA) in adult patients hospitalized in Florida with acute stroke increased the risk of in-hospital mortality.Secondary data analysis of 215,150 patients with ischemic and hemorrhagic stroke hospitalized in the state of Florida collected by the Florida Agency for Healthcare Administration from 2008 to 2012. The main outcome for this study was in-hospital mortality. The main exposure of this study was defined as the presence of VA. VA included the ICD-9 CM codes: paroxysmal ventricular tachycardia (427.1), ventricular fibrillation (427.41), ventricular flutter (427.42), ventricular fibrillation and flutter (427.4), and other - includes premature ventricular beats, contractions, or systoles (427.69). Differences in demographic and clinical characteristics and hospital outcomes were assessed between patients who developed versus did not develop VA during hospitalization (χ and t tests). Binary logistic regression was used to estimate unadjusted and adjusted odds ratios and 95% confidence intervals (CIs) between VA and in-hospital mortality.VA was associated with an increased risk of in-hospital mortality after adjusting for all covariates (odds ratio [OR]: 1.75; 95% CI: 1.6-1.2). There was an increased in-hospital mortality in women compared to men (OR: 1.1; 95% CI: 1.1-1.14), age greater than 85 years (OR: 3.9, 95% CI: 3.5-4.3), African Americans compared to Whites (OR: 1.1; 95% CI: 1.04-1.2), diagnosis of congestive heart failure (OR: 2.1; 95% CI: 2.0-2.3), and atrial arrhythmias (OR: 2.1, 95% CI: 2.0-2.2). Patients with hemorrhagic stroke had increased odds of in-hospital mortality (OR: 9.0; 95% CI: 8.6-9.4) compared to ischemic stroke.Identifying VAs in stroke patients may help in

QRS Complex Enlargement as a Predictor of Ventricular Arrhythmias in Patients Affected by Surgically Treated Tetralogy of Fallot: A Comprehensive Literature Review and Historical Overview

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Bassareo, Pier Paolo; Mercuro, Giuseppe

2013-01-01

Tetralogy of Fallot (TOF) is a congenital heart disease frequently treated by surgical repair to relieve symptoms and improve survival. However, despite the performing of an optimal surgical repair, TOF patients are at times characterized by a poor long-term survival rate, likely due to cardiac causes such as ventricular arrhythmias, with subsequent sudden death. In the 80s it was irrefutably demonstrated that QRS prolongation ≥180 msec at basal electrocardiogram is a strong predictor for refining risk stratification for ventricular tachycardia in these patients. The aim of this research was to undertake a review of all studies conducted to assess the impact of QRS duration on the development of life-threatening ventricular arrhythmias in repaired TOF subjects. PMID:23509638

Fatal cardiac arrhythmia after repeated exposure to 1,1-difluoroethane (DFE).

Science.gov (United States)

Avella, Joseph; Wilson, James C; Lehrer, Michael

2006-03-01

A 42-year-old man was found dead after repeated exposure to 1,1-difluoroethane (DFE, Freon 152a), a propellant found in CRC Duster, a product intended for the removal of dust and lint. Toxicologic analysis detected DFE in femoral blood 136.3 mg/L, brain 117.5 mg/kg, liver 87.6 mg/kg, lung 60.3 mg/kg, adipose 235.7 mg/kg, and vitreous fluid 25.1 mg/L. The cause of death was determined to be a fatal cardiac arrhythmia due to intoxication with 1,1-difluoroethane. After comparison to previously published cases involving DFE, we suggest that analysis of adipose tissue for DFE and similar compounds, along with blood and other tissues, may be useful in distinguishing between acute versus chronic exposure. Adipose may also be a valuable alternate specimen for detection in cases where loss or elimination from blood is likely to have occurred.

Percutaneous autonomic neural modulation: A novel technique to treat cardiac arrhythmia

International Nuclear Information System (INIS)

DeSimone, Christopher V.; Madhavan, Malini; Venkatachalam, Kalpathi L.; Knudson, Mark B.; Asirvatham, Samuel J.

2013-01-01

Ablation and anti-arrhythmic medications have shown promise but have been met with varying success and unwanted side effects such as myocardial injury, arrhythmias, and morbidity from invasive surgical intervention. The answer to improving efficacy of ablation may include modulation of the cardiac aspect of the autonomic nervous system. Our lab has developed a novel approach and device to navigate the oblique sinus and to use DC current and saline/alcohol irrigation to selectively stimulate and block the autonomic ganglia found on the epicardial side of the heart. This novel approach minimizes myocardial damage from thermal injury and provides a less invasive and targeted approach. For feasibility, proof-of-concept, and safety monitoring, we carried out canine studies to test this novel application. Our results suggest a safer and less invasive way of modulating arrhythmogenic substrate that may lead to improved treatment of AF in humans

Percutaneous autonomic neural modulation: A novel technique to treat cardiac arrhythmia

Energy Technology Data Exchange (ETDEWEB)

DeSimone, Christopher V.; Madhavan, Malini [Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Venkatachalam, Kalpathi L. [Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Jacksonville, FL (United States); Knudson, Mark B. [Mayo Clinic, Rochester, MN (United States); EnteroMedics, EnteroMedics, St. Paul, MN (United States); Asirvatham, Samuel J., E-mail: asirvatham.samuel@mayo.edu [Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (United States)

2013-05-15

Ablation and anti-arrhythmic medications have shown promise but have been met with varying success and unwanted side effects such as myocardial injury, arrhythmias, and morbidity from invasive surgical intervention. The answer to improving efficacy of ablation may include modulation of the cardiac aspect of the autonomic nervous system. Our lab has developed a novel approach and device to navigate the oblique sinus and to use DC current and saline/alcohol irrigation to selectively stimulate and block the autonomic ganglia found on the epicardial side of the heart. This novel approach minimizes myocardial damage from thermal injury and provides a less invasive and targeted approach. For feasibility, proof-of-concept, and safety monitoring, we carried out canine studies to test this novel application. Our results suggest a safer and less invasive way of modulating arrhythmogenic substrate that may lead to improved treatment of AF in humans.

Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

Directory of Open Access Journals (Sweden)

H. Rodriguez-Angulo

2013-01-01

Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

Effects of valsartan on ventricular arrhythmia induced by programmed electrical stimulation in rats with myocardial infarction

Science.gov (United States)

Jiao, Kun-Li; Li, Yi-Gang; Zhang, Peng-Pai; Chen, Ren-Hua; Yu, Yi

2012-01-01

Abstract The impact of angiotensin II receptor blockers (ARBs) on electrical remodelling after myocardial infarction (MI) remains unclear. The purpose of the present study was to evaluate the effect of valsartan on incidence of ventricular arrhythmia induced by programmed electrical stimulation (PES) and potential link to changes of myocardial connexins (Cx) 43 expression and distribution in MI rats. Fifty-nine rats were randomly divided into three groups: Sham (n = 20), MI (n = 20) and MI + Val (20 mg/kg/day per gavage, n = 19). After eight weeks, the incidence of PES-induced ventricular tachycardia (VT) and fibrillation (VF) was compared among groups. mRNA and protein expressions of Cx43, angiotensin II type 1 receptor (AT1R) in the LV border zone (BZ) and non-infarct zone (NIZ) were determined by real-time PCR and Western blot, respectively. Connexins 43 protein and collagen distribution were examined by immunohistochemistry in BZ and NIZ sections from MI hearts. Valsartan effectively improved the cardiac function, reduced the prolonged QTc (163.7 ± 3.7 msec. versus 177.8 ± 4.5 msec., P valsartan. The mRNA and protein expressions of Cx43 in BZ were significantly reduced after MI and up-regulated by valsartan. Increased collagen deposition and reduced Cx43 expression in BZ after MI could be partly attenuated by Valsartan. Valsartan reduced the incidence of PES-induced ventricular arrhythmia, this effect was possibly through modulating the myocardial AT1R and Cx43 expression. PMID:22128836

A novel NaV1.5 voltage sensor mutation associated with severe atrial and ventricular arrhythmias.

Science.gov (United States)

Wang, Hong-Gang; Zhu, Wandi; Kanter, Ronald J; Silva, Jonathan R; Honeywell, Christina; Gow, Robert M; Pitt, Geoffrey S

2016-03-01

Inherited autosomal dominant mutations in cardiac sodium channels (NaV1.5) cause various arrhythmias, such as long QT syndrome and Brugada syndrome. Although dozens of mutations throughout the protein have been reported, there are few reported mutations within a voltage sensor S4 transmembrane segment and few that are homozygous. Here we report analysis of a novel lidocaine-sensitive recessive mutation, p.R1309H, in the NaV1.5 DIII/S4 voltage sensor in a patient with a complex arrhythmia syndrome. We expressed the wild type or mutant NaV1.5 heterologously for analysis with the patch-clamp and voltage clamp fluorometry (VCF) techniques. p.R1309H depolarized the voltage-dependence of activation, hyperpolarized the voltage-dependence of inactivation, and slowed recovery from inactivation, thereby reducing the channel availability at physiologic membrane potentials. Additionally, p.R1309H increased the "late" Na(+) current. The location of the mutation in DIIIS4 prompted testing for a gating pore current. We observed an inward current at hyperpolarizing voltages that likely exacerbates the loss-of-function defects at resting membrane potentials. Lidocaine reduced the gating pore current. The p.R1309H homozygous NaV1.5 mutation conferred both gain-of-function and loss-of-function effects on NaV1.5 channel activity. Reduction of a mutation-induced gating pore current by lidocaine suggested a therapeutic mechanism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Numerous Brugada syndrome-associated genetic variants have no effect on J-point elevation, syncope susceptibility, malignant cardiac arrhythmia, and all-cause mortality

DEFF Research Database (Denmark)

Ghouse, Jonas; Have, Christian T; Skov, Morten W

2017-01-01

PURPOSE: We investigated whether Brugada syndrome (BrS)-associated variants identified in the general population have an effect on J-point elevation as well as whether carriers of BrS variants were more prone to experience syncope and malignant ventricular arrhythmia and had increased mortality c...

Right ventricular function assessed by 2D strain analysis predicts ventricular arrhythmias and sudden cardiac death in patients after acute myocardial infarction

DEFF Research Database (Denmark)

Risum, Niels; Valeur, Nana; Søgaard, Peter

2017-01-01

Aims: Left ventricular function is a well-established predictor of malignant ventricular arrhythmias, but little is known about the importance of right ventricular (RV) function. The aim of this study was to investigate the importance of RV function for prediction of sudden cardiac death (SCD) or...

Multigenerational links between mothers' experiences of autonomy in childhood and preschoolers' respiratory sinus arrhythmia: Variations by maltreatment status.

Science.gov (United States)

Noll, Laura K; Clark, Caron A C; Skowron, Elizabeth A

2015-11-01

Despite burgeoning evidence linking early exposure to child maltreatment (CM) to deficits in self-regulation, the pathways to strong regulatory development in these children are not well understood, and significant heterogeneity is observed in their outcomes. Experiences of autonomy may play a key role in transmitting self-regulatory capacity across generations and help explain individual differences in maltreatment outcomes. In this study, we investigated multigenerational associations between Generation 1 (G1)-Generation 2 (G2) mothers' early experience of warmth and autonomy in relation to their own mothers and their Generation 3 (G3) children's autonomic physiological regulation in CM (n = 85) and non-CM (n = 128) families. We found that G2 mothers who recalled greater autonomy in their childhood relationship with their G1 mothers had preschool-age G3 children with higher respiratory sinus arrhythmia at baseline when alone while engaged in individual challenge tasks, during social exchanges with their mother in joint challenge tasks, and during the portions of the strange situation procedure when the mother was present. Although no clear mediators of this association emerged, multigenerational links among G1-G2 relations, maternal representations of her child, child behavior, and child respiratory sinus arrhythmia differed by maltreatment status, thus possibly representing important targets for future research and intervention.

Percutaneous cardiopulmonary support for catheter ablation of unstable ventricular arrhythmias in high-risk patients.

Science.gov (United States)

Carbucicchio, Corrado; Della Bella, Paolo; Fassini, Gaetano; Trevisi, Nicola; Riva, Stefania; Giraldi, Francesco; Baratto, Francesca; Marenzi, Giancarlo; Sisillo, Erminio; Bartorelli, Antonio; Alamanni, Francesco

2009-11-01

In patients with severe cardiomyopathy, recurrent episodes of nontolerated ventricular tachycardia (VT) or electrical storm (ES) frequently cause acute heart failure and cardiac death; the suppression of the arrhythmia is therefore lifesaving, but feasibility of catheter ablation (CA) is precluded by the adverse hemodynamic conditions together with the characteristics of the arrhythmia that interdicts efficacious mapping. The use of the percutaneous cardiopulmonary support (CPS) for circulatory assistance may allow patient's stabilization and enhance efficacy and safety of CA in this emergency setting. 19 patients (19 males; mean age 61 +/- 6 years; chronic ischemic cardiomyopathy, eleven patients; primary dilated cardiomyopathy, six patients; arrhythmogenic right ventricular dysplasia/ cardiomyopathy, two patients) with recurrent nontolerated VT episodes undergoing CPS-assisted CA were retrospectively evaluated. Twelve patients had acute hemodynamic failure refractory to inotropic agents and ventilatory assistance, seven patients had undergone a failing nonconventional CA procedure. 14 patients presented with ES, and in twelve the procedure was undertaken under emergency conditions within 24 h from admission. Patients were ventilated under general anesthesia and assisted by a multidisciplinary team. The CPS system consisted in a Medtronic Bio-Medicus centrifugal pump and in a Maxima Plus oxygenator, a 15-F arterial cannula, and a 17-F venous cannula. Flows between 2 and 3 l/min were activated after induction of 56/62 forms of nontolerated VT, achieving hemodynamic stabilization in all patients. CA was mainly guided by conventional activation mapping and was effective in abolishing 45/56 supported VTs; in 10/19 patients all clinical VTs were suppressed by CA. Mean procedural time was 4 h and 20 min. Complete stabilization was achieved in 13 patients (68%) without VT recurrence during a 7-day in-hospital monitoring. A significant clinical improvement was observed in

Aconitine-induced Ca{sup 2+} overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

Energy Technology Data Exchange (ETDEWEB)

Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Hu, Jin; Zhang, Qiang; Liu, Bo [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Xu, Hui-bo, E-mail: xhb_6505@163.com [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Sun, Xiao-bo, E-mail: sun_xiaobo163@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China)

2014-08-15

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na{sup +} channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca{sup 2+} in aconitine poisoning. In this study, we explored the importance of pathological Ca{sup 2+} signaling in aconitine poisoning in vitro and in vivo. We found that Ca{sup 2+} overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca{sup 2+} handling proteins demonstrated that aconitine promoted Ca{sup 2+} overload through the expression regulation of Ca{sup 2+} handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca{sup 2+} overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca

Arritmias cardiacas generadas por heterogeneidad electrofisiológica: estudio mediante simulación Cardiac arrhythmias generated by electrophysiological heterogeneity: simulation study

Directory of Open Access Journals (Sweden)

Oscar Henao

2007-08-01

Full Text Available Las arritmias ventriculares usualmente se presentan como consecuencia de isquemia miocárdica aguda, lo cual causa la mayoría de las muertes súbitas. La heterogeneidad cardiaca tanto funcional (diferente comportamiento eléctrico en los miocitos como bioquímica (diferentes concentraciones iónicas en isquemia, altera el comportamiento eléctrico del ventrículo y genera dispersión en la repolarización del potencial de acción, por lo que se convierte en sustrato funcional para la generación de arritmias fatales. En este trabajo se revisan las técnicas experimentales para el estudio y la detección de arritmias por reentrada, y se valida un modelo geométrico de isquemia, en presencia de heterogeneidad eléctrica en la región transmural de la pared ventricular. Para ello se utilizaron simulaciones bidimensionales de un modelo biofísicamente detallado y se obtuvieron reentradas lobulares en diferentes configuraciones de las células M de la pared ventricular.Ventricular arrhythmias usually appear as consequence of acute myocardial ischemia, responsible for most of sudden deaths. Functional (different electrical behavior of myocytes as well as biochemical (different ionic concentrations during ischemia cardiac heterogeneity alter the ventricle electric performance and generate dispersion in the action potential repolarization that turns into functional substrate for the generation of fatal arrhythmias. In this work the experimental techniques for the study and detection of arrhythmias by re-entry are reviewed and a geometrical model of ischemia is validated in the presence of electrical heterogeneity in the trans-mural region of the ventricular wall. For this purpose, bi-dimensional simulations of a detailed biophysical model were used and lobular re-entries in different configurations of the M cells of the ventricular wall were obtained.

Respiratory Sinus Arrhythmia: A Transdiagnostic Biomarker of Emotion Dysregulation and Psychopathology

Science.gov (United States)

Beauchaine, Theodore P.

2015-01-01

In the past two decades, respiratory sinus arrhythmia (RSA)—an index of parasympathetic nervous system (PNS)-mediated cardiac control—has emerged as a reliable peripheral biomarker of emotion regulation (ER). Reduced RSA and excessive RSA reactivity (i.e., withdrawal) to emotional challenge are observed consistently among individuals with poor ER capabilities, including those with various forms of internalizing and externalizing psychopathology, and those with specific psychopathological syndromes, including anxiety, phobias, attention problems, autism, callousness, conduct disorder, depression, non-suicidal self-injury, panic disorder, and trait hostility. Emerging evidence suggests that low RSA and excessive RSA reactivity index poor ER because they are downstream peripheral markers of prefrontal cortex (PFC) dysfunction. Poorly modulated inhibitory efferent pathways from the medial PFC to the PNS result in reduced RSA and excessive RSA reactivity. According to this perspective, RSA is a non-invasive proxy for poor executive control over behavior, which characterizes most forms of psychopathology. PMID:25866835

Effects of Hydroalcoholic Extract of Cynodon Dactylon (L. Pers. on ISchemia/Reperfusion-Induced Arrhythmias

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A Garjani

2008-09-01

Full Text Available Background and purpose of the study: Probable antiarrhythmic effects of Cynodon dactylon (L. pers. (family Poaceae against ischemia/reperfusion (I/R-induced arrhythmias were investigated in isolated rat heart. Methods: The hearts were subjected to 30min regional ischemia followed by 30min reperfusion and perfused with hydroalcoholic extract of rhizome of C. dactylon (25, 50, 100 and 200µg/ml. Results: During ischemia, the extract produced marked reduction in the number, duration and incidences of ventricular tachycardia (VT at 25 and 50µg/ml (p<0.001 and p<0.01, respectively. Total number of ischemic ventricular ectopic beats (VEBs were lowered by 25-100µg/ml (p<0.001, p<0.001 and p<0.05, respectively. At the reperfusion phase, C. dactylon (25 and 50µg/ml decreased incidence of VT from 100% (control to 13 and 33% (p<0.001 and p<0.05 respectively. Duration and number of VT and total VF incidence were also reduced at the same concentration (p<0.05 for all. Perfusion of the extract (25-100µg/ml was markedly lowered reversible VF duration from 218±99sec to 0 sec, 0 sec and 10±5sec (p<0.01, p<0.01 and p<0.05 respectively. Moreover, C. dactylon (25 and 50µg/ml decreased number of total VEBs from 349±73 to 35±17 (p<0.001 and 66±26 (p<0.01. In this study, it was also shown that perfusion of the extract produced a marked and concentration-dependent positive inotropic effect. Conclusion: The findings of this study indicate that C. dactylon produce protective effects against I/R-induced arrhythmias in isolated rat hearts probably by increase in the myocardial contractility and as a result by improvement of hemodynamic factors.

Nonclinical cardiovascular safety of pitolisant: comparing International Conference on Harmonization S7B and Comprehensive in vitro Pro-arrhythmia Assay initiative studies.

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Ligneau, Xavier; Shah, Rashmi R; Berrebi-Bertrand, Isabelle; Mirams, Gary R; Robert, Philippe; Landais, Laurent; Maison-Blanche, Pierre; Faivre, Jean-François; Lecomte, Jeanne-Marie; Schwartz, Jean-Charles

2017-12-01

We evaluated the concordance of results from two sets of nonclinical cardiovascular safety studies on pitolisant. Nonclinical studies envisaged both in the International Conference on Harmonization (ICH) S7B guideline and Comprehensive in vitro Pro-arrhythmia Assay (CiPA) initiative were undertaken. The CiPA initiative included in vitro ion channels, stem cell-derived human ventricular myocytes, and in silico modelling to simulate human ventricular electrophysiology. ICH S7B-recommended assays included in vitro hERG (K V 11.1) channels, in vivo dog studies with follow-up investigations in rabbit Purkinje fibres and the in vivo Carlsson rabbit pro-arrhythmia model. Both sets of nonclinical data consistently excluded pitolisant from having clinically relevant QT-liability or pro-arrhythmic potential. CiPA studies revealed pitolisant to have modest calcium channel blocking and late I Na reducing activities at high concentrations, which resulted in pitolisant reducing dofetilide-induced early after-depolarizations (EADs) in the ICH S7B studies. Studies in stem cell-derived human cardiomyocytes with dofetilide or E-4031 given alone and in combination with pitolisant confirmed these properties. In silico modelling confirmed that the ion channel effects measured are consistent with results from both the stem cell-derived cardiomyocytes and rabbit Purkinje fibres and categorized pitolisant as a drug with low torsadogenic potential. Results from the two sets of nonclinical studies correlated well with those from two clinical QT studies. Our findings support the CiPA initiative but suggest that sponsors should consider investigating drug effects on EADs and the use of pro-arrhythmia models when the results from CiPA studies are ambiguous. © 2017 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

A model of cardiac ryanodine receptor gating predicts experimental Ca2+-dynamics and Ca2+-triggered arrhythmia in the long QT syndrome

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Wilson, Dan; Ermentrout, Bard; Němec, Jan; Salama, Guy

2017-09-01

Abnormal Ca2+ handling is well-established as the trigger of cardiac arrhythmia in catecholaminergic polymorphic ventricular tachycardia and digoxin toxicity, but its role remains controversial in Torsade de Pointes (TdP), the arrhythmia associated with the long QT syndrome (LQTS). Recent experimental results show that early afterdepolarizations (EADs) that initiate TdP are caused by spontaneous (non-voltage-triggered) Ca2+ release from Ca2+-overloaded sarcoplasmic reticulum (SR) rather than the activation of the L-type Ca2+-channel window current. In bradycardia and long QT type 2 (LQT2), a second, non-voltage triggered cytosolic Ca2+ elevation increases gradually in amplitude, occurs before overt voltage instability, and then precedes the rise of EADs. Here, we used a modified Shannon-Puglisi-Bers model of rabbit ventricular myocytes to reproduce experimental Ca2+ dynamics in bradycardia and LQT2. Abnormal systolic Ca2+-oscillations and EADs caused by SR Ca2+-release are reproduced in a modified 0-dimensional model, where 3 gates in series control the ryanodine receptor (RyR2) conductance. Two gates control RyR2 activation and inactivation and sense cytosolic Ca2+ while a third gate senses luminal junctional SR Ca2+. The model predicts EADs in bradycardia and low extracellular [K+] and cessation of SR Ca2+-release terminate salvos of EADs. Ca2+-waves, systolic cell-synchronous Ca2+-release, and multifocal diastolic Ca2+ release seen in subcellular Ca2+-mapping experiments are observed in the 2-dimensional version of the model. These results support the role of SR Ca2+-overload, abnormal SR Ca2+-release, and the subsequent activation of the electrogenic Na+/Ca2+-exchanger as the mechanism of TdP. The model offers new insights into the genesis of cardiac arrhythmia and new therapeutic strategies.

Automated respiratory sinus arrhythmia measurement: Demonstration using executive function assessment.

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Hegarty-Craver, Meghan; Gilchrist, Kristin H; Propper, Cathi B; Lewis, Gregory F; DeFilipp, Samuel J; Coffman, Jennifer L; Willoughby, Michael T

2017-08-08

Respiratory sinus arrhythmia (RSA) is a quantitative metric that reflects autonomic nervous system regulation and provides a physiological marker of attentional engagement that supports cognitive and affective regulatory processes. RSA can be added to executive function (EF) assessments with minimal participant burden because of the commercial availability of lightweight, wearable electrocardiogram (ECG) sensors. However, the inclusion of RSA data in large data collection efforts has been hindered by the time-intensive processing of RSA. In this study we evaluated the performance of an automated RSA-scoring method in the context of an EF study in preschool-aged children. The absolute differences in RSA across both scoring methods were small (mean RSA differences = -0.02-0.10), with little to no evidence of bias for the automated relative to the hand-scoring approach. Moreover, the relative rank-ordering of RSA across both scoring methods was strong (rs = .96-.99). Reliable changes in RSA from baseline to the EF task were highly similar across both scoring methods (96%-100% absolute agreement; Kappa = .83-1.0). On the basis of these findings, the automated RSA algorithm appears to be a suitable substitute for hand-scoring in the context of EF assessment.

TITERS OF ANTIBODIES TO Β1-ADRENOCEPTOR AND M2 CHOLINERGIC RECEPTORS IN PATIENTS WITH VENTRICULAR ARRHYTHMIAS WITHOUT AN ORGANIC CARDIOVASCULAR DISEASE AND THEIR POSSIBLE CLINICAL SIGNIFICANCE

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M. M. Rogova

2012-01-01

Full Text Available Aim. To identify the most promising epitopes that simulate various sites β1-adrenergic and M2-cholinergic receptors, and to evaluate their possible contribution to the development and maintenance of cardiac arrhythmias, particularly idiopathic ventricular arrhythmia. Material and methods. Patients with ventricular arrhythmias without organic cardiovascular disease (the study group; n=70 were included in the study. The control group consisted of 20 healthy volunteers. Evaluation of levels of antibodies to antigenic determinants, modeling various sites β1-adrenergic and M2-cholinergic performed in all patients. Causal treatment with clarithromycin and valacyclovir performed in part of patients. Results. Antibodies to different peptide sequences of β1-adrenergic and M2-cholinergic receptors have been identified in 25% of main group patients. A direct correlation between the frequency of episodes of ventricular tachycardia and IgG levels to MRI-MRIV (p=0.02 revealed. Increase in titre of antibodies to β1-adrenoceptors, to a peptide sequence β8 (p=0.02, and lower titers of antibodies to the M2 acetylcholine receptor — chimera MRI-MRIV IgM (p=0.06 and ARI-MRIV IgM (p=0.07 were observed when assessing the efficacy of the therapy in the causal dynamics in the group of "untreated" patients. IgG titer reduction of ARI-MRIV (p=0.02, which is 4 times out of 10 with reduction of ventricular ectopic activity , recorded after valacyclovir therapy. Clarithromycin therapy on the level of antibodies exerted no significant effect. Conclusion. Possible involvement of antibodies to β1-adrenoceptor and M2-cholinergic receptors in the development of idiopathic ventricular arrhythmias demonstrated. The relationship between the frequency of episodes of ventricular tachycardia and levels of antibody titers to M2-cholinergic receptors found. Attempt of causal treatment, depending on the possible mechanisms of the autoimmune process is executed. Further studies to

Non cancerous diseases following a chronic intern contamination by caesium 137: cataracts and cardiac arrhythmias

International Nuclear Information System (INIS)

Landon, G.

2008-07-01

This work of thesis joins within the framework of an analysis of the sanitary consequences of the nuclear accident of Chernobylsk. Since 2005, the I.R.S.N. is interested in the not cancerous pathologies (cataracts, and cardiac arrhythmias) observed among the children living on the contaminated territories after the fallout of Chernobylsk and has in this aim implemented a research programme called E.P.I.C.E. (Evaluation of the pathologies induced by a chronicle contamination by cesium) whom objective is to show an eventual link between the chronicle ingestion of contaminated food and these pathologies emergence. An exploitation of the results of the pilot study,first phase of the E.P.I.C.E. program was realized. The analysis was completed by two bibliographical reviews relative to the knowledge available on these diseases. The results of this pilot study suggest: on one hand, an absence of link between the activity in cesium 137 at the level of the heart, of the whole body and the emergence of disorder of the heart rhythm; on the other hand, for the cases of cataract, a link between the load in cesium 137 at the neck level and the emergence of the disease in 40 % of the cases. However, these results must be considered with caution because several limits and, in particular, a way of selection affect this study. concerning the scientific literature, this one stays rather poor because only thee articles make reference to a relationship between cesium 137 and the emergence of these non cancerous pathologies. After having exposed the context, this thesis draws up the situation of knowledge relative to cataracts and to cardiac arrhythmias and their possible relationship with ionizing radiations, collect the results stemming from the analysis of the pilot study and envisages future epidemiological studies. (N.C.)

Electrocardiogram interpretation and arrhythmia management: a primary and secondary care survey.

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Begg, Gordon; Willan, Kathryn; Tyndall, Keith; Pepper, Chris; Tayebjee, Muzahir

2016-05-01

There is increasing desire among service commissioners to treat arrhythmia in primary care. Accurate interpretation of the electrocardiogram (ECG) is fundamental to this. ECG interpretation has previously been shown to vary widely but there is little recent data. To examine the interpretation of ECGs in primary and secondary care. A cross-sectional survey of participants' interpretation of six ECGs and hypothetical management of patients based on those ECGs, at primary care educational events, and a cardiology department in Leeds. A total of 262 primary care clinicians and 20 cardiology clinicians were surveyed via questionnaire. Answers were compared with expert electrophysiologist opinion. In primary care, abnormal ECGs were interpreted as normal by 23% of responders. ST elevation and prolonged QT were incorrectly interpreted as normal by 1% and 22%, respectively. In cardiology, abnormal ECGs were interpreted as normal by 3%. ECG provision and interpretation remains inconsistent in both primary and secondary care. Primary care practitioners are less experienced and less confident with ECG interpretation than cardiologists, and require support in this area. © British Journal of General Practice 2016.

A NOVEL APPROACH TO ARRHYTHMIA CLASSIFICATION USING RR INTERVAL AND TEAGER ENERGY

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CHANDRAKAR KAMATH

2012-12-01

Full Text Available It is hypothesized that a key characteristic of electrocardiogram (ECG signal is its nonlinear dynamic behaviour and that the nonlinear component changes more significantly between normal and arrhythmia conditions than the linear component. The usual statistical descriptors used in RR (R to R interval analysis do not capture the nonlinear disposition of RR interval variability. In this paper we explore a novel approach to extract the features from nonlinear component of the RR interval signal using Teager energy operator (TEO. The key feature of Teager energy is that it models the energy of the source that generated the signal rather than the energy of the signal itself. Hence any deviations in regular rhythmic activity of the heart get reflected in the Teager energy function. The classification evaluated on MIT-BIH database, with RR interval and mean of Teager energy computed over RR interval as features, exhibits an average accuracy that exceeds 99.79%.

The efficacy of radiofrequency ablation in the treatment of pediatric arrhythmia and its effects on serum IL-6 and hs-CRP.

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Li, Chunli; Jia, Libo; Wang, Zhenzhou; Niu, Ling; An, Xinjiang

2017-10-01

The aim of this study was to investigate the efficacy of radiofrequency ablation in the treatment of pediatric arrhythmia and to assess the changes in serum interleukin-6 (IL-6) and hs-CRP levels after treatment. Hundred and six children with tachyarrhythmia who were admitted to Xuzhou Children's Hospital from November, 2014 to December, 2015 were recruited for study. The efficacies of radiofrequency in the treatment of different types of arrhythmia were analyzed. Successful ablation was found in 104 cases (98.11%) and recurrence was found in 7 cases (6.73%). Among 62 cases of atrioventricular reentrant tachycardia (AVRT), successful ablation was found in 60 cases (96.77%) and recurrence was found in 3 cases (4.84%). Among 33 cases of atrioventricular nodal reentrant tachycardia (AVNRT), successful ablation was found in 33 cases (100%) and recurrence was found in 2 cases (6.06%). Among 5 cases of ventricular tachycardia (VT), successful ablation was found in 5 cases (100%) and no recurrence was found. Among 4 cases of atrial tachycardia (AT), successful ablation was found in 4 cases (100%) and recurrence was found in 1 case (25%). Among 2 cases of atrial flutter (AFL), successful ablation was found in both (100%) and recurrence was found in 1 case (50%). After operation, the levels of IL-6 and hs-CRP were increased and were continually increased within 6 h after operation. The levels of IL-6 and hs-CRP at 24 h after operation were reduced but still higher than preoperative levels. The duration of radiofrequency and ablation energy were positively correlated with the levels of IL-6 and hs-CRP, while the number of discharges was not significantly correlated with either. In conclusion, radiofrequency ablation is a safe and effective treatment for pediatric arrhythmia. Postoperative monitoring of IL-6 and hs-CRP levels is conducive to understanding postoperative myocardial injury and inflammatory response.

Hypertension and cardiac arrhythmias: a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE).

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Lip, Gregory Y H; Coca, Antonio; Kahan, Thomas; Boriani, Giuseppe; Manolis, Antonis S; Olsen, Michael Hecht; Oto, Ali; Potpara, Tatjana S; Steffel, Jan; Marín, Francisco; de Oliveira Figueiredo, Márcio Jansen; de Simone, Giovanni; Tzou, Wendy S; Chiang, Chern-En; Williams, Bryan; Dan, Gheorghe-Andrei; Gorenek, Bulent; Fauchier, Laurent; Savelieva, Irina; Hatala, Robert; van Gelder, Isabelle; Brguljan-Hitij, Jana; Erdine, Serap; Lovic, Dragan; Kim, Young-Hoon; Salinas-Arce, Jorge; Field, Michael

2017-06-01

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit to comprehensively review the available evidence to publish a joint consensus document on hypertension and cardiac arrhythmias, and to provide up-to-date consensus recommendations for use in clinical practice. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and the patient in light of all of the circumstances presented by that patient. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Adapting detection sensitivity based on evidence of irregular sinus arrhythmia to improve atrial fibrillation detection in insertable cardiac monitors.

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Pürerfellner, Helmut; Sanders, Prashanthan; Sarkar, Shantanu; Reisfeld, Erin; Reiland, Jerry; Koehler, Jodi; Pokushalov, Evgeny; Urban, Luboš; Dekker, Lukas R C

2017-10-03

Intermittent change in p-wave discernibility during periods of ectopy and sinus arrhythmia is a cause of inappropriate atrial fibrillation (AF) detection in insertable cardiac monitors (ICM). To address this, we developed and validated an enhanced AF detection algorithm. Atrial fibrillation detection in Reveal LINQ ICM uses patterns of incoherence in RR intervals and absence of P-wave evidence over a 2-min period. The enhanced algorithm includes P-wave evidence during RR irregularity as evidence of sinus arrhythmia or ectopy to adaptively optimize sensitivity for AF detection. The algorithm was developed and validated using Holter data from the XPECT and LINQ Usability studies which collected surface electrocardiogram (ECG) and continuous ICM ECG over a 24-48 h period. The algorithm detections were compared with Holter annotations, performed by multiple reviewers, to compute episode and duration detection performance. The validation dataset comprised of 3187 h of valid Holter and LINQ recordings from 138 patients, with true AF in 37 patients yielding 108 true AF episodes ≥2-min and 449 h of AF. The enhanced algorithm reduced inappropriately detected episodes by 49% and duration by 66% with adapts sensitivity for AF detection reduced inappropriately detected episodes and duration with minimal reduction in sensitivity. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Cardiology

Failed anti-tachycardia pacing can be used to differentiate atrial arrhythmias from ventricular tachycardia in implantable cardioverter-defibrillators.

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Michael, Kevin A; Enriquez, Andres; Baranchuk, Adrian; Haley, Charlotte; Caldwell, Jane; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P

2015-01-01

Atrial fibrillation/tachycardia (AF/AT) may result in inappropriate therapies in implantable cardioverter-defibrillators (ICDs). The post-pacing interval (PPI) and tachycardia cycle length difference (PPI - TCL) has been previously demonstrated to indicate the proximity of the pacing site to a tachycardia origin. We postulated that the PPI and PPI - TCL would be greater in AT/AF vs. ventricular tachycardia (VT) after episodes of failed anti-tachycardia pacing (ATP). This was a single-centre, retrospective study evaluating consecutive patients implanted with dual (DR)/biventricular (BIV) ICDs. Stored electrograms were used to determine whether the ATP captured the arrhythmia and the arrhythmia did not present with primary or secondary termination. Measurements were done using manual calipers. A total of 155 patients were included. There were 79 BIV and 76 DR devices. In total, 39 episodes were identified in 20 patients over a 23-month follow-up period. A total of 76 sequences of ATP (burst/ramp) were delivered, 28 (37%) of them inappropriate. Fifty-one events (18 AT/AF and 33 VT) were compared. The mean PPI was 693 ± 96 vs. 512 ± 88 ms (P failed ATP differs significantly between AF/AT and VT and are therefore useful indices to discriminate between supraventricular tachycardia and VT in ICDs. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Cardiac Resynchronization Therapy Defibrillator Treatment in a Child with Heart Failure and Ventricular Arrhythmia

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Hak Ju Kim

2016-08-01

Full Text Available Cardiac resynchronization therapy (CRT is a new treatment for refractory heart failure. However, most patients with heart failure treated with CRT are adults, middle-aged or older with idiopathic or ischemic dilated cardiomyopathy. We treated a 12-year-old boy, who was transferred after cardiac arrest, with dilated cardiomyopathy, left bundle-branch block, and ventricular tachycardia. We performed cardiac resynchronization therapy with a defibrillator (CRT-D. After CRT-D, left ventricular ejection fraction improved from 22% to 4 4% a ssessed by e chocardiog ram 1 year p ostoperatively. On e lectrocardiog ram, Q RS d uration was shortened from 206 to 144 ms. The patient’s clinical symptoms also improved. For pediatric patients with refractory heart failure and ventricular arrhythmia, CRT-D could be indicated as an effective therapeutic option.

Noninvasive predictors of perioperative atrial arrhythmias in patients with tetralogy of Fallot undergoing pulmonary valve replacement.

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Cortez, Daniel; Barham, Waseem; Ruckdeschel, Emily; Sharma, Nandita; McCanta, Anthony C; von Alvensleben, Johannes; Sauer, William H; Collins, Kathryn K; Kay, Joseph; Patel, Sonali; Nguyen, Duy T

2017-08-01

Patients with tetralogy of Fallot (TOF) have increased risk of atrial arrhythmias. A measure of atrial dispersion, the P-wave vector magnitude (Pvm), can identify patients at risk for perioperative atrial flutter (AFL) or intra-atrial re-entrant tachycardia (IART) in a large TOF cohort. We performed a blinded, retrospective analysis of 158 TOF patients undergoing pulmonary valve replacement between 1997 and 2015. History of AFL/IART was documented using electrocardiogram, Holter monitor, exercise stress test, implanted cardiac device, and electrophysiology study. P-R intervals, Pvm, QRS duration, and QRS vector magnitude were assessed from resting sinus-rhythm 12-lead electrocardiograms and identification of those with AFL/IART was determined. Fourteen patients (8.9%) were found to have AFL/IART. Pvm, QRS duration, and QRS vector magnitude significantly differentiated those with AFL/IART from those without on univariate analysis: 0.09 ± 0.04 vs 0.18 ± 0.07 mV, 161.3 ± 21.9 vs 137.7 ± 31.4 ms, and 1.2 (interquartile range, 1.0-1.2) vs 1.6 mV (1.0-2.3), respectively (P < 0.05 for each). The Pvm had the highest area under the ROC curve (0.88) and was the only significant predictor on multivariate analysis, with odds ratio of 0.02 (95% confidence interval: 0.01-0.53). P-R duration, MRI volumes, and right-heart hemodynamics did not significantly differentiate those with vs those without AFL/IART. In TOF patients undergoing pulmonary valve replacement, Pvm has significant value in predicting those with perioperative AFL/IART. These clinical features may help further evaluate TOF patients at risk for perioperative atrial arrhythmias. Prospective studies are warranted. © 2017 Wiley Periodicals, Inc.

Noninvasive cardiac activation imaging of ventricular arrhythmias during drug-induced QT prolongation in the rabbit heart.

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Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; Zhou, Zhaoye; He, Bin

2013-10-01

Imaging myocardial activation from noninvasive body surface potentials promises to aid in both cardiovascular research and clinical medicine. To investigate the ability of a noninvasive 3-dimensional cardiac electrical imaging technique for characterizing the activation patterns of dynamically changing ventricular arrhythmias during drug-induced QT prolongation in rabbits. Simultaneous body surface potential mapping and 3-dimensional intracardiac mapping were performed in a closed-chest condition in 8 rabbits. Data analysis was performed on premature ventricular complexes, couplets, and torsades de pointes (TdP) induced during intravenous administration of clofilium and phenylephrine with combinations of various infusion rates. The drug infusion led to a significant increase in the QT interval (from 175 ± 7 to 274 ± 31 ms) and rate-corrected QT interval (from 183 ± 5 to 262 ± 21 ms) during the first dose cycle. All the ectopic beats initiated by a focal activation pattern. The initial beat of TdPs arose at the focal site, whereas the subsequent beats were due to focal activity from different sites or 2 competing focal sites. The imaged results captured the dynamic shift of activation patterns and were in good correlation with the simultaneous measurements, with a correlation coefficient of 0.65 ± 0.02 averaged over 111 ectopic beats. Sites of initial activation were localized to be ~5 mm from the directly measured initiation sites. The 3-dimensional cardiac electrical imaging technique could localize the origin of activation and image activation sequence of TdP during QT prolongation induced by clofilium and phenylephrine in rabbits. It offers the potential to noninvasively investigate the proarrhythmic effects of drug infusion and assess the mechanisms of arrhythmias on a beat-to-beat basis. © 2013 Heart Rhythm Society. All rights reserved.

The influence of type 2 diabetes mellitus on the frequency and complexity of ventricular arrhythmias and heart rate variability in patients after myocardial infarction

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Stoičkov Viktor

2016-01-01

Full Text Available Background/Aim. After myocardial infarction arrhythmic cardiac deaths are significantly more frequent compared to non-arrhythmic ones. The aim of the study was to investigate the influence of type 2 diabetes mellitus (T2DM on the frequency and complexity of ventricular arrhythmias after myocardial infarction. Methods. The study included 293 patients, mean age 59.5 ± 9.21 years, who were at least six months after acute myocardial infarction with the sinus rhythm, without atrioventricular blocks and branch blocks. In the clinical group 95 (32.42% patients were with T2DM, while 198 (67.57% patients were without diabetes. All of the patients were subjected to the following procedures: standard ECG according to which the corrected QT dispersion (QTdc was calculated, exercise stress test, and 24-hour holter monitoring according to which, the four parameters of time domain of heart rate variability (HRV were analyzed: standard deviation of all normal RR intervals during 24 hours (SDNN, standard deviation of the averages of normal RR intervals in all five-minute segments during 24 hours (SDANN, the square root of the mean of the sum of the squares of differences between adjacent normal (RMS-SD, and percentage of consequtive RR intervals which differed for more than 50 ms during 24 hours (NN > 50 ms. Results. In patients after myocardial infarction, patients with T2DM had significantly higher percentage of frequent and complex ventricular arrhythmias compared to the patients without diabetes (p 50 ms (p < 0.001, and significantly higher values of QTdc (p < 0.001 compared to the patients without diabetes. Conclusion. The study showed that type 2 diabetes mellitus has significant influence on ventricular arrhythmias, HRV parameters and QT dispersion in patients after myocardial infarction.

QUANTIFICATION OF RESPIRATORY SINUS ARRHYTHMIA WITH HIGH-FRAMERATE ELECTRICAL IMPEDANCE TOMOGRAPHY

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Christoph Hoog Antink

2013-12-01

Full Text Available Respiratory Sinus Arrhythmia, the variation in the heart rate synchronized with the breathing cycle, forms an interconnection between cardiac-related and respiratory-related signals. It can be used by itself for diagnostic purposes, or by exploiting the redundancies it creates, for example by extracting respiratory rate from an electrocardiogram (ECG. To perform quantitative analysis and patient specific modeling, however, simultaneous information about ventilation as well as cardiac activity needs to be recorded and analyzed. The recent advent of medically approved Electrical Impedance Tomography (EIT devices capable of recording up to 50 frames per second facilitates the application of this technology. This paper presents the automated selection of a cardiac-related signal from EIT data and quantitative analysis of this signal. It is demonstrated that beat-to-beat intervals can be extracted with a median absolute error below 20 ms. A comparison between ECG and EIT data shows a variation in peak delay time that requires further analysis. Finally, the known coupling of heart rate variability and tidal volume can be shown and quantified using global impedance as a surrogate for tidal volume.

Low vagally-mediated heart rate variability and increased susceptibility to ventricular arrhythmias in rats bred for high anxiety.

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Carnevali, Luca; Trombini, Mimosa; Graiani, Gallia; Madeddu, Denise; Quaini, Federico; Landgraf, Rainer; Neumann, Inga D; Nalivaiko, Eugene; Sgoifo, Andrea

2014-04-10

In humans, there is a documented association between anxiety disorders and cardiovascular disease. Putative underlying mechanisms may include an impairment of the autonomic nervous system control of cardiac function. The primary objective of the present study was to characterize cardiac autonomic modulation and susceptibility to arrhythmias in genetic lines of rats that differ largely in their anxiety level. To reach this goal, electrocardiographic recordings were performed in high-anxiety behavior (HAB, n=10) and low-anxiety behavior (LAB, n=10) rats at rest, during stressful stimuli and under autonomic pharmacological manipulations, and analyzed by means of time- and frequency-domain indexes of heart rate variability. During resting conditions, HAB rats displayed a reduced heart rate variability, mostly in terms of lower parasympathetic (vagal) modulation compared to LAB rats. In HAB rats, this relatively low cardiac vagal control was associated with smaller heart rate responsiveness to acute stressors compared to LAB counterparts. In addition, beta-adrenergic pharmacological stimulation induced a larger incidence of ventricular tachyarrhythmias in HABs compared to LABs. At sacrifice, a moderate increase in heart-body weight ratio was observed in HAB rats. We conclude that high levels of anxiety-related behavior in rats are associated with signs of i) impaired autonomic modulation of heart rate (low vagally-mediated heart rate variability), ii) poor adaptive heart rate responsiveness to stressful stimuli, iii) increased arrhythmia susceptibility, and iv) cardiac hypertrophy. These results highlight the utility of the HAB/LAB model for investigating the mechanistic basis of the comorbidity between anxiety disorders and cardiovascular disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of Exercise on Arrhythmia (and Viceversa): Lesson from the Greek Mythology.

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Lambiase, Caterina; Macerola, Silvia; Bosco, Giovanna; Messina, Elisa; Franciosa, Pasquale

2017-01-01

Exercise represents an important lifestyle factor in all human ages when felt in harmony with other psycho-physical and environmental variables that affect individual life (e. g. quality of interest, affections, environment, diet and food). Consequently, in addition to the training level, the amount, intensity and modality of exercise (ana-/aerobic, isometric/isotonic), need to be personalized, considering the underlying diseases, which may benefit from it or worsening.Greek mythology gives us good examples of the exercise concept's evolution.From Discus-thrower to Spear-carrier the idea of physical activity is more effectively expressed. The Myron Discobolus displays the enduring pattern of athletic energy translated into the dynamic force given by the exercise. In Doryphoros instead, the physical activity is oriented to the achievement of the required psyco-physical harmony, who's the concept is aimed of being expressed by the sculpture.As outlined below, even in the field of arrhythmia, scientific evidence as well as clinical experience, supports the same concept: physical activity may be important while safely managed and personalized.

Malignant arrhythmia as the first manifestation of Wolff-Parkinson-White syndrome: a case with minimal preexcitation on electrocardiography.

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Gungor, B; Alper, A T

2013-09-01

Wolff-Parkinson-White (WPW) syndrome is defined as the presence of an accessory atrioventricular pathway which is manifested as delta waves and short PR interval on electrocardiography (ECG). However, some WPW cases do not have typical findings on ECG and may remain undiagnosed unless palpitations occur. Sudden cardiac death may be the first manifestation of WPW and develops mostly secondary to degeneration of atrial fibrillation into ventricular fibrillation. In this report, we present a case of undiagnosed WPW with minimal preexcitation on ECG and who suffered an episode of malignant arrhythmia as the first manifestation of the disease.

Hypertension and cardiac arrhythmias: executive summary of a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE).

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Lip, Gregory Y H; Coca, Antonio; Kahan, Thomas; Boriani, Giuseppe; Manolis, Antonis S; Olsen, Michael Hecht; Oto, Ali; Potpara, Tatjana S; Steffel, Jan; Marín, Francisco; de Oliveira Figueiredo, Márcio Jansen; de Simone, Giovanni; Tzou, Wendy S; En Chiang, Chern; Williams, Bryan

2017-10-01

Hypertension (HTN) is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease (CAD), stroke, peripheral artery disease and chronic renal failure. Hypertensive heart disease can manifest as many types of cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in HTN patients, especially in those with left ventricular hypertrophy (LVH), CAD, or HF. In addition, high doses of thiazide diuretics commonly used to treat HTN, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesaemia), contributing further to arrhythmias, while effective blood pressure control may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between HTN and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit of comprehensively reviewing the available evidence and publishing a joint consensus document on HTN and cardiac arrhythmias, and providing up-to-date consensus recommendations for use in clinical practice. The ultimate judgment on the care of a specific patient must be made by the healthcare provider and the patient in light of all individual factors presented. This is an executive summary of the full document co-published by EHRA in EP-Europace. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

European Heart Rhythm Association (EHRA) position paper on arrhythmia management and device therapies in endocrine disorders, endorsed by Asia Pacific Heart Rhythm Society (APHRS) and Latin American Heart Rhythm Society (LAHRS)

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Gorenek, Bulent; Boriani, Giuseppe; Dan, Gheorge-Andrei

2018-01-01

Endocrine disorders are associated with various tachyarrhythmias, including atrial fibrillation (AF), ventricular tachycardia (VT), ventricular fibrillation (VF), and bradyarrhythmias. Along with underlying arrhythmia substrate, electrolyte disturbances, glucose, and hormone levels, accompanying ...

Arrhythmias and conduction abnormalities in children after repair of tetralogy of Fallot

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Kuzevska-Maneva Konstandina

2005-01-01

Full Text Available Aim. To find out types and frequency of cardiac arrhythmias and conduction abnormalities in the group of children who underwent surgery for tetralogy of Fallot (TOF. Methods. Fortysix pedicatric patients who underwent a complete repair of TOF at the age of 1 to 13 (mean 2.89 ± 2.36 were studied. Thirty-eight (82.60% had total correction and 8 (17.40% had palliative operation first, and total correction afterwards. Twenty-four-hour Holter ECG monitoring was performed in all 46 pediatric patients aged from 1 to 16 yrs (mean 6.48 ± 4.04 after surgery as follows: in 1 patient (2.17% after a year, in 20 patients (43.47% after 2 to 5 years and in 25 patients (54.34% after 5 years. Mean age of patients on Holter monitoring was 9.25 ± 4.39 (range 4−19. Twenty of them (43.47% were girls and 28 (56.53% were boys. All the patients were evaluated by standard methods (clinical signs, clinical findings, ECG before surgery, ECG before Holter monitoring and 2D Doppler echocardiography. Results. Types of heart rhythm found out by Holter monitoring were: sinus nodus dysfunction in 1 child (2.17%, significant premature atrial contraction (PAC in 8 (17.39%, supraventricular paroxysmal tachycardia in 3 (6.53%, transient nodal rhythm in 2 (4.34%, premature ventricular contraction (PVC Lown grade I-III in 9 (19.56% and Lown grade IV in 2 (4.34, atrioventricular (AV block grade I in 2, right bundle branch block (RBBB in all 46 (100% and RBBB + left anterior hemiblock (LAH in 4 (8.96%. There was no presence of atrial flutter, ventricular tachycardia or complete AV block. None of them experienced sudden death. Using cross procedure statistical methods, it was found that all the patients with PVC had right ventricular dilatation. There was no relation of other types of arrhythmia found on Holter monitoring to the other parameters from echocardiography, neither to the other standard methods. Children did not need the pace-maker, but 36.95% of the them required

Results of Cryoenergy and Radiofrequency-Based Catheter Ablation for Treating Ventricular Arrhythmias Arising From the Papillary Muscles of the Left Ventricle, Guided by Intracardiac Echocardiography and Image Integration.

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Rivera, Santiago; Ricapito, Maria de la Paz; Tomas, Leandro; Parodi, Josefina; Bardera Molina, Guillermo; Banega, Rodrigo; Bueti, Pablo; Orosco, Agustin; Reinoso, Marcelo; Caro, Milagros; Belardi, Diego; Albina, Gaston; Giniger, Alberto; Scazzuso, Fernando

2016-04-01

Catheter radiofrequency ablation of ventricular arrhythmias (VAs) arising from the left ventricle's papillary muscles has been associated with inconsistent results. The use of cryoenergy versus radiofrequency has not been compared yet. This study compares outcomes and complications of catheter ablation of VA from the papillary muscles of the left ventricle with either cryoenergy or radiofrequency. Twenty-one patients (40±12 years old; 47% males; median ejection fraction 59±7.3%) with drug refractory premature ventricular contractions or ventricular tachycardia underwent catheter cryoablation or radiofrequency ablation. VAs were localized using 3-dimensional mapping, multidetector computed tomography, and intracardiac echocardiography, with arrhythmia foci being mapped at either the anterolateral papillary muscle or posteromedial papillary muscles of the left ventricle. Focal ablation was performed using an 8-mm cryoablation catheter or a 4-mm open-irrigated radiofrequency catheter, via transmitral approach. Acute success rate was 100% for cryoenergy (n=12) and 78% for radiofrequency (n=9; P=0.08). Catheter stability was achieved in all patients (100%) treated with cryoenergy, and only in 2 (25%) patients treated with radiofrequency (P=0.001). Incidence of multiple VA morphologies was observed in 7 patients treated with radiofrequency (77.7%), whereas none was observed in those treated with cryoenergy (P=0.001). VA recurrence at 6 months follow-up was 0% for cryoablation and 44% for radiofrequency (P=0.03). Cryoablation was associated with higher success rates and lower recurrence rates than radiofrequency catheter ablation, better catheter stability, and lesser incidence of polymorphic arrhythmias. © 2016 American Heart Association, Inc.

Long-term pretreatment with desethylamiodarone (DEA) or amiodarone (AMIO) protects against coronary artery occlusion induced ventricular arrhythmias in conscious rats.

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Morvay, Nikolett; Baczkó, István; Sztojkov-Ivanov, Anita; Falkay, György; Papp, Julius Gy; Varró, András; Leprán, István

2015-09-01

The aim of this investigation was to compare the effectiveness of long-term pretreatment with amiodarone (AMIO) and its active metabolite desethylamiodarone (DEA) on arrhythmias induced by acute myocardial infarction in rats. Acute myocardial infarction was induced in conscious, male, Sprague-Dawley rats by pulling a previously inserted loose silk loop around the left main coronary artery. Long-term oral pretreatment with AMIO (30 or 100 mg·(kg body mass)(-1)·day(-1), loading dose 100 or 300 mg·kg(-1) for 3 days) or DEA (15 or 50 mg·kg(-1)·day(-1), loading dose 100 or 300 mg·kg(-1) for 3 days), was applied for 1 month before the coronary artery occlusion. Chronic oral treatment with DEA (50 mg·kg(-1)·day(-1)) resulted in a similar myocardial DEA concentration as chronic AMIO treatment (100 mg·kg(-1)·day(-1)) in rats (7.4 ± 0.7 μg·g(-1) and 8.9 ± 2.2 μg·g(-1)). Both pretreatments in the larger doses significantly improved the survival rate during the acute phase of experimental myocardial infarction (82% and 64% by AMIO and DEA, respectively, vs. 31% in controls). Our results demonstrate that chronic oral treatment with DEA resulted in similar cardiac tissue levels to that of chronic AMIO treatment, and offered an equivalent degree of antiarrhythmic effect against acute coronary artery ligation induced ventricular arrhythmias in conscious rats.

ECG-based 4D-dose reconstruction of cardiac arrhythmia ablation with carbon ion beams: application in a porcine model

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Richter, Daniel; Immo Lehmann, H.; Eichhorn, Anna; Constantinescu, Anna M.; Kaderka, Robert; Prall, Matthias; Lugenbiel, Patrick; Takami, Mitsuru; Thomas, Dierk; Bert, Christoph; Durante, Marco; Packer, Douglas L.; Graeff, Christian

2017-09-01

Noninvasive ablation of cardiac arrhythmia by scanned particle radiotherapy is highly promising, but especially challenging due to cardiac and respiratory motion. Irradiations for catheter-free ablation in intact pigs were carried out at the GSI Helmholtz Center in Darmstadt using scanned carbon ions. Here, we present real-time electrocardiogram (ECG) data to estimate time-resolved (4D) delivered dose. For 11 animals, surface ECGs and temporal structure of beam delivery were acquired during irradiation. R waves were automatically detected from surface ECGs. Pre-treatment ECG-triggered 4D-CT phases were synchronized to the R-R interval. 4D-dose calculation was performed using GSI’s in-house 4D treatment planning system. Resulting dose distributions were assessed with respect to coverage (D95 and V95), heterogeneity (HI  =  D5-D95) and normal tissue exposure. Final results shown here were performed offline, but first calculations were started shortly after irradiation The D95 for TV and PTV was above 95% for 10 and 8 out of 11 animals, respectively. HI was reduced for PTV versus TV volumes, especially for some of the animals targeted at the atrioventricular junction, indicating residual interplay effects due to cardiac motion. Risk structure exposure was comparable to static and 4D treatment planning simulations. ECG-based 4D-dose reconstruction is technically feasible in a patient treatment-like setting. Further development of the presented approach, such as real-time dose calculation, may contribute to safe, successful treatments using scanned ion beams for cardiac arrhythmia ablation.

Detection of Rapid Atrial Arrhythmias in SQUID Magnetocardiography

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Kim, Ki Woong; Kwon, Hyuk Chan; Kim, Ki Dam; Lee, Yong Ho; Kim, Jin Mok; Kim, In Seon; Lim, Hyun Kyoon; Park, Yong Ki [Biomagnetism Research, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kim, Doo Sang [Seoul Veterans Hospital, Seoul (Korea, Republic of); Lim, Seung Pyung [Chungnam National University Hospital, Daejeon (Korea, Republic of)

2005-10-15

We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was 10 fT/Hz(a) 1 Hz and 5 fT/Hz(a) 100 Hz. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

Chagas disease as a cause of heart failure and ventricular arrhythmias in patients long removed from endemic areas: an emerging problem in Europe.

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Vannucchi, Vieri; Tomberli, Benedetta; Zammarchi, Lorenzo; Fornaro, Alessandra; Castelli, Gabriele; Pieralli, Filippo; Berni, Andrea; Yacoub, Sophie; Bartoloni, Alessandro; Olivotto, Iacopo

2015-12-01

Chagas disease is a parasitic disease caused by the protozoan Trypanosoma cruzi. In endemic areas (South and Central America), Chagas disease represents a relevant public health issue, and is the most frequent cause of cardiomyopathy. In nonendemic areas, such as Europe, Chagas disease represents an emerging problem following the establishment of sizeable communities from Brazil and Bolivia. Chagas cardiomyopathy represents the most frequent and serious complication of chronic Chagas disease, affecting about 20-30% of patients, potentially leading to heart failure, arrhythmias, thromboembolism, stroke and sudden death. Because late complications of Chagas disease may develop several years or even decades after the acute infection, it may be extremely challenging to reach the correct diagnosis in patients long removed from the countries of origin. We report two examples of Chagas cardiomyopathy in South American women permanently residing in Italy for more than 20 years, presenting with cardiac manifestations ranging from left ventricular dysfunction and heart failure to isolated ventricular arrhythmias. The present review emphasizes that Chagas disease should be considered as a potential diagnosis in patients from endemic areas presenting with 'idiopathic' cardiac manifestations, even when long removed from their country of origin, with potential implications for treatment and control of Chagas disease transmission.

Respiratory sinus arrhythmia responses to cognitive tasks: effects of task factors and RSA indices.

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Overbeek, Thérèse J M; van Boxtel, Anton; Westerink, Joyce H D M

2014-05-01

Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable results. In 83 healthy subjects, we studied RSA responses to a working memory task requiring varying levels of cognitive control and a perceptual attention task not requiring strong cognitive control. RSA responses were quantified in the time and frequency domain and were additionally corrected for differences in mean interbeat interval and respiration rate, resulting in eight different RSA indices. The two tasks were clearly differentiated by heart rate and facial EMG reference measures. Cognitive control induced inhibition of RSA whereas perceptual attention generally did not. However, the results show several differences between different RSA indices, emphasizing the importance of methodological variables. Age and sex did not influence the results. Copyright © 2014 Elsevier B.V. All rights reserved.

The relation of respiratory sinus arrhythmia to later shyness: Moderation by neighborhood quality.

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Zhang, Hui; Spinrad, Tracy L; Eisenberg, Nancy; Zhang, Linlin

2018-05-21

The purpose of the study was to predict young children's shyness from both internal/biological (i.e., resting respiratory sinus arrhythmia; RSA) and external (i.e., neighborhood quality) factors. Participants were 180 children at 42 (Time 1; T1), 72 (T2), and 84 (T3) months of age. RSA data were obtained at T1 during a neutral film in the laboratory. Mothers reported perceived neighborhood quality at T2 and children's dispositional shyness at T1 and T3. Path analyses indicated that resting RSA interacted with neighborhood quality to predict T3 shyness, even after controlling for earlier family income and T1 shyness. Specifically, high levels of resting RSA predicted low levels of shyness in the context of high neighborhood quality. When neighborhood quality was low, resting RSA was positively related to later shyness. These findings indicate that children's shyness is predicted by more than biological processes and that consideration of the broader context is critical to understanding children's social behavior. © 2018 Wiley Periodicals, Inc.

Hydrogen Sulfide Targets the Cys320/Cys529 Motif in Kv4.2 to Inhibit the Ito Potassium Channels in Cardiomyocytes and Regularizes Fatal Arrhythmia in Myocardial Infarction

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Ma, Shan-Feng; Luo, Yan; Ding, Ying-Jiong; Chen, Ying; Pu, Shi-Xin; Wu, Hang-Jing; Wang, Zhong-Feng; Tao, Bei-Bei; Wang, Wen-Wei

2015-01-01

Abstract Aims: The mechanisms underlying numerous biological roles of hydrogen sulfide (H2S) remain largely unknown. We have previously reported an inhibitory role of H2S in the L-type calcium channels in cardiomyocytes. This prompts us to examine the mechanisms underlying the potential regulation of H2S on the ion channels. Results: H2S showed a novel inhibitory effect on Ito potassium channels, and this effect was blocked by mutation at the Cys320 and/or Cys529 residues of the Kv4.2 subunit. H2S broke the disulfide bridge between a pair of oxidized cysteine residues; however, it did not modify single cysteine residues. H2S extended action potential duration in epicardial myocytes and regularized fatal arrhythmia in a rat model of myocardial infarction. H2S treatment significantly increased survival by ∼1.4-fold in the critical 2-h time window after myocardial infarction with a protection against ventricular premature beats and fatal arrhythmia. However, H2S did not change the function of other ion channels, including IK1 and INa. Innovation and Conclusion: H2S targets the Cys320/Cys529 motif in Kv4.2 to regulate the Ito potassium channels. H2S also shows a potent regularizing effect against fatal arrhythmia in a rat model of myocardial infarction. The study provides the first piece of evidence for the role of H2S in regulating Ito potassium channels and also the specific motif in an ion channel labile for H2S regulation. Antioxid. Redox Signal. 23, 129–147. PMID:25756524

Role of Pre-incision, Intravenous Prophylactic Amiodarone to Control Arrhythmias in Patients with Rheumatic Valvular Heart Disease undergoing Mitral Valve Replacement

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Ahmad, K.; Naqvi, S.

2013-01-01

Objective: To evaluate the effect of intra-operative single intra venous dose of amiodarone on post operative cardiac arrhythmias in patients undergoing valvular heart surgery. Study Design: Randomized controlled trials. Place and Duration of surgery: This study was performed at Armed forces Institute of Cardiology Rawalpindi from Jan 01, 2011 to Dec 31, 2011. Patients and Methods: In this study 80 patients with rheumatic valvular heart disease and undergoing elective mitral valve replacement were randomly divided into two groups. Group I, n = 40 (Amiodarone group) was given single intravenous dose of amiodarone (5 mg/kg in 100 ml of saline over 30 min) before sternotomy incision. Group II, n = 40(control / placebo group) was given 100 ml of saline over 30 min. Result: In the amiodarone group, after removal of aortic cross clamp 75% patients had sinus rhythm compared to 47.5% in control group. p=0.045. Similarly 15% had AF, 5% JR and 5% VT/VF in amiodarone group in contrast to 32.5% with AF, 12.5% JR and 7.5% Vt/VF in control group. (p=0.045). Response to cardioversion was positive in 75% of the patients requiring shocks in amiodarone group as against 43.75% in the control group. (p=0.044). Conclusion: A single intravenous bolus dose of amiodarone is effective in decreasing the incidence of cardiac arrhythmias after mitral valve replacement in patients with rheumatic MVD. (author)

Ventricular arrhythmia and sudden cardiac death in Fabry disease: a systematic review of risk factors in clinical practice.

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Baig, Shanat; Edward, Nicky C; Kotecha, Dipak; Liu, Boyang; Nordin, Sabrina; Kozor, Rebecca; Moon, James C; Geberhiwot, Tarekegn; Steeds, Richard P

2017-10-17

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by deficiency of α-galactosidase A enzyme. Cardiovascular (CV) disease is a common cause of mortality in FD, in particular as a result of heart failure and arrhythmia, with a significant proportion of events categorized as sudden. There are no clear models for risk prediction in FD. This systematic review aims to identify the risk factors for ventricular arrhythmia (VA) and sudden cardiac deaths (SCD) in FD. A systematic search was performed following PRISMA guidelines of EMBASE, Medline, PubMed, Web of Science, and Cochrane from inception to August 2016, focusing on identification of risk factors for the development of VA or SCD. Thirteen studies were included in the review (n = 4185 patients) from 1189 articles, with follow-up of 1.2-10 years. Weighted average age was 37.6 years, and 50% were male. Death from any cause was reported in 8.3%. Of these, 75% was due to CV problems, with the majority being SCD events (62% of reported deaths). Ventricular tachycardia was reported in 7 studies, with an average prevalence of 15.3%. Risk factors associated with SCD events were age, male gender, left ventricular hypertrophy, late gadolinium enhancement on CV magnetic resonance imaging, and non-sustained ventricular tachycardia. Although a multi-system disease, FD is a predominantly cardiac disease from a mortality perspective, with death mainly from SCD events. Limited evidence highlights the importance of clinical and imaging risk factors that could contribute to improved decision-making in the management of FD. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

Left ventricular dysfunction in repaired tetralogy of Fallot: incidence and impact on atrial arrhythmias at long term-follow up.

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Ait Ali, Lamia; Trocchio, GianLuca; Crepaz, Roberto; Stuefer, Josef; Stagnaro, Nicola; Siciliano, Valeria; Molinaro, Sabrina; Sicari, Rosa; Festa, Pierluigi

2016-09-01

Left ventricle (LV) systolic dysfunction in repaired tetralogy of Fallot (TOF) has been identified as a risk factor for functional status and adverse outcome. The aims of this cross-sectional followed by a prospective study were: (1) to evaluate the prevalence of LV systolic dysfunction in a large cohort of adults with repaired tetralogy of Fallot, (2) to test the relationship between LV systolic dysfunction and other known risk factors and (3) to evaluate the impact of LV systolic dysfunction on adverse cardiac events. In a multicenter study, 237 adults repaired TOF (58 % males, age 30 ± 10 years) were evaluated by cardiac magnetic resonance (CMR). Demographics, surgical history, ECG, Echo-Color Doppler and follow-up data were recorded. LV was dilated (Z value >2) in 16 patients (6 %), however 56 patients (23.6 %) had a reduced LV systolic function left ventricle ejection fraction (LVEF) (Z value <-2). Patients with LV systolic dysfunction were mainly males (82 %), had reduced right ventricle ejection fraction (RVEF), and higher right and left Late Gadolinium Enhanced scores. In a multivariate regression analysis male gender and RVEF resulted to be independent factors associated to LV systolic dysfunction. Atrial arrhythmias were the main adverse cardiac event at the follow-up and were associated to higher biventricular volumes and lower biventricular ejection fraction (EF); however multivariable analysis identified age, right ventricle end-diastolic volume (RVEDVi) and tricuspid regurgitation as independents factors associated to atrial arrhythmias. At long term follow-up at least ¼ of repaired TOF has LV dysfunction. Lower LVEF is associated to male gender and lower RVEF.

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias.

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Barry D Kussman

Full Text Available The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males. Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05 with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia.

Rastreamento e diagnóstico ecocardiográfico das arritmias e cardiopatias congênitas fetais Screening and echocardiographic diagnosis of arrhythmias and congenital heart diseases in the fetus

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Sandra Regina Marques Carvalho

2006-05-01

program of arrhythmias and congenital heart disease in a reference hospital and the relevance of early diagnosis in the fetal and neonate evolution. METHODS: cardiac evaluation of 1159 fetuses was done in two different levels. Level I: by morphological ultrasound examination with the objective to detect the existence of either arrhythmias or structural cardiac malformations. Level II: by fetal echocardiography to establish the differential diagnosis. The results of level I in the arrhythmia group were compared with those of level II, and in the group with malformations the results of both levels were confronted with the neonate echocardiogram or necropsy. The kappa index was calculated to evaluate the concordance between the two levels. RESULTS: all detected arrhythmias in level I were confirmed in level II, there were no false negative cases and five patients with severe arrhythmia required pharmacological therapy. The diagnosis of structural malformation by level I had sensitivity of 72% and specificity of 98% and there were 28% of false-positive cases. In level II, the sensitivity and specificity of the diagnosis of congenital heart disease were 100 and 99%, respectively. The kappa index was 57% and indicated a moderate degree of concordance between the two levels. Fifty-one percent of the fetuses with diagnosis of cardiac malformations required pharmacological or invasive intervention immediately after birth. CONCLUSION: morphological ultrasound examination is a important tool in the screening of arrhythmias and congenital heart defects during fetal life. The sensitivity and specificity of the fetal echocardiogram were very high and the early diagnosis made it possible to treat the fetus with severe cardiac disease either during pregnancy or immediately after birth.

Computational model based approach to analysis ventricular arrhythmias: Effects of dysfunction calcium channels

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Gulothungan, G.; Malathi, R.

2018-04-01

Disturbed sodium (Na+) and calcium (Ca2+) handling is known to be a major predisposing factor for life-threatening cardiac arrhythmias. Cardiac contractility in ventricular tissue is prominent by Ca2+ channels like voltage dependent Ca2+ channels, sodium-calcium exchanger (Na+-Ca2+x) and sacroplasmicrecticulum (SR) Ca2+ pump and leakage channels. Experimental and clinical possibilities for studying cardiac arrhythmias in human ventricular myocardium are very limited. Therefore, the use of alternative methods such as computer simulations is of great importance. Our aim of this article is to study the impact on action potential (AP) generation and propagation in single ventricular myocyte and ventricular tissue under different dysfunction Ca2+ channels condition. In enhanced activity of Na+-Ca2+x, single myocyte produces AP duration (APD90) and APD50 is significantly smaller (266 ms and 235 ms). Its Na+-Ca2+x current at depolarization is increases 60% from its normal level and repolarization current goes more negative (nonfailing= -0.28 pA/pF and failing= -0.47 pA/pF). Similarly, same enhanced activity of Na+-Ca2+x in 10 mm region of ventricular sheet, raises the plateau potential abruptly, which ultimately affects the diastolic repolarization. Compare with normal ventricular sheet region of 10 mm, 10% of ventricular sheet resting state is reduces and ventricular sheet at time 250 ms is goes to resting state very early. In hypertrophy condition, single myocyte produces APD90 and APD50 is worthy of attention smaller (232 mS and 198 ms). Its sodium-potassium (Na+-K+) pump current is 75% reduces from its control conditions (0.13 pA/pF). Hypertrophy condition, 50% of ventricular sheet is reduces to minimum plateau potential state, that starts the repolarization process very early and reduces the APD. In a single failing SR Ca2+ channels myocyte, recovery of Ca2+ concentration level in SR reduces upto 15% from its control myocytes. At time 290 ms, 70% of ventricular sheet

Design and implementation of an electrocardiographical signal acquisition and digital processing system orientated to the detection of paroxysmal arrhythmias

International Nuclear Information System (INIS)

Braceli, Agustín Iriart; Morani, Jorge Exequiel

2011-01-01

This article describes the design, technical aspects and implementation of a device capable of acquiring electrocardiograph signals; visualize them in real time over a graphic liquid crystal display (GLCD), and the storage of these ECG registers on a SD memory card. It also details a noise suppression algorithm using the Wavelet Transform. This system was specially developed to cover some bankruptcy that presents actual Holters or ECG regarding the detection of paroxysmal arrhythmias. The contribution of this work is settled on its portability and low production cost. The filtering method used provides an ECG signal without any significant noise and appropriate to the diagnosis of cardiac pathologies.

Design and implementation of an electrocardiographical signal acquisition and digital processing system orientated to the detection of paroxysmal arrhythmias

Science.gov (United States)

Iriart Braceli, Agustín; Exequiel Morani, Jorge

2011-12-01

This article describes the design, technical aspects and implementation of a device capable of acquiring electrocardiograph signals; visualize them in real time over a graphic liquid crystal display (GLCD), and the storage of these ECG registers on a SD memory card. It also details a noise suppression algorithm using the Wavelet Transform. This system was specially developed to cover some bankruptcy that presents actual Holters or ECG regarding the detection of paroxysmal arrhythmias. The contribution of this work is settled on its portability and low production cost. The filtering method used provides an ECG signal without any significant noise and appropriate to the diagnosis of cardiac pathologies.

Beat-to-beat evaluation of left ventricular ejection in cardiac arrhythmias

International Nuclear Information System (INIS)

Itti, R.; Philippe, L.; Lorgeron, J.M.

1982-01-01

Conventional multi-gated cardiac blood pool studies suffer from two kinds of superimpositions: the spatial overlapping of various heart chambers and the temporal superimposition of a large number of cardiac cycles. The first problem can be partially solved by first pass techniques or by emission tomography. For the second one, which is specially critical arrhythmias, the single probe device (''nuclear stethoscope'') represents an original solution. Patients with normal cardiac rythm and patients presenting various kinds of cardiac rythm alterations were examined using a commercial ''nuclear stethoscope''. Some characteristic results achieved in these cases, were presented. For blood pool labeling, 20 mCi of 99mTc albumin was injected. The single probe detector was then positioned over the left ventricular area. The beat-to-beat left ventricular activity curve was then recorded for several minutes on paper in the same time as the E.C.G. signal. In cases with irregular cardiac rythm, the multigated techniques yield an average value of left ventricular ejection. Due to the relatively constant duration of systole, the superimposition of cycles may be valid during contration: differences mainly appear during diastole. But, as it could be demonstrated using the ''nuclear stethoscope'', individual cycles can show a large variability of ejection and average ejection fraction is only a very partial aspect of the real cardiac function

Morning surge of ventricular arrhythmias in a new arrhythmogenic canine model of chronic heart failure is associated with attenuation of time-of-day dependence of heart rate and autonomic adaptation, and reduced cardiac chaos.

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Zhu, Yujie; Hanafy, Mohamed A; Killingsworth, Cheryl R; Walcott, Gregory P; Young, Martin E; Pogwizd, Steven M

2014-01-01

Patients with chronic heart failure (CHF) exhibit a morning surge in ventricular arrhythmias, but the underlying cause remains unknown. The aim of this study was to determine if heart rate dynamics, autonomic input (assessed by heart rate variability (HRV)) and nonlinear dynamics as well as their abnormal time-of-day-dependent oscillations in a newly developed arrhythmogenic canine heart failure model are associated with a morning surge in ventricular arrhythmias. CHF was induced in dogs by aortic insufficiency & aortic constriction, and assessed by echocardiography. Holter monitoring was performed to study time-of-day-dependent variation in ventricular arrhythmias (PVCs, VT), traditional HRV measures, and nonlinear dynamics (including detrended fluctuations analysis α1 and α2 (DFAα1 & DFAα2), correlation dimension (CD), and Shannon entropy (SE)) at baseline, as well as 240 days (240 d) and 720 days (720 d) following CHF induction. LV fractional shortening was decreased at both 240 d and 720 d. Both PVCs and VT increased with CHF duration and showed a morning rise (2.5-fold & 1.8-fold increase at 6 AM-noon vs midnight-6 AM) during CHF. The morning rise in HR at baseline was significantly attenuated by 52% with development of CHF (at both 240 d & 720 d). Morning rise in the ratio of low frequency to high frequency (LF/HF) HRV at baseline was markedly attenuated with CHF. DFAα1, DFAα2, CD and SE all decreased with CHF by 31, 17, 34 and 7%, respectively. Time-of-day-dependent variations in LF/HF, CD, DFA α1 and SE, observed at baseline, were lost during CHF. Thus in this new arrhythmogenic canine CHF model, attenuated morning HR rise, blunted autonomic oscillation, decreased cardiac chaos and complexity of heart rate, as well as aberrant time-of-day-dependent variations in many of these parameters were associated with a morning surge of ventricular arrhythmias.

Morning surge of ventricular arrhythmias in a new arrhythmogenic canine model of chronic heart failure is associated with attenuation of time-of-day dependence of heart rate and autonomic adaptation, and reduced cardiac chaos.

Directory of Open Access Journals (Sweden)

Yujie Zhu

Full Text Available Patients with chronic heart failure (CHF exhibit a morning surge in ventricular arrhythmias, but the underlying cause remains unknown. The aim of this study was to determine if heart rate dynamics, autonomic input (assessed by heart rate variability (HRV and nonlinear dynamics as well as their abnormal time-of-day-dependent oscillations in a newly developed arrhythmogenic canine heart failure model are associated with a morning surge in ventricular arrhythmias. CHF was induced in dogs by aortic insufficiency & aortic constriction, and assessed by echocardiography. Holter monitoring was performed to study time-of-day-dependent variation in ventricular arrhythmias (PVCs, VT, traditional HRV measures, and nonlinear dynamics (including detrended fluctuations analysis α1 and α2 (DFAα1 & DFAα2, correlation dimension (CD, and Shannon entropy (SE at baseline, as well as 240 days (240 d and 720 days (720 d following CHF induction. LV fractional shortening was decreased at both 240 d and 720 d. Both PVCs and VT increased with CHF duration and showed a morning rise (2.5-fold & 1.8-fold increase at 6 AM-noon vs midnight-6 AM during CHF. The morning rise in HR at baseline was significantly attenuated by 52% with development of CHF (at both 240 d & 720 d. Morning rise in the ratio of low frequency to high frequency (LF/HF HRV at baseline was markedly attenuated with CHF. DFAα1, DFAα2, CD and SE all decreased with CHF by 31, 17, 34 and 7%, respectively. Time-of-day-dependent variations in LF/HF, CD, DFA α1 and SE, observed at baseline, were lost during CHF. Thus in this new arrhythmogenic canine CHF model, attenuated morning HR rise, blunted autonomic oscillation, decreased cardiac chaos and complexity of heart rate, as well as aberrant time-of-day-dependent variations in many of these parameters were associated with a morning surge of ventricular arrhythmias.

Associations between respiratory sinus arrhythmia (RSA) reactivity and effortful control in preschool-age children.

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Sulik, Michael J; Eisenberg, Nancy; Spinrad, Tracy L; Silva, Kassondra M

2015-07-01

We tested whether respiratory sinus arrhythmia (RSA) reactivity in response to each of three self-regulation tasks (bird and dragon; knock-tap; and gift wrap) would predict self-regulation performance in a sample of 101 preschool-age children (M age = 4.49, SD = .64). While controlling for baseline RSA, decreases in RSA from bird and dragon to knock-tap (but not from baseline to bird and dragon) predicted a latent variable measuring self-regulation. Furthermore, increases in RSA from the knock-tap to gift wrap-the only task involving delay of gratification-were related to concurrent task performance while controlling for the relation between RSA reactivity and the latent self-regulation variable. Results suggest that the relations between RSA reactivity and self-regulatory ability are influenced by task-specific demands and possibly by task order. Furthermore, RSA reactivity appears to relate differently to performance on motivationally salient self-regulation tasks such as delay of gratification relative to cool executive function tasks. © 2015 Wiley Periodicals, Inc.

The occurrence of new arrhythmias after catheter-ablation of accessory pathway: Delayed arrhythmic side-effect of curative radiofrequency lesion?

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Mujović Nebojša

2011-01-01

Full Text Available Introduction. New arrhythmias (NA may appear late after accessory pathway (AP ablation, but their relation to curative radiofrequency (RF lesion is unknown. Objective. The aim of this study was to determine the prevalence and predictors for NA occurrence after AP ablation and to investigate pro-arrhythmic effect of RF. Methods. Total of 124 patients (88 males, mean age 43±14 years with Wolff-Parkinson-White syndrome and single AP have been followed after successful RF ablation. Post-ablation finding of arrhythmia, not recorded before the procedure, was considered a NA. The origin of NA was assessed by analysis of P-wave and/or QRS-complex morphology, and, thereafter, it was compared with locations of previously ablated APs. Results. Over the follow-up of 4.3±3.9 years, NA was registered in 20 patients (16%. The prevalence of specific NAs was as follows: atrioventricular (AV block 0.8%, atrial premature beats 1.6%, atrial fibrillation 5.4%, atrial flutter 0.8%, sinus tachycardia 4.8%, ventricular premature beats (VPBs 7.3%. Multivariate Cox-regression analysis identified (1 pre-ablation history of pathway-mediated tachyarrhythmias >10 years (HR=3.54, p=0.016 and (2 septal AP location (HR=4.25, p=0.003, as the independent predictors for NA occurrence. In four NA cases (two cases of septal VPBs, one of typical AFL and one of AV-block presumed NA origin was identified in the vicinity of previous ablation target. Conclusion. NAs were found in 16% of patients after AP elimination. In few of these cases, late on-site arrhythmic effect of initially curative RF lesion might be possible. While earlier intervention could prevent NA occurrence, closer follow-up is advised after ablation of septal AP.

At-admission risk stratification for in-hospital life-threatening ventricular arrhythmias and death in non-ST elevation myocardial infarction patients.

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Zorzi, Alessandro; Turri, Riccardo; Zilio, Filippo; Spadotto, Veronica; Baritussio, Anna; Peruzza, Francesco; Gasparetto, Nicola; Marra, Martina Perazzolo; Cacciavillani, Luisa; Marzari, Armando; Tarantini, Giuseppe; Iliceto, Sabino; Corrado, Domenico

2014-12-01

Identification of patients with non-ST elevation acute myocardial infarction (NSTEMI) at higher risk of in-hospital life-threatening ventricular arrhythmias (LT-VA) and death is crucial for determining appropriate levels of care/monitoring during hospitalisation. We assessed predictors of in-hospital LT-VA and all-cause mortality in a consecutive series of NSTEMI patients. We prospectively studied 1325 consecutive patients (69.7% males, median age 70 (61-79) years) presenting with NSTEMI and undergoing continuous electrocardiographic monitoring. The primary study end-point was the occurrence of spontaneous (unrelated to coronary interventions) in-hospital LT-VA, including sustained ventricular tachycardia and ventricular fibrillation; the secondary end-point was in-hospital mortality from all causes. Of 1325 patients, 21 (1.5%) experienced LT-VA and 62 (4.7%) died from either arrhythmias (n=1) or other causes (n=61). Seven of the 20 patients who survived LT-VA subsequently died of heart failure. Independent predictors of in-hospital LT-VA were the Global Registry of Acute Coronary Events (GRACE) score >140 (odds ratio (OR)=7.5; 95% confidence interval (CI) 1.7-33.3; p=0.008) and left ventricular ejection fraction (LV-EF)140 (OR=14.6; 95% CI 3.4-62) and LV-EF 140 and LV-EF<35%, while it was respectively 0.2% and 0% among the 627 (47.3%) with GRACE score ≤140 and LV-EF ≥35%. Simple risk stratification at admission based on GRACE score and echocardiographic LV-EF allows early identification of NSTEMI patients at higher risk of both in-hospital LT-VA and all-cause mortality. © The European Society of Cardiology 2014.

Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis

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Adeyemi, Oladipupo; Alvarez-Laviada, Anita; Schultz, Francisca; Ibrahim, Effendi; Trauner, Michael; Williamson, Catherine; Glukhov, Alexey V.

2017-01-01

Background Increased maternal serum bile acid concentrations in intrahepatic cholestasis of pregnancy (ICP) are associated with fetal cardiac arrhythmias. Ursodeoxycholic acid (UDCA) has been shown to demonstrate anti-arrhythmic properties via preventing ICP-associated cardiac conduction slowing and development of reentrant arrhythmias, although the cellular mechanism is still being elucidated. Methods High-resolution fluorescent optical mapping of electrical activity and electrocardiogram measurements were used to characterize effects of UDCA on one-day-old neonatal and adult female Langendorff-perfused rat hearts. ICP was modelled by perfusion of taurocholic acid (TC, 400μM). Whole-cell calcium currents were recorded from neonatal rat and human fetal cardiomyocytes. Results TC significantly prolonged the PR interval by 11.0±3.5% (P<0.05) and slowed ventricular conduction velocity (CV) by 38.9±5.1% (P<0.05) exclusively in neonatal and not in maternal hearts. A similar CV decline was observed with the selective T-type calcium current (ICa,T) blocker mibefradil 1μM (23.0±6.2%, P<0.05), but not with the L-type calcium current (ICa,L) blocker nifedipine 1μM (6.9±6.6%, NS). The sodium channel blocker lidocaine (30μM) reduced CV by 60.4±4.5% (P<0.05). UDCA co-treatment was protective against CV slowing induced by TC and mibefradil, but not against lidocaine. UDCA prevented the TC-induced reduction in the ICa,T density in both isolated human fetal (−10.2±1.5 versus −5.5±0.9 pA/pF, P<0.05) and neonatal rat ventricular myocytes (−22.3±1.1 versus −9.6±0.8 pA/pF, P<0.0001), whereas UDCA had limited efficacy on the ICa,L. Conclusion Our findings demonstrate that ICa,T plays a significant role in ICP-associated fetal cardiac conduction slowing and arrhythmogenesis, and is an important component of the fetus-specific anti-arrhythmic activity of UDCA. PMID:28934223

Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis.

Directory of Open Access Journals (Sweden)

Oladipupo Adeyemi

Full Text Available Increased maternal serum bile acid concentrations in intrahepatic cholestasis of pregnancy (ICP are associated with fetal cardiac arrhythmias. Ursodeoxycholic acid (UDCA has been shown to demonstrate anti-arrhythmic properties via preventing ICP-associated cardiac conduction slowing and development of reentrant arrhythmias, although the cellular mechanism is still being elucidated.High-resolution fluorescent optical mapping of electrical activity and electrocardiogram measurements were used to characterize effects of UDCA on one-day-old neonatal and adult female Langendorff-perfused rat hearts. ICP was modelled by perfusion of taurocholic acid (TC, 400μM. Whole-cell calcium currents were recorded from neonatal rat and human fetal cardiomyocytes.TC significantly prolonged the PR interval by 11.0±3.5% (P<0.05 and slowed ventricular conduction velocity (CV by 38.9±5.1% (P<0.05 exclusively in neonatal and not in maternal hearts. A similar CV decline was observed with the selective T-type calcium current (ICa,T blocker mibefradil 1μM (23.0±6.2%, P<0.05, but not with the L-type calcium current (ICa,L blocker nifedipine 1μM (6.9±6.6%, NS. The sodium channel blocker lidocaine (30μM reduced CV by 60.4±4.5% (P<0.05. UDCA co-treatment was protective against CV slowing induced by TC and mibefradil, but not against lidocaine. UDCA prevented the TC-induced reduction in the ICa,T density in both isolated human fetal (-10.2±1.5 versus -5.5±0.9 pA/pF, P<0.05 and neonatal rat ventricular myocytes (-22.3±1.1 versus -9.6±0.8 pA/pF, P<0.0001, whereas UDCA had limited efficacy on the ICa,L.Our findings demonstrate that ICa,T plays a significant role in ICP-associated fetal cardiac conduction slowing and arrhythmogenesis, and is an important component of the fetus-specific anti-arrhythmic activity of UDCA.

Examining the relation between respiratory sinus arrhythmia and depressive symptoms in emerging adults: A longitudinal study.

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Yaptangco, Mona; Crowell, Sheila E; Baucom, Brian R; Bride, Daniel L; Hansen, Erik J

2015-09-01

Major depressive disorder (MDD) is a debilitating and prevalent disorder associated with lower quality of life and substantial economic burden. Recently, there has been strong interest in respiratory sinus arrhythmia (RSA) as a biological predictor of later depression. Theoretical work suggests that higher resting RSA indexes physiological flexibility and better emotion regulation whereas lower RSA may mark vulnerability for psychopathology. However, empirical findings have varied. This study examined whether lower resting RSA predicted later depressive symptoms in a sample of healthy young adults across one year (n=185). Results indicate that year one (Y1) resting RSA predicted Y2 depressive symptoms. This finding remained significant when accounting for the stability of RSA and depressive symptoms across both time points and when including trait anxiety, body mass index, and medication use in statistical models. Findings provide further support for RSA as a promising biological marker for understanding and predicting depressive symptoms. Copyright © 2015 Elsevier B.V. All rights reserved.

Sleep and cognitive performance: the role of income and respiratory sinus arrhythmia reactivity.

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Staton, Lori; Hinnant, J Benjamin; Buckhalt, Joseph; El-Sheikh, Mona

2014-11-01

A health disparities view suggests that low family income status acts as a risk factor for poor cognitive functioning. A biosystems view suggests that poor sleep and poor stress response system functioning are also risk factors. These views are rarely integrated to test multiplicative risk or protective effects from social-cultural and biological variables. We investigated interactions among familial income, children's sleep and respiratory sinus arrhythmia reactivity (RSA reactivity, indexing parasympathetic nervous system reactivity) in the prediction of cognitive performance of school-aged children. Participants were 282 children (146 boys; 35% African American and 65% European American; M age = 9.42 years, SD = .71). Mothers reported on family income. Children's sleep quality (efficiency) and duration (minutes) were assessed via a week of actigraphy. Children's RSA reactivity to an attention demanding and frustrating star tracing challenge was assessed in the lab. Children completed standardized cognitive assessments examining attention, processing speed, and crystallized cognitive functioning. Findings show that more optimal sleep efficiency and RSA reactivity interact to confer protection against poor cognitive performance, particularly for children from lower income homes. Results build on the literature and suggest that interactions between biological systems and socioeconomic variables are key for understanding children's cognitive performance. © 2014 Wiley Periodicals, Inc.

Respiratory sinus arrhythmia, effortful control, and parenting as predictors of children's sympathy across early childhood.

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Taylor, Zoe E; Eisenberg, Nancy; Spinrad, Tracy L

2015-01-01

The goal of this study was to examine physiological and environmental predictors of children's sympathy (an emotional response consisting of feelings of concern or sorrow for others who are distressed or in need) and whether temperamental effortful control mediated these relations. Specifically, in a study of 192 children (23% Hispanic; 54% male), respiratory sinus arrhythmia (RSA), a measure thought to reflect physiological regulation, and observed authoritative parenting (both at 42 months) were examined as predictors of children's effortful control (at 54 months) and, in turn, children's sympathy (at 72 and 84 months). Measures of both baseline RSA and RSA suppression were examined. In a structural equation model, observed parenting was positively related to children's subsequent sympathy through its positive relation to effortful control. Furthermore, the indirect path from baseline RSA to higher sympathy through effortful control was marginally significant. Authoritative parenting and baseline RSA uniquely predicted individual differences in children's effortful control. Findings highlight the potential role of both authoritative parenting and physiological regulation in the development of children's sympathy.

Associations between narcissism and emotion regulation difficulties: Respiratory sinus arrhythmia reactivity as a moderator.

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Zhang, Hui; Wang, Zhenhong; You, Xuqun; Lü, Wei; Luo, Yun

2015-09-01

The aim of the current study was to examine the direct and interactive effects of two types of narcissism (overt and covert) and respiratory sinus arrhythmia (RSA) reactivity on emotion regulation difficulties in 227 undergraduate students. Overt and covert narcissism and emotion regulation difficulties were assessed with self-report measures (narcissistic personality inventory (NPI)-16, hypersensitive narcissism scale (HSNS), and difficulties in emotion regulation scale (DERS)), and physiological data were measured during the baseline, stress (a public-speaking task), and recovery periods in the laboratory. Results indicated that overt narcissism was negatively related to a lack of emotional awareness and emotional clarity, whereas covert narcissism was positively related to overall emotion regulation difficulties, nonacceptance of emotional responses, impulse control difficulties, limited access to emotion regulation strategies, and a lack of emotional clarity. RSA reactivity in response to a mock job interview moderated the associations between covert narcissism (as a predictor) and overall emotion regulation difficulties and impulse control difficulties (as outcomes). This finding showed that a greater stress-induced RSA decrease may serve as a protective factor and ameliorate the effect of covert narcissism on individuals' emotion regulation difficulties. Copyright © 2015 Elsevier B.V. All rights reserved.

Improving Managers' Psychophysical Well-Being: Effectiveness of Respiratory Sinus Arrhythmia Biofeedback.

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Munafò, Marianna; Patron, Elisabetta; Palomba, Daniela

2016-06-01

High work stress has been consistently associated with disturbed autonomic balance, specifically, lowered vagal cardiac control and increased sympathetic activity, which may lead to increased cardiovascular risk. Stress management procedures have been proposed to reduce autonomic dysfunctions related to work stress in different categories of workers exposed to heightened work demands, while a limited number of studies addressed this issue in managers. The present study was aimed at evaluating the effectiveness of a respiratory sinus arrhythmia (RSA) biofeedback (BF) intervention on psychological and physiological outcomes, in managers with high-level work responsibilities. Thirty-one managers leading outstanding private or public companies were randomly assigned to either a RSA-BF training (RSA-BF; N = 16) or a control group (N = 15). The RSA-BF training consisted of five weekly 45 min sessions, designed to increase RSA, whereas controls had to provide a daily stress diary once a week. After the training, managers in both groups reported reduced heart rate at rest, lower anxiety levels and improvement in health-related quality of life. More importantly, managers in the RSA-BF group showed increased vagal control (as indexed by increased RSA), decreased sympathetic arousal (as indexed by reduced skin conductance and systolic blood pressure) and lower emotional interferences, compared to managers in the control group. Results from this study showed that RSA-BF training was effective in improving cardiac autonomic balance at rest. Moreover, findings from this study underline the effectiveness of biofeedback in reducing psychophysiological negative outcomes associated with stress in managers.

Ability of a 5-minute electrocardiography (ECG) for predicting arrhythmias in Doberman Pinschers with cardiomyopathy in comparison with a 24-hour ambulatory ECG.

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Wess, G; Schulze, A; Geraghty, N; Hartmann, K

2010-01-01

Ventricular premature contractions (VPCs) are common in the occult stage of cardiomyopathy in Doberman Pinschers. Although the gold standard for detecting arrhythmia is the 24-hour ambulatory electrocardiography (ECG) (Holter), this method is more expensive, time-consuming and often not as readily available as common ECG. Comparison of 5-minute ECGs with Holter examinations. Eight hundred and seventy-five 5-minute ECGs and Holter examinations of 431 Doberman Pinschers. Each examination included a 5-minute ECG and Holter examination. A cut-off value of > 100 VPCs/24 hours using Holter was considered diagnostic for the presence of cardiomyopathy. Statistical evaluation included calculation of sensitivity, specificity, positive predictive value, and negative predictive value. Holter examinations revealed > 100 VPCs/24 hours in 204/875 examinations. At least 1 VPC during a 5-minute ECG was detected in 131 (64.2%) of these 204 examinations. No VPCs were found in the 5-minute ECG in 73 (35.8%) examinations of affected Doberman Pinschers. A 5-minute ECG with at least 1 VPC as cut-off had a sensitivity of 64.2%, a specificity of 96.7%, a positive predictive value of 85.6% and a negative predictive value of 89.9% for the presence of > 100 VPCs/24 hours. A 5-minute ECG is a rather insensitive method for detecting arrhythmias in Doberman Pinschers. However, the occurrence of at least 1 VPC in 5 minutes strongly warrants further examination of the dog, because specificity (96.7%) and positive predictive value (85.6%) are high and could suggest occult cardiomyopathy.

CD36 overexpression predisposes to arrhythmias but reduces infarct size in spontaneously hypertensive rats: gene expression profile analysis

Czech Academy of Sciences Publication Activity Database

Neckář, Jan; Šilhavý, Jan; Zídek, Václav; Landa, Vladimír; Mlejnek, Petr; Šimáková, Miroslava; Seidman, J. G.; Seidman, Ch.; Kazdová, L.; Klevstig, M.; Novák, F.; Vecka, M.; Papoušek, František; Houštěk, Josef; Drahota, Zdeněk; Kurtz, T. W.; Kolář, František; Pravenec, Michal

2012-01-01

Roč. 44, č. 2 (2012), s. 173-182 ISSN 1094-8341 R&D Projects: GA MŠk(CZ) ME08006; GA MŠk(CZ) 1M0520; GA MŠk(CZ) OC08017; GA MŠk(CZ) 1M0510; GA MZd(CZ) NR9359; GA MZd(CZ) NR9387; GA MZd(CZ) NS9757; GA MZd(CZ) NS10504; GA AV ČR(CZ) IAA500110805; GA AV ČR(CZ) IAAX01110901; GA AV ČR(CZ) KAN200520703; GA ČR(CZ) GD305/08/H037; GA ČR GAP301/10/0756; GA MŠk 7E10067 Institutional research plan: CEZ:AV0Z50110509 Keywords : Cd36 * spontaneously hypertensive rat * arrhythmias * infarct size * gene expression profiles Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 2.806, year: 2012

Developmental trajectories of respiratory sinus arrhythmia and preejection period in middle childhood.

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Hinnant, J Benjamin; Elmore-Staton, Lori; El-Sheikh, Mona

2011-01-01

Autonomic nervous system (ANS) activity has been linked repeatedly to children's socioemotional and behavioral adaptive functioning and development, yet the literature on how various indexes of ANS activity develop in childhood is sparse. We utilized latent growth modeling to investigate the development of respiratory sinus arrhythmia (RSA), an established index of parasympathetic nervous system (PNS), and preejection period (PEP), a marker of sympathetic nervous system (SNS) influence on the heart, in children aged 8-10 years. At age 8, 251 children (128 girls, 123 boys; 162 European American, 89 African American) participated. Longitudinal data were collected during two additional waves when children were 9 and 10 years of age, with a 1-year lag between each wave. Children's RSA and PEP exhibited significant stability over time. Marginally significant variability was found among children in how RSA changed over time (slope), but there was no significant interindividual variability in PEP changes over development. A conditional growth curve model (i.e., one with predictor variables) showed that initial levels of RSA and PEP and the slope of RSA over time were predicted by several demographic factors including the child's sex and race; RSA of European American children showed significant increases over time while African American children had higher initial RSA but no significant change over time. Findings extend basic knowledge in developmental biopsychology and have implications for research focusing on ANS measures as important predictors, moderators, and mediators of childhood adaptation. © 2010 Wiley Periodicals, Inc.

Respiratory sinus arrhythmia during worry forecasts stress-related increases in psychological distress.

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Gouin, Jean-Philippe; Deschênes, Sonya S; Dugas, Michel J

2014-09-01

Respiratory sinus arrhythmia (RSA) has been conceptualized as an index of emotion regulation abilities. Although resting RSA has been associated with both concurrent and prospective affective responses to stress, the impact of RSA reactivity on emotional responses to stress is inconsistent across studies. The type of emotional stimuli used to elicit these phasic RSA responses may influence the adaptive value of RSA reactivity. We propose that RSA reactivity to a personally relevant worry-based stressor might forecast future affective responses to stress. To evaluate whether resting RSA and RSA reactivity to worry inductions predict stress-related increases in psychological distress, an academic stress model was used to prospectively examine changes in psychological distress from the well-defined low- and high-stress periods. During the low-stress period, 76 participants completed self-report mood measures and had their RSA assessed during a resting baseline, free worry period and worry catastrophizing interview. Participants completed another mood assessment during the high-stress period. Results indicated that baseline psychological distress predicted larger decreases in RSA during the worry inductions. Lower resting RSA and greater RSA suppression to the worry inductions at baseline prospectively predicted larger increases in psychological distress from the low- to high-stress period, even after accounting for the impact of baseline distress on RSA. These results provide further evidence that RSA may represent a unique index of emotion regulation abilities in times of stress.

Ventricular arrhythmia risk stratification in patients with tetralogy of Fallot at the time of pulmonary valve replacement.

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Sabate Rotes, Anna; Connolly, Heidi M; Warnes, Carole A; Ammash, Naser M; Phillips, Sabrina D; Dearani, Joseph A; Schaff, Hartzell V; Burkhart, Harold M; Hodge, David O; Asirvatham, Samuel J; McLeod, Christopher J

2015-02-01

Most patients with repaired tetralogy of Fallot require pulmonary valve replacement (PVR), but the evaluation for and management of ventricular arrhythmia remain unclear. This study is aimed at clarifying the optimal approach to this potentially life-threatening issue at the time of PVR. A retrospective analysis was performed on 205 patients with repaired tetralogy of Fallot undergoing PVR at our institution between 1988 and 2010. Median age was 32.9 (range, 25.6) years. Previous ventricular tachycardia occurred in 16 patients (8%) and 37 (16%) had left ventricular dysfunction, defined as left ventricular ejection fraction tetralogy of Fallot undergoing PVR with history of ventricular tachycardia or left ventricular dysfunction appear to be associated with a higher risk of arrhythmic events after operation. Events in the first year after PVR are rare, and in select high-risk patients, surgical cryoablation does not seem to increase arrhythmic events and may be protective. © 2014 American Heart Association, Inc.

Applications of Dynamic Clamp to Cardiac Arrhythmia Research: Role in Drug Target Discovery and Safety Pharmacology Testing

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Francis A. Ortega

2018-01-01

Full Text Available Dynamic clamp, a hybrid-computational-experimental technique that has been used to elucidate ionic mechanisms underlying cardiac electrophysiology, is emerging as a promising tool in the discovery of potential anti-arrhythmic targets and in pharmacological safety testing. Through the injection of computationally simulated conductances into isolated cardiomyocytes in a real-time continuous loop, dynamic clamp has greatly expanded the capabilities of patch clamp outside traditional static voltage and current protocols. Recent applications include fine manipulation of injected artificial conductances to identify promising drug targets in the prevention of arrhythmia and the direct testing of model-based hypotheses. Furthermore, dynamic clamp has been used to enhance existing experimental models by addressing their intrinsic limitations, which increased predictive power in identifying pro-arrhythmic pharmacological compounds. Here, we review the recent advances of the dynamic clamp technique in cardiac electrophysiology with a focus on its future role in the development of safety testing and discovery of anti-arrhythmic drugs.

Altered thyroid status affects myocardial expression of connexin-43 and susceptibility of rat heart to malignant arrhythmias that can be partially normalized by red palm oil intake

Czech Academy of Sciences Publication Activity Database

Szeiffová Bačová, B.; Vinczenzová, C.; Žurmanová, J.; Kašparová, Dita; Knezl, V.; Egan Beňová, T.; Pavelka, Stanislav; Soukup, Tomáš; Tribulová, N.

2017-01-01

Roč. 147, č. 1 (2017), s. 63-73 ISSN 0948-6143 R&D Projects: GA MŠk(CZ) LH15279; GA MŠk(CZ) 7AMB14SK123 Grant - others:AV ČR(CZ) SAV-15-03 Program:Bilaterální spolupráce Institutional support: RVO:67985823 Keywords : thyroid hormones * cardiac arrhythmias * connexin-43 * PKC * red palm oil Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 2.553, year: 2016

An Automated Platform for Assessment of Congenital and Drug-Induced Arrhythmia with hiPSC-Derived Cardiomyocytes

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Wesley L. McKeithan

2017-10-01

Full Text Available The ability to produce unlimited numbers of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs harboring disease and patient-specific gene variants creates a new paradigm for modeling congenital heart diseases (CHDs and predicting proarrhythmic liabilities of drug candidates. However, a major roadblock to implementing hiPSC-CM technology in drug discovery is that conventional methods for monitoring action potential (AP kinetics and arrhythmia phenotypes in vitro have been too costly or technically challenging to execute in high throughput. Herein, we describe the first large-scale, fully automated and statistically robust analysis of AP kinetics and drug-induced proarrhythmia in hiPSC-CMs. The platform combines the optical recording of a small molecule fluorescent voltage sensing probe (VoltageFluor2.1.Cl, an automated high throughput microscope and automated image analysis to rapidly generate physiological measurements of cardiomyocytes (CMs. The technique can be readily adapted on any high content imager to study hiPSC-CM physiology and predict the proarrhythmic effects of drug candidates.

Respiratory Sinus Arrhythmia, Effortful Control, and Parenting as Predictors of Children’s Sympathy Across Early Childhood

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Taylor, Zoe E.; Eisenberg, Nancy; Spinrad, Tracy L.

2015-01-01

The goal of this study was to examine physiological and environmental predictors of children’s sympathy (an emotional response consisting of feelings of concern or sorrow for others who are distressed or in need) and whether temperamental effortful control mediated these relations. Specifically, in a study of 192 children (23% Hispanic; 54% male), respiratory sinus arrhythmia (RSA), a measure thought to reflect physiological regulation, and observed authoritative parenting (both at 42 months) were examined as predictors of children’s effortful control (at 54 months) and, in turn, children’s sympathy (at 72 and 84 months). Measures of both baseline RSA and RSA suppression were examined. In a structural equation model, observed parenting was positively related to children’s subsequent sympathy through its positive relation to effortful control. Furthermore, the indirect path from baseline RSA to higher sympathy through effortful control was marginally significant. Authoritative parenting and baseline RSA uniquely predicted individual differences in children’s effortful control. Findings highlight the potential role of both authoritative parenting and physiological regulation in the development of children’s sympathy. PMID:25329555

Low-Cost Optical Mapping Systems for Panoramic Imaging of Complex Arrhythmias and Drug-Action in Translational Heart Models

Science.gov (United States)

Lee, Peter; Calvo, Conrado J.; Alfonso-Almazán, José M.; Quintanilla, Jorge G.; Chorro, Francisco J.; Yan, Ping; Loew, Leslie M.; Filgueiras-Rama, David; Millet, José

2017-02-01

Panoramic optical mapping is the primary method for imaging electrophysiological activity from the entire outer surface of Langendorff-perfused hearts. To date, it is the only method of simultaneously measuring multiple key electrophysiological parameters, such as transmembrane voltage and intracellular free calcium, at high spatial and temporal resolution. Despite the impact it has already had on the fields of cardiac arrhythmias and whole-heart computational modeling, present-day system designs precludes its adoption by the broader cardiovascular research community because of their high costs. Taking advantage of recent technological advances, we developed and validated low-cost optical mapping systems for panoramic imaging using Langendorff-perfused pig hearts, a clinically-relevant model in basic research and bioengineering. By significantly lowering financial thresholds, this powerful cardiac electrophysiology imaging modality may gain wider use in research and, even, teaching laboratories, which we substantiated using the lower-cost Langendorff-perfused rabbit heart model.

Sex Differences in the Contribution of Respiratory Sinus Arrhythmia and Trauma to Children's Psychopathology.

Science.gov (United States)

Gray, Sarah A O; Theall, Katherine; Lipschutz, Rebecca; Drury, Stacy

2017-03-01

Respiratory sinus arrhythmia (RSA), a marker of parasympathetic activity, has been shown to moderate the relation between adversity and child behavioral outcomes; however, this work has been conducted in primarily Caucasian samples and limited in focus to family-level adversity. The current analysis extends the previous literature to examine the co-contribution of exposure to potentially traumatic events (PTEs), baseline RSA, and RSA withdrawal to internalizing and externalizing behavior in a sample of primarily African American youth ( n = 92) recruited using neighborhood mapping techniques from communities high in epidemiological indicators of adversity. Exposure to PTEs was associated with lower baseline RSA. Complex interactions were observed between sex of the child, baseline RSA and RSA withdrawal, and PTE exposure predicting to internalizing behaviors. Among girls with high (4+) levels of PTEs, high baseline RSA and RSA withdrawal predicted higher internalizing; for RSA withdrawal only, the inverse was observed for girls with low PTE exposure, for whom high RSA withdrawal predicted lower internalizing. No associations were observed from RSA to externalizing, or among boys to internalizing. Findings are consistent with distinct patterns among primarily African American samples and suggest the need for sex-specific conceptualizations of the link between environmental adversity, physiological reactivity, and internalizing behaviors.

Respiratory sinus arrhythmia as a non-invasive index of ′brain-heart′ interaction in stress

Directory of Open Access Journals (Sweden)

Ingrid Tonhajzerova

2016-01-01

Full Text Available Respiratory sinus arrhythmia (RSA is accepted as a peripheral marker of cardiac-linked parasympathetic regulation. According to polyvagal theory, the RSA is also considered as the index of emotion regulation. The neurovisceral integration model posits that parasympathetic modulation of the heart marked by RSA is related to complex nervous regulation associated with emotional and cognitive processing. From this perspective, high resting RSA amplitude associated with a greater withdrawal during stressors and subsequent recovery could represent a flexible and adaptive physiological response system to a challenge. Conversely, low resting RSA accompanied by an inadequate reactivity to stress might reflect maladaptive regulatory mechanisms. The RSA reactivity is different with various types of stressors: while the RSA decreases to cognitive tasks indicating a vagal withdrawal, the RSA magnitude increases to emotional challenge indicating an effective cognitive processing of emotional stimuli. The RSA reactivity to stress could have important implications for several mental disorders, e.g. depressive or anxiety disorder. It seems that the study of the RSA, as a non-invasive index of ′brain-heart′ communication, could provide important information on the pathway linked to mental and physical health.

[The nonpharmacological treatment of tachyarrhythmias. The surgery of supraventricular arrhythmias not due to pre-excitation].

Science.gov (United States)

Viganò, M; Graffigna, A; Pagani, F; Salerno, J A

1991-12-01

Surgery can provide treatment for supraventricular tachyarrhythmias without operative risk and with a definite improvement of patients' quality of life. Ectopic atrial tachycardia is a rare but invalidating arrhythmia that may lead to cardiomyopathy: intraoperative mapping is necessary for the location of the location of the ectopic focus; in our experience, surgical, cryothermal or isolation ablation of the area were effective in 9 patients out of 9, with regression of the cardiomyopathy. Atrioventricular node reentry tachycardia is a reentry tachycardia which is often associated with Wolff-Parkinson-White syndrome and is amenable to surgical treatment. Discrete cryolesions around the Koch triangle are effective in interrupting the atrial inputs to the atrioventricular node and therefore the reentry mechanism: in our experience, 7 patients were successfully treated without operative mortality: 3 patients underwent surgical ablation of Kent bundles as well. Atrial fibrillation is not based on a well-defined mechanism, and therefore does not permit an electrically-guided surgical treatment. However, in case of atrial septal defect it is possible to isolate the enlarged right atrium in order to allow sinus rhythm to activate the left atrium and ventricles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic stimulation promotes T-wave alternans and arrhythmia inducibility in a TNF-alpha genetic mouse model of congestive heart failure.

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Shusterman, Vladimir; McTiernan, Charles F; Goldberg, Anna; Saba, Samir; Salama, Guy; London, Barry

2010-02-01

T-wave alternans (TWA) is a proarrhythmic repolarization instability that is common in congestive heart failure (CHF). Although transgenic mice are commonly used to study the mechanisms of arrhythmogenesis in CHF, little is known about the dynamics of TWA in these species. We hypothesized that TWA is present in a TNF-alpha model of CHF and can be further promoted by adrenergic stimulation. We studied 16 TNF-alpha mice and 12 FVB controls using 1) in vivo intracardiac electrophysiological testing and 2) ambulatory telemetry during 30 min before and after an intraperitoneal injection of isoproterenol. TWA was examined using both linear and nonlinear filtering applied in the time domain. In addition, changes in the mean amplitude of the T wave and area under the T wave were computed. During intracardiac electrophysiological testing, none of the animals had TWA or inducible arrhythmias before the injection of isoproterenol. After the injection, sustained TWA and inducible ventricular tachyarrhythmias were observed in TNF-alpha mice but not in FVB mice. In ambulatory telemetry, before the isoproterenol injection, the cardiac cycle length (CL) was longer in TNF-alpha mice than in FVB mice (98 +/- 9 and 88 +/- 3 ms, P = 0.04). After the injection of isoproterenol, the CL became 8% and 6% shorter in TNF-alpha and FVB mice (P mice, the magnitude of TWA was 1.5-2 times greater than in FVB mice both before and after the isoproterenol injection. The magnitude of TWA increased significantly after the isoproterenol injection compared with the baseline in TNF-alpha mice (P = 0.003) but not in FVB mice. The mean amplitude of the T wave and area under the T wave increased 60% and 80% in FVB mice (P = 0.006 and 0.009) but not in TNF-alpha mice. In conclusion, TWA is present in a TNF-alpha model of CHF and can be further promoted by adrenergic stimulation, along with the enhanced susceptibility for ventricular arrhythmias.

Respiratory sinus arrhythmia responses to induced emotional states: effects of RSA indices, emotion induction method, age, and sex.

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Overbeek, Thérèse J M; van Boxtel, Anton; Westerink, Joyce H D M

2012-09-01

The literature shows large inconsistencies in respiratory sinus arrhythmia (RSA) responses to induced emotional states. This may be caused by differences in emotion induction methods, RSA quantification, and non-emotional demands of the situation. In 83 healthy subjects, we studied RSA responses to pictures and film fragments eliciting six different discrete emotions relative to neutral baseline stimuli. RSA responses were quantified in the time and frequency domain and were additionally corrected for differences in mean heart rate and respiration rate, resulting in eight different RSA response measures. Subjective ratings of emotional stimuli and facial electromyographic responses indicated that pictures and film fragments elicited the intended emotions. Although RSA measures showed various emotional effects, responses were quite heterogeneous and frequently nonsignificant. They were substantially influenced by methodological factors, in particular time vs. frequency domain response measures, correction for changes in respiration rate, use of pictures vs. film fragments, and sex of participants. Copyright © 2012 Elsevier B.V. All rights reserved.

Gated blood pool imaging in the diagnosis and management of arrhythmia

International Nuclear Information System (INIS)

Yamamoto, Shuhei; Kawai, Naoki; Okada, Mitsuhiro; Matsushima, Hideo; Kato, Rinya; Sotobata, Iwao; Tanahashi, Yoshibumi.

1985-01-01

The usefulness of multigated cardiac blood pool imaging in evaluating left ventricular function and ventricular activation was studied in patients with cardiac arrhythmias. Subjects consisted of 12 patients with the Wolff-Parkinson-White (WPW) syndrome; 20 with ventricular premature contractions (VPC); 21 with various modes of artificial pacemakers; and two normal controls. 1. Phase analysis was useful in localizing the bypass tract in patients with the WPW syndrome. In four patients with the WPW syndrome and five with VVI pacing, the phase difference between the posterolateral wall of the left ventricle (LV) and the right ventricular apex correlated significantly with the activation time difference between these two regions as assessed by endocardial electrograms (r = 0.94, p < 0.001). 2. Images of VPC were obtained using the bad beat rejection program in an ADAC computer system. The origin of VPCs evaluated by phase image coincided with results of standard 12-lead electrograms. 3. The LV ejection fraction (LVEF) decreased significantly (p < 0.001) after the injection of lidocaine (-3.7 %) or disopyramide (-6.2 %). The percent reduction in LVEF was significantly greater with disopyramide than with lidocaine (-15.1 vs -11.2 %). There was a significant correlation between the percent reduction in LVEF and the disopyramide plasma concentrations (r = -0.62, p < 0.001). 4. The influence of the pacing mode and exercise on LV function was studied in 21 patients with artificial pacemakers. In the VDD and DDD modes, end-diastolic volume (EDV) and cardiac output (CO) decreased after converting to VVI mode. CO increased markedly to approximately 250 % of the control value in the VDD and DDD, and moderately in the VVI and AAI modes during ergometer exercise. (J.P.N.)

Hypertension and cardiac arrhythmias : A consensus document fromthe European Heart RhythmAssociation (EHRA) and ESC Council on Hypertension, endorsed by the Heart RhythmSociety (HRS), Asia-Pacific Heart RhythmSociety (APHRS) and Sociedad Latinoamericana de Estimulacion Cardiaca y Electrofisiologia (SOLEACE)

NARCIS (Netherlands)

Lip, Gregory Y. H.; Coca, Antonio; Kahan, Thomas; Boriani, Giuseppe; Manolis, Antonis S.; Olsen, Michael Hecht; Oto, Ali; Potpara, Tatjana S.; Steffel, Jan; Marin, Francisco; de Oliveira Figueiredo, Marcio Jansen; de Simone, Giovanni; Tzou, Wendy S.; Chiang, Chern-En; Williams, Bryan; Dan, Gheorghe-Andrei; Gorenek, Bulent; Fauchier, Laurent; Savelieva, Irina; Hatala, Robert; van Gelder, Isabelle; Brguljan-Hitij, Jana; Erdine, Serap; Lovic, Dragan; Kim, Young-Hoon; Salinas-Arce, Jorge; Field, Michael

2017-01-01

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both

Fusion of ECG and ABP signals based on wavelet transform for cardiac arrhythmias classification.

Science.gov (United States)

Arvanaghi, Roghayyeh; Daneshvar, Sabalan; Seyedarabi, Hadi; Goshvarpour, Atefeh

2017-11-01

Each of Electrocardiogram (ECG) and Atrial Blood Pressure (ABP) signals contain information of cardiac status. This information can be used for diagnosis and monitoring of diseases. The majority of previously proposed methods rely only on ECG signal to classify heart rhythms. In this paper, ECG and ABP were used to classify five different types of heart rhythms. To this end, two mentioned signals (ECG and ABP) have been fused. These physiological signals have been used from MINIC physioNet database. ECG and ABP signals have been fused together on the basis of the proposed Discrete Wavelet Transformation fusion technique. Then, some frequency features were extracted from the fused signal. To classify the different types of cardiac arrhythmias, these features were given to a multi-layer perceptron neural network. In this study, the best results for the proposed fusion algorithm were obtained. In this case, the accuracy rates of 96.6%, 96.9%, 95.6% and 93.9% were achieved for two, three, four and five classes, respectively. However, the maximum classification rate of 89% was obtained for two classes on the basis of ECG features. It has been found that the higher accuracy rates were acquired by using the proposed fusion technique. The results confirmed the importance of fusing features from different physiological signals to gain more accurate assessments. Copyright © 2017 Elsevier B.V. All rights reserved.

Young adults' internet addiction: Prediction by the interaction of parental marital conflict and respiratory sinus arrhythmia.

Science.gov (United States)

Zhang, Hui; Spinrad, Tracy L; Eisenberg, Nancy; Luo, Yun; Wang, Zhenhong

2017-10-01

The aim of the current study was to address the potential moderating roles of respiratory sinus arrhythmia (RSA; baseline and suppression) and participant sex in the relation between parents' marital conflict and young adults' internet addiction. Participants included 105 (65 men) Chinese young adults who reported on their internet addiction and their parents' marital conflict. Marital conflict interacted with RSA suppression to predict internet addiction. Specifically, high RSA suppression was associated with low internet addiction, regardless of parental marital conflict; however, for participants with low RSA suppression, a positive relation between marital conflict and internet addiction was found. Internet addiction also was predicted by a significant three-way interaction among baseline RSA, marital conflict, and participant sex. Specifically, for men, marital conflict positively predicted internet addiction under conditions of low (but not high) baseline RSA. For women, marital conflict positively predicted internet addiction under conditions of high (but not low) baseline RSA. Findings highlight the importance of simultaneous consideration of physiological factors, in conjunction with family factors, in the prediction of young adults' internet addiction. Copyright © 2017 Elsevier B.V. All rights reserved.

Respiratory sinus arrhythmia reactivity to a sad film predicts depression symptom improvement and symptomatic trajectory.

Science.gov (United States)

Panaite, Vanessa; Hindash, Alexandra Cowden; Bylsma, Lauren M; Small, Brent J; Salomon, Kristen; Rottenberg, Jonathan

2016-01-01

Respiratory sinus arrhythmia (RSA) reactivity, an index of cardiac vagal tone, has been linked to self-regulation and the severity and course of depression (Rottenberg, 2007). Although initial data supports the proposition that RSA withdrawal during a sad film is a specific predictor of depression course (Fraguas, 2007; Rottenberg, 2005), the robustness and specificity of this finding are unclear. To provide a stronger test, RSA reactivity to three emotion films (happy, sad, fear) and to a more robust stressor, a speech task, were examined in currently depressed individuals (n=37), who were assessed for their degree of symptomatic improvement over 30weeks. Robust RSA reactivity to the sad film uniquely predicted overall symptom improvement over 30weeks. RSA reactivity to both sad and stressful stimuli predicted the speed and maintenance of symptomatic improvement. The current analyses provide the most robust support to date that RSA withdrawal to sad stimuli (but not stressful) has specificity in predicting the overall symptomatic improvement. In contrast, RSA reactivity to negative stimuli (both sad and stressful) predicted the trajectory of depression course. Patients' engagement with sad stimuli may be an important sign to attend to in therapeutic settings. Copyright © 2015 Elsevier B.V. All rights reserved.

Sex Differences in the Contribution of Respiratory Sinus Arrhythmia and Trauma to Children’s Psychopathology

Science.gov (United States)

Gray, Sarah A. O.; Theall, Katherine; Lipschutz, Rebecca; Drury, Stacy

2016-01-01

Respiratory sinus arrhythmia (RSA), a marker of parasympathetic activity, has been shown to moderate the relation between adversity and child behavioral outcomes; however, this work has been conducted in primarily Caucasian samples and limited in focus to family-level adversity. The current analysis extends the previous literature to examine the co-contribution of exposure to potentially traumatic events (PTEs), baseline RSA, and RSA withdrawal to internalizing and externalizing behavior in a sample of primarily African American youth (n = 92) recruited using neighborhood mapping techniques from communities high in epidemiological indicators of adversity. Exposure to PTEs was associated with lower baseline RSA. Complex interactions were observed between sex of the child, baseline RSA and RSA withdrawal, and PTE exposure predicting to internalizing behaviors. Among girls with high (4+) levels of PTEs, high baseline RSA and RSA withdrawal predicted higher internalizing; for RSA withdrawal only, the inverse was observed for girls with low PTE exposure, for whom high RSA withdrawal predicted lower internalizing. No associations were observed from RSA to externalizing, or among boys to internalizing. Findings are consistent with distinct patterns among primarily African American samples and suggest the need for sex-specific conceptualizations of the link between environmental adversity, physiological reactivity, and internalizing behaviors. PMID:28479668

Disturbance of cardiac gene expression and cardiomyocyte structure predisposes Mecp2-null mice to arrhythmias

Science.gov (United States)

Hara, Munetsugu; Takahashi, Tomoyuki; Mitsumasu, Chiaki; Igata, Sachiyo; Takano, Makoto; Minami, Tomoko; Yasukawa, Hideo; Okayama, Satoko; Nakamura, Keiichiro; Okabe, Yasunori; Tanaka, Eiichiro; Takemura, Genzou; Kosai, Ken-ichiro; Yamashita, Yushiro; Matsuishi, Toyojiro

2015-01-01

Methyl-CpG-binding protein 2 (MeCP2) is an epigenetic regulator of gene expression that is essential for normal brain development. Mutations in MeCP2 lead to disrupted neuronal function and can cause Rett syndrome (RTT), a neurodevelopmental disorder. Previous studies reported cardiac dysfunction, including arrhythmias in both RTT patients and animal models of RTT. In addition, recent studies indicate that MeCP2 may be involved in cardiac development and dysfunction, but its role in the developing and adult heart remains unknown. In this study, we found that Mecp2-null ESCs could differentiate into cardiomyocytes, but the development and further differentiation of cardiovascular progenitors were significantly affected in MeCP2 deficiency. In addition, we revealed that loss of MeCP2 led to dysregulation of endogenous cardiac genes and myocardial structural alterations, although Mecp2-null mice did not exhibit obvious cardiac functional abnormalities. Furthermore, we detected methylation of the CpG islands in the Tbx5 locus, and showed that MeCP2 could target these sequences. Taken together, these results suggest that MeCP2 is an important regulator of the gene-expression program responsible for maintaining normal cardiac development and cardiomyocyte structure. PMID:26073556

Life-threatening Arrhythmias in a Becker Muscular Dystrophy Family due to the Duplication of Exons 3-4 of the Dystrophin Gene.

Science.gov (United States)

Ishizaki, Masatoshi; Fujimoto, Akiko; Ueyama, Hidetsugu; Nishida, Yasuto; Imamura, Shigehiro; Uchino, Makoto; Ando, Yukio

2015-01-01

We herein present a report of three patients with Becker muscular dystrophy in the same family who developed complete atrioventricular block or ventricular tachycardia with severe cardiomyopathy. Our cases became unable to walk in their teens, and were introduced to mechanical ventilation due to respiratory muscle weakness in their twenties and thirties. In all three cases, a medical device such as a permanent cardiac pacemaker or an implantable cardiac defibrillator was considered to be necessary. The duplication of exons 3-4 in the dystrophin gene was detected in two of the patients. In patients with Becker muscular dystrophy, complete atrioventricular block or ventricular tachycardia within a family has rarely been reported. Thus attention should be paid to the possibility of severe arrhythmias in the severe phenotype of Becker muscular dystrophy.

The atherosclerosis of the sinus node artery is associated with an increased history of supra-ventricular arrhythmias: a retrospective study on 541 standard coronary angiograms

Directory of Open Access Journals (Sweden)

Michele M. Ciulla

2015-08-01

Full Text Available Background. The ischemic damage of the sinus node (SN is a well known cause of cardiac arrhythmias and can be a consequence of any flow abnormality in the sinus node artery (SNA. Accordingly we aimed this retrospective study to: (1 evaluate the suitability of the standard coronary angiography to study the SNA and (2 determine if the percentage of subjects with a positive retrospective history of supra-ventricular arrhythmias (SVA differs in patients with normal and diseased SNA ascertained at the time of coronary angiography.Methods and Results. Out of the 541 coronary angiograms reviewed the SNA was visible for its entire course in 486 cases (89.8%. It was found to arise from the right side of the coronary circulation in 266 cases (54.7% slightly more often than from the left, 219 cases (45.1%. One patient had 2 distinct SNA arising from either side of the coronary circulation. For the second objective, we studied the 333 patients with: (a coronary artery disease (CAD, (b properly evaluable SNA and (c complete clinical history available. In 51 (15.3% a SNA disease was found, 41.2% of them had a positive SVA history, mainly atrial fibrillation (AF, whereas only 7.4% of patients with a positive history of SVA could be found in the non-SNA diseased. This difference was statistically significant (P < 0.001.Conclusions. (1 The evaluation of the SNA is feasible in clinical practice during a standard coronary angiography; (2 this may be relevant since angiographically detectable SNA disease was significantly associated with a positive history of SVA.

Plakophilin-2 c.419C>T and risk of heart failure and arrhythmias in the general population

DEFF Research Database (Denmark)

Christensen, Alex Hørby; Kamstrup, Pia Rørbœk; Gandjbakhch, Estelle

2016-01-01

A rare genetic variant in the desmosomal gene plakophilin-2 (PKP2) c.419C>T(p.(S140F)) has repeatedly been identified in patients with dilated cardiomyopathy (DCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC). Whether this is a disease-causing variant remains highly controversial. We...... ratios as a function of c.419C>T genotype were 2.11 (0.50-8.99) for ARVC, 0.72 (0.16-3.28) for hypertrophic cardiomyopathy (HCM)/DCM, and 1.28 (0.46-3.54) for end points combined. Third, in in vitro studies cellular localization of plakophilin-2, plakoglobin, connexin-43, or N-cadherin were similar...... in cells transfected with wild-type or mutant plakophilin-2. In conclusion, combining epidemiological data, with data on patients referred for genetic testing for ARVC or HCM/DCM, and data from in vitro studies, PKP2 c.419C>T did not associate with heart failure, arrhythmias, or premature death, with ARVC...

Mechanical Dyssynchrony by Tissue Doppler Cross-Correlation is Associated with Risk for Complex Ventricular Arrhythmias after Cardiac Resynchronization Therapy

DEFF Research Database (Denmark)

Tayal, Bhupendar; Gorcsan, John; Delgado-Montero, Antonia

2015-01-01

BACKGROUND: Tissue Doppler cross-correlation analysis has been shown to be associated with long-term survival after cardiac resynchronization defibrillator therapy (CRT-D). Its association with ventricular arrhythmia (VA) is unknown. METHODS: From two centers 151 CRT-D patients (New York Heart...... Association functional classes II-IV, ejection fraction ≤ 35%, and QRS duration ≥ 120 msec) were prospectively included. Tissue Doppler cross-correlation analysis of myocardial acceleration curves from the basal segments in the apical views both at baseline and 6 months after CRT-D implantation was performed...... with a substantially increased risk for VA (hazard ratio [HR], 4.4; 95% CI, 1.2-16.3; P = .03) and VA or death (HR, 4.0; 95% CI, 1.7-9.6; P = .002) after adjusting for other covariates. Similarly, patients with new dyssynchrony had increased risk for VA (HR, 10.6; 95% CI, 2.8-40.4; P = .001) and VA or death (HR, 5...

Relational victimization and proactive versus reactive relational aggression: The moderating effects of respiratory sinus arrhythmia and skin conductance.

Science.gov (United States)

Wagner, Caitlin R; Abaied, Jamie L

2015-01-01

This research examined the moderating effect of the autonomic nervous system (ANS) on the associations between relational victimization and reactive and proactive relational aggression. Both branches of the ANS, the parasympathetic nervous system (indexed by respiratory sinus arrhythmia reactivity; RSA-Reactivity) and the sympathetic nervous system (indexed by skin conductance level reactivity; SCL-Reactivity), were examined. Emerging adults (N = 168) self-reported on relational victimization and proactive and reactive relational aggression; RSA-Reactivity and SCL-Reactivity were assessed in response to a laboratory stressor. Relational victimization predicted heightened reactive relational aggression given RSA augmentation/high SCL-Reactivity (i.e., coactivation) and RSA withdrawal/low SCL-Reactivity (i.e., coinhibition). In addition, relational victimization predicted heightened reactive relational aggression given RSA augmentation/low SCL-Reactivity (i.e., reciprocal parasympathetic activation). This study extends previous research on relational victimization and provides novel evidence that (a) exposure to relational victimization is associated with reactive relational aggression, but not proactive relational aggression, and (b) parasympathetic and sympathetic nervous system reactivity jointly moderate the link between relational victimization and reactive relational aggression. © 2015 Wiley Periodicals, Inc.

Automatic detection of measurement points for non-contact vibrometer-based diagnosis of cardiac arrhythmias

Science.gov (United States)

Metzler, Jürgen; Kroschel, Kristian; Willersinn, Dieter

2017-03-01

Monitoring of the heart rhythm is the cornerstone of the diagnosis of cardiac arrhythmias. It is done by means of electrocardiography which relies on electrodes attached to the skin of the patient. We present a new system approach based on the so-called vibrocardiogram that allows an automatic non-contact registration of the heart rhythm. Because of the contactless principle, the technique offers potential application advantages in medical fields like emergency medicine (burn patient) or premature baby care where adhesive electrodes are not easily applicable. A laser-based, mobile, contactless vibrometer for on-site diagnostics that works with the principle of laser Doppler vibrometry allows the acquisition of vital functions in form of a vibrocardiogram. Preliminary clinical studies at the Klinikum Karlsruhe have shown that the region around the carotid artery and the chest region are appropriate therefore. However, the challenge is to find a suitable measurement point in these parts of the body that differs from person to person due to e. g. physiological properties of the skin. Therefore, we propose a new Microsoft Kinect-based approach. When a suitable measurement area on the appropriate parts of the body are detected by processing the Kinect data, the vibrometer is automatically aligned on an initial location within this area. Then, vibrocardiograms on different locations within this area are successively acquired until a sufficient measuring quality is achieved. This optimal location is found by exploiting the autocorrelation function.

Susceptibility of rats with altered thyroid status to malignant arrhythmias is primarily related to myocardial levels of connexin-43 and can be partially ameliorated by supplementation with red palm oil

Czech Academy of Sciences Publication Activity Database

Bačová, B.; Vinczenzová, C.; Žurmanová, J.; Kašparová, Dita; Knezl, V.; Radošinská, J.; Beňová, T.; Pavelka, Stanislav; Soukup, Tomáš; Tribulová, N.

2013-01-01

Roč. 18, Suppl A (2013), 41A-46A ISSN 1205-6626 R&D Projects: GA MŠk(CZ) 7AMB12SK158; GA ČR(CZ) GA305/09/1228; GA ČR(CZ) GAP304/12/0259 Grant - others:Univerzita Karlova(CZ) 628412 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : thyroid hormones * cardiac arrhythmias * connexin-43 * PKC.epsilon * red palm oil Subject RIV: ED - Physiology Impact factor: 0.758, year: 2013

Prolonged hypoxia increases survival even in Zebrafish (Danio rerio showing cardiac arrhythmia.

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Renate Kopp

Full Text Available Tolerance towards hypoxia is highly pronounced in zebrafish. In this study even beneficial effects of hypoxia, specifically enhanced survival of zebrafish larvae, could be demonstrated. This effect was actually more pronounced in breakdance mutants, which phenotypically show cardiac arrhythmia. Breakdance mutants (bre are characterized by chronically reduced cardiac output. Despite an about 50% heart rate reduction, they become adults, but survival rate significantly drops to 40%. Normoxic bre animals demonstrate increased hypoxia inducible factor 1 a (Hif-1α expression, which indicates an activated hypoxic signaling pathway. Consequently, cardiovascular acclimation, like cardiac hypertrophy and increased erythrocyte concentration, occurs. Thus, it was hypothesized, that under hypoxic conditions survival might be even more reduced. When bre mutants were exposed to hypoxic conditions, they surprisingly showed higher survival rates than under normoxic conditions and even reached wildtype values. In hypoxic wildtype zebrafish, survival yet exceeded normoxic control values. To specify physiological acclimation, cardiovascular and metabolic parameters were measured before hypoxia started (3 dpf, when the first differences in survival rate occurred (7 dpf and when survival rate plateaued (15 dpf. Hypoxic animals expectedly demonstrated Hif-1α accumulation and consequently enhanced convective oxygen carrying capacity. Moreover, bre animals showed a significantly enhanced heart rate under hypoxic conditions, which reached normoxic wildtype values. This improvement in convective oxygen transport ensured a sufficient oxygen and nutrient supply and was also reflected in the significantly higher mitochondrial activity. The highly optimized energy metabolism observed in hypoxic zebrafish larvae might be decisive for periods of higher energy demand due to organ development, growth and increased activity. However, hypoxia increased survival only during a

chronic sleep deprevation and ventricular arrhythmias: effect of symphatic nervous system

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Samira Choopani

2016-04-01

Full Text Available Introduction: We assessed the effect of chronic sleep deprivation on incidence of ischemia/reperfusion-induced ventricular arrhythmias (ventricular tachycardia and ventricular fibrillation and the role of the sympathetic nervous system in this respect. Material and methods: Rats were randomly divided into four groups; 1 ischemia/reperfusion group (IR: 30 minutes ischemia followed by 60 minutes reperfusion was induced, 2 control group (CON: rats has been placed in large multiple platforms for 72h prior to ischemia and reperfusion, 3 Chronic sleep deprivation group( SD: 72h sleep deprivation was induced by using small  multiple platform prior to ischemia and reperfusion, 4 Sympathectomy group (SYM: chemical sympathectomy was done 24h before to chronic sleep deprivation and then underwent ischemia and reperfusion. The heart isolated and perfused by langendorff apparatus. After thoracotomy and aorta cannulation, the hearts perfused in the langendorff apparatus using krebs-Henseleit buffer. Hearts were allowed to recovery for 15 min. After recovery period, 15 minutes was considered as baseline prior to 30 minutes ischemia followed by 60 minutes reperfusion.Tow thin stainless stell electrodes fixed on the ventricular apex and right atrium for recording the lead II of electrocardiogram (ECG.Results: There were no significant differences between heart rates between groups, and ventricular tachycardia significantly increased in chronic sleep deprivation group As compared with IR group in ischemia period. Sympathectomy significantly reduced ventricular tachycardia incidence when compared with SD. There is no difference in incidence of ventricular tachycardia between control group and IR group. The incidence of ventricular fibrillation during early reperfusion was significantly augmented (P<0.05 in sleep deprivation group as compared with IR group and Sympathectomy significantly could reverse ventricular fibrillation incidence to IR group level as

The Effect of Threshold Values and Weighting Factors on the Association between Entropy Measures and Mortality after Myocardial Infarction in the Cardiac Arrhythmia Suppression Trial (CAST

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Christopher Mayer

2016-04-01

Full Text Available Heart rate variability (HRV is a non-invasive measurement based on the intervals between normal heart beats that characterize cardiac autonomic function. Decreased HRV is associated with increased risk of cardiovascular events. Characterizing HRV using only moment statistics fails to capture abnormalities in regulatory function that are important aspects of disease risk. Thus, entropy measures are a promising approach to quantify HRV for risk stratification. The purpose of this study was to investigate this potential for approximate, corrected approximate, sample, fuzzy, and fuzzy measure entropy and its dependency on the parameter selection. Recently, published parameter sets and further parameter combinations were investigated. Heart rate data were obtained from the "Cardiac Arrhythmia Suppression Trial (CAST RR Interval Sub-Study Database" (Physionet. Corresponding outcomes and clinical data were provided by one of the investigators. The use of previously-reported parameter sets on the pre-treatment data did not significantly add to the identification of patients at risk for cardiovascular death on follow-up. After arrhythmia suppression treatment, several parameter sets predicted outcomes for all patients and patients without coronary artery bypass grafting (CABG. The strongest results were seen using the threshold parameter as a multiple of the data’s standard deviation ( r = 0 . 2 · σ . Approximate and sample entropy provided significant hazard ratios for patients without CABG and without diabetes for an entropy maximizing threshold approximation. Additional parameter combinations did not improve the results for pre-treatment data. The results of this study illustrate the influence of parameter selection on entropy measures’ potential for cardiovascular risk stratification and support the potential use of entropy measures in future studies.

Sympathetic overactivity and arrhythmias in tetanus: electrocardiographic analysis Hiperatividade simpática e arritmias no tétano: análise eletrocardiográfica

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Gustavo Trindade Henriques Filho

2007-02-01

Full Text Available As a result of the advances in the control of pulmonary insufficiency in tetanus, the cardiovascular system has increasingly been shown to be a determining factor in morbidity and mortality but detailed knowledge of the cardiovascular complications in tetanus is scanty. The 24h-Holter was carried out in order to detect arrhythmias and sympathetic overactivity in 38 tetanus patients admitted to an ICU. The SDNN Index (standard deviation from the normal R-to-R intervals, was useful in detecting adrenergic tonus, and ranged from 64.1 ± 27 in the more severe forms of tetanus to 125 ± 69 in the milder ones. Sympathetic overactivity occurred in 86.2% of the more severe forms of the disease, but was also detected in 33% of the milder forms. Half the patients had their sympathetic overactivity detected only by the Holter. The most frequent arrhythmias were isolated supraventricular (55.2% and ventricular (39.4% extrasystoles. There was no association of the arrhythmias with the clinical form of tetanus or with the presence of sympathetic overactivity. The present study demonstrated that major cardiovascular dysfunction, particularly sympathetic overactivity, occurs in all forms of tetanus, even in the milder ones. This has not been effectively detected with traditional monitoring in ICU and may not be properly treated.Com os avanços no controle da insuficiência respiratória no tétano, o sistema cardiovascular tem participado de forma crescente na morbidade e mortalidade da doença, mas o conhecimento dessas complicações é escasso. No intuito de detectar arritmias e hiperatividade simpática, o holter de 24 h foi utilizado em 38 pacientes com tétano admitidos numa UTI de doenças infecciosas. O índice SDNN (desvio standard dos intervalos normais R-a-R, foi útil na detecção do tônus adrenérgico, e variou de 64,1 ± 27 nas formas mais severas de tétano a 125 ± 69 nas formas mais leves. Hiperatividade simpática ocorreu em 86,2% das formas

Respiratory Sinus Arrhythmia Activity Predicts Internalizing and Externalizing Behaviors in Non-referred Boys

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Wei Zhang

2017-09-01

Full Text Available Atypical respiratory sinus arrhythmia (RSA, a biomarker of emotion dysregulation, is associated with both externalizing and internalizing behaviors. In addition, social adversity and gender may moderate this association. In this study, we investigated if RSA (both resting RSA and RSA reactivity in an emotion regulation task predicts externalizing and/or internalizing behaviors and the extent to which social adversity moderates this relationship. Two hundred and fifty-three children (at Time 1, mean age = 9.05, SD = 0.60, 48% boys and their caregivers from the community participated in this study. Resting RSA and RSA reactivity were assessed, and caregivers reported children’s externalizing and internalizing behaviors at both Time 1 and Time 2 (1 year later. We found that lower resting RSA (but not RSA reactivity at Time 1 was associated with increased externalizing and internalizing behaviors at Time 2 in boys, even after controlling for the effects of Time 1 behavioral problems and Time 2 age. Moreover, there was a significant interaction effect between Time 1 resting RSA and social adversity such that lower resting RSA predicted higher externalizing and internalizing behaviors in boys only under conditions of high social adversity. Follow-up analyses revealed that these predictive effects were stronger for externalizing behavior than for internalizing behavior. No significant effects were found for girls. Our findings provide further evidence that low resting RSA may be a transdiagnostic biomarker of emotion dysregulation and a predisposing risk factor for both types of behavior problems, in particular for boys who grow up in adverse environments. We conclude that biosocial interaction effects and gender differences should be considered when examining the etiological mechanisms of child psychopathology.

Image integration into 3-dimensional-electro-anatomical mapping system facilitates safe ablation of ventricular arrhythmias originating from the aortic root and its vicinity.

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Jularic, Mario; Akbulak, Ruken Özge; Schäffer, Benjamin; Moser, Julia; Nuehrich, Jana; Meyer, Christian; Eickholt, Christian; Willems, Stephan; Hoffmann, Boris A

2018-03-01

During ablation in the vicinity of the coronary arteries establishing a safe distance from the catheter tip to the relevant vessels is mandatory and usually assessed by fluoroscopy alone. The aim of the study was to investigate the feasibility of an image integration module (IIM) for continuous monitoring of the distance of the ablation catheter tip to the main coronary arteries during ablation of ventricular arrhythmias (VA) originating in the sinus of valsalva (SOV) and the left ventricular summit part of which can be reached via the great cardiac vein (GCV). Of 129 patients undergoing mapping for outflow tract arrhythmias from June 2014 till October 2015, a total of 39 patients (52.4 ± 18.1 years, 17 female) had a source of origin in the SOV or the left ventricular summit. Radiofrequency (RF) ablation was performed when a distance of at least 5 mm could be demonstrated with IIM. A safe distance in at least one angiographic plane could be demonstrated in all patients with a source of origin in the SOV, whereas this was not possible in 50% of patients with earliest activation in the summit area. However, using the IIM a safe position at an adjacent site within the GCV could be obtained in three of these cases and successful RF ablation performed safely without any complications. Ablation was successful in 100% of patients with an origin in the SOV, whereas VAs originating from the left ventricular summit could be abolished completely in only 60% of cases. Image integration combining electroanatomical mapping and fluoroscopy allows assessment of the safety of a potential ablation site by continuous real-time monitoring of the spatial relations of the catheter tip to the coronary vessels prior to RF application. It aids ablation in anatomically complex regions like the SOV or the ventricular summit providing biplane angiograms merged into the three-dimensional electroanatomical map. Published on behalf of the European Society of Cardiology. All rights reserved. �

Delayed Repolarization Underlies Ventricular Arrhythmias in Rats With Heart Failure and Preserved Ejection Fraction.

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Cho, Jae Hyung; Zhang, Rui; Kilfoil, Peter J; Gallet, Romain; de Couto, Geoffrey; Bresee, Catherine; Goldhaber, Joshua I; Marbán, Eduardo; Cingolani, Eugenio

2017-11-21

Heart failure with preserved ejection fraction (HFpEF) represents approximately half of heart failure, and its incidence continues to increase. The leading cause of mortality in HFpEF is sudden death, but little is known about the underlying mechanisms. Dahl salt-sensitive rats were fed a high-salt diet (8% NaCl) from 7 weeks of age to induce HFpEF (n=38). Rats fed a normal-salt diet (0.3% NaCl) served as controls (n=13). Echocardiograms were performed to assess systolic and diastolic function from 14 weeks of age. HFpEF-verified and control rats underwent programmed electrical stimulation. Corrected QT interval was measured by surface ECG. The mechanisms of ventricular arrhythmias (VA) were probed by optical mapping, whole-cell patch clamp to measure action potential duration and ionic currents, and quantitative polymerase chain reaction and Western blotting to investigate changes in ion channel expression. After 7 weeks of a high-salt diet, 31 of 38 rats showed diastolic dysfunction and preserved ejection fraction along with signs of heart failure and hence were diagnosed with HFpEF. Programmed electric stimulation demonstrated increased susceptibility to VA in HFpEF rats ( P hearts demonstrated prolonged action potentials ( P hearts. Susceptibility to VA was markedly increased in rats with HFpEF. Underlying abnormalities include QT prolongation, delayed repolarization from downregulation of potassium currents, and multiple reentry circuits during VA. Our findings are consistent with the hypothesis that potassium current downregulation leads to abnormal repolarization in HFpEF, which in turn predisposes to VA and sudden cardiac death. © 2017 American Heart Association, Inc.

Discrete prepotential as an indicator of successful ablation in patients with coronary cusp ventricular arrhythmia.

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Hachiya, Hitoshi; Yamauchi, Yasuteru; Iesaka, Yoshito; Yagishita, Atsuhiko; Sasaki, Takeshi; Higuchi, Koji; Kawabata, Mihoko; Sugiyama, Koji; Tanaka, Yasuaki; Kusa, Shigeki; Nakamura, Hiroaki; Miyazaki, Shinsuke; Taniguchi, Hiroshi; Isobe, Mitsuaki; Hirao, Kenzo

2013-10-01

Although coronary cusp (CC) ventricular arrhythmia (VA) can be treated by catheter ablation, reliable indicators of successful ablation sites have not been fully identified. This study comprised 392 patients undergoing radiofrequency catheter ablation for outflow tract-VA at 3 institutions from January 2007 to August 2012. The successful ablation site was on the left CC or right CC in 35 (8.9%) of the 392 patients. In 9 (26%) of these 35 patients, a discrete prepotential was recognized, 5 of whom had left CC-VAs and 4 of whom had right CC-VAs. Radiofrequency catheter ablation was successful at the site of the prepotential in all 9 of these patients. The duration of the isoelectric line between the end of the discrete prepotential and the onset of the ventricular electrogram was 27±13 ms. The time from onset of the discrete prepotential at the successful ablation site on the CC to the QRS onset (activation time) was 69±20 ms (range, 50-98 ms). Pace mapping was graded as excellent at the successful ablation site in only 1 patient. No discrete prepotential was recorded in any successful right outflow tract-VA ablation case in this study. A discrete prepotential was seen in 9 (26%) of 35 patients with CC-VA. In left and right CC-VA, the site of a discrete prepotential with ≥50 ms activation time may indicate a successful ablation site.

Executive Summary: European Heart Rhythm Association Consensus Document on the Management of Supraventricular Arrhythmias: Endorsed by Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardiaca y Electrofisiologia (SOLAECE).

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Katritsis, Demosthenes G; Boriani, Giuseppe; Cosio, Francisco G; Jais, Pierre; Hindricks, Gerhard; Josephson, Mark E; Keegan, Roberto; Knight, Bradley P; Kuck, Karl-Heinz; Lane, Deirdre A; Lip, Gregory Yh; Malmborg, Helena; Oral, Hakan; Pappone, Carlo; Themistoclakis, Sakis; Wood, Kathryn A; Young-Hoon, Kim; Lundqvist, Carina Blomström

2016-01-01

This paper is an executive summary of the full European Heart Rhythm Association (EHRA) consensus document on the management of supraventricular arrhythmias, published in Europace . It summarises developments in the field and provides recommendations for patient management, with particular emphasis on new advances since the previous European Society of Cardiology guidelines. The EHRA consensus document is available to read in full at http://europace.oxfordjournals.org.

Innovation in cardiovascular disease in Europe with focus on arrhythmias: current status, opportunities, roadblocks, and the role of multiple stakeholders.

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Prinzen, Frits W; Dagres, Nikolaos; Bollmann, Andreas; Arnar, David O; Bove, Sylvie; Camm, John; Casadei, Barbara; Kirchhof, Paulus; Kuck, Karl-Heinz; Lumens, Joost; Michel, Martin C; Schwartz, Peter J; Van Vleymen, Betty; Vardas, Panos; Hindricks, Gerhard

2018-05-01

The European Heart Rhythm Association (EHRA) held an Innovation Forum in February 2016, to consider issues around innovation. The objective of the forum was to extend the innovation debate outside of the narrow world of arrhythmia specialists and cardiology in general, and seek input from all stakeholders including regulators, strategists, technologists, industry, academia, health providers, medical societies, payers, and patients. Innovation is indispensable for a continuing improvement in health care, preferably at higher efficacy and lower costs. It requires people who have been trained in a good scientific environment, high-quality research for achieving ground breaking inventions and the certainty of return on innovation investments. In the context of cardiovascular disease, innovation can imply better risk assessment and stratification, device technology, drug development, and process design. Several areas of promising developments were identified as well as several roadblocks to innovation. To drive innovation forward all stakeholders need to play a significant role. In a globalized and extremely competitive world, the leading role of Europe in medical innovation can only be achieved through a combined and well-coordinated effort from all involved parties.

Association of Smoking, Sleep Apnea, and Plasma Alkalosis With Nocturnal Ventricular Arrhythmias in Men With Systolic Heart Failure

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Shukla, Rakesh; Wexler, Laura

2012-01-01

Background: Excess sudden death due to ventricular tachyarrhythmias remains a major mode of mortality in patients with systolic heart failure. The aim of this study was to determine the association of nocturnal ventricular arrhythmias in patients with low ejection fraction heart failure. We incorporated a large number of known pathophysiologic triggers to identify potential targets for therapy to reduce the persistently high incidence of sudden death in this population despite contemporary treatment. Methods: Eighty-six ambulatory male patients with stable low (≤ 45%) ejection fraction heart failure underwent full-night attendant polysomnography and simultaneous Holter recordings. Patients were divided into groups according to the presence or absence of couplets (paired premature ventricular excitations) and ventricular tachycardia (VT) (at least three consecutive premature ventricular excitations) during sleep. Results: In multiple regression analysis, four variables (current smoking status, increased number of arousals, plasma alkalinity, and old age) were associated with VT and two variables (apnea-hypopnea index and low right ventricular ejection fraction) were associated with couplets during sleep. Conclusions: We speculate that cessation of smoking, effective treatment of sleep apnea, and plasma alkalosis could collectively decrease the incidence of nocturnal ventricular tachyarrhythmias and the consequent risk of sudden death, which remains high despite the use of β blockades. PMID:22172636

Evaluation of lidocaine treatment on frequency of cardiac arrhythmias, acute kidney injury, and hospitalization time in dogs with gastric dilatation volvulus.

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Bruchim, Yaron; Itay, Srugo; Shira, Ben-Halevy; Kelmer, Efrat; Sigal, Yudelecitch; Itamar, Aroch; Gilad, Segev

2012-08-01

To assess the efficacy of IV lidocaine in decreasing complication rate and improving the outcome in dogs with gastric dilatation volvulus (GDV). Prospective non-controlled study of 83 lidocaine-treated dogs with GDV compared to 47 untreated historical controls with GDV. University veterinary teaching hospital. One hundred and thirty client-owned dogs with naturally occurring GDV. Study group dogs were treated at presentation with lidocaine (2 mg/kg, IV bolus) followed by constant rate infusion (CRI) of 0.05 mg/kg/min for 24 h. Historical control dogs did not receive any lidocaine. There were no group differences in age, body weight, time lag from onset of clinical signs to presentation, rectal temperature and pulse rate at presentation, and proportion of gastric wall necrosis. The proportions of cardiac arrhythmias and acute kidney injury (AKI) were significantly (Pdogs with GDV compared to untreated historical controls. Due to the nonblinded, placebo-uncontrolled, nonrandomized nature of the current study, further evaluation of the efficacy of lidocaine in dogs with GDV is warranted. © Veterinary Emergency and Critical Care Society 2012.

Alterações contráteis segmentares e sua associação com arritmias ventriculares complexas, em pacientes chagásicos com eletrocardiograma normal ou borderline Regional left ventricular dysfunction and its association with complex ventricular arrhythmia, in chagasic patients with normal or borderline electrocardiogram

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Flavia Vernin de Oliveira Terzi

2010-10-01

Full Text Available INTRODUÇÃO: Morte súbita representa a principal causa de óbito em chagásicos. Eventos fatais em pacientes saudáveis, com anormalidades contráteis, foram documentados. O objetivo deste trabalho é determinar a associação entre alteração contrátil e arritmias ventriculares complexas em pacientes chagásicos, classe funcional I, eletrocardiograma normal ou borderline e função ventricular preservada. MÉTODOS: Quarenta e nove pacientes com doença de Chagas e eletrocardiograma normal ou borderline realizaram ecocardiograma, teste ergométrico e Holter. Avaliou-se a contratilidade global e segmentar dos ventrículos e a presença de arritmias ventriculares complexas induzidas no esforço e espontâneas, respectivamente. A análise estatística foi feita pelo modelo Log-Linear geral. RESULTADOS: Idade média de 56 anos; 55% mulheres. Alterações contráteis segmentares em 24,5% dos pacientes; 12% dos Holter e 18% dos testes ergométricos positivos. Houve associação entre arritmia e alteração segmentar condicionada à presença da disfunção sistólica leve do ventrículo esquerdo. CONCLUSÕES: Alterações contráteis, na presença de disfunção global leve, indicam pacientes sob maior risco de arritmias complexas.INTRODUCTION: Sudden death is the major cause of death among chagasic patients. A significant number of fatal events in patients without apparent heart disease and borderline electrocardiogram, but with contractile ventricular dysfunction, have been documented. This work aimed to determine the association between regional dysfunction and the presence of ventricular arrhythmia in chagasic patients without apparent heart disease. METHODS: Forty-nine patients with normal or borderline electrocardiogram were submitted to echocardiogram, exercise stress test and Holter. The presence of cardiac contractile alterations and complex ventricular arrhythmia was analyzed. Statistic analysis used the general Log-Linear model. RESULTS

Rate of cardiac arrhythmias and silent brain lesions in experienced marathon runners: rationale, design and baseline data of the Berlin Beat of Running study

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Haeusler Karl

2012-08-01

Full Text Available Abstract Background Regular exercise is beneficial for cardiovascular health but a recent meta-analysis indicated a relationship between extensive endurance sport and a higher risk of atrial fibrillation, an independent risk factor for stroke. However, data on the frequency of cardiac arrhythmias or (clinically silent brain lesions during and after marathon running are missing. Methods/ Design In the prospective observational “Berlin Beat of Running” study experienced endurance athletes underwent clinical examination (CE, 3 Tesla brain magnetic resonance imaging (MRI, carotid ultrasound imaging (CUI and serial blood sampling (BS within 2-3 days prior (CE, MRI, CUI, BS, directly after (CE, BS and within 2 days after (CE, MRI, BS the 38th BMW BERLIN-MARATHON 2011. All participants wore a portable electrocardiogram (ECG-recorder throughout the 4 to 5 days baseline study period. Participants with pathological MRI findings after the marathon, troponin elevations or detected cardiac arrhythmias will be asked to undergo cardiac MRI to rule out structural abnormalities. A follow-up is scheduled after one year. Results Here we report the baseline data of the enrolled 110 athletes aged 36-61 years. Their mean age was 48.8 ± 6.0 years, 24.5% were female, 8.2% had hypertension and 2.7% had hyperlipidaemia. Participants have attended a mean of 7.5 ± 6.6 marathon races within the last 5 years and a mean of 16 ± 36 marathon races in total. Their weekly running distance prior to the 38th BMW BERLIN-MARATHON was 65 ± 17 km. Finally, 108 (98.2% Berlin Beat-Study participants successfully completed the 38th BMW BERLIN-MARATHON 2011. Discussion Findings from the “Berlin Beats of Running” study will help to balance the benefits and risks of extensive endurance sport. ECG-recording during the marathon might contribute to identify athletes at risk for cardiovascular events. MRI results will give new insights into the link

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Respiratory sinus arrhythmia stabilizes mean arterial blood pressure at high-frequency interval in healthy humans.

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Elstad, Maja; Walløe, Lars; Holme, Nathalie L A; Maes, Elke; Thoresen, Marianne

2015-03-01

Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.

Effects of local cardiac denervation on cardiac innervation and ventricular arrhythmia after chronic myocardial infarction.

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Xudong Liu

Full Text Available Modulation of the autonomic nervous system (ANS has already been demonstrated to display antiarrhythmic effects in patients and animals with MI. In this study, we investigated whether local cardiac denervation has any beneficial effects on ventricular electrical stability and cardiac function in the chronic phase of MI.Twenty-one anesthetized dogs were randomly assigned into the sham-operated, MI and MI-ablation groups, respectively. Four weeks after local cardiac denervation, LSG stimulation was used to induce VPCs and VAs. The ventricular fibrillation threshold (VFT and the incidence of inducible VPCs were measured with electrophysiological protocol. Cardiac innervation was determined with immunohistochemical staining of growth associated protein-43 (GAP43 and tyrosine hydroxylase (TH. The global cardiac and regional ventricular function was evaluated with doppler echocardiography in this study.Four weeks after operation, the incidence of inducible VPC and VF in MI-ablation group were significantly reduced compared to the MI dogs (p<0.05. Moreover, local cardiac denervation significantly improved VFT in the infarcted border zone (p<0.05. The densities of GAP43 and TH-positive nerve fibers in the infarcted border zone in the MI-ablation group were lower than those in the MI group (p<0.05. However, the local cardiac denervation did not significantly improve cardiac function in the chronic phase of MI, determined by the left ventricle diameter (LV, left atrial diameter (LA, ejection fraction (EF.Summarily, in the chronic phase of MI, local cardiac denervation reduces the ventricular electrical instability, and attenuates spatial heterogeneity of sympathetic nerve reconstruction. Our study suggests that this methodology might decrease malignant ventricular arrhythmia in chronic MI, and has a great potential for clinical application.

Left ventricular outflow tract arrhythmias with divergent QRS morphology: mapping of different exits and ablation strategy.

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Reithmann, Christopher; Fiek, Michael

2018-01-01

Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) can have multiple exits exhibiting divergent ECG features. In a series of 131 patients with VAs with LVOT origin, 10 patients presented with divergent QRS morphologies. Multisite endo- and epicardial mapping of different exit sites was performed. The earliest ventricular activity of 23 LVOT VAs in 10 patients was detected in the endocardium of the LV in 7 patients, the aortic sinuses of Valsalva (SoV) in 3 patients, the distal coronary sinus in 6 patients, the anterior interventricular vein in 3 patients, and the posterior right ventricular outflow tract (RVOT) in 4 patients. Simultaneous elimination of two divergent QRS morphologies of LVOT VAs by ablation from a single site was achieved in 5 patients (aorto-mitral continuity in 3 patients, SoV and RVOT in each 1 patient) using a mean maximum ablation energy of 46 ± 5 W. Sequential ablation from two or three different sites, including trans-pericardial and distal coronary sinus ablation in each 2 patients, led to elimination of the divergent VA QRS morphologies in the other 5 patients. During the follow-up of 28 ± 29 months, 4 of the 10 patients had recurrence of at least one LVOT VA. A 43-year-old patient with muscular dystrophy Curschmann-Steinert had recurrence of sustained LVOT VTs and died of sudden cardiac death. Multisite mapping of different exit sites of LVOT VAs can guide ablation of intramural foci but the recurrence rate after initially successful ablation was high.

Comparison of objective methods to classify the pattern of respiratory sinus arrhythmia during mechanical ventilation and paced spontaneous breathing

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Carvalho, N C; Beda, A; Granja-Filho, P; Jandre, F C; Giannella-Neto, A; De Abreu, M G; Spieth, P M

2009-01-01

Respiratory sinus arrhythmia (RSA) is a fluctuation of heart period that occurs during a respiratory cycle. It has been suggested that inspiratory heart period acceleration and expiratory deceleration during spontaneous ventilation (henceforth named positive RSA) improve the efficiency of gas exchange compared to the absence or the inversion of such a pattern (negative RSA). During mechanical ventilation (MV), for which maximizing the efficiency of gas exchange is of critical importance, the pattern of RSA is still the object of debate. In order to gain a better insight into this matter, we compared five different methods of RSA classification using the data of five mechanically ventilated piglets. The comparison was repeated using the data of 15 volunteers undergoing a protocol of paced spontaneous breathing, which is expected to result in a positive RSA pattern. The results showed that the agreement between the employed methods is limited, suggesting that the lack of a consensus about the RSA pattern during MV is, at least in part, of methodological origin. However, independently of the method used, the pattern of RSA within the respiratory cycle was not consistent among the subjects and conditions of MV considered. Also, the outcomes showed that even during paced spontaneous breathing a negative RSA pattern might be present, when a low respiratory frequency is imposed

Toxicokinetics of ibogaine and noribogaine in a patient with prolonged multiple cardiac arrhythmias after ingestion of internet purchased ibogaine.

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Henstra, Marieke; Wong, Liza; Chahbouni, Abdel; Swart, Noortje; Allaart, Cor; Sombogaard, Ferdi

2017-07-01

Ibogaine is an agent that has been evaluated as an unapproved anti-addictive agent for the management of drug dependence. Sudden cardiac death has been described to occur secondary to its use. We describe the clinical effects and toxicokinetics of ibogaine and noribogaine in a single patient. For this purpose, we developed a LC-MS/MS-method to measure ibogaine and noribogaine plasma-concentrations. We used two compartments with first order absorption. The maximum concentration of ibogaine was 1.45 mg/L. Our patient developed markedly prolonged QTc interval of 647ms maximum, several multiple cardiac arrhythmias (i.e., atrial tachycardia and ventricular tachycardia and Torsades des Pointes). QTc-prolongation remained present until 12 days after ingestion, several days after ibogaine plasma-levels were low, implicating clinically relevant noribogaine concentrations long after ibogaine had been cleared from the plasma. The ratio k 12 /k 21 for noribogaine was 21.5 and 4.28 for ibogaine, implicating a lower distribution of noribogaine from the peripheral compartment into the central compartment compared to ibogaine. We demonstrated a linear relationship between the concentration of the metabolite and long duration of action, rather than with parent ibogaine. Therefore, after (prolonged) ibogaine ingestion, clinicians should beware of long-term effects due to its metabolite.

A Novel Nonsense Variant in Nav1.5 Cofactor MOG1 Eliminates Its Sodium Current Increasing Effect and May Increase the Risk of Arrhythmias

DEFF Research Database (Denmark)

Olesen, Morten S; Jensen, Niels F; Holst, Anders G

2011-01-01

at a lower frequency (1.8% vs 0.4%, P = 0.078). Electrophysiological investigation showed that the p.E61X variant completely eliminates the sodium current-increasing effect of MOG1 and thereby causes loss of function in the sodium current. When mimicking heterozygosity by coexpression of Nav1.5 with wild......BACKGROUND: The protein MOG1 is a cofactor of the cardiac sodium channel, Nav1.5. Overexpression of MOG1 in Nav1.5-expressing cells increases sodium current markedly. Mutations in the genes encoding Nav1.5 and its accessory proteins have been associated with cardiac arrhythmias of significant...... and 23 were patients with Brugada syndrome. The effect of one variant was investigated functionally by patch-clamping CHO-K1 cells coexpressing Nav1.5 with MOG1. RESULTS: We uncovered a novel heterozygous nonsense variant, c.181G>T (p.E61X), that, however, was also present in control subjects, albeit...

Applying non-linear dynamics to atrial appendage flow data to understand and characterize atrial arrhythmia

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Chandra, S.; Grimm, R.A.; Katz, R.; Thomas, J.D.

1996-01-01

The aim of this study was to better understand and characterize left atrial appendage flow in atrial fibrillation. Atrial fibrillation and flutter are the most common cardiac arrhythmias affecting 15% of the older population. The pulsed Doppler velocity profile data was recorded from the left atrial appendage of patients using transesophageal echocardiography. The data was analyzed using Fourier analysis and nonlinear dynamical tools. Fourier analysis showed that appendage mechanical frequency (f f ) for patients in sinus rhythm was always lower (around1 Hz) than that in atrial fibrillation (5-8 Hz). Among patients with atrial fibrillation spectral power below f f was significantly different suggesting variability within this group of patients. Results that suggested the presence of nonlinear dynamics were: a) the existence of two arbitrary peak frequencies f 1 , f 2 , and other peak frequencies as linear combinations thereof (mf 1 ±nf 2 ), and b) the similarity between the spectrum of patient data and that obtained using the Lorenz equation. Nonlinear analysis tools, including Phase plots and differential radial plots, were also generated from the velocity data using a delay of 10. In the phase plots, some patients displayed a torus-like structure, while others had a more random-like pattern. In the differential radial plots, the first set of patients (with torus-like phase plots) showed fewer values crossing an arbitrary threshold of 10 than did the second set (8 vs. 27 in one typical example). The outcome of cardioversion was different for these two set of patients. Fourier analysis helped to: differentiate between sinus rhythm and atrial fibrillation, understand the characteristics of the wide range of atrial fibrillation patients, and provide hints that atrial fibrillation could be a nonlinear process. Nonlinear dynamical tools helped to further characterize and sub-classify atrial fibrillation

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Systemic right ventricular fibrosis detected by cardiovascular magnetic resonance is associated with clinical outcome, mainly new-onset atrial arrhythmia, in patients after atrial redirection surgery for transposition of the great arteries.

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Rydman, Riikka; Gatzoulis, Michael A; Ho, Siew Yen; Ernst, Sabine; Swan, Lorna; Li, Wei; Wong, Tom; Sheppard, Mary; McCarthy, Karen P; Roughton, Michael; Kilner, Philip J; Pennell, Dudley J; Babu-Narayan, Sonya V

2015-05-01

We hypothesized that fibrosis detected by late gadolinium enhancement (LGE) cardiovascular magnetic resonance predicts outcomes in patients with transposition of the great arteries post atrial redirection surgery. These patients have a systemic right ventricle (RV) and are at risk of arrhythmia, premature RV failure, and sudden death. Fifty-five patients (aged 27±7 years) underwent LGE cardiovascular magnetic resonance and were followed for a median 7.8 (interquartile range, 3.8-9.6) years in a prospective single-center cohort study. RV LGE was present in 31 (56%) patients. The prespecified composite clinical end point comprised new-onset sustained tachyarrhythmia (atrial/ventricular) or decompensated heart failure admission/transplantation/death. Univariate predictors of the composite end point (n=22 patients; 19 atrial/2 ventricular tachyarrhythmia, 1 death) included RV LGE presence and extent, RV volumes/mass/ejection fraction, right atrial area, peak Vo(2), and age at repair. In bivariate analysis, RV LGE presence was independently associated with the composite end point (hazard ratio, 4.95 [95% confidence interval, 1.60-15.28]; P=0.005), and only percent predicted peak Vo(2) remained significantly associated with cardiac events after controlling for RV LGE (hazard ratio, 0.80 [95% confidence interval, 0.68-0.95]; P=0.009/5%). In 8 of 9 patients with >1 event, atrial tachyarrhythmia, itself a known risk factor for mortality, occurred first. There was agreement between location and extent of RV LGE at in vivo cardiovascular magnetic resonance and histologically documented focal RV fibrosis in an explanted heart. There was RV LGE progression in a different case restudied for clinical indications. Systemic RV LGE is strongly associated with adverse clinical outcome especially arrhythmia in transposition of the great arteries, thus LGE cardiovascular magnetic resonance should be incorporated in risk stratification of these patients. © 2015 American Heart

Safe Oral Triiodo-L-Thyronine Therapy Protects from Post-Infarct Cardiac Dysfunction and Arrhythmias without Cardiovascular Adverse Effects.

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Viswanathan Rajagopalan

Full Text Available A large body of evidence suggests that thyroid hormones (THs are beneficial for the treatment of cardiovascular disorders. We have shown that 3 days of triiodo-L-thyronine (T3 treatment in myocardial infarction (MI rats increased left ventricular (LV contractility and decreased myocyte apoptosis. However, no clinically translatable protocol is established for T3 treatment of ischemic heart disease. We hypothesized that low-dose oral T3 will offer safe therapeutic benefits in MI.Adult female rats underwent left coronary artery ligation or sham surgeries. T3 (~6 μg/kg/day was available in drinking water ad libitum immediately following MI and continuing for 2 month(s (mo. Compared to vehicle-treated MI, the oral T3-treated MI group at 2 mo had markedly improved anesthetized Magnetic Resonance Imaging-based LV ejection fraction and volumes without significant negative changes in heart rate, serum TH levels or heart weight, indicating safe therapy. Remarkably, T3 decreased the incidence of inducible atrial tachyarrhythmias by 88% and improved remodeling. These were accompanied by restoration of gene expression involving several key pathways including thyroid, ion channels, fibrosis, sympathetic, mitochondria and autophagy.Low-dose oral T3 dramatically improved post-MI cardiac performance, decreased atrial arrhythmias and cardiac remodeling, and reversed many adverse changes in gene expression with no observable negative effects. This study also provides a safe and effective treatment/monitoring protocol that should readily translate to humans.

Frequency of exercise-induced ST-T-segment deviations and cardiac arrhythmias in recreational endurance athletes during a marathon race: results of the prospective observational Berlin Beat of Running study.

Science.gov (United States)

Herm, Juliane; Töpper, Agnieszka; Wutzler, Alexander; Kunze, Claudia; Krüll, Matthias; Brechtel, Lars; Lock, Jürgen; Fiebach, Jochen B; Heuschmann, Peter U; Haverkamp, Wilhelm; Endres, Matthias; Jungehulsing, Gerhard Jan; Haeusler, Karl Georg

2017-08-03

While regular physical exercise has many health benefits, strenuous physical exercise may have a negative impact on cardiac function. The 'Berlin Beat of Running' study focused on feasibility and diagnostic value of continuous ECG monitoring in recreational endurance athletes during a marathon race. We hypothesised that cardiac arrhythmias and especially atrial fibrillation are frequently found in a cohort of recreational endurance athletes. The main secondary hypothesis was that pathological laboratory findings in these athletes are (in part) associated with cardiac arrhythmias. Prospective observational cohort study including healthy volunteers. One hundred and nine experienced marathon runners wore a portable ECG recorder during a marathon race in Berlin, Germany. Athletes underwent blood tests 2-3 days prior, directly after and 1-2 days after the race. Overall, 108 athletes (median 48 years (IQR 45-53), 24% women) completed the marathon in 249±43 min. Blinded ECG analysis revealed abnormal findings during the marathon in 18 (16.8%) athletes. Ten (9.3%) athletes had at least one episode of non-sustained ventricular tachycardia, one of whom had atrial fibrillation; eight (7.5%) individuals showed transient ST-T-segment deviations. Abnormal ECG findings were associated with advanced age (OR 1.11 per year, 95% CI 1.01 to 1.23), while sex and cardiovascular risk profile had no impact. Directly after the race, high-sensitive troponin T was elevated in 18 (16.7%) athletes and associated with ST-T-segment deviation (OR 9.9, 95% CI 1.9 to 51.5), while age, sex and cardiovascular risk profile had no impact. ECG monitoring during a marathon is feasible. Abnormal ECG findings were present in every sixth athlete. Exercise-induced transient ST-T-segment deviations were associated with elevated high-sensitive troponin T (hsTnT) values. ClinicalTrials.gov NCT01428778; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article

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Non cancerous diseases following a chronic intern contamination by caesium 137: cataracts and cardiac arrhythmias; Pathologies non cancereuses potentiellement consecutives a une contamination interne chronique par le cesium 137: cataractes et arythmies cardiaques

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Landon, G

2008-07-15

This work of thesis joins within the framework of an analysis of the sanitary consequences of the nuclear accident of Chernobylsk. Since 2005, the I.R.S.N. is interested in the not cancerous pathologies (cataracts, and cardiac arrhythmias) observed among the children living on the contaminated territories after the fallout of Chernobylsk and has in this aim implemented a research programme called E.P.I.C.E. (Evaluation of the pathologies induced by a chronicle contamination by cesium) whom objective is to show an eventual link between the chronicle ingestion of contaminated food and these pathologies emergence. An exploitation of the results of the pilot study,first phase of the E.P.I.C.E. program was realized. The analysis was completed by two bibliographical reviews relative to the knowledge available on these diseases. The results of this pilot study suggest: on one hand, an absence of link between the activity in cesium 137 at the level of the heart, of the whole body and the emergence of disorder of the heart rhythm; on the other hand, for the cases of cataract, a link between the load in cesium 137 at the neck level and the emergence of the disease in 40 % of the cases. However, these results must be considered with caution because several limits and, in particular, a way of selection affect this study. concerning the scientific literature, this one stays rather poor because only thee articles make reference to a relationship between cesium 137 and the emergence of these non cancerous pathologies. After having exposed the context, this thesis draws up the situation of knowledge relative to cataracts and to cardiac arrhythmias and their possible relationship with ionizing radiations, collect the results stemming from the analysis of the pilot study and envisages future epidemiological studies. (N.C.)

Does respiratory sinus arrhythmia (RSA) predict anxiety reduction during cognitive behavioral therapy (CBT) for social anxiety disorder (SAD)?

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Mathewson, Karen J; Schmidt, Louis A; Miskovic, Vladimir; Santesso, Diane L; Duku, Eric; McCabe, Randi E; Antony, Martin M; Moscovitch, David A

2013-05-01

Modifying dysfunctional emotion regulation is an important goal in psychological treatments for social anxiety disorder (SAD). Antecedent-focused strategies learned in cognitive behavioral therapy (CBT), such as cognitive reappraisal, have proven more effective in reducing social anxiety than response-focused strategies, such as expressive suppression. Still, not all patients with SAD respond well to CBT. Medications and physiological factors may also influence the clinical response. The purpose of the present study was to examine the role that these factors play in determining treatment response following CBT for SAD. Using multilevel modeling, we examined associations across four separate laboratory visits between change in self-reported anxiety and indices of reappraisal, suppression, medication status, and resting respiratory sinus arrhythmia (RSA), a proxy measure of self-regulatory capacity, in 23 socially anxious adults during a 12-week program of CBT. Most participants were ultimately classified as responders to CBT (n=15), but in some, anxiety levels remained unchanged (n=8). Medication use explained substantial variance related to individual differences in anxiety among participants. When modeled separately, reappraisal, suppression, and RSA each accounted for significant variance related to anxiety. However, the best-fitting model included reappraisal and RSA. Moreover, RSA reactivity (change in RSA levels over time) was more important for predicting anxiety reduction than were baseline levels of RSA. These findings suggest that reappraisal and parasympathetic responsiveness may be important in reducing anxiety in adults with SAD who respond well to CBT. Copyright © 2013 Elsevier B.V. All rights reserved.

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Force Trends and Pulsatility for Catheter Contact Identification in Intracardiac Electrograms during Arrhythmia Ablation.

Science.gov (United States)

Rivas-Lalaleo, David; Muñoz-Romero, Sergio; Huerta, Mónica; Erazo-Rodas, Mayra; Sánchez-Muñoz, Juan José; Rojo-Álvarez, José Luis; García-Alberola, Arcadi

2018-05-02

The intracardiac electrical activation maps are commonly used as a guide in the ablation of cardiac arrhythmias. The use of catheters with force sensors has been proposed in order to know if the electrode is in contact with the tissue during the registration of intracardiac electrograms (EGM). Although threshold criteria on force signals are often used to determine the catheter contact, this may be a limited criterion due to the complexity of the heart dynamics and cardiac vorticity. The present paper is devoted to determining the criteria and force signal profiles that guarantee the contact of the electrode with the tissue. In this study, we analyzed 1391 force signals and their associated EGM recorded during 2 and 8 s, respectively, in 17 patients (82 ± 60 points per patient). We aimed to establish a contact pattern by first visually examining and classifying the signals, according to their likely-contact joint profile and following the suggestions from experts in the doubtful cases. First, we used Principal Component Analysis to scrutinize the force signal dynamics by analyzing the main eigen-directions, first globally and then grouped according to the certainty of their tissue-catheter contact. Second, we used two different linear classifiers (Fisher discriminant and support vector machines) to identify the most relevant components of the previous signal models. We obtained three main types of eigenvectors, namely, pulsatile relevant, non-pulsatile relevant, and irrelevant components. The classifiers reached a moderate to sufficient discrimination capacity (areas under the curve between 0.84 and 0.95 depending on the contact certainty and on the classifier), which allowed us to analyze the relevant properties in the force signals. We conclude that the catheter-tissue contact profiles in force recordings are complex and do not depend only on the signal intensity being above a threshold at a single time instant, but also on time pulsatility and trends. These

Electromagnetic fields and health effects-epidemiologic studies of cancer, diseases of the central nervous system and arrhythmia-related heart disease

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Johansen, C.

2004-07-01

This epidemiologic investigation comprised separate studies of the risk of cancer, cause-specific mortality rates, risks for neurodegenerative diseases, and the risk of arrhythmia-related heart disease among employees exposed to extremely low- frequency (50-Hz) electromagnetic fields (EMF) in the Danish utility industry. All the employees in this industry were followed-up in several registers. The risk of disease was analyzed in relation to occupational exposure to EMF, latency, and duration of employment. A specific job-exposure matrix was developed and validated by comparison with direct measurements of EMF during a workday. Linkage with the Danish Cancer Register did not identify increased risks for the cancers suggested a priori to be associated with exposure to EMF, including leukemia, brain tumors, and breast cancer. Significantly increased risks for lung cancer and mesothelioma were identified for workers highly exposed to asbestos. Linkage with the National Mortality Register revealed a significantly increased overall mortality rate from amyotrophic lateral sclerosis (ALS), with an increasing trend with duration of employment and EMF exposure. In addition, a significantly increased mortality rate from electric accidents was observed. It was hypothesized that the observation of increased mortality from ALS was associated with exposure to EMF or electric shocks. No increased mortality rate from cardiovascular or cerebrovascular disease was observed. Linkage with the National Hospital Register also revealed an increased risk of ALS and, thereby confirmed the finding of an increased mortality rate for this disease in the previous study. Linkage of the cohort with the Multiple Sclerosis Register revealed an increased risk of multiple sclerosis, which was not, however, significant Linkage with the Pacemaker Register showed no increased risk of severe arrhythmia-related heart disease. The second part of the study included the establishment of a large, nationwide

Use of myocardial tomo-scintigraphy by {sup 123}I - MIBG in right ventricle arrhythmia-gen dysplasia; Interet de la tomoscintigraphie myocardique a la {sup 123}I - MIBG dans la dysplasie arrythmogene du ventricule droit

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Agostini, D.; Manrique, A.; Darlas, Y. [Service de Medecine Nucleaire, CHU Cote de Nacre, Caen (France); Loiselet, P.; Scanu, P.; Grollier, G.; Potier, J.C. [Service de Cardiologie, CHU Cote de Nacre, Caen (France); Bouvard, G. [Service de Medecine Nucleaire, CHU Cote de Nacre, Caen (France)

1997-12-31

The dysfunction of myocardial sympathetic system was implied in occurrence of ventricular arrhythmias in patients with a right ventricle arrhythmia-gen dysplasia (RVAD). The goal of this study is to evaluate the myocardial pre-synaptic adrenergic regional function by using the cardiac tomo-scintigraphy with {sup 123}I - meta-iodo-benzyl-guanidine (MIBG). Fourteen patients (12 M, 2 F, age: 46{+-} 13) in whom the disease`s diagnosis was done on the basis of the parameters of European Task Force (electric, angiographic, histologic), were studied. Six healthy subjects (32 {+-} 12 years) were at the same time studied as control group. Each patient benefited by an at-rest tomo-scintigraphy by {sup 201}Tl to eliminate any hypo-perfusion which could hinder the interpretation of MIBG fixation. A 48 h delay was necessary between the two isotopic examinations. After blocking the thyroid by Lugol fort, an at-rest tomo-scintigraphy by {sup 123}I - MIBG was effected 4 h after the injection IV of 259 MBq of tracer following a classical acquisition of a myocardial tomography with a tracer-adopted collimator (Elscint camera). Global and regional evaluations of the cardiac adrenergic neuronal function were effected by using the cardio-mediastinal ratio (CMR) and the circumferential profile, respectively, for the localization, extension and amplitude of regional adrenergic defects. The CMR is within the normal limits (236 {+-} 39% vs 234 {+-} 14% in healthy subjects). The adrenergic defects are present in 11/14 patients (a reduction of 50% of capture of MIBG as compared with the control group, < average - 2 ET) in the anterior and lateral regions of left ventricle. In conclusion, the tomo-scintigraphy by {sup 123}I - MIBG allows the detecting of presence of a sympathetic dys-innervation of left ventricle in patients afflicted with RVAD

[Effects of synthetic antioxidant ionol on bioelectric activity of cardiomyocytes and arrhythmia in global ischemia and reperfusion of the isolated rat heart].

Science.gov (United States)

Belkina, L M; Vovk, V I; Meerson, F Z

1992-04-01

Isolated rat hearts were subjected to global ischemia (15 min) and reperfusion (20 min). Transmembrane potentials were recorded on the epicardial surface and contractile force was measured. Ischemia reduced the resting potential, the action potential (AP) amplitude and the AP duration (APD) in control animals. Pretreatment with synthetic antioxidant ionol (BHT, 50 mg/kg, per os) didn't influence the time course of changes in the resting potential and AP amplitude during ischemia, but significantly increased APD. In the pretreated group, 5 min after the aorta clamping, the APD at 50% and 90% levels of repolarization was 36% (p less than 0.05) and 13% (p less than 0.1) higher in comparison to the preischemic level and 10 min after clamping by 27% (p less than 0.1) and 29% (p less than 0.05), respectively. By the end of ischemia in the pretreated group, APD re-decreased almost to basal level, but in control group, it remained decreased. During reperfusion BHT improved the recovery of bioelectrical activity and the contractile function. The BHT 10-fold reduced the malignant arrhythmias duration and 2.5-fold the incidence of ventricular tachycardia and fibrillation during reperfusion. These results indicate that the induced by BHT increase in APD can contribute to the mechanism of BHT antiarrhythmic action.

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

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Gimelli, Alessia; Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia; Marzullo, Paolo

2016-01-01

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic "9"9"mTc-tetrofosmin and "1"2"3I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target. (orig.)

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

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Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia [University Hospital of Pisa, Cardio-Thoracic and Vascular Department, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)

2016-12-15

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic {sup 99m}Tc-tetrofosmin and {sup 123}I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target

Feasibility of implementation of a "simplified, No-X-Ray, no-lead apron, two-catheter approach" for ablation of supraventricular arrhythmias in children and adults.

Science.gov (United States)

Stec, Sebastian; Śledź, Janusz; Mazij, Mariusz; Raś, Małgorzata; Ludwik, Bartosz; Chrabąszcz, Michał; Śledź, Arkadiusz; Banasik, Małgorzata; Bzymek, Magdalena; Młynarczyk, Krzysztof; Deutsch, Karol; Labus, Michał; Śpikowski, Jerzy; Szydłowski, Lesław

2014-08-01

Although the "near-zero-X-Ray" or "No-X-Ray" catheter ablation (CA) approach has been reported for treatment of various arrhythmias, few prospective studies have strictly used "No-X-Ray," simplified 2-catheter approaches for CA in patients with supraventricular tachycardia (SVT). We assessed the feasibility of a minimally invasive, nonfluoroscopic (MINI) CA approach in such patients. Data were obtained from a prospective multicenter CA registry of patients with regular SVTs. After femoral access, 2 catheters were used to create simple, 3D electroanatomic maps and to perform electrophysiologic studies. Medical staff did not use lead aprons after the first 10 MINI CA cases. A total of 188 patients (age, 45 ± 21 years; 17% 0.05), major complications (0% vs. 0%, P > 0.05) and acute (98% vs. 98%, P > 0.05) and long-term (93% vs. 94%, P > 0.05) success rates were similar in the "No-X-Ray" and control groups. Implementation of a strict "No-X-Ray, simplified 2-catheter" CA approach is safe and effective in majority of the patients with SVT. This modified approach for SVTs should be prospectively validated in a multicenter study. © 2014 Wiley Periodicals, Inc.

The potential of a heavy particle radiotherapy as the definitive noninvasive treatment for the life threatening ventricular tachy-arrhythmias

International Nuclear Information System (INIS)

Amino, Mari; Yoshioka, Kouichiro; Tanabe, Teruhisa

2006-01-01

Ionizing radiation has been shown to increase intercellular communication in skin and lungs through an increase of expression of connexin43 (Cx43). If analogous upregulation of Cx43 is induced in the heart, it would provide a new perspective for radiation therapy of arrhythmias. Non-transmural MI was created by microsphere injection into coronary arteries. Targeted heavy ion radiation (THIR, 15 Gy) was carried out 2w after MI by using an accelerator (HIMAC, Chiba, Japan). The hearts excised 2w later were employed for immunohistochemistry and high-resolution optical mapping. In MI hearts, a reduction of immunoreactive Cx43 and its displacement from the intercalated disc (ID) region were recognized in the peri-infarct zone. Application of THIR to MI resulted in a significant increase of Cx43 expression (by 61±25%). Optical signals in LV free wall of MI (n=6) were characterized by a marked increase of APD dispersion (APDD: 23±9.1 ms in MI vs. 13±3.8 ms in Control, p<0.05). In MI+THIR (n=4), APDD was reduced to 15±5.0 ms (p<0.05 vs. MI). VTs ere induced by premature stimuli in 5/6 MI, whereas 2/4 MI+THIR. VTs in MI showed disorganized rotors which were easily deteriorated in VF. VTs in MI+THIR showed more organized excitation and did not transformed into VF. THIR increases Cx43 expression, and improves the electrical stability of rabbit ventricles after MI. (author)

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Late gadolinium enhancement by magnetic resonance explains adverse cardiac events in individuals with ventricular arrhythmia; Realce tardío con gadolinio por resonancia magnética explica eventos cardíacos adversos en individuos con arritmia ventricular

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Courtis, J.; Vasallo, J.; Arabia, L. [Departamento de Imágenes, Cardiología Intervencionista y Electrofisiología Instituto Oulton, Córdoba (Argentina); Dimitroff, M.; Gonzalez, A. [Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Códoba (Argentina); Tibaldi, M., E-mail: javiercourtis@oulton.com.ar [Técnicas no Invasivas y Arritmias, Instituto Modelo de Cardiología, Córdoba (Argentina)

2012-07-01

Objective: To determine whether the presence of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) predict adverse cardiac events in patients with ventricular arrhythmia. Methods: We selected 74 consecutive patients with symptomatic ventricular arrhythmia (premature ventricular contractions and ventricular tachycardia) and left ventricular ejection fraction (LVEF) >55% sent to CMR for evaluation of structural heart disease previously undetected by other complementary methods. LGE, systolic function and volumes of both ventricles were analyzed. At follow-up was assessed a combined end point: hospitalization for ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy and cardiac death. Results: During a median follow up of 575 days (interquartile range 24-1120 days) and by analyzing the population according to the presence (n=9, 12%) or not (n=65, 88%) LGE was observed that the group with positive Gd had lower LVEF (58% vs. 66% respectively, p=0.01) and larger volumes (EDV: 185 ml vs. 123 ml respectively, p=0.01 and ESV: 81 ml vs. 42 ml respectively, p=0.01) than the other group. Two (22%) patients in the LGE + group vs. one (4%) of those without LGE showed the combined endpoint (p=0.01) and when performing a logistic regression analysis it was found that the LGE is a predictor of adverse cardiac events analyzed (p=0.029). Conclusions: In this consecutive series of patients with ventricular arrhythmia we demonstrate a strong association between myocardial LGE and adverse cardiac events; this supports the hypothesis that myocardial fibrosis is an important arrhythmogenic substrate. In addition, almost all individuals without LGE were free of events during follow-up suggesting that it is possible to identify through the CMR low-risk individuals who can be treated conservatively. (authors) [Spanish] Objetivo: determinar si la presencia de realce tardío con gadolinio (RTG) por resonancia magnética cardiovascular (RMC

Respiratory sinus arrhythmia as a predictor of eating disorder symptoms in college students: Moderation by responses to stress and parent psychological control.

Science.gov (United States)

Abaied, Jamie L; Wagner, Caitlin; Breslend, Nicole Lafko; Flynn, Megan

2016-04-01

This longitudinal study examined the prospective contribution of respiratory sinus arrhythmia (RSA), a key physiological indicator of self-regulation, to eating disorder symptoms in college students, and whether this link was moderated by maladaptive responses to stress and parent psychological control. At Wave 1, college students' RSA was measured at rest. At Waves 1 and 2 (six-month follow-up), students reported on their eating disorder symptoms, coping and involuntary responses to stress, and perceptions of their parents' use of psychological control. Significant three-way interactions indicated that the link between RSA and subsequent eating disorder symptoms was contingent on responses to stress and parent psychological control. In the context of maladaptive responses to stress and high psychological control, RSA predicted increased eating disorder symptoms over time. In the absence of parent psychological control, high RSA was beneficial in most cases, even when individuals reported maladaptive responses to stress. This study presents novel evidence that high RSA contributes to risk for or resilience to eating disorder symptoms over time. RSA can be protective against eating disorder symptoms, but in some contexts, the self-regulation resources that high RSA provides may be inappropriately applied to eating cognitions and behaviors. This research highlights the importance of examining physiological functioning conjointly with other risk factors as precursors to eating disorder symptoms over time. Copyright © 2016. Published by Elsevier Ltd.

Drug-induced Inhibition and Trafficking Disruption of ion Channels: Pathogenesis of QT Abnormalities and Drug-induced Fatal Arrhythmias

Science.gov (United States)

Cubeddu, Luigi X.

2016-01-01

Risk of severe and fatal ventricular arrhythmias, presenting as Torsade de Pointes (TdP), is increased in congenital and acquired forms of long QT syndromes (LQTS). Drug-induced inhibition of K+ currents, IKs, IKr, IK1, and/or Ito, delay repolarization, prolong QT, and increase the risk of TdP. Drug-induced interference with IKr is the most common cause of acquired LQTS/TdP. Multiple drugs bind to KNCH2-hERG-K+ channels affecting IKr, including antiarrythmics, antibiotics, antivirals, azole-antifungals, antimalarials, anticancer, antiemetics, prokinetics, antipsychotics, and antidepressants. Azithromycin has been recently added to this list. In addition to direct channel inhibition, some drugs interfere with the traffic of channels from the endoplasmic reticulum to the cell membrane, decreasing mature channel membrane density; e.g., pentamidine, geldalamicin, arsenic trioxide, digoxin, and probucol. Other drugs, such as ketoconazole, fluoxetine, norfluoxetine, citalopram, escitalopram, donepezil, tamoxifen, endoxifen, atazanavir, and roxitromycin, induce both direct channel inhibition and impaired channel trafficking. Although many drugs prolong the QT interval, TdP is a rare event. The following conditions increase the risk of drug-induced TdP: a) Disease states/electrolyte levels (heart failure, structural cardiac disease, bradycardia, hypokalemia); b) Pharmacogenomic variables (presence of congenital LQTS, subclinical ion-channel mutations, history of or having a relative with history of drug-induced long QT/TdP); c) Pharmacodynamic and kinetic factors (high doses, women, elderly, metabolism inhibitors, combining two or more QT prolonging drugs, drugs that prolong the QT and increase QT dispersion, and drugs with multiple actions on ion channels). Because most of these conditions are preventable, careful evaluation of risk factors and increased knowledge of drug use associated with repolarization abnormalities are strongly recommended. PMID:26926294

About Arrhythmia

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... heart beats 60 to 100 times a minute. Electrocardiography (ECG or EKG) is a painless, non-invasive procedure that records ... patient sheets Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

[Late arrhythmias in the operated interatrial communication. Analysis of sinus node function and the conduction pathways by His bundle electrocardiography].

Science.gov (United States)

Ramírez, A; Gil, M; Martínez Ríos, M A; Cárdenas, M; Pliego, J; Zamora, C; Mata, L A

1982-01-01

Four hundred patients with atrial septal defect treated surgically were reviewed. Thirty five (8.7%) developed arrhytmias post-surgery which persisted for over a year. Sinus bradycardia was found in 10 patients, nodal rhythm in 21, and atrial fibrilation and flutter in 4 patients. Thirty five per cent of the patients with late arrhythmias developed related symptomatology. In 14 patients the function of the sinus node was studied with electrical stimulation of the atrium and with His registry. The interatrial conduction time, AV node and His Purkinje were analized employing various stimulation frequencies. All the cases studied had normal intra-atrial conduction; the response of the atrio-ventricular node to increasing frequencies was normal, an the intraventricular conduction remained constant. In 8 patients (52%), alterations of the sinus node were found; these consisted of prolonged post-stimulation pauses, Wenckebach's type sinoatrial block and suppression of sinus automatism employing vagal procedures or through electrical stimulation. A patient with severe bradycardia detected by dynamic electrocardiography had to be treated with a permanent pacemaker. We confirm that these arrhytmias are not produced by lesions of the internodal tracts, and that an alteration of the sinus node is frequent without a concomitant lesion of the intraventricular pathway. The lesion to the nutrient artery could be due to trauma and/or surgically induced. The response to anticholinergic drugs was good. Prolonged observation of these patients could increase the morbility of these arrythmias and raise doubts of the surgical indications in cases with moderate hemodynamic repercussion.

Effect of amiodarone therapy on mortality in patients with left ventricular dysfunction and asymptomatic complex ventricular arrhythmias: Argentine Pilot Study of Sudden Death and Amiodarone (EPAMSA).

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Garguichevich, J J; Ramos, J L; Gambarte, A; Gentile, A; Hauad, S; Scapin, O; Sirena, J; Tibaldi, M; Toplikar, J

1995-09-01

The efficiency of prophylactic antiarrhythmic treatment with amiodarone in reducing 1-year mortality in patients with reduced left ventricular ejection fraction ( < 35%) and asymptomatic ventricular arrhythmias (Lown classes 2 and 4) was investigated in a prospective, multicenter, randomized, controlled study. Among 127 patients who entered the study, 61 were assigned to no antiarrhythmic therapy (control group [CG] and 66 to amiodarone treatment (amiodarone group [AG]). Amiodarone was administered at a dosage of 800 mg/day for 2 weeks followed by 400 mg/day thereafter. A 12-month follow-up was completed for 106 patients (57 in the AG and 49 in the CG). Amiodarone reduced the overall mortality rate, which was 10.5% in the AG versus 28.6% in the CG (odds ratio [OR] 0.29; 95% confidence interval [CI] 0.10 to 0.84; log-rank test 0.02) and sudden death rate, which was 7.0% in the AG versus 20.4% in the CG (OR 0.29; 95% CI 0.08 to 1.00; log-rank test 0.04). Side effects were rare, and in only three patients did amiodarone treatment have to be discontinued.

Have the Findings from Clinical Risk Prediction and Trials Any Key Messages for Safety Pharmacology?

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Jem D. Lane

2017-11-01

Full Text Available Anti-arrhythmic drugs are a mainstay in the management of symptoms related to arrhythmias, and are adjuncts in prevention and treatment of life-threatening ventricular arrhythmias. However, they also have the potential for pro-arrhythmia and thus the prediction of arrhythmia predisposition and drug response are critical issues. Clinical trials are the latter stages in the safety testing and efficacy process prior to market release, and as such serve as a critical safeguard. In this review, we look at some of the lessons to be learned from approaches to arrhythmia prediction in patients, clinical trials of drugs used in the treatment of arrhythmias, and the implications for the design of pre-clinical safety pharmacology testing.

ALCOHOL AND HEART RHYTHM DISORDERS

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A. O. Yusupova

2015-01-01

Full Text Available Alcohol abuse and particularly extension of alcohol consumption in alcohol diseas increases the risk of cardiac arrhythmias development and aggravates existing arrhythmias. Patients do not always receive the necessary specific treatment due to lack of detection of the ethanol genesis of these arrhythmias. Management of patients with alcohol abuse and alcohol dependence, including its cardiac complications among other cardiac arrhythmias should use both antiarrhythmic and anti-alcohol drugs and antidepressants. Such issues as diagnosis and management of patients with alcohol-induced cardiac arrhythmias are presented.

Merits and limitations of the mode switching rate stabilization pacing algorithms in the implantable cardioverter defibrillator.

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Dijkman, B; Wellens, H J

2001-09-01

The 7250 Jewel AF Medtronic model of ICD is the first implantable device in which both therapies for atrial arrhythmias and pacing algorithms for atrial arrhythmia prevention are available. Feasibility of that extensive atrial arrhythmia management requires correct and synergic functioning of different algorithms to control arrhythmias. The ability of the new pacing algorithms to stabilize the atrial rate following termination of treated atrial arrhythmias was evaluated in the marker channel registration of 600 spontaneously occurring episodes in 15 patients with the Jewel AF. All patients (55+/-15 years) had structural heart disease and documented atrial and ventricular arrhythmias. Dual chamber rate stabilization pacing was present in 245 (41 %) of episodes following arrhythmia termination and was a part of the mode switching operation during which pacing was provided in the dynamic DDI mode. This algorithm could function as the atrial rate stabilization pacing only when there was a slow spontaneous atrial rhythm or in presence of atrial premature beats conducted to the ventricles with a normal AV time. In case of atrial premature beats with delayed or absent conduction to the ventricles and in case of ventricular premature beats, the algorithm stabilized the ventricular rate. The rate stabilization pacing in DDI mode during sinus rhythm following atrial arrhythmia termination was often extended in time due to the device-based definition of arrhythmia termination. This was also the case in patients, in whom the DDD mode with true atrial rate stabilization algorithm was programmed. The rate stabilization algorithms in the Jewel AF applied after atrial arrhythmia termination provide pacing that is not based on the timing of atrial events. Only under certain circumstances the algorithm can function as atrial rate stabilization pacing. Adjustments in availability and functioning of the rate stabilization algorithms might be of benefit for the clinical performance of

Cardiac ablation

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Kelly Ratheal

2016-01-01

Full Text Available Cardiac ablation is a procedure that uses either radiofrequency or cryothermal energy to destroy cells in the heart to terminate and/or prevent arrhythmias. The indications for cardiac catheter ablation include refractory, symptomatic arrhythmias, with more specific guidelines for atrial fibrillation in particular. The ablation procedure itself involves mapping the arrhythmia and destruction of the aberrant pathway in an effort to permanently prevent the arrhythmia. There are many types of arrhythmias, and they require individualized approaches to ablation based on their innately different electrical pathways. Ablation of arrhythmias, such as Wolff-Parkinson-White syndrome, AV nodal reentrant tachycardia, and atrial-fibrillation, is discussed in this review. Ablation has a high success rate overall and minimal complication rates, leading to improved quality of life in many patients.

Diagnosis and therapy of atrial tachyarrhythmias in the dual chamber implantable cardioverter defibrillator.

Science.gov (United States)

Dijkman, B; Wellens, H J

2000-11-01

Devices capable of monitoring and treating atrial tachyarrhythmias provide information about the natural history of the arrhythmias and potentially can influence their natural course by electrical therapy early after onset. Types of atrial arrhythmias and efficacy of device therapies were evaluated in 30 patients implanted with the Medtronic model 7250 Jewel AF implantable cardioverter defibrillator (ICD). All patients had structural heart disease and documented sustained ventricular and atrial arrhythmias (27 with atrial fibrillation [AF]) before implant. Twenty patients were taking amiodarone, and three were taking sotalol. During 20+/-10 months of follow-up, 600 atrial arrhythmia recurrences were documented in 50% of patients. AF was diagnosed in 19%, fast polymorphic atrial tachycardia (AT) in 20%, fast monomorphic AT in 57%, and slow AT in 4% of episodes. The two adaptive pacing therapies, burst and ramp, together with the 50-Hz burst, were successful in 57% of detected atrial arrhythmias. Burst and ramp were responsible for 49% and 50-Hz burst for 51% of successfully treated arrhythmias; 33% of the episodes terminated spontaneously. No ventricular proarrhythmia was observed due to atrial pacing therapies. In 30% of episodes, dual chamber pacing was required due to post termination bradycardia. Atrial arrhythmia recurrences in patients with dilated cardiomyopathy were not amenable to pacing therapies. Several aspects of atrial arrhythmia diagnosis, therapy, and documentation that are specific for functioning of the Jewel AF are discussed. Atrial arrhythmias in ICD patients with diseased hearts who are taking Class III antiarrhythmics frequently had longer cycle lengths than AF. Half of these arrhythmias could be terminated with pacing therapies; one third terminated spontaneously.

Coping with Feelings

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Full Text Available ... Advocate for Heart.org Giving for Heart.org Media for Heart.org Arrhythmia About Arrhythmia Why Arrhythmia ... Defects Children & Adults About Congenital Heart Defects ... about community and social service resources that can help you with home ...

Antiarrhythmic effect of heat adaptation in ischemic and reperfusion injury to the heart.

Science.gov (United States)

Monastyrskaya, E A; Belkina, L M; Manukhina, E B; Malyshev, I Yu

2007-01-01

Study on a model of 6-day dosed adaptation to heat in rats showed that this adaptation decreased the severity of cardiac arrhythmias during ischemic and reperfusion injury. The duration of arrhythmias decreased not only in the ischemic period, but also under conditions of reperfusion. Adaptation delayed the development of arrhythmias during ischemia, decreased the number of animals with late reperfusion arrhythmias, and improved recovery of the heart after ischemia and reperfusion.

Antiarrhythmic effect of carvedilol after acute myocardial infarction: results of the Carvedilol Post-Infarct Survival Control in Left Ventricular Dysfunction (CAPRICORN) trial

DEFF Research Database (Denmark)

McMurray, John; Køber, Lars; Robertson, Michele

2005-01-01

OBJECTIVES: Whether beta-blockers reduce atrial arrhythmias and, when added to an angiotensin-converting enzyme (ACE) inhibitor, ventricular arrhythmia is unknown. BACKGROUND: Ventricular and atrial arrhythmias are common after acute myocardial infarction (AMI) and are associated with a poor prog...

Prophylactic digitalisation in pulmonary surgery.

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Ritchie, A J; Danton, M; Gibbons, J R

1992-01-01

Prophylactic digoxin is widely used in patients undergoing pulmonary surgery to prevent or control cardiac arrhythmias, but whether it is helpful or not is uncertain. An open, controlled randomised prospective clinical study of 111 patients was undertaken to compare the incidence of cardiac arrhythmias in the 58 patients who received preoperative digoxin and the 53 who did not. Cardiac arrhythmia occurred in half (29/58) of those given prophylactic digoxin and in 36% (19/53) of those who were not. The overall incidence of arrhythmia was 43%, with no statistically significant difference between the groups. Cardiac arrhythmias remain an important complication of pulmonary surgery and the incidence is not reduced by prophylactic digoxin.

Avaliação clínica e funcional tardia de arritmias em crianças operadas de Tetralogia de Fallot Evaluación clínica y funcional tardía de arritmias en niños operados de tetralogía de Fallot Late clinical and functional assessment of arrhythmias in children after repair of Tetralogy of Fallot

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Maria Eulália Thebit Pfeiffer

2010-09-01

. OBJETIVO: Evaluar la ocurrencia de arritmias cardíacas en niños y adolescentes operados de TF, asociándolas a los aspectos clínicos y de exámenes complementarios. MÉTODOS: Estudio transversal en 37 pacientes sometidos a cirugía de TF en el Instituto Estadual de Cardiología Aloysio de Castro (RJ. Tras revisión de prontuarios y evaluación clínica, los pacientes fueron sometidos a electrocardiograma (ECG, ecocardiograma (Eco, Holter 24h (Holter y prueba ergométrica (PE, siendo los resultados sometidos al análisis estadístico. RESULTADOS: Estudiados 37 pacientes, el 54% masculinos, edad 9,7 ± 3,5 años, seguimiento promedio de 4,7 ± 1,9 años. Cambio más prevalentes: ECG: bloqueo de rama derecha (89%; Eco: insuficiencia pulmonar severa (43%, estenosis pulmonar ligera (73%, hipertrofia ventricular derecha (HVD moderada (57%. En la PE, baja capacidad de ejercicio (90%, déficit cronotrópico (40%, arritmias (20%. Al Holter, el 59% presentó arritmias: ventriculares el 44%, supraventriculares el 38% y ambas el 24%, con predominio de extrasístoles poco frecuentes y benignas. Cinco pacientes (15% presentaron extrasístoles polimórficas. Hubo asociación entre arritmia ventricular y HVD moderada y severa (p=0,026 y también con gradiente ventrículo derecho-arteria pulmonar (VD/AP >45 mmHg (p=0,004. A través de la Regresión Logística, el aumento del gradiente VD/AP fue factor predictivo independiente para arritmia ventricular (p=0,017. CONCLUSIÓN: Las arritmias cardíacas fueron un hallazgo común en gran parte de los niños y adolescentes tras reparación quirúrgica de TF, sin embargo, poco frecuentes y benignas, en la mayoría de los casos. El gradiente de presión VD-AP se consideró como un fuerte predictor para arritmia ventricular.BACKGROUND: Cardiac arrhythmias are the major cause of late sudden death in patients undergoing repair of Tetralogy of Fallot (TF. OBJECTIVE: To evaluate the occurrence of cardiac arrhythmias in children and adolescents

Power Spectral Analysis of Short-Term Heart Rate Variability in Healthy and Arrhythmia Subjects by the Adaptive Continuous Morlet Wavelet Transform

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Ram Sewak SINGH

2017-12-01

Full Text Available Power spectral analysis of short-term heart rate variability (HRV can provide instant valuable information to understand the functioning of autonomic control over the cardiovascular system. In this study, an adaptive continuous Morlet wavelet transform (ACMWT method has been used to describe the time-frequency characteristics of the HRV using band power spectra and the median value of interquartile range. Adaptation of the method was based on the measurement of maximum energy concentration. The ACMWT has been validated on synthetic signals (i.e. stationary, non-stationary as slow varying and fast changing frequency with time modeled as closest to dynamic changes in HRV signals. This method has been also tested in the presence of additive white Gaussian noise (AWGN to show its robustness towards the noise. From the results of testing on synthetic signals, the ACMWT was found to be an enhanced energy concentration estimator for assessment of power spectral of short-term HRV time series compared to adaptive Stockwell transform (AST, adaptive modified Stockwell transform (AMST, standard continuous Morlet wavelet transform (CMWT and Stockwell transform (ST estimators at statistical significance level of 5%. Further, the ACMWT was applied to real HRV data from Fantasia and MIT-BIH databases, grouped as healthy young group (HYG, healthy elderly group (HEG, arrhythmia controlled medication group (ARCMG, and supraventricular tachycardia group (SVTG subjects. The global results demonstrate that spectral indices of low frequency power (LFp and high frequency power (HFp of HRV were decreased in HEG compared to HYG subjects (p<0.0001. While LFp and HFp indices were increased in ARCMG compared to HEG (p<0.00001. The LFp and HFp components of HRV obtained from SVTG were reduced compared to other group subjects (p<0.00001.

Medications for Arrhythmia

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... pharmacist to help you come up with a coding system for your medications that makes them easier to take. Some pharmacists will prepare blister packs for daily or weekly medications. Make an instruction sheet for yourself by taping a sample of each ...

Categories of Arrhythmias

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... which is found in coffee, tea, sodas, and chocolate. Some kinds of over-the-counter cough and ... reason, many patients with atrial fibrillation need antiplatelet therapy . These medicines can prevent blood clots from forming ...

Genetically engineered excitable cardiac myofibroblasts coupled to cardiomyocytes rescue normal propagation and reduce arrhythmia complexity in heterocellular monolayers.

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Luqia Hou

Full Text Available The use of genetic engineering of unexcitable cells to enable expression of gap junctions and inward rectifier potassium channels has suggested that cell therapies aimed at establishing electrical coupling of unexcitable donor cells to host cardiomyocytes may be arrhythmogenic. Whether similar considerations apply when the donor cells are electrically excitable has not been investigated. Here we tested the hypothesis that adenoviral transfer of genes coding Kir2.1 (I(K1, Na(V1.5 (I(Na and connexin-43 (Cx43 proteins into neonatal rat ventricular myofibroblasts (NRVF will convert them into fully excitable cells, rescue rapid conduction velocity (CV and reduce the incidence of complex reentry arrhythmias in an in vitro model.We used adenoviral (Ad- constructs encoding Kir2.1, Na(V1.5 and Cx43 in NRVF. In single NRVF, Ad-Kir2.1 or Ad-Na(V1.5 infection enabled us to regulate the densities of I(K1 and I(Na, respectively. At varying MOI ratios of 10/10, 5/10 and 5/20, NRVF co-infected with Ad-Kir2.1+ Na(V1.5 were hyperpolarized and generated action potentials (APs with upstroke velocities >100 V/s. However, when forming monolayers only the addition of Ad-Cx43 made the excitable NRVF capable of conducting electrical impulses (CV = 20.71±0.79 cm/s. When genetically engineered excitable NRVF overexpressing Kir2.1, Na(V1.5 and Cx43 were used to replace normal NRVF in heterocellular monolayers that included neonatal rat ventricular myocytes (NRVM, CV was significantly increased (27.59±0.76 cm/s vs. 21.18±0.65 cm/s, p<0.05, reaching values similar to those of pure myocytes monolayers (27.27±0.72 cm/s. Moreover, during reentry, propagation was faster and more organized, with a significantly lower number of wavebreaks in heterocellular monolayers formed by excitable compared with unexcitable NRVF.Viral transfer of genes coding Kir2.1, Na(V1.5 and Cx43 to cardiac myofibroblasts endows them with the ability to generate and propagate APs. The results

Islands of spatially discordant APD alternans underlie arrhythmogenesis by promoting electrotonic dyssynchrony in models of fibrotic rat ventricular myocardium

Science.gov (United States)

Majumder, Rupamanjari; Engels, Marc C.; de Vries, Antoine A. F.; Panfilov, Alexander V.; Pijnappels, Daniël A.

2016-04-01

Fibrosis and altered gap junctional coupling are key features of ventricular remodelling and are associated with abnormal electrical impulse generation and propagation. Such abnormalities predispose to reentrant electrical activity in the heart. In the absence of tissue heterogeneity, high-frequency impulse generation can also induce dynamic electrical instabilities leading to reentrant arrhythmias. However, because of the complexity and stochastic nature of such arrhythmias, the combined effects of tissue heterogeneity and dynamical instabilities in these arrhythmias have not been explored in detail. Here, arrhythmogenesis was studied using in vitro and in silico monolayer models of neonatal rat ventricular tissue with 30% randomly distributed cardiac myofibroblasts and systematically lowered intercellular coupling achieved in vitro through graded knockdown of connexin43 expression. Arrhythmia incidence and complexity increased with decreasing intercellular coupling efficiency. This coincided with the onset of a specialized type of spatially discordant action potential duration alternans characterized by island-like areas of opposite alternans phase, which positively correlated with the degree of connexinx43 knockdown and arrhythmia complexity. At higher myofibroblast densities, more of these islands were formed and reentrant arrhythmias were more easily induced. This is the first study exploring the combinatorial effects of myocardial fibrosis and dynamic electrical instabilities on reentrant arrhythmia initiation and complexity.

Radiofrequency catheter ablation of idiopathic ventricular arrhythmias originating from intramural foci in the left ventricular outflow tract: efficacy of sequential versus simultaneous unipolar catheter ablation.

Science.gov (United States)

Yamada, Takumi; Maddox, William R; McElderry, H Thomas; Doppalapudi, Harish; Plumb, Vance J; Kay, G Neal

2015-04-01

Idiopathic ventricular arrhythmias (VAs) originating from the left ventricular outflow tract (LVOT) sometimes require catheter ablation from the endocardial and epicardial sides for their elimination, suggesting the presence of intramural VA foci. This study investigated the efficacy of sequential and simultaneous unipolar radiofrequency catheter ablation from the endocardial and epicardial sides in treating intramural LVOT VAs. Fourteen consecutive LVOT VAs, which required sequential or simultaneous irrigated unipolar radiofrequency ablation from the endocardial and epicardial sides for their elimination, were studied. The first ablation was performed at the site with the earliest local ventricular activation and best pace map on the endocardial or epicardial side. When the first ablation was unsuccessful, the second ablation was delivered on the other surface. If this sequential unipolar ablation failed, simultaneous unipolar ablation from both sides was performed. The first ablation was performed on the epicardial side in 9 VAs and endocardial side in 5 VAs. The intramural LVOT VAs were successfully eliminated by the sequential (n=9) or simultaneous (n=5) unipolar catheter ablation. Simultaneous ablation was most likely to be required for the elimination of the VAs when the distance between the endocardial and epicardial ablation sites was >8 mm and the earliest local ventricular activation time relative to the QRS onset during the VAs of sequential unipolar radiofrequency ablation and sometimes required simultaneous ablation from both the endocardial and epicardial sides. © 2015 American Heart Association, Inc.

Dual Optical Recordings for Action Potentials and Calcium Handling in Induced Pluripotent Stem Cell Models of Cardiac Arrhythmias Using Genetically Encoded Fluorescent Indicators

Science.gov (United States)

Song, LouJin; Awari, Daniel W.; Han, Elizabeth Y.; Uche-Anya, Eugenia; Park, Seon-Hye E.; Yabe, Yoko A.; Chung, Wendy K.

2015-01-01

Reprogramming of human somatic cells to pluripotency has been used to investigate disease mechanisms and to identify potential therapeutics. However, the methods used for reprogramming, in vitro differentiation, and phenotyping are still complicated, expensive, and time-consuming. To address the limitations, we first optimized a protocol for reprogramming of human fibroblasts and keratinocytes into pluripotency using single lipofection and the episomal vectors in a 24-well plate format. This method allowed us to generate multiple lines of integration-free and feeder-free induced pluripotent stem cells (iPSCs) from seven patients with cardiac diseases and three controls. Second, we differentiated human iPSCs derived from patients with Timothy syndrome into cardiomyocytes using a monolayer differentiation method. We found that Timothy syndrome cardiomyocytes showed slower, irregular contractions and abnormal calcium handling compared with the controls. The results are consistent with previous reports using a retroviral method for reprogramming and an embryoid body-based method for cardiac differentiation. Third, we developed an efficient approach for recording the action potentials and calcium transients simultaneously in control and patient cardiomyocytes using genetically encoded fluorescent indicators, ArcLight and R-GECO1. The dual optical recordings enabled us to observe prolonged action potentials and abnormal calcium handling in Timothy syndrome cardiomyocytes. We confirmed that roscovitine rescued the phenotypes in Timothy syndrome cardiomyocytes and that these findings were consistent with previous studies using conventional electrophysiological recordings and calcium imaging with dyes. The approaches using our optimized methods and dual optical recordings will improve iPSC applicability for disease modeling to investigate mechanisms underlying cardiac arrhythmias and to test potential therapeutics. PMID:25769651

General anxiety, depression, and physical health in relation to symptoms of heart-focused anxiety- a cross sectional study among patients living with the risk of serious arrhythmias and sudden cardiac death

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Hamang Anniken

2011-11-01

Full Text Available Abstract Objective To investigate the role of three distinct symptoms of heart-focused anxiety (cardio-protective avoidance, heart-focused attention, and fear about heart sensations in relation to general anxiety, depression and physical health in patients referred to specialized cardio-genetics outpatient clinics in Norway for genetic investigation and counseling. Methods Participants were 126 patients (mean age 45 years, 53.5% women. All patients were at higher risk than the average person for serious arrhythmias and sudden cardiac death (SCD because of a personal or a family history of an inherited cardiac disorder (familial long QT syndrome or hypertrophic cardiomyopathy. Patients filled in, Hospital Anxiety and Depression Scale, Short-Form 36 Health Survey, and Cardiac Anxiety Questionnaire, two weeks before the scheduled counseling session. Results The patients experienced higher levels of general anxiety than expected in the general population (mean difference 1.1 (p Conclusion Avoidance and fear may be potentially modifiable symptoms. Because these distinct symptoms may have important roles in determining general anxiety, depression and physical health in at-risk individuals of inherited cardiac disorders, the present findings may have implications for the further development of genetic counseling for this patient group.

Sudden Cardiac Death As a Result of Neglected Hypopituitarism

OpenAIRE

Hajsheikholeslami, Farhad; Yazdani, Shahrooz

2013-01-01

Cardiac involvement infrequently occurs in hypopituitarism, and lethal cardiac arrhythmias are rarely reported. We present a middle age female who died as a consequence of refractory ventricular arrhythmia whose medical history and previous laboratory investigation were consistent with hypopituitarism. We conclude that hypopituitarism may lead to electrocardiographic changes and malignant ventricular arrhythmia and should be included in laboratory investigation and differential diagnosis of p...

Anti-ischemic intervention as prognosis improvement in patients with coronary artery disease, with special focus on verapamil

DEFF Research Database (Denmark)

Jespersen, C M

1996-01-01

dysfunction, and thereby heart failure. In postinfarction patients intervention with verapamil significantly reduced the use of diuretics compared with placebo, indicating that anti-ischemic intervention may prevent heart failure. Ventricular arrhythmias are significantly associated with arrhythmic as well...... as non-arrhythmic death. The lack of preferential association of ventricular arrhythmias with arrhythmic death rather than nonarrhythmic death may imply that arrhythmias are provoked by ischemia. Antiarrhythmic intervention in postinfarction patients significantly increases death and arrhythmic events...... compared with placebo, especially in patients with residual ischemia. This may be due to a significant slowing of conduction during ischemia in patients treated with antiarrhythmic agents. In animal studies anti-ischemic agents prevent or suppress ventricular arrhythmias during ischemia, whereas...

Coping with Feelings

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Full Text Available ... Treatment of Arrhythmia Arrhythmia Tools & Resources Cholesterol About Cholesterol HDL, LDL & Triglycerides Causes of High Cholesterol How To Get Your Cholesterol Tested Prevention & Treatment ...

Communicating with Professionals

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Full Text Available ... change in the heart's normal electrical conduction system can result in an arrhythmia or irregular heartbeat. An arrhythmia can be an abnormally slow heartbeat, or an abnormally ...

Voxelwise distribution of acute ischemic stroke lesions in patients with newly diagnosed atrial fibrillation: Trigger of arrhythmia or only target of embolism?

Directory of Open Access Journals (Sweden)

Timolaos Rizos

Full Text Available Atrial fibrillation (AF is frequently detected after ischemic stroke for the first time, and brain regions involved in autonomic control have been suspected to trigger AF. We examined whether specific brain regions are associated with newly detected AF after ischemic stroke.Patients with acute cerebral infarctions on diffusion-weighted magnetic resonance imaging were included in this lesion mapping study. Lesions were mapped and modeled voxelwise using Bayesian Spatial Generalised Linear Mixed Modeling to determine differences in infarct locations between stroke patients with new AF, without AF and with AF already known before the stroke.582 patients were included (median age 68 years; 63.2% male. AF was present in 109/582 patients [(18.7%; new AF: 39/109 (35.8%, known AF: 70/109 (64.2%]. AF patients had larger infarct volumes than patients without AF (mean: 29.7 ± 45.8 ml vs. 15.2 ± 35.1 ml; p<0.001. Lesions in AF patients accumulated in the right central middle cerebral artery territory. Increasing stroke size predicted progressive cortical but not pontine and thalamic involvement. Patients with new AF had more frequently lesions in the right insula compared to patients without AF when stroke size was not accounted for, but no specific brain region was more frequently involved after adjustment for infarct volume. Controlled for stroke size, left parietal involvement was less likely for patients with new AF than for those without AF or with known AF.In the search for brain areas potentially triggering cardiac arrhythmias infarct size should be accounted for. After controlling for infarct size, there is currently no evidence that ischemic stroke lesions of specific brain areas are associated with new AF compared to patients without AF. This challenges the neurogenic hypothesis of AF according to which a relevant proportion of new AF is triggered by ischemic brain lesions of particular locations.

Meta-analysis of randomized controlled trials on magnesium in addition to beta-blocker for prevention of postoperative atrial arrhythmias after coronary artery bypass grafting

Directory of Open Access Journals (Sweden)

Wu Xiaosan

2013-01-01

Full Text Available Abstract Background Atrial arrhythmia (AA is the most common complication after coronary artery bypass grafting (CABG. Only beta-blockers and amiodarone have been convincingly shown to decrease its incidence. The effectiveness of magnesium on this complication is still controversial. This meta-analysis was performed to evaluate the effect of magnesium as a sole or adjuvant agent in addition to beta-blocker on suppressing postoperative AA after CABG. Methods We searched the PubMed, Medline, ISI Web of Knowledge, Cochrane library databases and online clinical trial database up to May 2012. We used random effects model when there was significant heterogeneity between trials and fixed effects model when heterogeneity was negligible. Results Five randomized controlled trials were identified, enrolling a total of 1251 patients. The combination of magnesium and beta-blocker did not significantly decrease the incidence of postoperative AA after CABG versus beta-blocker alone (odds ratio (OR 1.12, 95% confidence interval (CI 0.86-1.47, P = 0.40. Magnesium in addition to beta-blocker did not significantly affect LOS (weighted mean difference −0.14 days of stay, 95% CI −0.58 to 0.29, P = 0.24 or the overall mortality (OR 0.59, 95% CI 0.08-4.56, P = 0.62. However the risk of postoperative adverse events was higher in the combination of magnesium and beta-blocker group than beta-blocker alone (OR 2.80, 95% CI 1.66-4.71, P = 0.0001. Conclusions This meta-analysis offers the more definitive evidence against the prophylactic administration of intravenous magnesium for prevention of AA after CABG when beta-blockers are routinely administered, and shows an association with more adverse events in those people who received magnesium.

Post-infarctus, ischémie myocardique: importance clinique et facteur de risque

DEFF Research Database (Denmark)

Jespersen, C

1995-01-01

disease surviving out of hospital cardiac arrest - improves the prognosis, indicates that transient ischaemic attacks might be the trigger of malignant ventricular arrhythmias in patients with prior myocardial infarction. Patients with large infarct scars (heart failure) have an increased incidence...... and the release of abnormal automatic responses of the partially repolarised cells. The mechanism(s) by which complex ventricular arrhythmias is/are transformed into malignant arrhythmias has/have not yet been definitely proven. The observation that coronary revascularization - in patients with ischaemic heart......, indicating that residual ischaemia might be the major risk variable in patients with heart failure. Ischaemia is one of several risk markers for transient supraventricular arrhythmias in patients recovering from an acute myocardial infarction (AMI). In addition, anti-ischaemic intervention in patients...

Diagnosis of traumatic cardiac contusion

International Nuclear Information System (INIS)

Waxman, K.; Soliman, M.H.; Braunstein, P.; Formosa, P.; Cohen, A.J.; Matsuura, P.; Mason, G.R.

1986-01-01

Cardiac contusion following blunt chest trauma remains a diagnostic problem because of a lack of sensitive diagnostic tests. This study evaluated thallous chloride Tl 201 single-photon-emission computed tomography in a series of 48 patients following blunt chest trauma. Of the 48 patients, 23 had normal scans. None of these patients proved to have serious arrhythmias during three days of continuous monitoring. Of 25 patients with abnormal or ambiguous studies, five (20%) developed serious arrhythmias requiring therapy. Single-photon-emission computed tomography scanning thus was sensitive in indicating that group of patients at risk of serious arrhythmias, and may therefore prove to be a useful screening test to determine the need for hospitalization and arrhythmia monitoring following blunt chest trauma

Acebutolol in Cardiac Arrhythmias

African Journals Online (AJOL)

1974-04-20

Apr 20, 1974 ... of VPSs in 1 patient with digitalis excess, and was. -ineffective in the other 2. It was given orally in another. 3 patients; it reduced the number of VPSs per minute in one, was effective for a short period in another, and was ineffective in the third. Ventricular tachycardia (VT). Acebutolol was given intravenously ...

Treating Arrhythmias in Children

Science.gov (United States)

... drugs may need to be tried before the right one is found. Some children must take medication every ... is done with several catheters in the heart. One is positioned right over the area that's causing the tachycardia. Then ...

SU-C-303-06: Treatment Planning Study for Non-Invasive Cardiac Arrhythmia Ablation with Scanned Carbon Ions in An Animal Model

International Nuclear Information System (INIS)

Eichhorn, A; Constantinescu, A; Prall, M; Kaderka, R; Durante, M; Graeff, C; Lehmann, H I; Takami, M; Packer, D L; Lugenbiel, P; Thomas, D; Richter, D; Bert, C

2015-01-01

Purpose: Scanned carbon ion beams might offer a non-invasive alternative treatment for cardiac arrhythmia, which are a major health-burden. We studied the feasibility of this procedure in an animal model. The underlying treatment planning and motion mitigation strategies will be presented. Methods: The study was carried out in 15 pigs, randomly distributed to 3 target groups: atrioventricular node (AVN, 8 animals with 25, 40, and 55 Gy target dose), left ventricular free-wall (LV, 4 animals with 40 Gy) and superior pulmonary vein (SPV, 3 animals with 40 Gy). Breathing motion was suppressed by repeated enforced breathholds at end exhale. Cardiac motion was mitigated by an inhomogeneous rescanning scheme with up to 15 rescans. The treatment planning was performed using the GSI in-house software TRiP4D on cardiac-gated 4DCTs, applying a range-considering ITV based on an extended CTV. For AVN and SPV isotropic 5 mm margins were applied to the CTV, while for the LV 2mm+2% range margins were used. The opposing fields for AVN and LV targets were optimized independently (SFUD), while SPV treatments were optimized as IMPT deliveries, including dose restrictions to the radiosensitive AVN. Results: Median value of D 95 over all rescanning simulations was 99.1% (AVN), 98.0% (SPV) and 98.3% (LV) for the CTV and 94.7% (AVN) and 92.7% (SPV) for the PTV, respectively. The median D 5 -D 95 was improved with rescanning compared to unmitigated delivery from 13.3 to 6.5% (CTV) and from 23.4 to 11.6% (PTV). ICRP dose limits for aorta, trachea, esophagus and skin were respected. The maximal dose in the coronary arteries was limited to 30 Gy. Conclusion: We demonstrated the feasibility of a homogeneous dose delivery to different cardiac structures in a porcine model using a time-optimized inhomogeneous rescanning scheme. The presented treatment planning strategies were applied in a pig study with the analysis ongoing. Funding: This work was supported in part by the Helmholtz Association

SU-C-303-06: Treatment Planning Study for Non-Invasive Cardiac Arrhythmia Ablation with Scanned Carbon Ions in An Animal Model

Energy Technology Data Exchange (ETDEWEB)

Eichhorn, A; Constantinescu, A; Prall, M; Kaderka, R; Durante, M; Graeff, C [GSI Helmholtz Center, Darmstadt, DE (Germany); Lehmann, H I; Takami, M; Packer, D L [Mayo Clinic, Rochester, Minnesota (United States); Lugenbiel, P; Thomas, D [University of Heidelberg, Heidelberg, DE (Germany); Richter, D; Bert, C [University Clinic Erlangen, Erlagen, DE (Germany)

2015-06-15

Purpose: Scanned carbon ion beams might offer a non-invasive alternative treatment for cardiac arrhythmia, which are a major health-burden. We studied the feasibility of this procedure in an animal model. The underlying treatment planning and motion mitigation strategies will be presented. Methods: The study was carried out in 15 pigs, randomly distributed to 3 target groups: atrioventricular node (AVN, 8 animals with 25, 40, and 55 Gy target dose), left ventricular free-wall (LV, 4 animals with 40 Gy) and superior pulmonary vein (SPV, 3 animals with 40 Gy). Breathing motion was suppressed by repeated enforced breathholds at end exhale. Cardiac motion was mitigated by an inhomogeneous rescanning scheme with up to 15 rescans. The treatment planning was performed using the GSI in-house software TRiP4D on cardiac-gated 4DCTs, applying a range-considering ITV based on an extended CTV. For AVN and SPV isotropic 5 mm margins were applied to the CTV, while for the LV 2mm+2% range margins were used. The opposing fields for AVN and LV targets were optimized independently (SFUD), while SPV treatments were optimized as IMPT deliveries, including dose restrictions to the radiosensitive AVN. Results: Median value of D{sub 95} over all rescanning simulations was 99.1% (AVN), 98.0% (SPV) and 98.3% (LV) for the CTV and 94.7% (AVN) and 92.7% (SPV) for the PTV, respectively. The median D{sub 5}-D{sub 95} was improved with rescanning compared to unmitigated delivery from 13.3 to 6.5% (CTV) and from 23.4 to 11.6% (PTV). ICRP dose limits for aorta, trachea, esophagus and skin were respected. The maximal dose in the coronary arteries was limited to 30 Gy. Conclusion: We demonstrated the feasibility of a homogeneous dose delivery to different cardiac structures in a porcine model using a time-optimized inhomogeneous rescanning scheme. The presented treatment planning strategies were applied in a pig study with the analysis ongoing. Funding: This work was supported in part by the

Acute hyperkalemia leading to flaccid paralysis: a review of hyperkalemic manifestations

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Paras Karmacharya

2015-06-01

Full Text Available Hyperkalemia can present with a spectrum of clinical manifestations with progressive EKG changes and life-threatening arrhythmias. Although no formal guidelines exist as to when to initiate treatment for hyperkalemia, it is generally recommended in clinically symptomatic patients with or without EKG changes. Timely diagnosis and reversal can relieve symptoms and prevent life-threatening arrhythmias. We review the EKG changes associated with hyperkalemia and management principles along with an example of a case of severe hyperkalemia resulting in arrhythmia and flaccid paralysis.

A single exposure to acrolein causes arrhythmogenesis, cardiac electrical dysfunction and decreased heart rate variability in hypertensive rats

Science.gov (United States)

Epidemiological studies demonstrate an association between cardiovascular morbidity, arrhythmias, and exposure to air toxicants such as acrolein. We hypothesized that a single exposure to acrolein would increase arrhythmias and cause changes in the electrocardiogram (ECG) of hype...

Air pollution and arrhythmic risk: the smog is yet to clear.

Science.gov (United States)

Watkins, Alex; Danilewitz, Marlon; Kusha, Marjan; Massé, Stéphane; Urch, Bruce; Quadros, Kenneth; Spears, Danna; Farid, Talha; Nanthakumar, Kumaraswamy

2013-06-01

Epidemiologic evidence has demonstrated that air pollution may impair cardiovascular health, leading to potentially life-threatening arrhythmias. Efforts have been made, with the use of epidemiologic data and controlled exposures in diverse animal and human populations, to verify the relationship between air pollution and arrhythmias. The purpose of this review is to examine and contrast the epidemiologic and toxicologic evidence to date that relates airborne pollutants with cardiac arrhythmia. We have explored the potential biological mechanisms driving this association. Using the PubMed database, we conducted a literature search that included the terms "air pollution" and "arrhythmia" and eventually divergent synonyms such as "particulate matter," "bradycardia," and "atrial fibrillation." We reviewed epidemiologic studies and controlled human and animal exposures independently to determine whether observational conclusions were corroborated by toxicologic results. Numerous pollutants have demonstrated some arrhythmic capacity among healthy and health-compromised populations. However, some exposure studies have shown no significant correlation of air pollutants with arrhythmia, which suggests some uncertainty about the arrhythmogenic potential of air pollution and the mechanisms involved in arrhythmogenesis. While data from an increasing number of controlled exposures with human volunteers suggest a potential mechanistic link between air pollution and altered cardiac electrophysiology, definite conclusions regarding air pollution and arrhythmia are elusive as the direct arrhythmic effects of air pollutants are not entirely consistent across all studies. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Arrhythmogenic KCNE gene variants: current knowledge and future challenges

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Shawn M Crump

2014-01-01

Full Text Available There are twenty-five known inherited cardiac arrhythmia susceptibility genes, all of which encode either ion channel pore-forming subunits or proteins that regulate aspects of ion channel biology such as function, trafficking and localization. The human KCNE gene family comprises five potassium channel regulatory subunits, sequence variants in each of which are associated with cardiac arrhythmias. KCNE gene products exhibit promiscuous partnering and in some cases ubiquitous expression, hampering efforts to unequivocally correlate each gene to specific native potassium currents. Likewise, deducing the molecular etiology of cardiac arrhythmias in individuals harboring rare KCNE gene variants, or more common KCNE polymorphisms, can be challenging. In this review we provide an update on putative arrhythmia-causing KCNE gene variants, and discuss current thinking and future challenges in the study of molecular mechanisms of KCNE-associated cardiac rhythm disturbances.

Ventricular fibrillation development following atrial fibrillation after the ingestion of sildenaphil in a patient with Wolff-Parkinson-White syndrome.

Science.gov (United States)

Inci, Sinan; Izgu, Ibrahim; Aktas, Halil; Dogan, Pinar; Dogan, Ali

2015-08-01

Complications in the accessory pathway in Wolff-Parkinson-White (WPW) syndrome could cause different clinical conditions by inducing different arrhythmias. Atrial fibrillation (AF) is one of these arrhythmias and is important as it causes life-threatening arrhythmias. It is known that some drugs, underlying cardiac diseases, and the number of accessory pathways, cause a predisposition to this condition. In the current report, we presented a patient with WPW who was admitted to the emergency department with AF, wide QRS and a rapid ventricular response that progressed to ventricular fibrillation.

Doxorubicin-induced second degree and complete atrioventricular block.

Science.gov (United States)

Kilickap, Saadettin; Akgul, Ebru; Aksoy, Sercan; Aytemir, Kudret; Barista, Ibrahim

2005-05-01

Doxorubicin is one of the most effective chemotherapeutic agents used in the treatment of malignancies. Cardiotoxicity is the most important dose-limiting toxicity of doxorubicin. Although cardiomyopathy is the most well known side effect of doxorubicin, it usually occurs many years after the treatment and relates to cumulative doxorubicin dosage. Another form of doxorubicin cardiotoxicity is arrhythmia which may occur at any time and after any dosage. However, doxorubicin-induced arrhythmia is rarely a life-threatening side effect. In this report, we present a case in which there were doxorubicin-induced life-threatening arrhythmias.

[Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease.

DEFF Research Database (Denmark)

Holst, Anders Gaarsdal; Tfelt-Hansen, 1jacob; Olesen, Morten S

2010-01-01

or cardiac arrest. The arrhythmias are usually triggered by exercise or emotional affection. The diagnosis is often made using exercise electrocardiogram, which typically triggers arrhythmias. The treatment consists of beta blockers, frequently in combination with implantation of a cardioverter...

Bradycardia Following Oral Corticosteroid Use: Case Report and ...

African Journals Online (AJOL)

Introduction: Corticosteroids are used in various clinical conditions that include many immune-mediated inflammatory diseases. Different side effects were described including cardiac arrhythmias. Most of those arrhythmias were in the form of bradycardia which usually occurs with high intravenous steroid doses.

Myocardial impulse propagation is impaired in right ventricular tissue of Zucker Diabetic Fatty (ZDF) rats

DEFF Research Database (Denmark)

Olsen, Kristine Boisen; Axelsen, Lene Nygaard; Braunstein, Thomas Hartig

2013-01-01

Diabetes increases the risk of cardiovascular complications including arrhythmias, but the underlying mechanisms remain to be established. Decreased conduction velocity (CV), which is an independent risk factor for re-entry arrhythmias, is present in models with streptozotocin (STZ) induced type ...

Katekolaminerg polymorf ventrikulaer takykardi er en sjaelden arvelig hjertesygdom

DEFF Research Database (Denmark)

Holst, Anders Gaarsdal; Tfelt-Hansen, Jacob; Olesen, Morten S

2010-01-01

or cardiac arrest. The arrhythmias are usually triggered by exercise or emotional affection. The diagnosis is often made using exercise electrocardiogram, which typically triggers arrhythmias. The treatment consists of beta blockers, frequently in combination with implantation of a cardioverter-defibrillator....