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Sample records for arrhythmias cardiac

  1. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008407 Effects of sympathetic nerve stimulation on connexin43 and ventricular arrhythmias during acute myocardial ischemia: experiment with rats. HU Xiaorong(胡笑容), et al. Dept Cardiol, Renmin Hosp, Wuhan Univ, Wuhan 430060. Natl Med J China 2008;88(24):1707-1710. Objective To investigate the effects of sympathetic nerve stimulation (SNS) on connexin43 (Cx43) and ventricular arrhythmias during acute myocardial ischemia (MI).

  2. Cardiac metabolism and arrhythmias

    OpenAIRE

    Barth, Andreas S.; Tomaselli, Gordon F.

    2009-01-01

    Sudden cardiac death remains a leading cause of mortality in the Western world, accounting for up to 20% of all deaths in the U.S.1, 2 The major causes of sudden cardiac death in adults age 35 and older are coronary artery disease (70–80%) and dilated cardiomyopathy (10–15%).3 At the molecular level, a wide variety of mechanisms contribute to arrhythmias that cause sudden cardiac death, ranging from genetic predisposition (rare mutations and common polymorphisms in ion channels and structural...

  3. Cardiac arrhythmia classification using autoregressive modeling

    OpenAIRE

    Srinivasan Narayanan; Ge Dingfei; Krishnan Shankar M

    2002-01-01

    Abstract Background Computer-assisted arrhythmia recognition is critical for the management of cardiac disorders. Various techniques have been utilized to classify arrhythmias. Generally, these techniques classify two or three arrhythmias or have significantly large processing times. A simpler autoregressive modeling (AR) technique is proposed to classify normal sinus rhythm (NSR) and various cardiac arrhythmias including atrial premature contraction (APC), premature ventricular contraction (...

  4. Molecular therapies for cardiac arrhythmias

    NARCIS (Netherlands)

    G.J.J. Boink

    2013-01-01

    Despite the ongoing advances in pharmacology, devices and surgical approaches to treat heart rhythm disturbances, arrhythmias are still a significant cause of death and morbidity. With the introduction of gene and cell therapy, new avenues have arrived for the local modulation of cardiac disease. Th

  5. Platelets and cardiac arrhythmia

    Directory of Open Access Journals (Sweden)

    Jonas S De Jong

    2010-12-01

    Full Text Available Sudden cardiac death remains one of the most prevalent modes of death in industrialized countries, and myocardial ischemia due to thrombotic coronary occlusion is its primary cause. The role of platelets in the occurrence of SCD extends beyond coronary flow impairment by clot formation. Here we review the substances released by platelets during clot formation and their arrhythmic properties. Platelet products are released from three types of platelet granules: dense core granules, alpha-granules, and platelet lysosomes. The physiologic properties of dense granule products are of special interest as a potential source of arrhythmic substances. They are released readily upon activation and contain high concentrations of serotonin, histamine, purines, pyrimidines, and ions such as calcium and magnesium. Potential arrhythmic mechanisms of these substances, e.g. serotonin and high energy phosphates, include induction of coronary constriction, calcium overloading, and induction of delayed after-depolarizations. Alpha-granules produce thromboxanes and other arachidonic acid products with many potential arrhythmic effects mediated by interference with cardiac sodium, calcium and potassium channels. Alpha-granules also contain hundreds of proteins that could potentially serve as ligands to receptors on cardiomyocytes. Lysosomal products probably do not have an important arrhythmic effect. Platelet products and ischemia can induce coronary permeability, thereby enhancing interaction with surrounding cardiomyocytes. Antiplatelet therapy is known to improve survival after myocardial infarction. Although an important part of this effect results from prevention of coronary clot formation, there is evidence to suggest that antiplatelet therapy also induces anti-arrhythmic effects during ischemia by preventing the release of platelet activation products.

  6. 10.2.Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930257 Electrophysiologic study of reperfu-sion arrhythmias.YIN Hong (尹红),et al.Af-fil Hosp,Shandong Med Univ,Jinan.Chin CirJ 1993;8(1):37—39.Twenty dogs of experimental ischemic reper-fusion were studied with a three-dimensionalmapping system of cardiac electric activity andmultiple—level myocardial recordings by bipolarplunge—needle electrodes.27% of the nonsus-tained ventricular tachycardia (NSVT) of intra-mural reentry occurred in the ischemic subendo-

  7. Cardiac arrhythmias during or after epileptic seizures

    Science.gov (United States)

    van der Lende, Marije; Surges, Rainer; Sander, Josemir W; Thijs, Roland D

    2016-01-01

    Seizure-related cardiac arrhythmias are frequently reported and have been implicated as potential pathomechanisms of Sudden Unexpected Death in Epilepsy (SUDEP). We attempted to identify clinical profiles associated with various (post)ictal cardiac arrhythmias. We conducted a systematic search from the first date available to July 2013 on the combination of two terms: ‘cardiac arrhythmias’ and ‘epilepsy’. The databases searched were PubMed, Embase (OVID version), Web of Science and COCHRANE Library. We attempted to identify all case reports and case series. We identified seven distinct patterns of (post)ictal cardiac arrhythmias: ictal asystole (103 cases), postictal asystole (13 cases), ictal bradycardia (25 cases), ictal atrioventricular (AV)-conduction block (11 cases), postictal AV-conduction block (2 cases), (post)ictal atrial flutter/atrial fibrillation (14 cases) and postictal ventricular fibrillation (3 cases). Ictal asystole had a mean prevalence of 0.318% (95% CI 0.316% to 0.320%) in people with refractory epilepsy who underwent video-EEG monitoring. Ictal asystole, bradycardia and AV-conduction block were self-limiting in all but one of the cases and seen during focal dyscognitive seizures. Seizure onset was mostly temporal (91%) without consistent lateralisation. Postictal arrhythmias were mostly found following convulsive seizures and often associated with (near) SUDEP. The contrasting clinical profiles of ictal and postictal arrhythmias suggest different pathomechanisms. Postictal rather than ictal arrhythmias seem of greater importance to the pathophysiology of SUDEP. PMID:26038597

  8. Cardiac autonomic nerve distribution and arrhythmia

    Institute of Scientific and Technical Information of China (English)

    Quan Liu; Dongmei Chen; Yonggang Wang; Xin Zhao; Yang Zheng

    2012-01-01

    OBJECTIVE: To analyze the distribution characteristics of cardiac autonomic nerves and to explore the correlation between cardiac autonomic nerve distribution and arrhythmia.DATA RETRIEVAL: A computer-based retrieval was performed for papers examining the distribution of cardiac autonomic nerves, using "heart, autonomic nerve, sympathetic nerve, vagus nerve, nerve distribution, rhythm and atrial fibrillation" as the key words.SELECTION CRITERIA: A total of 165 studies examining the distribution of cardiac autonomic nerve were screened, and 46 of them were eventually included.MAIN OUTCOME MEASURES: The distribution and characteristics of cardiac autonomic nerves were observed, and immunohistochemical staining was applied to determine the levels of tyrosine hydroxylase and acetylcholine transferase (main markers of cardiac autonomic nerve distribution). In addition, the correlation between cardiac autonomic nerve distribution and cardiac arrhythmia was investigated.RESULTS: Cardiac autonomic nerves were reported to exhibit a disordered distribution in different sites, mainly at the surface of the cardiac atrium and pulmonary vein, forming a ganglia plexus. The distribution of the pulmonary vein autonomic nerve was prominent at the proximal end rather than the distal end, at the upper left rather than the lower right, at the epicardial membrane rather than the endocardial membrane, at the left atrium rather than the right atrium, and at the posterior wall rather than the anterior wall. The main markers used for cardiac autonomic nerves were tyrosine hydroxylase and acetylcholine transferase. Protein gene product 9.5 was used to label the immunoreactive nerve distribution, and the distribution density of autonomic nerves was determined using a computer-aided morphometric analysis system.CONCLUSION: The uneven distribution of the cardiac autonomic nerves is the leading cause of the occurrence of arrhythmia, and the cardiac autonomic nerves play an important role in the

  9. Cardiac arrhythmia classification using autoregressive modeling

    Directory of Open Access Journals (Sweden)

    Srinivasan Narayanan

    2002-11-01

    Full Text Available Abstract Background Computer-assisted arrhythmia recognition is critical for the management of cardiac disorders. Various techniques have been utilized to classify arrhythmias. Generally, these techniques classify two or three arrhythmias or have significantly large processing times. A simpler autoregressive modeling (AR technique is proposed to classify normal sinus rhythm (NSR and various cardiac arrhythmias including atrial premature contraction (APC, premature ventricular contraction (PVC, superventricular tachycardia (SVT, ventricular tachycardia (VT and ventricular fibrillation (VF. Methods AR Modeling was performed on ECG data from normal sinus rhythm as well as various arrhythmias. The AR coefficients were computed using Burg's algorithm. The AR coefficients were classified using a generalized linear model (GLM based algorithm in various stages. Results AR modeling results showed that an order of four was sufficient for modeling the ECG signals. The accuracy of detecting NSR, APC, PVC, SVT, VT and VF were 93.2% to 100% using the GLM based classification algorithm. Conclusion The results show that AR modeling is useful for the classification of cardiac arrhythmias, with reasonably high accuracies. Further validation of the proposed technique will yield acceptable results for clinical implementation.

  10. Cardiac arrhythmias associated with spinal cord injury

    DEFF Research Database (Denmark)

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

    2013-01-01

    describing the chronic phase of SCI, showed that individuals with SCI did not have a higher incidence of cardiac arrhythmias compared with able-bodied controls. Furthermore, their heart rate did not differ significantly. Penile vibro-stimulation was the procedure investigated most likely to cause bradycardia......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......) contained original data (2) on cardiac arrhythmias (3) in humans with (4) traumatic SCI. RESULTS: In the acute phase of SCI (1-14 days after injury) more cranial as well as more severe injuries seemed to increase the incidence of bradycardia. Articles not covering the first 14 days after injury, thus...

  11. Cardiac arrhythmia as initial presentation of aneurysmal subarachnoid hemorrhage

    NARCIS (Netherlands)

    van der Kleij, FGH; Henselmans, JML; van de Loosdrecht, AA

    1999-01-01

    Cardiac arrhythmia and sudden death are most frequently caused by preexisting heart disease. Rarely, cardiac arrhythmia is a first symptom of an acute neurological event. We describe a patient with asystole and other cardiac arrhythmias, as initial symptoms of acute aneurysmal subarachnoid hemorrhag

  12. Fetal cardiac arrhythmias: diagnosis and management.

    Science.gov (United States)

    Feit, L R

    2001-05-01

    The diagnosis and management of fetal cardiac arrhythmias requires complex skills and knowledge, and has had a great impact on the care of infants with congenital heart disease and their families. Optimal benefits will be derived from a thoughtful team approach, with skillful internal communication, and especially when parental involvement is encouraged in the decision making process. PMID:11392955

  13. Cardiac Arrhythmias and Abnormal Electrocardiograms After Acute Stroke.

    Science.gov (United States)

    Ruthirago, Doungporn; Julayanont, Parunyou; Tantrachoti, Pakpoom; Kim, Jongyeol; Nugent, Kenneth

    2016-01-01

    Cardiac arrhythmias and electrocardiogram (ECG) abnormalities occur frequently but are often underrecognized after strokes. Acute ischemic and hemorrhagic strokes in some particular area of brain can disrupt central autonomic control of the heart, precipitating cardiac arrhythmias, ECG abnormalities, myocardial injury and sometimes sudden death. Identification of high-risk patients after acute stroke is important to arrange appropriate cardiac monitoring and effective management of arrhythmias, and to prevent cardiac morbidity and mortality. More studies are needed to better clarify pathogenesis, localization of areas associated with arrhythmias and practical management of arrhythmias and abnormal ECGs after acute stroke. PMID:26802767

  14. MicroRNAs in cardiac arrhythmia

    DEFF Research Database (Denmark)

    Hedley, Paula L; Carlsen, Anting L; Christiansen, Kasper M;

    2014-01-01

    Long QT syndrome (LQTS) is a genetic cardiac condition associated with prolonged ventricular repolarization, primarily a result of perturbations in cardiac ion channels, which predisposes individuals to life-threatening arrhythmias. Using DNA screening and sequencing methods, over 700 different...... LQTS-causing mutations have been identified in 13 genes worldwide. Despite this, the genetic cause of 30-50% of LQTS is presently unknown. MicroRNAs (miRNAs) are small (∼ 22 nucleotides) noncoding RNAs which post-transcriptionally regulate gene expression by binding complementary sequences within...... cardiovascular diseases. MiR-1 and MiR-133A are the most abundant miRNAs in the heart and have both been reported to regulate cardiac ion channels. We hypothesized that, as a consequence of their role in regulating cardiac ion channels, genetic variation in the genes which encode MiR-1 and MiR-133A might explain...

  15. A vertical approach to cardiac arrhythmias.

    Science.gov (United States)

    Vaughan Williams, E M

    1987-10-01

    Study of cardiac arrhythmia may be pursued vertically, as up the rungs of a ladder, from symptom to ECG, to EPS, to local lesion, to intracellular metabolism and to alterations of the latter and their effects on charge-transfer by ions across the cell membrane. Raised intracellular cAMP and calcium concentrations are responses to normal physiological controls, and highly abnormal ECGs occur in normal people under stress without progressing to life threatening arrhythmias, yet do so in susceptible individuals. Conversely, appropriate stimulation can precipitate ventricular fibrillation in normal myocardium. Selective stimulation of different types of adrenoceptor has differing electrophysiological effects. Beta 1-adrenoceptors increase contraction and calcium current, and shorten action potential duration (APD) by increasing potassium conductance. Beta 2-adrenoceptors do not increase calcium entry, but shorten APD by stimulating electrogenic Na/K pumping, alpha-adrenoceptors prolong contractions and lengthen APD. It is suggested that the tachycardia, extrasystoles and shortening of APD occurring in response to adrenergic stimuli and hypoxia, are accessory factors, not primary causes, in the development of arrhythmias, and constitute a danger when there is an appropriate anatomical substrate for re-entry. Serious arrhythmias are of multifactorial origin, of which "calcium overload" is but one, not proven to be a frequent one.

  16. Microwave Treatment for Cardiac Arrhythmias

    Science.gov (United States)

    Hernandez-Moya, Sonia

    2009-01-01

    NASA seeks to transfer the NASA developed microwave ablation technology, designed for the treatment of ventricular tachycardia (irregular heart beat), to industry. After a heart attack, many cells surrounding the resulting scar continue to live but are abnormal electrically; they may conduct impulses unusually slowly or fire when they would typically be silent. These diseased areas might disturb smooth signaling by forming a reentrant circuit in the muscle. The objective of microwave ablation is to heat and kill these diseased cells to restore appropriate electrical activity in the heart. This technology is a method and apparatus that provides for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In comparison with other methods that involve direct-current pulses or radio frequencies below 1 GHz, this method may prove more effective in treating ventricular tachycardia. This is because the present method provides for greater control of the location, cross-sectional area, and depth of a lesion via selection of the location and design of the antenna and the choice of microwave power and frequency.

  17. Sinoatrial node dysfunction induces cardiac arrhythmias in diabetic mice

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Speerschneider, Tobias; Winther, Sine V;

    2014-01-01

    recovery time was prolonged in diabetic mice. Adrenoreceptor stimulation increased heart rate in all mice and elicited cardiac arrhythmias in db/db mice only. The arrhythmias emanated from the SAN and were characterized by large RR fluctuations. Moreover, nerve density was reduced in the SAN region.......ConclusionsEnhanced systolic function and reduced diastolic function indicates early ventricular remodeling in obese and diabetic mice. They have SAN dysfunction, and adrenoreceptor stimulation triggers cardiac arrhythmia originating in the SAN. Thus, dysfunction of the intrinsic cardiac pacemaker and remodeling...

  18. 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.

  19. Cardiac arrhythmias during exercise testing in healthy men.

    Science.gov (United States)

    Beard, E. F.; Owen, C. A.

    1973-01-01

    Clinically healthy male executives who participate in a long-term physical conditioning program have demonstrated cardiac arrhythmia during and after periodic ergometric testing at submaximal and maximal levels. In 1,385 tests on 248 subjects, it was found that 34% of subjects demonstrated an arrhythmia at some time and 13% of subjects developed arrhythmia on more than one test. Premature systoles of ventricular origin were most common, but premature systoles of atrial origin, premature systoles of junctional origin, paroxysmal atrial tachycardia, atrioventricular block, wandering pacemaker, and pre-excitation were also seen. Careful post-test monitoring and pulse rate regulated training sessions are suggested for such programs.

  20. Cardiac Arrhythmias in a Septic ICU Population: A Review

    Directory of Open Access Journals (Sweden)

    Schwartz Andrei

    2015-10-01

    Full Text Available Progressive cardiovascular deterioration plays a central role in the pathogenesis of multiple organ failure (MOF caused by sepsis. Evidence of various cardiac arrhythmias in septic patients has been reported in many published studies. In the critically ill septic patients, compared to non-septic patients, new onset atrial fibrillation episodes are associated with high mortality rates and poor outcomes, amongst others being new episodes of stroke, heart failure and long vasopressor usage. The potential mechanisms of the development of new cardiac arrhythmias in sepsis are complex and poorly understood. Cardiac arrhythmias in critically ill septic patients are most likely to be an indicator of the severity of pre-existing critical illness.

  1. Ion channelopathy and hyperphosphorylation contributing to cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    De-zai DAI; Feng YU

    2005-01-01

    The occurrence of cardiac arrhythmias is related to the abnormality of ion channels not only in sarcolemma but also in the sarcoplasmic reticulum, which regulates the process of calcium release and up-take intracellularly. Patterns of ion channelopathy in the sarcolemma can be divided into single channel disorder from gene mutations and multiple channels disorder in a diseased hypertrophied heart. Abnormal RyR2, FKBP12.6, SERCA2a, and PLB are also involved in the initiation of cardiac arrhythmias. Maladjustment by hyperphosphorylation on the ion channels in the sarcolemma and RyR2-FKBP12.6 and SERCA2a-PLB is discussed. Hyperphosphorylation, which is the main abnormality upstream to ion channels, can be targeted for suppressing the deterioration of ion channelopathy in terms of new drug discovery in the treatment and prevention of malignant cardiac arrhythmias.

  2. 78 FR 36787 - Rechanneling the Current Cardiac Risk Paradigm: Arrhythmia Risk Assessment During Drug...

    Science.gov (United States)

    2013-06-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Rechanneling the Current Cardiac Risk Paradigm: Arrhythmia... the Current Cardiac Risk Paradigm: Arrhythmia Risk Assessment During Drug Development Without...

  3. Nonlinear interpolation fractal classifier for multiple cardiac arrhythmias recognition

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C.-H. [Department of Electrical Engineering, Kao-Yuan University, No. 1821, Jhongshan Rd., Lujhu Township, Kaohsiung County 821, Taiwan (China); Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)], E-mail: eechl53@cc.kyu.edu.tw; Du, Y.-C.; Chen Tainsong [Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)

    2009-11-30

    This paper proposes a method for cardiac arrhythmias recognition using the nonlinear interpolation fractal classifier. A typical electrocardiogram (ECG) consists of P-wave, QRS-complexes, and T-wave. Iterated function system (IFS) uses the nonlinear interpolation in the map and uses similarity maps to construct various data sequences including the fractal patterns of supraventricular ectopic beat, bundle branch ectopic beat, and ventricular ectopic beat. Grey relational analysis (GRA) is proposed to recognize normal heartbeat and cardiac arrhythmias. The nonlinear interpolation terms produce family functions with fractal dimension (FD), the so-called nonlinear interpolation function (NIF), and make fractal patterns more distinguishing between normal and ill subjects. The proposed QRS classifier is tested using the Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) arrhythmia database. Compared with other methods, the proposed hybrid methods demonstrate greater efficiency and higher accuracy in recognizing ECG signals.

  4. Cardiac arrhythmias in adults with congenital heart disease

    NARCIS (Netherlands)

    Z. Koyak

    2016-01-01

    Arrhythmias are a major cause of hospital admissions and morbidity in adults with congenital heart disease (CHD). Furthermore, the leading cause of death in adults with CHD is sudden cardiac death (SCD) of presumed arrhythmic aetiology. The main objectives of this thesis were to identify risk factor

  5. 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...

  6. Cardiac Arrhythmia Classification by Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Hadji Salah

    2015-05-01

    Full Text Available Cardiovascular diseases are the major public health parameter; they are the leading causes of mortality in the world. In fact many studies have been implemented to reduce the risk, including promoting education, prevention, and monitoring of patients at risk. In this paper we propose to develop classification system heartbeats. This system is based mainly on Wavelet Transform to extract features and Kohonen self-organization map the arrhythmias are considered in this study: N,(Normal, V(PrematureVentricular, A(AtrialPremature, S(Extrasystolesupraventriculaire, F(FusionN+S, R(RightBundle Branch.

  7. An Unusual Cause of Cardiac Arrhythmias; Mediastinal Schwannoma

    Directory of Open Access Journals (Sweden)

    Serdar Ozkan

    2014-02-01

    Full Text Available Schwannomas are rare tumours, which originated from neural crest cells. Thoracic schwannomas are very rare and most commonly seen in posterior mediastinum. In a 39 year old female patient whose tumor story dated back to 4 years, a 14 cm extra parenchymal intrathoracic tumor was observed to put minimal pressure on the heart. The patient%u2019s arrhythmia, who had preoperative complaints of palpitations, was improved after tumor excision. Although schwannomas generally are asympthomatic masses, they can lead mass effect according to their localization. In this study, patient with thoracic schwannoma presented with cardiac arrhythmia which never reported in literature so far.

  8. Electrocardiographic abnormalities and cardiac arrhythmias in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Goudis, Christos A; Konstantinidis, Athanasios K; Ntalas, Ioannis V; Korantzopoulos, Panagiotis

    2015-11-15

    Chronic obstructive pulmonary disease (COPD) is independently associated with an increased burden of cardiovascular disease. Besides coronary artery disease (CAD) and congestive heart failure (CHF), specific electrocardiographic (ECG) abnormalities and cardiac arrhythmias seem to have a significant impact on cardiovascular prognosis of COPD patients. Disturbances of heart rhythm include premature atrial contractions (PACs), premature ventricular contractions (PVCs), atrial fibrillation (AF), atrial flutter (AFL), multifocal atrial tachycardia (MAT), and ventricular tachycardia (VT). Of note, the identification of ECG abnormalities and the evaluation of the arrhythmic risk may have significant implications in the management and outcome of patients with COPD. This article provides a concise overview of the available data regarding ECG abnormalities and arrhythmias in these patients, including an elaborated description of the underlying arrhythmogenic mechanisms. The clinical impact and prognostic significance of ECG abnormalities and arrhythmias in COPD as well as the appropriate antiarrhythmic therapy and interventions in this setting are also discussed. PMID:26218181

  9. PERFORMANCE ANALYSIS OF SOFT COMPUTING TECHNIQUES FOR CLASSIFYING CARDIAC ARRHYTHMIA

    Directory of Open Access Journals (Sweden)

    R GANESH KUMAR

    2014-01-01

    Full Text Available Cardiovascular diseases kill more people than other diseases. Arrhythmia is a common term used for cardiac rhythm deviating from normal sinus rhythm. Many heart diseases are detected through electrocardiograms (ECG analysis. Manual analysis of ECG is time consuming and error prone. Thus, an automated system for detecting arrhythmia in ECG signals gains importance. Features are extracted from time series ECG data with Discrete Cosine Transform (DCT computing the distance between RR waves. The feature is the beat’s extracted RR interval. Frequency domain extracted features are classified using Classification and Regression Tree (CART, Radial Basis Function (RBF, Support Vector Machine (SVM and Multilayer Perceptron Neural Network (MLP-NN. Experiments were conducted on the MIT-BIH arrhythmia database.

  10. Ambulatory Cardiac Monitoring for Discharged Emergency Department Patients with Possible Cardiac Arrhythmias

    Directory of Open Access Journals (Sweden)

    Donald Scheiber

    2014-03-01

    Full Text Available Introduction: Many emergency department (ED patients have symptoms that may be attributed to arrhythmias, necessitating outpatient ambulatory cardiac monitoring. Consensus is lacking on the optimal duration of monitoring. We describe the use of a novel device applied at ED discharge that provides continuous prolonged cardiac monitoring. Methods: We enrolled discharged adult ED patients with symptoms of possible cardiac arrhythmia. A novel, single use continuous recording patch (Zio®Patch was applied at ED discharge. Patients wore the device for up to 14 days or until they had symptoms to trigger an event. They then returned the device by mail for interpretation. Significant arrhythmias are defined as: ventricular tachycardia (VT ≥4 beats, supraventricular tachycardia (SVT ≥4 beats, atrial fibrillation, ≥3 second pause, 2nd degree Mobitz II, 3rd degree AV Block, or symptomatic bradycardia. Results: There were 174 patients were enrolled and all mailed back their devices. The average age was 52.2 (± 21.0 years, and 55% were female. The most common indications for device placement were palpitations 44.8%, syncope 24.1% and dizziness 6.3%. Eighty-three patients (47.7% had ≥1 arrhythmias and 17 (9.8% were symptomatic at the time of their arrhythmia. Median time to first arrhythmia was 1.0 days (IQR 0.2-2.8 and median time to first symptomatic arrhythmia was 1.5 days (IQR 0.4-6.7. 93 (53.4% of symptomatic patients did not have any arrhythmia during their triggered events. The overall diagnostic yield was 63.2% Conclusion: The Zio®Patch cardiac monitoring device can efficiently characterize symptomatic patients without significant arrhythmia and has a higher diagnostic yield for arrhythmias than traditional 24-48 hour Holter monitoring. It allows for longer term monitoring up to 14 days. [West J Emerg Med. 2014;15(2:194–198.

  11. New-onset atrial fibrillation predicts malignant arrhythmias in post-myocardial infarction patients - A Cardiac Arrhythmias and RIsk Stratification after acute Myocardial infarction (CARISMA) substudy

    DEFF Research Database (Denmark)

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

    2013-01-01

    After myocardial infarction (MI) the risk of sudden cardiac death due to arrhythmias is substantial.......After myocardial infarction (MI) the risk of sudden cardiac death due to arrhythmias is substantial....

  12. Cardiac arrhythmia and heart failure: From bench to bedside

    Institute of Scientific and Technical Information of China (English)

    Yong-Fu Xiao

    2011-01-01

    @@ Cardiac arrhythmia is an abnormal rate and/or rhythm of a heart due to its abnormal electrical impulse origination and/or propagation.Various etiologies can cause arrhythnuas.Heart failure(HF)is a clinical syndrome due to an impaired heart that can not pump sufficient blood to meet the systemic metabolic needs.The common causes of HF include myocardial infarction,hypertension,valvular heart disease,and cardiomyopathy.

  13. Noninvasive Cardiac Screening in Young Athletes With Ventricular Arrhythmias

    OpenAIRE

    Steriotis, Alexandros Klavdios; Nava, Andrea; Rigato, Ilaria; Mazzotti, Elisa; Daliento, Luciano; Thiene, Gaetano; Basso, Cristina; Corrado, Domenico; Bauce, Barbara

    2013-01-01

    The aim of this study was to analyze using noninvasive cardiac examinations a series of young athletes discovered to have ventricular arrhythmias (VAs) during the preparticipation screening program for competitive sports. One hundred forty-five athletes (mean age 17 ± 5 years) were evaluated. The study protocol included electrocardiography (ECG), exercise testing, 2-dimensional and Doppler echocardiography, 24-hour Holter monitoring, signal-averaged ECG, and in selected cases contrast-enhance...

  14. Is it Safe? Adverse drug effects and cardiac arrhythmias

    OpenAIRE

    Varkevisser, R.

    2014-01-01

    The potentially life-threatening polymorphic ventricular arrhythmia Torsade de Pointes (TdP) generally occurs in the setting of delayed ventricular repolarization, as reflected on the ECG by a prolonged QT interval. A growing number of drugs are associated with QT prolongation and/or TdP, as a result, development of promising new drugs has been aborted, and already marketed drugs have received severe restrictions or have been withdrawn. To address this cardiac safety issue, international guid...

  15. Arrhythmia as a cardiac manifestation in MELAS syndrome

    Directory of Open Access Journals (Sweden)

    Tamara Thomas

    2015-09-01

    Full Text Available 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.

  16. 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.

  17. Long-term recording of cardiac arrhythmias with an implantable cardiac monitor in patients with reduced ejection fraction after acute myocardial infarction: the Cardiac Arrhythmias and Risk Stratification After Acute Myocardial Infarction (CARISMA) study

    DEFF Research Database (Denmark)

    Bloch Thomsen, Poul Erik; Jons, Christian; Raatikainen, M J Pekka;

    2010-01-01

    Knowledge about the incidence of cardiac arrhythmias after acute myocardial infarction has been limited by the lack of traditional ECG recording systems to document and confirm asymptomatic and symptomatic arrhythmias. The Cardiac Arrhythmias and Risk Stratification After Myocardial Infarction...... (CARISMA) trial was designed to study the incidence and prognostic significance of arrhythmias documented by an implantable cardiac monitor among patients with acute myocardial infarction and reduced left ventricular ejection fraction....

  18. Electrocardiographic abnormalities and cardiac arrhythmias in structural brain lesions.

    Science.gov (United States)

    Katsanos, Aristeidis H; Korantzopoulos, Panagiotis; Tsivgoulis, Georgios; Kyritsis, Athanassios P; Kosmidou, Maria; Giannopoulos, Sotirios

    2013-07-31

    Cardiac arrhythmias and electrocardiographic abnormalities are frequently observed after acute cerebrovascular events. The precise mechanism that leads to the development of these arrhythmias is still uncertain, though increasing evidence suggests that it is mainly due to autonomic nervous system dysregulation. In massive brain lesions sympathetic predominance and parasympathetic withdrawal during the first 72 h are associated with the occurrence of severe secondary complications in the first week. Right insular cortex lesions are also related with sympathetic overactivation and with a higher incidence of electrocardiographic abnormalities, mostly QT prolongation, in patients with ischemic stroke. Additionally, female sex and hypokalemia are independent risk factors for severe prolongation of the QT interval which subsequently results in malignant arrhythmias and poor outcome. The prognostic value of repolarization changes commonly seen after aneurysmal subarachnoid hemorrhage, such as ST segment, T wave, and U wave abnormalities, still remains controversial. In patients with traumatic brain injury both intracranial hypertension and cerebral hypoperfusion correlate with low heart rate variability and increased mortality. Given that there are no firm guidelines for the prevention or treatment of the arrhythmias that appear after cerebral incidents this review aims to highlight important issues on this topic. Selected patients with the aforementioned risk factors could benefit from electrocardiographic monitoring, reassessment of the medications that prolong QTc interval, and administration of antiadrenergic agents. Further research is required in order to validate these assumptions and to establish specific therapeutic strategies.

  19. Hospital discharge diagnoses of ventricular arrhythmias and cardiac arrest were useful for epidemiologic research

    DEFF Research Database (Denmark)

    De Bruin, M L; van Hemel, N M; Leufkens, H G M;

    2005-01-01

    OBJECTIVE: We investigated the validity of hospital discharge diagnosis regarding ventricular arrhythmias and cardiac arrest. METHODS: We identified patients whose record in the PHARMO record linkage system database showed a code for ventricular or unspecified cardiac arrhythmias according to cod...... according to ICD-9-CM as paroxysmal ventricular tachycardia, ventricular fibrillation, ventricular flutter, ventricular premature beats, or cardiac arrest) have a high PPV and are useful for selecting events in epidemiological studies on drug-induced arrhythmias....

  20. Effect of Encoding Method on the Distribution of Cardiac Arrhythmias

    CERN Document Server

    Mora, Luis A

    2011-01-01

    This paper presents the evaluation of the effect of the method of ECG signal encoding, based on nonlinear characteristics such as information entropy and Lempel-Ziv complexity, on the distribution of cardiac arrhythmias. Initially proposed a procedure electrocardiographic gating to compensate for errors inherent in the process of filtering segments. For the evaluation of distributions and determine which of the different encoding methods produces greater separation between different kinds of arrhythmias studied (AFIB, AFL, SVTA, VT, Normal's), use a function based on the dispersion of the elements on the centroid of its class, the result being that the best encoding for the entire system is through the method of threshold value for a ternary code with E = 1 / 12.

  1. Classification enhancible grey relational analysis for cardiac arrhythmias discrimination.

    Science.gov (United States)

    Lin, Chia-Hung

    2006-04-01

    This paper proposes a method for electrocardiogram (ECG) heartbeat recognition using classification enhancible grey relational analysis (GRA). The ECG beat recognition can be divided into a sequence of stages, starting with feature extraction and then according to characteristics to identify the cardiac arrhythmias including the supraventricular ectopic beat, bundle branch ectopic beat, and ventricular ectopic beat. Gaussian wavelets are used to enhance the features from each heartbeat, and GRA performs the recognition tasks. With the MIT-BIH arrhythmia database, the experimental results demonstrate the efficiency of the proposed non-invasive method. Compared with artificial neural network, the test results also show high accuracy, good adaptability, and faster processing time for the detection of heartbeat signals. PMID:16937172

  2. Multiple cardiac arrhythmia recognition using adaptive wavelet network.

    Science.gov (United States)

    Lin, Chia-Hung; Chen, Pei-Jarn; Chen, Yung-Fu; Lee, You-Yun; Chen, Tainsong

    2005-01-01

    This paper proposes a method for electrocardiogram (ECG) heartbeat pattern recognition using adaptive wavelet network (AWN). The ECG beat recognition can be divided into a sequence of stages, starting from feature extraction and conversion of QRS complexes, and then identifying cardiac arrhythmias based on the detected features. The discrimination method of ECG beats is a two-subnetwork architecture, consisting of a wavelet layer and a probabilistic neural network (PNN). Morlet wavelets are used to extract the features from each heartbeat, and then PNN is used to analyze the meaningful features and perform discrimination tasks. The AWN is suitable for application in a dynamic environment, with add-in and delete-off features using automatic target adjustment and parameter tuning. The experimental results obtained by testing the data of the MIT-BIH arrhythmia database demonstrate the efficiency of the proposed method. PMID:17281539

  3. Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

    International Nuclear Information System (INIS)

    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)

  4. Cardiac arrhythmia in Wilson's disease: An oversighted and overlooked entity!

    Science.gov (United States)

    Bajaj, Bhupender Kumar; Wadhwa, Ankur; Singh, Richa; Gupta, Saurabh

    2016-01-01

    Wilson's disease is a multisystem disorder which manifests with hepatic, neurological, musculoskeletal, hematological, renal, and cardiac symptoms. The hepatic and neurological manifestations often overshadow the other system involvement including cardiac symptoms and signs, which may prove fatal. We report a case of a young female who presented with progressive parkinsonian features and dystonia for around 4 months followed 2 months later by the complaint of episodes of light-headedness. She was diagnosed to have Wilson's disease based on the presence of Kayser–Fleischer ring and laboratory parameters of copper metabolism. Electrocardiography of the patient incidentally revealed 2nd degree Mobitz type-1 atrioventricular block explaining her episodes of light-headedness. She was started on penicillamine and trihexyphenidyl. The heart block improved spontaneously. Cardiac autonomic function tests including blood pressure response to standing and heart rate response to standing were observed to be normal. We review the literature on cardiac manifestations of Wilson's disease and emphasize that patients with Wilson's disease should be assessed for cardiac arrhythmia and cardiac dysfunction as these may have therapeutic and prognostic implications.

  5. Cardiac arrhythmia in Wilson's disease: An oversighted and overlooked entity!

    Science.gov (United States)

    Bajaj, Bhupender Kumar; Wadhwa, Ankur; Singh, Richa; Gupta, Saurabh

    2016-01-01

    Wilson's disease is a multisystem disorder which manifests with hepatic, neurological, musculoskeletal, hematological, renal, and cardiac symptoms. The hepatic and neurological manifestations often overshadow the other system involvement including cardiac symptoms and signs, which may prove fatal. We report a case of a young female who presented with progressive parkinsonian features and dystonia for around 4 months followed 2 months later by the complaint of episodes of light-headedness. She was diagnosed to have Wilson's disease based on the presence of Kayser–Fleischer ring and laboratory parameters of copper metabolism. Electrocardiography of the patient incidentally revealed 2nd degree Mobitz type-1 atrioventricular block explaining her episodes of light-headedness. She was started on penicillamine and trihexyphenidyl. The heart block improved spontaneously. Cardiac autonomic function tests including blood pressure response to standing and heart rate response to standing were observed to be normal. We review the literature on cardiac manifestations of Wilson's disease and emphasize that patients with Wilson's disease should be assessed for cardiac arrhythmia and cardiac dysfunction as these may have therapeutic and prognostic implications. PMID:27695244

  6. Link between Hypoglycemia and Cardiac Arrhythmias: An Answer to Why Tight Glycemic Control May Increase Mortality in ...

    Science.gov (United States)

    ... Size: A A A Listen The Link Between Hypoglycemia and Cardiac Arrhythmias: An Answer to Why Tight ... from the University of Sheffield found that overnight hypoglycemia was associated with increased susceptibility to cardiac arrhythmias ...

  7. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    Science.gov (United States)

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia.

  8. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    Science.gov (United States)

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia. PMID:27521094

  9. Exact coherent structures: from fluid turbulence to cardiac arrhythmias

    Science.gov (United States)

    Grigoriev, Roman; Marcotte, Christopher; Byrne, Gregory

    2014-03-01

    Ventricular fibrillation, a life threatening cardiac arrhythmia, is an example of spatiotemporally chaotic state dominated by multiple interacting spiral waves. Recent studies of weak fluid turbulence suggest that spatiotemporal chaos in general can be understood as a walk among exact unstable regular solutions (exact coherent states, ECS) of nonlinear evolution equations. Several classes of ECS are believed to play a dominant role; most typically these are equilibria and periodic orbits or relative equilibria and relative periodic orbits for systems with global continuous symmetries. Numerical methods originally developed in the context of fluid turbulence can also be applied to models of cardiac dynamics which possess translational and rotational symmetries and, indeed, allowed us to identify relative equilibria and periodic orbits describing isolated spirals with, respectively, fixed and drifting cores. In order to find regular solutions featuring multiple interacting spirals a new approach is required that takes into consideration the dynamics of slowly drifting cores associated with local, rather than global, symmetries. We describe how local symmetries can be reduced and more general types of ECS computed that dominate spiral wave chaos in models of cardiac tissue.

  10. Cardiac arrhythmias during fiberoptic bronchoscopy and relation with oxygen saturation

    Directory of Open Access Journals (Sweden)

    Hassan G

    2005-01-01

    Full Text Available To evaluate the occurrence of electrocardiographic abnormalities during fiberoptic bronchoscopy, in relation to specific stages of the procedures, patients′ age, sex, smoking, pre-existing lung disease, premedication and oxygen saturation, a prospective study was conducted on 56 patients aged 35 to 75 (mean 62 years without pre-existing cardiovascular disease. Patients were connected to a 12-lead computerized electrocardiographic recorder and pulse oximeter. Fall of oxygen saturation from mean of 95.12% before the procedure to below 80% was observed in 12 (21.4% patients and below 75% in 5 (8.9% patients, at various stages. Statistically highly significant (p < 0.001 fall of oxygen saturation was observed during the procedures while bronchoscope was introduced into the airways and tracheobronchial tree examined. Major disturbances of cardiac rhythm (i.e. atrial, ventricular or both developed in 23 (41.07% patients. Out of these, sinus tachycardia was noted in 16 (69.5%, ventricular premature complexes in 5 (21.7% and paroxysmal supraventricular tachycardia in 2 (8.6% patients. Arrhythmias were most frequent in association with periods of maximum oxygen desaturation in 18 (78.2% of these 23 patients. Oxygen desaturation persisted for more than half an hour in 38 (67.8% of the 56 patients. However, no correlation was observed between the frequency of arrhythmias during bronchoscopy and patients′ age, sex pre-medication or pre-existing pulmonary disease.

  11. Intra-beat Scaling Properties of Cardiac Arrhythmias and Sudden Cardiac Death

    Science.gov (United States)

    Rodríguez, Eduardo; Lerma, Claudia; Echeverría, Juan C.; Alvarez-Ramirez, Jose

    2008-02-01

    We applied detrended fluctuation analysis (DFA) to characterize the intra-beat scaling dynamics of electrocardiographic (ECG) recordings from the PhysioNet Sudden Cardiac Death Holter Database. The main finding of this contribution is that, in such recordings involving different types of arrhythmias; the ECG waveform, besides showing a less-random intra-beat dynamics, becomes more regular during bigeminy, ventricular tachycardia (VT) or even atrial fibrillation (AFIB) and ventricular fibrillation (VF) despite the appearance of erratic traces. Thus, notwithstanding that these cardiac rhythm abnormalities are generally considered as irregular and some of them generated by random impulses or wavefronts, the intra-beat scaling properties suggest that regularity dominates the underlying mechanisms of arrhythmias. Among other explanations, this may result from shorted or restricted -less complex- pathways of conduction of the electrical activity within the ventricles.

  12. 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

  13. 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 gen

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

    OpenAIRE

    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 ablation lesions. Transmurality is essential for conduction block and is depending on many factors, such as tissue ablation duration, thickness of the cardiac wall, ablation technique used, cathete...

  15. Aconitine Challenge Test Reveals a Single Exposure to Air Pollution Causes Increased Cardiac Arrhythmia Risk in Hypertensive Rats - Abstract

    Science.gov (United States)

    Epidemiological studies demonstrate a significant association between arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electrical dysfunction. In this study, ...

  16. Over-phosphorylation of FKBP12.6, phospholamban,relating to exacerbation of cardiac arrhythmias and failure

    Institute of Scientific and Technical Information of China (English)

    De-zaiDAI

    2004-01-01

    AIM: Cardiac arrhythmias occur severely in diseased and failing hearts and remain an important cause of mortality in cardiovascular disorders. It was intended to explore mechanisms of abnormal ion channels underlying cardiac arrhythmias and failure and in responses to drug interventions. METHODS: Chronic infarction plus isoproterenol (ISO) medication or L-thyroxin (THY) repetitive medication promote cardiac remodeling and exaggerated

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

    Science.gov (United States)

    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.

  18. Sympathetic restraint of respiratory sinus arrhythmia: implications for vagal-cardiac tone assessment in humans

    Science.gov (United States)

    Taylor, J. A.; Myers, C. W.; Halliwill, J. R.; Seidel, H.; Eckberg, D. L.

    2001-01-01

    Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 frequencies, from 15 to 3 breaths/min, before and after beta-adrenergic blockade. We fitted changes of respiratory frequency R-R interval spectral power with a damped oscillator model: frequency-dependent oscillations with a resonant frequency, generated by driving forces and modified by damping influences. beta-Adrenergic blockade enhanced respiratory sinus arrhythmia at all frequencies (at some, fourfold). The damped oscillator model fit experimental data well (39 of 40 ramps; r = 0.86 +/- 0.02). beta-Adrenergic blockade increased respiratory sinus arrhythmia by amplifying respiration-related driving forces (P arrhythmia is mediated simply by vagal-cardiac nerve activity. These results have important implications for clinical and experimental estimation of human vagal cardiac tone.

  19. Arrhythmias

    Science.gov (United States)

    ... Atrial myxoma Cardiac ablation procedures Heart attack Heart failure - overview Heart pacemaker Pulse Stroke Patient Instructions Atrial fibrillation - discharge Heart pacemaker - discharge Taking warfarin (Coumadin, Jantoven) - ...

  20. Design and implementation of a simple portable biomedical electronic device to diagnose cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    H. Azucena

    2015-06-01

    Full Text Available This paper presents the development of a simple portable biomedical electronic device to detect cardiac arrhythmias in humans. It identifies three main parts: an electrocardiograph, a device for data communication and a personal computer with software for diagnosis. The system performs automatic diagnosis of cardiac arrhythmias by comparing the patient’s electrocardiogram with those contained in a database stored in a personal computer. The biomedical device performance is satisfactory and it demonstrated its usefulness even in the absence of medical specialist in cardiology.

  1. 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)

  2. 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

    -prolonging drugs. A statistically nonsignificant increased risk for arrhythmias (OR 1.2, 95% CI 0.8 to 1.9) was observed in patients who received QTc-prolonging drugs. A clearly increased risk of arrhythmias was, however, found in patients with a history of asthma (OR 9.9, 95% CI 1.0 to 100) and in patients using...... with a history of asthma and patients taking potassium-lowering drugs. The use of QTc-prolonging drugs should therefore be either avoided or monitored closely in these specific patients....

  3. Is it Safe? Adverse drug effects and cardiac arrhythmias

    NARCIS (Netherlands)

    Varkevisser, R.

    2014-01-01

    The potentially life-threatening polymorphic ventricular arrhythmia Torsade de Pointes (TdP) generally occurs in the setting of delayed ventricular repolarization, as reflected on the ECG by a prolonged QT interval. A growing number of drugs are associated with QT prolongation and/or TdP, as a resul

  4. Fetal cardiac arrhythmia: antepartum diagnosis of a case of congenital atrial flutter.

    OpenAIRE

    Anderson, K. J.; Simmons, S. C.; Hallidie-Smith, K A

    1981-01-01

    A case of antepartum atrial tachyarrhythmia was detected in the 36th week of pregnancy. Cardiotocograph recordings done twice daily enabled close surveillance of the fetal condition after oxytoxin challenge testing had failed to show evidence of hypoxia. After a diagnosis of fetal cardiac arrhythmia had been made, elective caesarean section in the 40th week of pregnancy resulted in delivery of an infant in atrial flutter and cardiac failure. Both these problems were soon resolved by cardiover...

  5. Acute Effects of Fine Particulate Air Pollution on Cardiac Arrhythmia: The APACR Study

    OpenAIRE

    He, Fan; Michele L. Shaffer; Rodriguez-Colon, Sol; Yanosky, Jeff D.; Bixler, Edward; Cascio, Wayne E; Liao, Duanping

    2011-01-01

    Background: The mechanisms underlying the relationship between particulate matter (PM) air pollution and cardiac disease are not fully understood. Objectives: We examined the effects and time course of exposure to fine PM [aerodynamic diameter ≤ 2.5 μm (PM2.5)] on cardiac arrhythmia in 105 middle-age community-dwelling healthy nonsmokers in central Pennsylvania. Methods: The 24-hr beat-to-beat electrocardiography data were obtained using a high-resolution Holter system. After visually identif...

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

    NARCIS (Netherlands)

    De Bruin, M L; van Puijenbroek, E P; Egberts, A C G; Hoes, A W; Leufkens, H G M

    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

  7. 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; Gang, Uffe; Thomsen, Poul Erik Bloch;

    2014-01-01

    ventricular ejection fraction (LVEF) ≤40%. All patients were implanted with an implantable cardiac monitor (ICM) within 5 to 21 days post-MI and followed every three months for two years. Atrial fibrillation, bradyarrhythmias and ventricular tachycardias were diagnosed using the ICM, pacemaker or ICD......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...

  8. Cardiac arrhythmia classification using multi-modal signal analysis.

    Science.gov (United States)

    Kalidas, V; Tamil, L S

    2016-08-01

    In this paper, as a contribution to the Physionet/Computing in Cardiology 2015 Challenge, we present individual algorithms to accurately classify five different life threatening arrhythmias with the goal of suppressing false alarm generation in intensive care units. Information obtained by analysing electrocardiogram, photoplethysmogram and arterial blood pressure signals was utilized to develop the classification models. Prior to classification, the signals were subject to a signal pre-processing stage for quality analysis. Classification was performed using a combination of support vector machine based machine learning approach and logical analysis techniques. The predicted result for a certain arrhythmia classification model was verified by logical analysis to aid in reduction of false alarms. Separate feature vectors were formed for predicting the presence or absence of each arrhythmia, using both spectral and time-domain information. The training and test data were obtained from the Physionet/CinC Challenge 2015 database. Classification algorithms were written for two different categories of data, namely real-time and retrospective, whose data lengths were 10 s and an additional 30 s, respectively. For the real-time test dataset, sensitivity of 94% and specificity of 82% were obtained. Similarly, for the retrospective test dataset, sensitivity of 94% and specificity of 86% were obtained. PMID:27454417

  9. Pharmacological and Biological Risk Factors for Cardiac Arrhythmias

    NARCIS (Netherlands)

    C. van Noord (Charlotte)

    2009-01-01

    textabstractSudden death is among the most common causes of death in developed countries. Sudden death from cardiac causes accounts for approximately 50% of all deaths from cardiovascular diseases and 20% of all deaths. The majority (80-85%) of sudden cardiac deaths are caused by acute ventricular a

  10. Sodium Channel (Dys)Function and Cardiac Arrhythmias

    NARCIS (Netherlands)

    C.A. Remme; C.R. Bezzina

    2010-01-01

    P>Cardiac voltage-gated sodium channels are transmembrane proteins located in the cell membrane of cardiomyocytes. Influx of sodium ions through these ion channels is responsible for the initial fast upstroke of the cardiac action potential. This inward sodium current thus triggers the initiation an

  11. Incidence of cardiac arrhythmias in asymptomatic hereditary hemochromatosis subjects with C282Y homozygosity.

    Science.gov (United States)

    Shizukuda, Yukitaka; Tripodi, Dorothy J; Zalos, Gloria; Bolan, Charles D; Yau, Yu-Ying; Leitman, Susan F; Waclawiw, Myron A; Rosing, Douglas R

    2012-03-15

    It is not well known whether systemic iron overload per se in hereditary hemochromatosis (HH) is associated with cardiac arrhythmias before other signs and symptoms of cardiovascular disease occur. In the present study, we examined the incidence of cardiac arrhythmia in cardiac asymptomatic subjects with HH (New York Heart Association functional class I) and compared it to that in age- and gender-matched normal volunteers. The 42 subjects with HH and the 19 normal control subjects were recruited through the National Heart, Lung, and Blood Institute-sponsored "Heart Study of Hemochromatosis." They completed 48-hour Holter electrocardiography ambulatory monitoring at the baseline evaluation. The subjects with HH were classified as newly diagnosed (group A) and chronically treated (group B) subjects. All subjects with HH had C282Y homozygosity, and the normal volunteers lacked any HFE gene mutations known to cause HH. Although statistically insignificant, the incidence of ventricular and supraventricular ectopy tended to be greater in the combined HH groups than in the controls. Supraventricular ectopy was more frequently noted in group B compared to in the controls (ectopy rate per hour 11.1 ± 29.9 vs 1.5 ± 3.5, p examples of heart block, other than first-degree atrioventricular node block, were seen in any of the subjects. The incidence of cardiac arrhythmias was not significantly reduced after 6 months of intensive iron removal therapy in the group A subjects. No life-threatening arrhythmias were observed in our subjects with HH. In conclusion, our data suggest that the incidence of cardiac arrhythmias is, at most, marginally increased in asymptomatic subjects with HH. A larger clinical study is warranted to further clarify our observation. PMID:22196777

  12. Postoperative Arrhythmias after Cardiac Surgery: Incidence, Risk Factors, and Therapeutic Management

    Directory of Open Access Journals (Sweden)

    Giovanni Peretto

    2014-01-01

    Full Text Available Arrhythmias are a known complication after cardiac surgery and represent a major cause of morbidity, increased length of hospital stay, and economic costs. However, little is known about incidence, risk factors, and treatment of early postoperative arrhythmias. Both tachyarrhythmias and bradyarrhythmias can present in the postoperative period. In this setting, atrial fibrillation is the most common heart rhythm disorder. Postoperative atrial fibrillation is often self-limiting, but it may require anticoagulation therapy and either a rate or rhythm control strategy. However, ventricular arrhythmias and conduction disturbances can also occur. Sustained ventricular arrhythmias in the recovery period after cardiac surgery may warrant acute treatment and long-term preventive strategy in the absence of reversible causes. Transient bradyarrhythmias may be managed with temporary pacing wires placed at surgery, but significant and persistent atrioventricular block or sinus node dysfunction can occur with the need for permanent pacing. We provide a complete and updated review about mechanisms, risk factors, and treatment strategies for the main postoperative arrhythmias.

  13. Postoperative arrhythmias after cardiac surgery: incidence, risk factors, and therapeutic management.

    Science.gov (United States)

    Peretto, Giovanni; Durante, Alessandro; Limite, Luca Rosario; Cianflone, Domenico

    2014-01-01

    Arrhythmias are a known complication after cardiac surgery and represent a major cause of morbidity, increased length of hospital stay, and economic costs. However, little is known about incidence, risk factors, and treatment of early postoperative arrhythmias. Both tachyarrhythmias and bradyarrhythmias can present in the postoperative period. In this setting, atrial fibrillation is the most common heart rhythm disorder. Postoperative atrial fibrillation is often self-limiting, but it may require anticoagulation therapy and either a rate or rhythm control strategy. However, ventricular arrhythmias and conduction disturbances can also occur. Sustained ventricular arrhythmias in the recovery period after cardiac surgery may warrant acute treatment and long-term preventive strategy in the absence of reversible causes. Transient bradyarrhythmias may be managed with temporary pacing wires placed at surgery, but significant and persistent atrioventricular block or sinus node dysfunction can occur with the need for permanent pacing. We provide a complete and updated review about mechanisms, risk factors, and treatment strategies for the main postoperative arrhythmias. PMID:24511410

  14. 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.

  15. Fibroblast growth factor homologous factors in the heart: a potential locus for cardiac arrhythmias.

    Science.gov (United States)

    Wei, Eric Q; Barnett, Adam S; Pitt, Geoffrey S; Hennessey, Jessica A

    2011-10-01

    The four fibroblast growth factor homologous factors (FHFs; FGF11-FGF14) are intracellular proteins that bind and modulate voltage-gated sodium channels (VGSCs). Although FHFs have been well studied in neurons and implicated in neurologic disease, their role in cardiomyocytes was unclear until recently. This review discusses the expression profile and function of FHFs in mouse and rat ventricular cardiomyocytes. Recent data show that FGF13 is the predominant FHF in the murine heart, directly binds the cardiac VGSC α subunit, and is essential for normal cardiac conduction. FHF loss-of-function mutations may be unrecognized causes of cardiac arrhythmias, such as long QT and Brugada syndromes.

  16. Cardiac ultrasonography in structural abnormalities and arrhythmias. Recognition and treatment.

    OpenAIRE

    Brook, M. M.; Silverman, N H; Villegas, M.

    1993-01-01

    Fetal cardiac ultrasonography has become an important tool in the evaluation of fetuses at risk for cardiac anomalies. It can both guide prenatal treatment and assist the management and timing of delivery. We recommend that a fetal echocardiogram be done when there is a family history of congenital heart disease; maternal disease that may affect the fetus; a history of maternal drug use, either therapeutic or illegal; evidence of other fetal abnormalities; or evidence of fetal hydrops. The op...

  17. Mouse models of SCN5A-related cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    Flavien eCharpentier

    2012-06-01

    Full Text Available Mutations of SCN5A gene, which encodes the α-subunit of the voltage-gated Na+ channel NaV1.5, underlie hereditary cardiac arrhythmic syndromes such as the type 3 long QT syndrome, cardiac conduction diseases, the Brugada syndrome, the sick sinus syndrome, atrial standstill and numerous overlap syndromes. Patch-clamp studies in heterologous expression systems have provided important information to understand the genotype-phenotype relationships of these diseases. However, they could not clarify how SCN5A mutations can be responsible for such a large spectrum of diseases, for the late age of onset or the progressiveness of some of these diseases and for the overlapping syndromes. Genetically modified mice rapidly appeared as promising tools for understanding the pathophysiological mechanisms of cardiac SCN5A-related arrhythmic syndromes and several mouse models have been established. This paper reviews some of the results obtained on these models that, for most of them, recapitulate the clinical phenotypes of the patients. It also points out that these models also have their own limitations. Overall, mouse models appear as powerful tools to elucidate the pathophysiological mechanisms of SCN5A-related diseases and offer the opportunity to investigate the secondary cellular consequences of SCN5A mutations such as the expression remodelling of other genes that might participate to the overall phenotype. Finally, they constitute useful tools for addressing the role of genetic and environmental modifiers on cardiac electrical activity.

  18. 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 th....... Our findings, however, strongly suggest that the increased risk identified can at least partly be explained by reporting bias as a result of publications about and mass media attention for antihistamine induced arrhythmias.......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...... was not significantly higher than 1 (OR 1.37 [95% CI: 0.85, 2.23]), whereas the risk estimate calculated after the governmental decision did significantly differ from 1 (OR 4.19 [95% CI: 2.49, 7.05]). CONCLUSIONS: Our data suggest that non-sedating antihistamines might have an increased risk for inducing arrhythmias...

  19. Electrocardiographic Presentation, Cardiac Arrhythmias, and Their Management in β-Thalassemia Major Patients.

    Science.gov (United States)

    Russo, Vincenzo; Rago, Anna; Papa, Andrea Antonio; Nigro, Gerardo

    2016-07-01

    Beta-thalassemia major (β-TM) is a genetic hemoglobin disorder characterized by an absent synthesis of globin chains that are essential for hemoglobin formation, causing chronic hemolytic anemia. Clinical management of thalassemia major consists in regular long-life red blood cell transfusions and iron chelation therapy to remove iron introduced in excess with transfusions. Iron deposition in combination with inflammatory and immunogenic factors is involved in the pathophysiology of cardiac dysfunction in these patients. Heart failure and arrhythmias, caused by myocardial siderosis, are the most important life-limiting complications of iron overload in beta-thalassemia patients. Cardiac complications are responsible for 71% of global death in the beta-thalassemia major patients. The aim of this review was to describe the most frequent electrocardiographic abnormalities and arrhythmias observed in β-TM patients, analyzing their prognostic impact and current treatment strategies. PMID:27324981

  20. Cardiac Mechano-Gated Ion Channels and Arrhythmias.

    Science.gov (United States)

    Peyronnet, Rémi; Nerbonne, Jeanne M; Kohl, Peter

    2016-01-22

    Mechanical forces will have been omnipresent since the origin of life, and living organisms have evolved mechanisms to sense, interpret, and respond to mechanical stimuli. The cardiovascular system in general, and the heart in particular, is exposed to constantly changing mechanical signals, including stretch, compression, bending, and shear. The heart adjusts its performance to the mechanical environment, modifying electrical, mechanical, metabolic, and structural properties over a range of time scales. Many of the underlying regulatory processes are encoded intracardially and are, thus, maintained even in heart transplant recipients. Although mechanosensitivity of heart rhythm has been described in the medical literature for over a century, its molecular mechanisms are incompletely understood. Thanks to modern biophysical and molecular technologies, the roles of mechanical forces in cardiac biology are being explored in more detail, and detailed mechanisms of mechanotransduction have started to emerge. Mechano-gated ion channels are cardiac mechanoreceptors. They give rise to mechano-electric feedback, thought to contribute to normal function, disease development, and, potentially, therapeutic interventions. In this review, we focus on acute mechanical effects on cardiac electrophysiology, explore molecular candidates underlying observed responses, and discuss their pharmaceutical regulation. From this, we identify open research questions and highlight emerging technologies that may help in addressing them.

  1. Recommendations of the Brazilian Society of Cardiac Arrhythmias for Holter Monitoring Services

    OpenAIRE

    Lorga Filho, Adalberto; Cintra, Fatima Dumas; Lorga, Adalberto; Grupi, Cesar José; Pinho, Claudio; Moreira, Dalmo Antonio Ribeiro; Dario C. Sobral Filho; de Brito, Fabio Sandoli; Kruse, José Claudio Lupi; Neto, José Sobral

    2013-01-01

    Background There are innumerous indicators to assure the quality of a service. However, medical competence and the proper performance of a procedure determine its final quality. The Brazilian Society of Cardiac Arrhythmias recommends minimum parameters necessary to guarantee the excellence of ambulatory electrocardiographic monitoring services. Objective To recommend minimum medical competences and the information required to issue a Holter monitoring report. Methods This study was grounded i...

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

    International Nuclear Information System (INIS)

    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)

  3. DESIGNING A VIRTUAL MACHINE FOR IDENTIFICATION OF CARDIAC ARRHYTHMIAS USING LAB VIEW

    OpenAIRE

    B. Subha; Subha.S.V; Anitha, M.; M.Eniya; M.Gaayathri

    2013-01-01

    Various projects have been proposed for acquiring and analysis of ECG signals using differentsoftware. To be in advance this work focuses not only on acquiring and analysis of ECG signal but also onidentification of cardiac arrhythmias. This would bridge the gap between medical physicians and engineers.Our project is carried out with the help of LabVIEW software (version 8.2). This model work collects thewaveform from the affected person, analyzed and particular disease is identified. Initial...

  4. Rule Based Identification of Cardiac Arrhythmias from Enhanced ECG Signals Using Multi-Scale PCA

    OpenAIRE

    K. Sharmila; E. Hari Krishna; K. Ashoka Reddy

    2013-01-01

    The detection of abnormal cardiac rhythms, automatic discrimination from rhythmic heart activity, became a thrust area in clinical research. Arrhythmia detection is possible by analyzing the electrocardiogram (ECG) signal features. The presence of interference signals, like power line interference (PLI), Electromyogram (EMG) and baseline drift interferences, could cause serious problems during the recording of ECG signals. Many a time, they pose problem in modern control and signal processing...

  5. Colorectal patients and cardiac arrhythmias detected on the surgical high dependency unit.

    OpenAIRE

    Batra, G. S.; Molyneux, J.; N. A. Scott

    2001-01-01

    INTRODUCTION: Surgical high dependency unit (SHDU) care is becoming an integral feature of colorectal surgical practice. Routine ECG monitoring is a feature of surgical care in this setting. The aim of this study was to determine the incidence and outcome of cardiac arrhythmias detected in an SHDU population of colorectal patients. PATIENTS AND METHODS: 226 patients over a 12 month period were admitted to a 6-bedded SHDU under the care of 3 colorectal surgeons. A total of 29 patients (13%) ha...

  6. Induced pluripotent stem cell derived cardiomyocytes as models for cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    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

  7. Cardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capability and Risk for Cardiac Arrhythmias

    Science.gov (United States)

    Levine, Benjamin D.; Bungo, Michael W.; Platts, Steven H.; Hamilton, Douglas R.; Johnston, Smith L.

    2009-01-01

    Cardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capability and Risk for Cardiac Arrhythmias (Integrated Cardiovascular) will quantify the extent of long-duration space flightassociated cardiac atrophy (deterioration) on the International Space Station crewmembers.

  8. Dual-Chamber Pacing for Cardiac Arrhythmias: Controversies in Cloning the Conduction System

    OpenAIRE

    Parsonnet, Victor; Bernstein, Alan D.; Norman, John C.

    1984-01-01

    From the outset, the art and science of cardiac pacing has been beset with a variety of problems. With the passage of time and concentrated effort in the interrelated sciences, many have been solved. We no longer are concerned with premature battery failure or leaking pulse-generator capsules, but now focus on an entirely new set of issues that beg for resolution. Foremost among these is the true role of dual-chamber pacing in the treatment of slow and fast cardiac arrhythmias of a multitude ...

  9. The pioneering work of George Mines on cardiac arrhythmias: groundbreaking ideas that remain influential in contemporary cardiac electrophysiology.

    Science.gov (United States)

    Aguilar, Martin; Nattel, Stanley

    2016-05-01

    George Mines was a pioneering physiologist who, despite an extremely short period of professional activity and only primitive experimental methodology, succeeded in formulating concepts that continue to be of great influence today. Here, we review some of his most important discoveries and their impact on contemporary concepts and clinical practice. Mines' greatest contribution was his conceptualization and characterization of circus movement reentry. His observations and ideas about the basis for cardiac reentrant activity underlie how we understand and manage a wide range of important clinical rhythm disturbances today. The notions he introduced regarding the influence of premature extrastimuli on reentry (termination, resetting and entrainment) are central to contemporary assessment of arrhythmia mechanisms in clinical electrophysiology laboratories and modern device therapy of cardiac tachyarrhythmias. Refinements of his model of reentry have led to sophisticated biophysical theories of the mechanisms underlying cardiac fibrillation. His seminal observations on the influence of electrolyte derangements and autonomic tone on the heart are relevant to our understanding of the physiology and pharmacology of arrhythmias caused by cardiac pathology. In this era of advanced technology, it is important to appreciate that ideas of lasting impact come from great minds and do not necessarily require great tools. PMID:26607760

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

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

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

    2015-02-01

    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. PMID:25582837

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

    Science.gov (United States)

    Kim, Hak Ju; Cho, Sungkyu; Kim, Woong-Han

    2016-08-01

    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 44% assessed by echocardiogram 1 year postoperatively. On electrocardiogram, QRS duration 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. PMID:27525239

  13. Cardiac arrhythmia in Wilson′s disease: An oversighted and overlooked entity!

    Directory of Open Access Journals (Sweden)

    Bhupender Kumar Bajaj

    2016-01-01

    Full Text Available Wilson's disease is a multisystem disorder which manifests with hepatic, neurological, musculoskeletal, hematological, renal, and cardiac symptoms. The hepatic and neurological manifestations often overshadow the other system involvement including cardiac symptoms and signs, which may prove fatal. We report a case of a young female who presented with progressive parkinsonian features and dystonia for around 4 months followed 2 months later by the complaint of episodes of light-headedness. She was diagnosed to have Wilson's disease based on the presence of Kayser–Fleischer ring and laboratory parameters of copper metabolism. Electrocardiography of the patient incidentally revealed 2nd degree Mobitz type-1 atrioventricular block explaining her episodes of light-headedness. She was started on penicillamine and trihexyphenidyl. The heart block improved spontaneously. Cardiac autonomic function tests including blood pressure response to standing and heart rate response to standing were observed to be normal. We review the literature on cardiac manifestations of Wilson's disease and emphasize that patients with Wilson's disease should be assessed for cardiac arrhythmia and cardiac dysfunction as these may have therapeutic and prognostic implications.

  14. Cell and gene therapy for arrhythmias: Repair of cardiac conduction damage

    Institute of Scientific and Technical Information of China (English)

    Yong-Fu Xiao

    2011-01-01

    Action potentials generated in the sinoatrial node(SAN)dominate the rhythm and rate of a healthy human heart.Subsequently,these action potentials propagate to the whole heart via its conduction system .Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias.For example,SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker.On the other hand conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies,including defibrillation and tissue ablation.However,drug therapies sometimes may not be effective or are associated with serious side effects.Device-based therapies for cardiac arrhythmias,even with well developed technology,still face inadequacies,limitations,hardware complications,and other challenges.Therefore,scientists are actively seeking other alternatives for antiarrhythmic therapy.In particular,cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo.Despite the complexities of the excitation and conduction systems of the heart,cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac anhythmias.This review summarizes some highlights of recent research progress in this field.

  15. Risk factors for the occurrence of cardiac arrhythmias in patients on continuous ambulatory peritoneal dialysis.

    Science.gov (United States)

    Canziani, M E; Saragoça, M A; Draibe, S A; Barbieri, A; Ajzen, H

    1993-01-01

    In order to evaluate the risk factors for the occurrence of ventricular arrhythmias (VA) in continuous ambulatory peritoneal dialysis (CAPD), we studied 47 patients by echocardiography, dipyridamole-thallium tests, and biochemical profile. We observed that the group with VA had a greater cardiac mass index dependent only on an increased left ventricular internal diameter. Septum and posterior wall thickness, as well as biochemical variables, were not associated with the presence of VA in CAPD patients. In addition, altered myocardial perfusion was not associated with VA in these patients. PMID:8399625

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

    Science.gov (United States)

    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 (LQTS) and hypertrophic cardiomyopathy (HCM) became technically possible. In multidisciplinary outpatient academic clinics, an adjusted protocol for genetic counselling, originally derived from predictive testing in Huntington's disease, is being used. 1110 individuals, including 842 relatives of index patients, were informed about their risks, and most were tested molecularly and/or clinically for carriership of the disease present in their family. Of 345 relatives who were referred for cardiologic follow-up, 189 are being treated, because of an increased risk of life-threatening arrhythmias. Evaluation of the psychological and social consequences of family screening for inherited arrhythmias can be performed by using the adapted criteria of Wilson and Jüngner, i.e., from a point of view of public health. Preliminary results of psychological research show that parents of children at risk for LQTS show high levels of distress. Many other aspects have to be evaluated yet, making final conclusions about the feasibility of family screening difficult, particularly in HCM. Clinical guidelines are urgently needed. Population screening by molecular testing, for instance in athletic preparticipation screening, will become possible in the future and has its own prerequisites for success. PMID:15176433

  17. Influence of ambient temperature and diurnal temperature range on incidence of cardiac arrhythmias

    Science.gov (United States)

    Kim, Jayeun; Kim, Ho

    2016-08-01

    We investigated the association between ambient temperature and diurnal temperature range (DTR) and the exacerbation of arrhythmia symptoms, using data from 31,629 arrhythmia-related emergency department (ED) visits in Seoul, Korea. Linear regression analyses with allowances for over-dispersion were applied to temperature variables and ED visits, adjusted for various environmental factors. The effects were expressed as percentage changes in the risk of arrhythmia-related ED visits up to 5 days later, with 95 % confidence intervals (CI), per 1 °C increase in DTR and 1 °C decrease in mean temperature. The overall risk of ED visits increased by 1.06 % (95 % CI 0.39 %, 1.73 %) for temperature and by 1.84 % (0.34, 3.37 %) for DTR. A season-specific effect was detected for temperature during both fall (1.18 % [0.01, 2.37 %]) and winter (0.87 % [0.07, 1.67 %]), and for DTR during spring (3.76 % [0.34, 7.29 %]). Females were more vulnerable, with 1.57 % [0.56, 2.59 %] and 3.84 % [1.53, 6.20 %] for the changes in temperature and DTR, respectively. An age-specific effect was detected for DTR, with 3.13 % [0.95, 5.36 %] for age ≥ 65 years, while a greater increased risk with temperature decrease was observed among those aged <65 (1.08 % [0.17, 2.00 %]) than among those aged ≥65 (1.02 % [0.06, 1.99 %]). Cardiac arrest was inversely related with temperature (1.61 % [0.46, 2.79 %]), while other cardiac arrhythmias depended more on the change in DTR (4.72 % [0.37, 9.26 %]). These findings provide evidence that low-temperature and elevated DTR influence the occurrence of arrhythmia exacerbations or symptoms, suggesting a possible strategy for reducing risk by encouraging vulnerable populations to minimize exposure.

  18. Cardiac arrhythmia

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008032 Efficacy of integrated three-dimensional electroanatomic mapping with preacquired magnetic resonance images guide catheter atrial fibrillation ablation. YU Ronghui(喻荣辉), et al. Dept Cardiol, Beijing Anzhen Hosp, Capital Med Univ, Beijing 100029. Chin J Cardiol 2007;35(11):1029-1033. Objective To investigate the efficacy of integrated electroanatomic mapping with preacquired magnetic resonance (MR) images guided catheter at

  19. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970281 Clinical efficacy and safety of intravenous es-molol in the treatment of supraventricular tachyarrth-mias: multiple centers analysis of 309 cases. YOU Kai(游凯), et a1. PUMC Hosp, Beijing, 100730. Chin JCardiol 1996; 24(6): 404-407。

  20. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008272 Prospective study on the prognosis in patients with ventricular tachycardia or fibrillation treated with implantable automatic cardiovertor defibrillator. LIU Zhongmei(刘中梅), et al. Dept Cardiol, 1st Affili Hosp, Kunming Med Coll, Kunming 650032. Chin J Cardiol 2008;36(4):309-312.Objective To explore the effect of implantable automatic cardiovertor defibrillator(ICD)on improvement of the prognosis of patients with ventricular tachycardia or fibrillation(VT/VF).To compare the advantages and

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

    Science.gov (United States)

    MacRae, Calum A.

    2010-01-01

    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 biology

  2. Ablation of triadin causes loss of cardiac Ca2+ release units, impaired excitation-contraction coupling, and cardiac arrhythmias.

    Science.gov (United States)

    Chopra, Nagesh; Yang, Tao; Asghari, Parisa; Moore, Edwin D; Huke, Sabine; Akin, Brandy; Cattolica, Robert A; Perez, Claudio F; Hlaing, Thinn; Knollmann-Ritschel, Barbara E C; Jones, Larry R; Pessah, Isaac N; Allen, Paul D; Franzini-Armstrong, Clara; Knollmann, Björn C

    2009-05-01

    Heart muscle excitation-contraction (E-C) coupling is governed by Ca(2+) release units (CRUs) whereby Ca(2+) influx via L-type Ca(2+) channels (Cav1.2) triggers Ca(2+) release from juxtaposed Ca(2+) release channels (RyR2) located in junctional sarcoplasmic reticulum (jSR). Although studies suggest that the jSR protein triadin anchors cardiac calsequestrin (Casq2) to RyR2, its contribution to E-C coupling remains unclear. Here, we identify the role of triadin using mice with ablation of the Trdn gene (Trdn(-/-)). The structure and protein composition of the cardiac CRU is significantly altered in Trdn(-/-) hearts. jSR proteins (RyR2, Casq2, junctin, and junctophilin 1 and 2) are significantly reduced in Trdn(-/-) hearts, whereas Cav1.2 and SERCA2a remain unchanged. Electron microscopy shows fragmentation and an overall 50% reduction in the contacts between jSR and T-tubules. Immunolabeling experiments show reduced colocalization of Cav1.2 with RyR2 and substantial Casq2 labeling outside of the jSR in Trdn(-/-) myocytes. CRU function is impaired in Trdn(-/-) myocytes, with reduced SR Ca(2+) release and impaired negative feedback of SR Ca(2+) release on Cav1.2 Ca(2+) currents (I(Ca)). Uninhibited Ca(2+) influx via I(Ca) likely contributes to Ca(2+) overload and results in spontaneous SR Ca(2+) releases upon beta-adrenergic receptor stimulation with isoproterenol in Trdn(-/-) myocytes, and ventricular arrhythmias in Trdn(-/-) mice. We conclude that triadin is critically important for maintaining the structural and functional integrity of the cardiac CRU; triadin loss and the resulting alterations in CRU structure and protein composition impairs E-C coupling and renders hearts susceptible to ventricular arrhythmias. PMID:19383796

  3. Rule Based Identification of Cardiac Arrhythmias from Enhanced ECG Signals Using Multi-Scale PCA

    Directory of Open Access Journals (Sweden)

    K. Sharmila

    2013-09-01

    Full Text Available The detection of abnormal cardiac rhythms, automatic discrimination from rhythmic heart activity, became a thrust area in clinical research. Arrhythmia detection is possible by analyzing the electrocardiogram (ECG signal features. The presence of interference signals, like power line interference (PLI, Electromyogram (EMG and baseline drift interferences, could cause serious problems during the recording of ECG signals. Many a time, they pose problem in modern control and signal processing applications by being narrow in-band interference near the frequencies carrying crucial information. This paper presents an approach for ECG signal enhancement by combining the attractive properties of principal component analysis (PCA and wavelets, resulting in multi-scale PCA. In Multi-Scale Principal Component Analysis (MSPCA, the PCA’s ability to decorrelate the variables by extracting a linear relationship and wavelet analysis are utilized. MSPCA method effectively processed the noisy ECG signal and enhanced signal features are used for clear identification of arrhythmias. In MSPCA, the principal components of the wavelet coefficients of the ECG data at each scale are computed first and are then combined at relevant scales. Statistical measures computed in terms of root mean square deviation (RMSD, root mean square error (RMSE, root mean square variation (RMSV and improvement in signal to noise ratio (SNRI revealed that the Daubechies based MSPCA outperformed the basic wavelet based processing for ECG signal enhancement. With enhanced signal features obtained after MSPCA processing, the detectable measures, QRS duration and R-R interval are evaluated. By using the rule base technique, projecting the detectable measures on a two dimensional area, various arrhythmias are detected depending upon the beat falling into particular place of the two dimensional area.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Anti-Ro/SSA antibodies and cardiac arrhythmias in the adult: facts and hypotheses.

    Science.gov (United States)

    Lazzerini, P E; Capecchi, P L; Laghi-Pasini, F

    2010-09-01

    It is well established that the passive trans-placental passage of anti-Ro/SSA antibodies from mother to foetus is associated with the risk to develop an uncommon syndrome named neonatal lupus (NLE), where the congenital heart block represents the most severe clinical feature. Recent evidence demonstrated that also adult heart, classically considered invulnerable to the anti-Ro/SSA antibodies, may represent a target of the arrhythmogenicity of these autoantibodies. In particular, the prolongation of the QTc interval appears the most frequent abnormality observed in adults with circulating anti-Ro/SSA antibodies, with some data suggesting an association with an increased risk of ventricular arrhythmias, also life threatening. Moreover, even though the association between anti-Ro/SSA antibodies and conduction disturbances is undoubtedly less evident in adults than in infants, from the accurate dissection of the literature data the possibility arises that sometimes also the adult cardiac conduction tissue may be affected by such antibodies. The exact arrhythmogenic mechanisms involved in foetus/newborns and adults, respectively, have not been completely clarified as yet. However, increasing evidence suggests that anti-Ro/SSA antibodies may trigger rhythm disturbances through an inhibiting cross-reaction with several cardiac ionic channels, particularly the calcium channels (L-type and T-type), but also the potassium channel hERG, whose different expression and involvement in the cardiac electrophysiology during lifespan might account for the occurrence of age-related differences.

  6. Rapidly detecting disorder in rhythmic biological signals: a spectral entropy measure to identify cardiac arrhythmias

    CERN Document Server

    Staniczenko, Phillip P A; Jones, Nick S

    2008-01-01

    We consider the use of a running measure of power spectrum disorder to distinguish between the normal sinus rhythm of the heart and two forms of cardiac arrhythmia: atrial fibrillation and atrial flutter. This is motivated by characteristic differences in the spectra of beats during the three rhythms. We plot patient data derived from 10-beat windows on a `disorder map' and identify rhythm-defining ranges in the level and variance of spectral entropy values. Employing the spectral entropy within an automatic arrhythmia detection algorithm enables the classification of periods of atrial fibrillation from the time series of patients' beats. When the algorithm is set to identify abnormal rhythms within 6s it agrees with 85.7% of the annotations of professional rhythm assessors; for a response time of 30s this becomes 89.5%, and with 60s it is 90.3%. The algorithm provides a rapid way to detect atrial fibrillation, demonstrating usable response times as low as six seconds. Measures of disorder in the frequency do...

  7. Low dialysate potassium concentration: an overrated risk factor for cardiac arrhythmia?

    Science.gov (United States)

    Abuelo, J Gary

    2015-01-01

    Serum potassium concentrations rise with dietary potassium intake between dialysis sessions and are often at hyperkalemic levels by the next session. Conversely, potassium concentrations fall during each hemodialysis, and sometimes reach hypokalemic levels by the end. Low potassium dialysate, which rapidly decreases serum potassium and often brings it to hypokalemic levels, is almost universally considered a risk factor for life-threatening arrhythmias. While there is little doubt about the threat of lethal arrhythmias due to hyperkalemia, convincing evidence for the danger of low potassium dialysate and rapid or excess potassium removal has not been forthcoming. The original report of more frequent ventricular ectopy in early dialysis that was improved by reducing potassium removal has received very little confirmation from subsequent studies. Furthermore, the occurrence of ventricular ectopy during dialysis does not appear to predict mortality. Studies relating sudden deaths to low potassium dialysate are countered by studies with more thorough adjustment for markers of poor health. Dialysate potassium concentrations affect the excursions of serum potassium levels above or below the normal range, and have the potential to influence dialysis safety. Controlled studies of different dialysate potassium concentration and their effect on mortality and cardiac arrests have not been done. Until these results become available, I propose interim guidelines for the setting of dialysate potassium levels that may better balance risks and benefits.

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

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. Automatic cardiac arrhythmia detection and classification using vectorcardiograms and complex networks.

    Science.gov (United States)

    Queiroz, Vinícius; Luz, Eduardo; Moreira, Gladston; Guarda, Álvaro; Menotti, David

    2015-01-01

    This paper intends to bring new insights in the methods for extracting features for cardiac arrhythmia detection and classification systems. We explore the possibility for utilizing vectorcardiograms (VCG) along with electrocardiograms (ECG) to get relevant informations from the heartbeats on the MIT-BIH database. For this purpose, we apply complex networks to extract features from the VCG. We follow the ANSI/AAMI EC57:1998 standard, for classifying the beats into 5 classes (N, V, S, F and Q), and de Chazal's scheme for dataset division into training and test set, with 22 folds validation setup for each set. We used the Support Vector Machinhe (SVM) classifier and the best result we chose had a global accuracy of 84.1%, while still obtaining relatively high Sensitivities and Positive Predictive Value and low False Positive Rates, when compared to other papers that follows the same evaluation methodology that we do. PMID:26737464

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    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.)

  13. Treating cardiac arrhythmias detected with an implantable cardiac monitor in patients after an acute myocardial infarction

    DEFF Research Database (Denmark)

    Jøns, Christian; Thomsen, Poul Erik Bloch

    2012-01-01

    OPINION STATEMENT: Using an implantable cardiac monitor (ICM) in patients with acute myocardial infarction (MI) allows continuous electrocardiogram monitoring and provides a much more detailed picture of the incidence of brady- and tachyarrhythmias than conventional follow-up. The CARISMA study...... was the first to use the ICM in post-MI patients with moderate to severe left ventricular systolic dysfunction. Atrial fibrillation (AF) events lasting longer than 30 s were associated with an almost threefold increase in the risk of major cardiac events. This confirms the current definition of clinically...... causes of AF such as progressive left ventricular dysfunction or myocardial ischemia. Asymptomatic, especially nightly, bradycardia episodes including high-degree 2°-3° atrioventricular (AV) block, sinus bradycardia, and sinus arrest were frequently documented by ICM in the CARISMA study. Ten percent...

  14. Prolonged hypoxia increases survival even in Zebrafish (Danio rerio showing cardiac arrhythmia.

    Directory of Open Access Journals (Sweden)

    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

  15. SpiNon- Invasive Diagnostics and Results of Interventive Treatment of Cardiac Arrhythmia Using the New System of Non-Invasive Surface Mapping “Amycard 01K”

    Directory of Open Access Journals (Sweden)

    Revishvili A. Sh.

    2012-09-01

    Conclusion. Using results of the surface activation mapping in patients with various cardiac arrhythmias shows its high diagnostic value and the necessity for a preoperative examination. Previously held topical diagnosis of arrhythmogenic substrate will reduce the time of the arrhythmia origin finding, to avoid possible adverse intraoperative complications such as a damage of coronary vessels, as well as reduce the time of intraoperative fluoroscopy.

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

    Science.gov (United States)

    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...

  17. 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.......0; 95% CI, 1.8-13.5; P = .002). CONCLUSIONS: Persistent and new mechanical dyssynchrony after CRT-D was associated with subsequent complex VA. Dyssynchrony after CRT-D is a marker of poor prognosis....

  18. Cardiac sympathetic denervation in patients with refractory ventricular arrhythmias or electrical storm: Intermediate and long-term follow-up

    OpenAIRE

    Vaseghi, M; Gima, J; Kanaan, C; Ajijola, OA; Marmureanu, A; Mahajan, A.; Shivkumar, K

    2014-01-01

    Background Left and bilateral cardiac sympathetic denervation (CSD) have been shown to reduce burden of ventricular arrhythmias acutely in a small number of patients with ventricular tachyarrhythmia (VT) storm. The effects of this procedure beyond the acute setting are unknown. Objective The purpose of this study was to evaluate the intermediate and long-term effects of left and bilateral CSD in patients with cardiomyopathy and refractory VT or VT storm. Methods Retrospective analysis of medi...

  19. Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient.

    Science.gov (United States)

    Jang, Yongwon; Noh, Hyung Wook; Lee, I B; Jung, Ji-Wook; Song, Yoonseon; Lee, Sooyeul; Kim, Seunghwan

    2012-01-01

    A patch type embedded cardiac function monitoring system was developed to detect arrhythmias such as PVC (Premature Ventricular Contraction), pause, ventricular fibrillation, and tachy/bradycardia. The overall system is composed of a main module including a dual processor and a Bluetooth telecommunication module. The dual microprocessor strategy minimizes power consumption and size, and guarantees the resources of embedded software programs. The developed software was verified with standard DB, and showed good performance.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Optimization of helical pitch in cardiac MDCT acquisition in patients with arrhythmia requiring ECG-edit

    International Nuclear Information System (INIS)

    The electrocardiogram (ECG)-edit is necessary in cardiac multidetector-row CT (MDCT) in arrhythmias [premature atrial contraction (PAC) or premature ventricular contraction (PVC)]; however, it sometimes results in a data deficit. Therefore, a thinner helical pitch (HP) should be set to avoid data deficits. The thinner helical pitch creates more radiation exposure. The purpose is to optimize HP in PAC or PVC. In a phantom study, an acrylic phantom (10 x 10 x 500 mm) was scanned by MDCT (Aquilion 64) using an artificial pacemaker at various gantry rotation speeds (r) and HP. We evaluated the relationships between HP and the maximal table moving length (Lmax) in the border of data deficit, and among r, HP, and the maximum data collection time interval (Tmax). In the clinical study, cardiac MDCT was performed in 44 cases (M/F: 26/18, 71.4±10.6 yrs) including 30 PAC and 14 PVC using the optimal HP derived from Tmax+10%. In the phantom study, there were significant correlations between HP and Lmax (Lmax=34.94-0.32 HP, r=0.999, P<0.0001), and Tmax [Tmax=(69.88/HP-0.64) x r] was calculated using formula. In 42/44 patients, high-quality images were obtained using the optimal HP; however, it resulted in data deficits in 2 patients, because of heart rate decreasing and a couple of PAC during scanning. Optimal HP significantly (P<0.0001) reduced radiation dose (-11.4%) compared with conventional HP. In conclusion, the optimal HP in PAC or PVC was calculated from the phantom study, provided fine images in 95% patients, and could reduce radiation dose. (author)

  2. Using Mixture Structures of Neural Networks in Order to Detect Cardiac Arrhythmias Using Fusion of Temporal and Wavelet Features

    Directory of Open Access Journals (Sweden)

    syed mohammd Razavi

    2011-05-01

    Full Text Available In recent years the use of intelligent systems in science and engineering, especially in the diagnosis of disease, is increasingly growing. In this paper a smart way to diagnose heart disease (cardiac arrhythmias is presented. This method is based on a combination of structures using neural networks for classification of normal operation and four abnormal heart functions. In the combination of these structures, some neural networks as a mediator, and some of them have been used as a specialist. In the proposed method firstly for removing noise from ECG signal, preprocessing was performed. The various time features (including fifteen properties and wavelet features (includes fifteen feature are extracted from the noise free signal and given the large number of selected features, principal components analysis is used for feature reduction to eight features. The proposed structures of MLP neural networks and RBF neural networks are appropriately trained for classification of arrhythmias and their performance has been evaluated. The results of the implementation of the proposed method on MIT / BIH database show the better performance in the diagnosis of cardiac arrhythmias compared to previous approaches.

  3. Short-Term Exposure to Air Pollution and Cardiac Arrhythmia: A Meta-Analysis and Systematic Review

    Directory of Open Access Journals (Sweden)

    Xuping Song

    2016-06-01

    Full Text Available The objective was to assess the transient association between air pollution and cardiac arrhythmia. Five databases were searched for studies investigating the association between daily increases in air pollutants (PM2.5, PM10, carbon monoxide, nitrogen dioxide, sulfur dioxide and ozone and arrhythmia hospitalization or arrhythmia mortality. Two reviewers independently selected studies, extracted data, and assessed risk of bias. Outcomes were analyzed via a random-effects model and reported as relative risk and 95% confidence interval. 25 studies satisfied our inclusion criteria and 23 contributed to the meta-analysis. Arrhythmia hospitalization or mortality were associated with increases in PM2.5 (RR = 1.015 per 10 μg/m3, 95% CI: 1.006–1.024, PM10 (RR = 1.009 per 10 μg/m3, 95% CI: 1.004–1.014, carbon monoxide (RR = 1.041 per 1 ppm, 95% CI: 1.017–1.065, nitrogen dioxide (RR = 1.036 per 10 ppb, 95% CI: 1.020–1.053, and sulfur dioxide (RR = 1.021 per 10 ppb, 95% CI: 1.003–1.039, but not ozone (RR = 1.012 per 10 ppb, 95% CI: 0.997–1.027. Both particulate and gaseous components, with the exception of ozone, have a temporal association with arrhythmia hospitalization or mortality. Compared with Europe and North America, a stronger association was noted in Asia.

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

    International Nuclear Information System (INIS)

    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

  5. Acute and Chronic Changes and Predictive Value of Tpeak-Tend for Ventricular Arrhythmia Risk in Cardiac Resynchronization Therapy Patients

    Science.gov (United States)

    Xue, Cong; Hua, Wei; Cai, Chi; Ding, Li-Gang; Liu, Zhi-Min; Fan, Xiao-Han; Zhao, Yun-Zi; Zhang, Shu

    2016-01-01

    Background: Prolongation of the Tpeak-Tend (TpTe) interval as a measurement of transmural dispersion of repolarization (TDR) is an independent risk factor for chronic heart failure mortality. However, the cardiac resynchronization therapy's (CRT) effect on TDR is controversial. Therefore, this study aimed to evaluate CRTs acute and chronic effects on repolarization dispersion. Furthermore, we aimed to investigate the relationship between TpTe changes and ventricular arrhythmia. Methods: The study group consisted of 101 patients treated with CRT-defibrillator (CRT-D). According to whether TpTe was shortened, patients were grouped at immediate and 1-year follow-up after CRT, respectively. The echocardiogram index and ventricular arrhythmia were observed and compared in these subgroups. Results: For all patients, TpTe slightly increased immediately after CRT-D implantation, and then decreased at the 1-year follow-up (from 107 ± 23 to 110 ± 21 ms within 24 h, to 94 ± 24 ms at 1-year follow-up, F = 19.366, P arrhythmia. PMID:27625093

  6. Examining the role of TRPA1 in air pollution-induced cardiac arrhythmias and autonomic imbalance

    Science.gov (United States)

    Here we describe how air pollution causes cardiac arrhythmogenesis through sensory irritation in the airways. Time-series studies show the risk of adverse cardiac events increases significantly in the hours to days after expos...

  7. Comprehensive Analysis Elderly Health Check-up Asymptomatic Cardiac Arrhythmias%老年健康体检无症状心律失常综合分析

    Institute of Scientific and Technical Information of China (English)

    季敏娜

    2013-01-01

    Objective:To study the reasons and characteristics of asymptomatic cardiac arrhythmia in the elderly occur,and preventive measures. Method:880 cases of elderly patients with asymptomatic cardiac arrhythmia for the rural and urban residents in the free health checks,check diagnose by 12 lead ecg machine of arrhythmia patients and 1083 cases of elderly patients with symptomatic cardiac arrhythmias by combining synthetical consolidation and rehabilitation physical examination data,analysed the characteristics of asymptomatic cardiac arrhythmia and reason.Result:Senile asymptomatic cardiac arrhythmia obviously increased with age (P<0.01).Conclusion:The occurrence of senile asymptomatic cardiac arrhythmias have direct relationship with underlying heart disease,along with the age growth significantly higher incidence of arrhythmia,active prevention,diagnosis and treatment in time,can effectively reduce various cardiac risk the occurrence of adverse events.%目的:探讨老年人无症状心律失常发生的原因、特点、以及防范措施。方法:880例老年无症状心律失常患者为农村和城镇居民免费健康体检中通过十二导联心电图机检查确诊的心律失常患者,与1083例老年有症状的心律失常患者通过结合全身检查综合整理资料,分析无症状心律失常的特点与原因。结果:老年无症状心律失常随年龄增长而明显增多。结论:老年无症状心律失常的发生与基础心脏疾病有直接关系,随着年龄增长心律失常的发病率明显增高,积极预防,及时诊断治疗,可以有效减少各种心脏危险不良事件的发生。

  8. 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 h

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

    Directory of Open Access Journals (Sweden)

    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.

  10. The effects of B0, B20 and B100 soy biodiesel exhaust on aconitine-induced cardiac arrhythmia in spontaneously hypertensive rats

    Science.gov (United States)

    CONTEXT: Diesel exhaust (DE) has been shown to increase the risk of cardiac arrhythmias. Although biodiesel has been proposed as a "safer" alternative to diesel, it is still uncertain whether it actually poses less threat.OBJECTIVE: We hypothesized that exposure to pure or 20% so...

  11. Air pollution and incidence of cardiac arrhythmia; Pollution de l'air et incidence de l'arythmie cardiaque

    Energy Technology Data Exchange (ETDEWEB)

    Peters, A.; Liu, E.; Verrier, R.L.; Schwartz, J.; Gold, D.R.; Mittleman, M.; Baliff, J.; Oh, J.A.; Allen, G.; Monahan, K.; Dockery, D.W.

    2001-01-01

    The aim of this pilot study is the evaluation of the feasibility of short-dated relations analysis between the atmospheric pollutant level and the incidence of cardiac arrhythmia or ventricular fibrillation for automatic defibrillator carrier patients. (A.L.B.)

  12. Classification of Cardiac Arrhythmia Using WT, HRV, and Fuzzy C-Means Clustering

    OpenAIRE

    A. Dallali, A. Kachouri & M. Samet

    2011-01-01

    The classification of the electrocardiogram registration into different pathologies disease devisesis a complex pattern recognition task. In this paper, we propose a generic feature extraction forclassification of ECG arrhythmias using a fuzzy c-means (FCM) clustering and Heart Ratevariability (HRV). The traditional methods of diagnosis and classification present someinconveniences; seen that the precision of credit note one diagnosis exact depends on thecardiologist experience and the rate c...

  13. Classification of Cardiac Arrhythmia Using WT, HRV, and Fuzzy C-Means Clustering

    Directory of Open Access Journals (Sweden)

    A. Dallali, A. Kachouri & M. Samet

    2011-08-01

    Full Text Available The classification of the electrocardiogram registration into different pathologies disease devisesis a complex pattern recognition task. In this paper, we propose a generic feature extraction forclassification of ECG arrhythmias using a fuzzy c-means (FCM clustering and Heart Ratevariability (HRV. The traditional methods of diagnosis and classification present someinconveniences; seen that the precision of credit note one diagnosis exact depends on thecardiologist experience and the rate concentration. Due to the high mortality rate of heartdiseases, early detection and precise discrimination of ECG arrhythmia is essential for thetreatment of patients. During the recording of ECG signal, different forms of noise can besuperimposed in the useful signal. The pre-treatment of ECG imposes the suppression of theseperturbation signals. The row date is preprocessed, normalized and then data points areclustered using FCM technique.In this work, four different structures, FCM-HRV, PCM-HRV, FCMC-HRV and FPCM-HRV areformed by using heart rate variability technique and fuzzy c-means clustering. In addition, FCMHRVis the new method proposed for classification of ECG.This paper presents a comparative study of the classification accuracy of ECG signals by usingthese four structures for computationally efficient diagnosis. The ECG signals taken from MIT-BIHECG database are used in training to classify 4 different arrhythmias (Atrial FibrillationTermination.All of the structures are tested by using the same ECG records. The test results suggest thatFCMC-HRV structure can generalize better and is faster than the other structures.

  14. The Power of Exercise-Induced T-wave Alternans to Predict Ventricular Arrhythmias in Patients with Implanted Cardiac Defibrillator

    Directory of Open Access Journals (Sweden)

    Laura Burattini

    2013-01-01

    Full Text Available The power of exercise-induced T-wave alternans (TWA to predict the occurrence of ventricular arrhythmias was evaluated in 67 patients with an implanted cardiac defibrillator (ICD. During the 4-year follow-up, electrocardiographic (ECG tracings were recorded in a bicycle ergometer test with increasing workload ranging from zero (NoWL to the patient's maximal capacity (MaxWL. After the follow-up, patients were classified as either ICD_Cases (n = 29, if developed ventricular tachycardia/fibrillation, or ICD_Controls (n = 38. TWA was quantified using our heart-rate adaptive match filter. Compared to NoWL, MaxWL was characterized by faster heart rates and higher TWA in both ICD_Cases (12-18 μ V vs. 20-39 μ V; P < 0.05 and ICD_Controls (9-15 μ V vs. 20-32 μ V; P < 0.05. Still, TWA was able to discriminate the two ICD groups during NoWL (sensitivity = 59-83%, specificity = 53-84% but not MaxWL (sensitivity = 55-69%, specificity = 39-74%. Thus, this retrospective observational case-control study suggests that TWA's predictive power for the occurrence of ventricular arrhythmias could increase at low heart rates.

  15. When the clock strikes: Modeling the relation between circadian rhythms and cardiac arrhythmias

    CERN Document Server

    Seenivasan, Pavithraa; Sridhar, S; Sinha, Sitabhra

    2016-01-01

    It has recently been observed that the occurrence of sudden cardiac death has a close statistical relationship with the time of day, viz., ventricular fibrillation is most likely to occur between 12 am-6 am, with 6 pm-12 am being the next most likely period. Consequently there has been significant interest in understanding how cardiac activity is influenced by the circadian clock, i.e., temporal oscillations in physiological activity with a period close to 24 hours and synchronized with the day-night cycle. Although studies have identified the genetic basis of circadian rhythms at the intracellular level, the mechanisms by which they influence cardiac pathologies are not yet fully understood. Evidence has suggested that diurnal variations in the conductance properties of ion channel proteins that govern the excitation dynamics of cardiac cells may provide the crucial link. In this paper, we investigate the relationship between the circadian rhythm as manifested in modulations of ion channel properties and the...

  16. Safe Oral Triiodo-L-Thyronine Therapy Protects from Post-Infarct Cardiac Dysfunction and Arrhythmias without Cardiovascular Adverse Effects.

    Directory of Open Access Journals (Sweden)

    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.

  17. 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...

  18. Derivation of Human Induced Pluripotent Stem (iPS) Cells to Heritable Cardiac Arrhythmias

    Science.gov (United States)

    2016-03-14

    Inherited Cardiac Arrythmias; Long QT Syndrome (LQTS); Brugada Syndrome (BrS); Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT); Early Repolarization Syndrome (ERS); Arrhythmogenic Cardiomyopathy (AC, ARVD/C); Hypertrophic Cardiomyopathy (HCM); Dilated Cardiomyopathy (DCM); Muscular Dystrophies (Duchenne, Becker, Myotonic Dystrophy); Normal Control Subjects

  19. Results of treatment of congenital coronary artery fistulae in combination with cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    Bockeria L.A.

    2013-03-01

    and quality of life. Coronary angiography and computed tomography are the main diagnostic methods allowing to examine CAF. Hemodynamically non-compromised CAF coincided with CA require a follow-up and, if necessary, surgical and/or medical therapy of CA. Main indications for embolization are proximal location and single CAF. Indications for surgical on-pump repair are concomitant cardiac pathology and relatively large and wide CAF.

  20. Real-Time Cardiac Arrhythmia Detection Using WOLA Filterbank Analysis of EGM Signals

    Directory of Open Access Journals (Sweden)

    Sheikhzadeh Hamid

    2007-01-01

    Full Text Available Novel methods of cardiac rhythm detection are proposed that are based on time-frequency analysis by a weighted overlap-add (WOLA oversampled filterbank. Cardiac signals are obtained from intracardiac electrograms and decomposed into the time-frequency domain and analyzed by parallel peak detectors in selected frequency subbands. The coherence (synchrony of the subband peaks is analyzed and employed to detect an optimal peak sequence representing the beat locations. By further analysis of the synchrony of the subband beats and the periodicity and regularity of the optimal beat, various possible cardiac events (including fibrillation, flutter, and tachycardia are detected. The Ann Arbor Electrogram Library is used to evaluate the proposed detection method in clean and in additive noise. The evaluation results show that the method never misses any episode of fibrillation or flutter in clean or in noise and is robust to far-field R-wave interference. Furthermore, all other misclassification errors were within the acceptable limits.

  1. Cardiac Arrhythmias Classification Method Based on MUSIC, Morphological Descriptors, and Neural Network

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available An electrocardiogram (ECG beat classification scheme based on multiple signal classification (MUSIC algorithm, morphological descriptors, and neural networks is proposed for discriminating nine ECG beat types. These are normal, fusion of ventricular and normal, fusion of paced and normal, left bundle branch block, right bundle branch block, premature ventricular concentration, atrial premature contraction, paced beat, and ventricular flutter. ECG signal samples from MIT-BIH arrhythmia database are used to evaluate the scheme. MUSIC algorithm is used to calculate pseudospectrum of ECG signals. The low-frequency samples are picked to have the most valuable heartbeat information. These samples along with two morphological descriptors, which deliver the characteristics and features of all parts of the heart, form an input feature vector. This vector is used for the initial training of a classifier neural network. The neural network is designed to have nine sample outputs which constitute the nine beat types. Two neural network schemes, namely multilayered perceptron (MLP neural network and a probabilistic neural network (PNN, are employed. The experimental results achieved a promising accuracy of 99.03% for classifying the beat types using MLP neural network. In addition, our scheme recognizes NORMAL class with 100% accuracy and never misclassifies any other classes as NORMAL.

  2. Cardiac Arrhythmias Classification Method Based on MUSIC, Morphological Descriptors, and Neural Network

    Science.gov (United States)

    Naghsh-Nilchi, Ahmad R.; Kadkhodamohammadi, A. Rahim

    2009-12-01

    An electrocardiogram (ECG) beat classification scheme based on multiple signal classification (MUSIC) algorithm, morphological descriptors, and neural networks is proposed for discriminating nine ECG beat types. These are normal, fusion of ventricular and normal, fusion of paced and normal, left bundle branch block, right bundle branch block, premature ventricular concentration, atrial premature contraction, paced beat, and ventricular flutter. ECG signal samples from MIT-BIH arrhythmia database are used to evaluate the scheme. MUSIC algorithm is used to calculate pseudospectrum of ECG signals. The low-frequency samples are picked to have the most valuable heartbeat information. These samples along with two morphological descriptors, which deliver the characteristics and features of all parts of the heart, form an input feature vector. This vector is used for the initial training of a classifier neural network. The neural network is designed to have nine sample outputs which constitute the nine beat types. Two neural network schemes, namely multilayered perceptron (MLP) neural network and a probabilistic neural network (PNN), are employed. The experimental results achieved a promising accuracy of 99.03% for classifying the beat types using MLP neural network. In addition, our scheme recognizes NORMAL class with 100% accuracy and never misclassifies any other classes as NORMAL.

  3. Complexity-Measure-Based Sequential Hypothesis Testing for Real-Time Detection of Lethal Cardiac Arrhythmias

    Directory of Open Access Journals (Sweden)

    Chen Szi-Wen

    2007-01-01

    Full Text Available A novel approach that employs a complexity-based sequential hypothesis testing (SHT technique for real-time detection of ventricular fibrillation (VF and ventricular tachycardia (VT is presented. A dataset consisting of a number of VF and VT electrocardiogram (ECG recordings drawn from the MIT-BIH database was adopted for such an analysis. It was split into two smaller datasets for algorithm training and testing, respectively. Each ECG recording was measured in a 10-second interval. For each recording, a number of overlapping windowed ECG data segments were obtained by shifting a 5-second window by a step of 1 second. During the windowing process, the complexity measure (CM value was calculated for each windowed segment and the task of pattern recognition was then sequentially performed by the SHT procedure. A preliminary test conducted using the database produced optimal overall predictive accuracy of . The algorithm was also implemented on a commercial embedded DSP controller, permitting a hardware realization of real-time ventricular arrhythmia detection.

  4. Complexity-Measure-Based Sequential Hypothesis Testing for Real-Time Detection of Lethal Cardiac Arrhythmias

    Science.gov (United States)

    Chen, Szi-Wen

    2006-12-01

    A novel approach that employs a complexity-based sequential hypothesis testing (SHT) technique for real-time detection of ventricular fibrillation (VF) and ventricular tachycardia (VT) is presented. A dataset consisting of a number of VF and VT electrocardiogram (ECG) recordings drawn from the MIT-BIH database was adopted for such an analysis. It was split into two smaller datasets for algorithm training and testing, respectively. Each ECG recording was measured in a 10-second interval. For each recording, a number of overlapping windowed ECG data segments were obtained by shifting a 5-second window by a step of 1 second. During the windowing process, the complexity measure (CM) value was calculated for each windowed segment and the task of pattern recognition was then sequentially performed by the SHT procedure. A preliminary test conducted using the database produced optimal overall predictive accuracy of[InlineEquation not available: see fulltext.]. The algorithm was also implemented on a commercial embedded DSP controller, permitting a hardware realization of real-time ventricular arrhythmia detection.

  5. Complexity-Measure-Based Sequential Hypothesis Testing for Real-Time Detection of Lethal Cardiac Arrhythmias

    Directory of Open Access Journals (Sweden)

    Szi-Wen Chen

    2007-01-01

    Full Text Available A novel approach that employs a complexity-based sequential hypothesis testing (SHT technique for real-time detection of ventricular fibrillation (VF and ventricular tachycardia (VT is presented. A dataset consisting of a number of VF and VT electrocardiogram (ECG recordings drawn from the MIT-BIH database was adopted for such an analysis. It was split into two smaller datasets for algorithm training and testing, respectively. Each ECG recording was measured in a 10-second interval. For each recording, a number of overlapping windowed ECG data segments were obtained by shifting a 5-second window by a step of 1 second. During the windowing process, the complexity measure (CM value was calculated for each windowed segment and the task of pattern recognition was then sequentially performed by the SHT procedure. A preliminary test conducted using the database produced optimal overall predictive accuracy of 96.67%. The algorithm was also implemented on a commercial embedded DSP controller, permitting a hardware realization of real-time ventricular arrhythmia detection.

  6. 迷走神经在心律失常发生中的研究进展%Role of vagal nerve in cardiac arrhythmia

    Institute of Scientific and Technical Information of China (English)

    冯璇; 臧伟进; 周筠

    2012-01-01

    作为遗传性心律失常之一的长QT综合征(LQTS),现已发现有12型,其中在中国以LQT2为常见,可诱发尖端扭转型室性心动过速及室颤,临床上以反复发作的晕厥及常导致的猝死为特征.自主神经通过释放神经递质作用于受体调节离子通道,从而对某些心律失常起到一定的作用,而迷走神经通过直接或间接作用对多种心律失常具有一定的保护作用.本文主要对LQT2的研究进展、迷走神经与LQT2的关系以及其在心律失常中发挥的作用作一综述.%As one of the familial abnormalities of cardiac rhythm, Long QT syndrome ( LQTS) has been found in 12 different genes. LQT2 is one of the most common LQTS in China, which can lead to Torsade de Points (TdP) and ventricular fibrillation ( VF). Clinically it is characterized by recurrent syncope and sudden cardiac death. The autonomic nervous system plays a vital role in some cases of cardiac arrhythmia through the release of neurotransmitter to regulate ion channel. Recently, studies have shown that vagal nerve can reduce the occurrence of certain kinds of cardiac arrhythmia and may play an important role in maintaining normal cardiac rhythm and rate. This paper mainly reviews the recent advances of LQT2, the complex relationship between vagal nerve and LQT2, and the role of vagal nerve in cardiac arrhythmia.

  7. Ablation of triadin causes loss of cardiac Ca2+ release units, impaired excitation–contraction coupling, and cardiac arrhythmias

    OpenAIRE

    Chopra, Nagesh; Yang, Tao; Asghari, Parisa; Moore, Edwin D.; Huke, Sabine; Akin, Brandy; Cattolica, Robert A.; Perez, Claudio F.; Hlaing, Thinn; Knollmann-Ritschel, Barbara E. C.; Jones, Larry R.; Pessah, Isaac N; Allen, Paul D.; Franzini-Armstrong, Clara; Knollmann, Björn C.

    2009-01-01

    Heart muscle excitation–contraction (E-C) coupling is governed by Ca2+ release units (CRUs) whereby Ca2+ influx via L-type Ca2+ channels (Cav1.2) triggers Ca2+ release from juxtaposed Ca2+ release channels (RyR2) located in junctional sarcoplasmic reticulum (jSR). Although studies suggest that the jSR protein triadin anchors cardiac calsequestrin (Casq2) to RyR2, its contribution to E-C coupling remains unclear. Here, we identify the role of triadin using mice with ablation of the Trdn gene (...

  8. Effect of regional differences in cardiac cellular electrophysiology on the stability of ventricular arrhythmias: a computational study

    Science.gov (United States)

    Clayton, Richard H.; Holden, Arun V.

    2003-01-01

    Re-entry is an important mechanism of cardiac arrhythmias. During re-entry a wave of electrical activation repeatedly propagates into recovered tissue, rotating around a rod-like filament. Breakdown of a single re-entrant wave into multiple waves is believed to underlie the transition from ventricular tachycardia to ventricular fibrillation. Several mechanisms of breakup have been identified including the effect of anisotropic conduction in the ventricular wall. Cells in the inner and outer layers of the ventricular wall have different action potential durations (APD), and support re-entrant waves with different periods. The aim of this study was to use a computational approach to study twisting and breakdown in a transmural re-entrant wave spanning these regions, and examine the relative role of this effect and anisotropic conduction. We used a simplified model of action potential conduction in the ventricular wall that we modified so that it supported stable re-entry in an anisotropic model with uniform APD. We first examined the effect of regional differences on breakdown in an isotropic model with transmural differences in APD, and found that twisting of the re-entrant filament resulted in buckling and breakdown during the second cycle of re-entry. We found that breakdown was amplified in the anisotropic model, resulting in complex activation in the region of longest APD. This study shows that regional differences in cardiac electrophysiology are a potentially important mechanism for destabilizing re-entry and may act synergistically with other mechanisms to mediate the transition from ventricular tachycardia to ventricular fibrillation.

  9. A proton leak current through the cardiac sodium channel is linked to mixed arrhythmia and the dilated cardiomyopathy phenotype.

    Directory of Open Access Journals (Sweden)

    Pascal Gosselin-Badaroudine

    Full Text Available Cardiac Na(+ channels encoded by the SCN5A gene are essential for initiating heart beats and maintaining a regular heart rhythm. Mutations in these channels have recently been associated with atrial fibrillation, ventricular arrhythmias, conduction disorders, and dilated cardiomyopathy (DCM.We investigated a young male patient with a mixed phenotype composed of documented conduction disorder, atrial flutter, and ventricular tachycardia associated with DCM. Further family screening revealed DCM in the patient's mother and sister and in three of the mother's sisters. Because of the complex clinical phenotypes, we screened SCN5A and identified a novel mutation, R219H, which is located on a highly conserved region on the fourth helix of the voltage sensor domain of Na(v1.5. Three family members with DCM carried the R219H mutation.The wild-type (WT and mutant Na(+ channels were expressed in a heterologous expression system, and intracellular pH (pHi was measured using a pH-sensitive electrode. The biophysical characterization of the mutant channel revealed an unexpected selective proton leak with no effect on its biophysical properties. The H(+ leak through the mutated Na(v1.5 channel was not related to the Na(+ permeation pathway but occurred through an alternative pore, most probably a proton wire on the voltage sensor domain.We propose that acidification of cardiac myocytes and/or downstream events may cause the DCM phenotype and other electrical problems in affected family members. The identification of this clinically significant H(+ leak may lead to the development of more targeted treatments.

  10. Effects of Acupuncture at the Yintang and the Chengjiang Acupoints on Cardiac Arrhythmias and Neurocardiogenic Syncope in Emergency First Aid.

    Science.gov (United States)

    Fabrin, Saulo; Soares, Nayara; Pezarezi Yoshimura, Daiana; Hallak Regalo, Simone Cecilio; Donizetti Verri, Edson; de Freitas Vianna, Jacqueline Rodrigues; Gatti Regueiro, Eloisa Maria; Torres da Silva, Josie Resende

    2016-02-01

    This study evaluated the effectiveness of YinTang and ChengJiang acupoints on patients with cardiac arrhythmia and neurocardiogenic syncope in emergency first aid. A 45 year old woman underwent acupuncture. She had a previous history of a valvuloplasty for rheumatic disease and two acute myocardial infarctions, followed by four catheterizations and an angioplasty. Needling of the YinTang acupoint and stimulation of the ChengJiang acupoint through acupressure were performed for 20 minutes soon after syncope and during tachycardia, hypertension, tachypnea, and precordial pain, without any effect on peripheral oxygen saturation (SpO2) or the glycemic index. Data were analyzed comparatively by using the following parameters at rest, during syncope, and at 1 minute and 10 minutes after an emergency acupuncture procedure: blood pressure; heart rate; SpO2; and respiratory rate. We found that acupuncture at YinTang and ChenJiang acupoints induced cardiovascular responses, increased the limits of the body's homeostasis, and normalized the patient's condition in the case of syncope. Acupuncture using a combination of ChengJiang and YinTang acupoints had an immediate effect on the autonomic nervous system and on maintaining homeostasis and energy balance in the body. Although this technique was effective, the patient was still referred to the Emergency Room. PMID:26896074

  11. Prevalence of Cardiac Arrhythmias During and After Pregnancy in Women with Chagas' Disease without Apparent Heart Disease

    Directory of Open Access Journals (Sweden)

    Achá Renato Enrique Sologuren

    2002-01-01

    Full Text Available OBJECTIVE: To evaluate cardiac arrhythmias during and after pregnancy in women with Chagas' disease without apparent heart disease using dynamic electrocardiography. METHODS: Twenty pregnant women with Chagas' disease without apparent heart disease aged 19 to 42 years (26.96 ± 3.6 and a control group of 20 non-chagasic pregnant patients aged 16 to 34 years (22.5 ± 4.8. The patients were submitted to passive hemagglutination and indirect immunofluorescence for the detection of Trypanosoma cruzi evaluation, and electrocardiography, echocardiography and 24-h dynamic electrocardiography. RESULTS: Supraventricular premature depolarizations were observed in 18 (90% patients and ventricular premature depolarization in 11 (55% patients of both groups during pregnancy. After delivery, supraventricular premature depolarizations were present in 13 (60% chagasic patients and in 16 (89.4% control patients (P<=0.05. Ventricular premature depolarization were observed in 9 (45% chagasic patients and 11 (57.8% control patients. CONCLUSION: The prevalence of ventricular premature depolarization was similar for the chagasic and control groups during and after pregnancy. The incidence of supraventricular premature depolarizations was similar in the two groups during pregnancy, while after delivery a predominance was observed in the control group compared to the chagasic group.

  12. Implications of the Turing completeness of reaction-diffusion models, informed by GPGPU simulations on an XBox 360: cardiac arrhythmias, re-entry and the Halting problem.

    Science.gov (United States)

    Scarle, Simon

    2009-08-01

    In the arsenal of tools that a computational modeller can bring to bare on the study of cardiac arrhythmias, the most widely used and arguably the most successful is that of an excitable medium, a special case of a reaction-diffusion model. These are used to simulate the internal chemical reactions of a cardiac cell and the diffusion of their membrane voltages. Via a number of different methodologies it has previously been shown that reaction-diffusion systems are at multiple levels Turing complete. That is, they are capable of computation in the same manner as a universal Turing machine. However, all such computational systems are subject to a limitation known as the Halting problem. By constructing a universal logic gate using a cardiac cell model, we highlight how the Halting problem therefore could limit what it is possible to predict about cardiac tissue, arrhythmias and re-entry. All simulations for this work were carried out on the GPU of an XBox 360 development console, and we also highlight the great gains in computational power and efficiency produced by such general purpose processing on a GPU for cardiac simulations.

  13. Effects of Intrinsic and Extrinsic Cardiac Nerves on Atrial Arrhythmia in Experimental Pulmonary Artery Hypertension.

    Science.gov (United States)

    Zhao, Qingyan; Deng, Hongping; Jiang, Xuejun; Dai, Zixuan; Wang, Xiaozhan; Wang, Xule; Guo, Zongwen; Hu, Wei; Yu, Shengbo; Yang, Bo; Tang, Yanhong; Huang, Congxin

    2015-11-01

    Atrial arrhythmia, which includes atrial fibrillation (AF) and atrial flutter (AFL), is common in patients with pulmonary arterial hypertension (PAH), who often have increased sympathetic nerve activity. Here, we tested the hypothesis that autonomic nerves play important roles in vulnerability to AF/AFL in PAH. The atrial effective refractory period and AF/AFL inducibility at baseline and after anterior right ganglionated plexi ablation were determined during left stellate ganglion stimulation or left renal sympathetic nerve stimulation in beagle dogs with or without PAH. Then, sympathetic nerve, β-adrenergic receptor densities and connexin 43 expression in atrial tissues were assessed. The sum of the window of vulnerability to AF/AFL was increased in the right atrium compared with the left atrium at baseline in the PAH dogs but not in the controls. The atrial effective refractory period dispersion was increased in the control dogs, but not in the PAH dogs, during left stellate ganglion stimulation. The voltage thresholds for inducing AF/AFL during anterior right ganglionated plexi stimulation were lower in the PAH dogs than in the controls. The AF/AFL inducibility was suppressed after ablation of the anterior right ganglionated plexi in the PAH dogs. The PAH dogs had higher sympathetic nerve and β1-adrenergic receptor densities, increased levels of nonphosphorylated connexin 43, and heterogeneous connexin 43 expression in the right atrium when compared with the control dogs. The anterior right ganglionated plexi play important roles in the induction of AF/AFL. AF/AFL induction was associated with right atrium substrate remodeling in dogs with PAH.

  14. Significance of classifying antiarrhythmic actions since the cardiac arrhythmia suppression trial.

    Science.gov (United States)

    Vaughan Williams, E M

    1991-02-01

    The Cardiac Antiarrhythmic Suppression Trial (CAST) showed flecainide and encainide induced excess mortality compared with placebo. Labeling drugs as Class 1C is based on clinical observations, comprising measurements of the electrocardiographic parameters QRS. H-V and J-T intervals and of effective refractory period (ERP) as follows: 1--(QRS) wide, 2--(HV) long, 3--(ERP) unchanged, 4--(JT) unchanged. In vitro electrophysiology helped to explain the clinical findings. Flecainide and encainide rendered Na channels as nonconducting, but F and E were only slowly released from the channels after repolarization. At any given drug concentration, a proportion of total channels were eliminated, and the steady-state proportion increased at rising heart rate. It is not proven that the properties that lead to classification of a drug as 1C were those that caused excess deaths in the CAST. The proarrhythmic tendency of 1C drugs can be reduced by beta-blockade, and the mechanisms of adrenergic arrhythmogenicity are discussed. Propafenone is both a 1C drug and a beta-blocker, and its pharmacologic profile is reviewed to illustrate how it resembles and differs from flecainide and encainide. Some features of the CAST are assessed with particular reference to the extent to which conclusions drawn from the results may be justifiably extrapolated to other drugs classified as 1C.

  15. Pharmacological management of arrhythmias in the elderly

    NARCIS (Netherlands)

    VanGelder, IC; Brugemann, J; Crijns, HJGM

    1997-01-01

    The incidence of cardiac arrhythmia increases with advancing age, as does the prevalence of structural heart disease. Serious arrhythmias, such as sustained ventricular tachycardias, are uncommon in elderly patients, but nonsustained ventricular tachycardias and atrial fibrillation are relatively fr

  16. Cardioprotective activity of alcoholic extract of Tinospora cordifolia (Willd.) Miers in calcium chloride-induced cardiac arrhythmia in rats

    OpenAIRE

    Sharma, Ashish Kumar; Kishore, Kunal; Sharma, Divya; B P Srinivasan; Agarwal, Shyam Sunder; Sharma, Ashok; Singh, Santosh Kumar; Gaur, Samir; Jatav, Vijay Singh

    2011-01-01

    The present study investigated the antiarrhythmic activity of alcoholic extract of Tinospora cordifolia (T. cordifolia) in CaCl2 induced arrhythmia. CaCl2 (25 mg/kg) was administered by intravenous infusion (iv) to produce arrhythmia in rats. The animals were then treated with T. cordifolia extract (150, 250, and 450 mg/kg) and verapamil (5 mg/kg,iv). Lead II electrocardiogram was monitored. Plasma calcium, sodium and potassium levels were measured. In CaCl2 induced arrhythmia, heart rate was...

  17. Relationship of cardiac arrhythmias to myocar- dial remodeling and expression of adhesion molecules in patients with mitral valve prolapse

    Directory of Open Access Journals (Sweden)

    A.V. Yagoda

    Conclusion. Myocardial remodeling and dysregulation of cell adhesion proteins are recorded in young patients with MVP and arrhythmias. Relaionship of severity of arrhythmic syndrome to myocardial remodeling and VCAM-1 level was revealed.

  18. Genetically engineered excitable cardiac myofibroblasts coupled to cardiomyocytes rescue normal propagation and reduce arrhythmia complexity in heterocellular monolayers.

    Directory of Open Access Journals (Sweden)

    Luqia Hou

    Full Text Available RATIONALE AND OBJECTIVE: 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. METHODS AND RESULTS: 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. CONCLUSION: Viral transfer of genes coding Kir2.1, Na(V1.5 and Cx43 to cardiac myofibroblasts endows them with

  19. Genetic basis of ventricular arrhythmias.

    NARCIS (Netherlands)

    Boussy, T.; Paparella, G.; Asmundis, C. de; Sarkozy, A.; Chierchia, G.B.; Brugada, J.; Brugada, R.; Brugada, P.

    2010-01-01

    Sudden cardiac death caused by malignant ventricular arrhythmias is the most important cause of death in the industrialized world. Most of these lethal arrhythmias occur in the setting of ischemic heart disease. A significant number of sudden deaths, especially in young individuals, are caused by in

  20. 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

  1. 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......: In middle-aged and elderly subjects with no manifest heart disease, mild hypokalaemia is associated with increased rate of ventricular but not supraventricular arrhythmias. Hypokalaemia interacts synergistically with increased ventricular ectopy to increase the risk of adverse events....

  2. Arrhythmias in the Muscular Dystrophies

    OpenAIRE

    Rajdev, Archana; William J Groh

    2015-01-01

    In patients with muscular dystrophies, cardiac involvement leading to cardiomyopathy and arrhythmias occur with variable prevalence mirroring the phenotypic variability seen among and within the various hereditary myopathies. These patients are at risk for development for bradyarrhythmias and tachyarrhythmias including sudden cardiac death. Knowledge of the incidence of arrhythmias and predictors of sudden death in the various hereditary myopathies can help guide screening and appropriate man...

  3. Coxsackie and adenovirus receptor is a modifier of cardiac conduction and arrhythmia vulnerability in the setting of myocardial ischemia.

    NARCIS (Netherlands)

    Marsman, R.F.; Bezzina, C.R.; Freiberg, F.; Verkerk, A.O.; Adriaens, M.E.; Podliesna, S.; Chen, C.; Purfurst, B.; Spallek, B.; Koopmann, T.T.; Baczko, I.; Remedios, C.G. Dos; George AL, J.r.; Bishopric, N.H.; Lodder, E.M.; Bakker, J.M. de; Fischer, R.; Coronel, R.; Wilde, A.A.; Gotthardt, M.; Remme, C.A.

    2014-01-01

    OBJECTIVES: The aim of this study was to investigate the modulatory effect of the coxsackie and adenovirus receptor (CAR) on ventricular conduction and arrhythmia vulnerability in the setting of myocardial ischemia. BACKGROUND: A heritable component in the risk of ventricular fibrillation during myo

  4. [Maternal arrhythmias during pregnancy. Practical review].

    Science.gov (United States)

    Kornacewicz-Jach, Zdzisława; Peregud-Pogorzelska, Małgorzata

    2014-01-01

    Pregnancy is accompanied by a variety of cardiovascular changes in normal women, and these changes can increased incidence of maternal cardiac arrhythmias. Supraventricular and ventricular arrhythmias reguiring treatment are rarely seen during pregnancy in healthy women. Structural cardiac defects or residual defects after repair may contribute to the occurrence of clinically relevant arrhythmias. Arrhythmias during pregnancy include a wide spectrum. The most common are simple ventricular and atrial ectopy, sinusal tachycardia and supraventricular tachycardia. The foetus may suffer both haemodynamic alternations and adverse effects of the treatment (teratogenic risk, foetal growth and development). The management of arrhythmias in pregnant women is similar to that taken in patients who are not pregnant.

  5. Clinical Study on Amiodarone in the Treatment of Cardiac Arrhythmia%胺碘酮治疗心律失常的临床研究

    Institute of Scientific and Technical Information of China (English)

    赵明琴

    2016-01-01

    Objective Amiodarone treatment method and its effect for patients with cardiac arrhythmia are to be investigated.MethodsChose 66 patients with cardiac arrhythmia who were treated in hospital from August 2014 to September 2015 and separated them into two groups at random, 37 patients in study group were given Amiodarone treatment, while another 29 patients in control group were given Lidocaine treatment, and then compared treatment effects between two groups.Results Patients’treatment efficacy was 91.89% in study group, which was much higher than 82.76% in control group, thus, treatment efficacy in study group was much better and such a differential had statistic value(P<0.05).Conclusion For patients with cardiac arrhythmia, Amiodarone treatment is quite effective and safe to improve their physical symptom with few side effect.%目的:探究心律失常患者采取胺碘酮治疗的方法和效果。方法选取2014年8月~2015年9月收治的66例心律失常患者进行治疗研究,随机分组,实验组37例患者采取胺碘酮治疗,对照组29例患者选择利多卡因治疗,比较两组患者的治疗效果。结果实验组治疗总有效率为91.89%,对照组治疗总有效率为82.76%,实验组治疗总有效率高于对照组,差异有统计学意义(P<0.05)。结论心律失常患者采取胺碘酮治疗,可改善身体症状,效果显著,不良反应较少,安全性高。

  6. [Arrhythmias from swallowing].

    Science.gov (United States)

    Palazzuoli, V; Mondillo, S; Faglia, S; D'Aprile, N; De Luca, G; Kristodhullu, A; Corba, E

    1992-01-01

    We describe the case of a 51-year old, non cardiopathic patient, with recurrent attacks of supraventricular tachycardia induced by swallowing. In the existing literature we found several descriptions of hypokinetic arrhythmias, easily explained by a mechanism of vagal inhibition. The cases of predominantly hyperkinetic arrhythmias, however, are much less common. In these patients the origin of the disease seems to be due to sympathetic oesophageal fibers and superior and medium cardiac nerves. In the present case, as in the others reported in the literature, the drug of choice seems to be Amiodarone which appears to be the most effective in preventing tachyarrhythmias caused by swallowing.

  7. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa

    2015-02-01

    Full Text Available Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

  8. [Alcohol and arrhythmias].

    Science.gov (United States)

    Pfeiffer, D; Jurisch, D; Neef, M; Hagendorff, A

    2016-09-01

    The effects of alcohol on induction of arrhythmias is dose-dependent, independent of preexisting cardiovascular diseases or heart failure and can affect otherwise healthy subjects. While the probability of atrial fibrillation increases with the alcohol dosage, events of sudden cardiac death are less frequent with low and moderate consumption but occur more often in heavy drinkers with alcoholic cardiomyopathy. Men are first affected at higher dosages of alcohol but women can suffer from arrhythmias at lower dosages. Thromboembolisms and ischemic stroke can occur less often at lower dosages of alcohol; however, hemorrhagic stroke and subarachnoid hemorrhage are increased with higher alcohol dosages. Recognizable protective mechanisms of alcohol with respect to cardiovascular diseases only occur with lower amounts of alcohol of less than 10 g per day. Underlying mechanisms explain these controversial effects. Specific therapeutic options for alcohol-related arrhythmias apart from abstinence from alcohol consumption are not known. PMID:27582366

  9. Computers and clinical arrhythmias.

    Science.gov (United States)

    Knoebel, S B; Lovelace, D E

    1983-02-01

    Cardiac arrhythmias are ubiquitous in normal and abnormal hearts. These disorders may be life-threatening or benign, symptomatic or unrecognized. Arrhythmias may be the precursor of sudden death, a cause or effect of cardiac failure, a clinical reflection of acute or chronic disorders, or a manifestation of extracardiac conditions. Progress is being made toward unraveling the diagnostic and therapeutic problems involved in arrhythmogenesis. Many of the advances would not be possible, however, without the availability of computer technology. To preserve the proper balance and purposeful progression of computer usage, engineers and physicians have been exhorted not to work independently in this field. Both should learn some of the other's trade. The two disciplines need to come together to solve important problems with computers in cardiology. The intent of this article was to acquaint the practicing cardiologist with some of the extant and envisioned computer applications and some of the problems with both. We conclude that computer-based database management systems are necessary for sorting out the clinical factors of relevance for arrhythmogenesis, but computer database management systems are beset with problems that will require sophisticated solutions. The technology for detecting arrhythmias on routine electrocardiograms is quite good but human over-reading is still required, and the rationale for computer application in this setting is questionable. Systems for qualitative, continuous monitoring and review of extended time ECG recordings are adequate with proper noise rejection algorithms and editing capabilities. The systems are limited presently for clinical application to the recognition of ectopic rhythms and significant pauses. Attention should now be turned to the clinical goals for detection and quantification of arrhythmias. We should be asking the following questions: How quantitative do systems need to be? Are computers required for the detection of

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

    Science.gov (United States)

    Gilchrist, Kristin H; 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 5minute recordings at multiple time points (0.5, 1, 2 and 4h) 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. PMID:26232523

  11. Rate of cardiac arrhythmias and silent brain lesions in experienced marathon runners: rationale, design and baseline data of the Berlin Beat of Running study

    Directory of Open Access Journals (Sweden)

    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

  12. Early Echocardiographic Deformation Analysis for the Prediction of Sudden Cardiac Death and Life-Threatening Arrhythmias After Myocardial Infarction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Valeur, Nana; Andersen, Mads Jønsson;

    2013-01-01

    This study sought to hypothesize that global longitudinal strain (GLS) as a measure of infarct size, and mechanical dispersion (MD) as a measure of myocardial deformation heterogeneity, would be of incremental importance for the prediction of sudden cardiac death (SCD) or malignant ventricular ar...

  13. 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

  14. 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)

    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 D95 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 D5-D95 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, the

  15. Non-invasive Drosophila ECG recording by using eutectic gallium-indium alloy electrode: a feasible tool for future research on the molecular mechanisms involved in cardiac arrhythmia.

    Directory of Open Access Journals (Sweden)

    Po-Hung Kuo

    electrophysiological signal research on the molecular mechanism involved in cardiac arrhythmia, as well as research related to drug screening and development.

  16. Absence of triadin, a protein of the calcium release complex, is responsible for cardiac arrhythmia with sudden death in human

    Science.gov (United States)

    Roux-Buisson, Nathalie; Cacheux, Marine; Fourest-Lieuvin, Anne; Fauconnier, Jeremy; Brocard, Julie; Denjoy, Isabelle; Durand, Philippe; Guicheney, Pascale; Kyndt, Florence; Leenhardt, Antoine; Le Marec, Hervé; Lucet, Vincent; Mabo, Philippe; Probst, Vincent; Monnier, Nicole; Ray, Pierre F.; Santoni, Elodie; Trémeaux, Pauline; Lacampagne, Alain; Fauré, Julien; Lunardi, Joël; Marty, Isabelle

    2012-01-01

    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease so far related to mutations in the cardiac ryanodine receptor (RYR2) or the cardiac calsequestrin (CASQ2) genes. Because mutations in RYR2 or in CASQ2 are not retrieved in all CPVT cases, we searched for mutations in the physiological protein partners of RyR2 and CSQ2 in a large cohort of CPVT patients with no detected mutation in these two genes. Based on a candidate gene approach, we focused our investigations on triadin and junctin, two proteins that link RyR2 and CSQ2. Mutations in the triadin (TRDN) and in the junctin (ASPH) genes were searched in a cohort of 97 CPVT patients. We identified three mutations in triadin which cosegregated with the disease on a recessive mode of transmission in two families, but no mutation was found in junctin. Two TRDN mutations, a 4 bp deletion and a nonsense mutation, resulted in premature stop codons; the third mutation, a p.T59R missense mutation, was further studied. Expression of the p.T59R mutant in COS-7 cells resulted in intracellular retention and degradation of the mutant protein. This was confirmed after in vivo expression of the mutant triadin in triadin knock-out mice by viral transduction. In this work, we identified TRDN as a new gene responsible for an autosomal recessive form of CPVT. The mutations identified in the two families lead to the absence of the protein, thereby demonstrating the importance of triadin for the normal function of the cardiac calcium release complex in humans. PMID:22422768

  17. Weather-induced ischemia and arrhythmia in patients undergoing cardiac rehabilitation: another difference between men and women

    Science.gov (United States)

    Schneider, Alexandra; Schuh, Angela; Maetzel, Friedrich-Karl; Rückerl, Regina; Breitner, Susanne; Peters, Annette

    2008-07-01

    Given the accumulating evidence that people with underlying heart disease are a particularly vulnerable group for triggers like changing meteorological parameters, the objective of this longitudinal study was to analyze the influence of weather parameters on blood pressure, arrhythmia and ischemia in cardiovascular patients. A panel study with repeated measurements was conducted in a rehabilitation clinic in Timmendorfer Strand (Baltic Sea, Germany) with 872 cardiovascular patients. Heart rate, blood pressure and electrocardiography changes were measured during repeated bicycle ergometries. Generalized Estimating Equations were used for regression analyses of immediate, delayed and cumulative influences of the daily measured meteorological data. For men, a decrease in air temperature and in water vapor pressure doubled the risk of ST-segment depression during ergometry [odds ratio (OR) for 1 day delay: 1.88 (1.24; 2.83) for air temperature] with a delay of 1-2 days. For women, an increase of their heart rate before the start of the ergometry [same day: 4.36 beats/min (0.99; 7.74) for air temperature] and a 2- to 3-fold higher risk for ventricular ectopic beats [1 day delay: OR 2.43 (1.17; 5.05) for air temperature] was observed with an increase in temperature and water vapor pressure in almost all analyzed time-windows. The study indicates that meteorological parameters can induce changes in heart function which may lead to adverse cardiovascular events especially in susceptible, diseased individuals. The observed effect on ST-segment depression could be a link between the association of weather changes and cardiovascular morbidity and mortality.

  18. Recurrent Muscle Weakness with Rhabdomyolysis, Metabolic Crises, and Cardiac Arrhythmia Due to Bi-allelic TANGO2 Mutations.

    Science.gov (United States)

    Lalani, Seema R; Liu, Pengfei; Rosenfeld, Jill A; Watkin, Levi B; Chiang, Theodore; Leduc, Magalie S; Zhu, Wenmiao; Ding, Yan; Pan, Shujuan; Vetrini, Francesco; Miyake, Christina Y; Shinawi, Marwan; Gambin, Tomasz; Eldomery, Mohammad K; Akdemir, Zeynep Hande Coban; Emrick, Lisa; Wilnai, Yael; Schelley, Susan; Koenig, Mary Kay; Memon, Nada; Farach, Laura S; Coe, Bradley P; Azamian, Mahshid; Hernandez, Patricia; Zapata, Gladys; Jhangiani, Shalini N; Muzny, Donna M; Lotze, Timothy; Clark, Gary; Wilfong, Angus; Northrup, Hope; Adesina, Adekunle; Bacino, Carlos A; Scaglia, Fernando; Bonnen, Penelope E; Crosson, Jane; Duis, Jessica; Maegawa, Gustavo H B; Coman, David; Inwood, Anita; McGill, Jim; Boerwinkle, Eric; Graham, Brett; Beaudet, Art; Eng, Christine M; Hanchard, Neil A; Xia, Fan; Orange, Jordan S; Gibbs, Richard A; Lupski, James R; Yang, Yaping

    2016-02-01

    The underlying genetic etiology of rhabdomyolysis remains elusive in a significant fraction of individuals presenting with recurrent metabolic crises and muscle weakness. Using exome sequencing, we identified bi-allelic mutations in TANGO2 encoding transport and Golgi organization 2 homolog (Drosophila) in 12 subjects with episodic rhabdomyolysis, hypoglycemia, hyperammonemia, and susceptibility to life-threatening cardiac tachyarrhythmias. A recurrent homozygous c.460G>A (p.Gly154Arg) mutation was found in four unrelated individuals of Hispanic/Latino origin, and a homozygous ∼34 kb deletion affecting exons 3-9 was observed in two families of European ancestry. One individual of mixed Hispanic/European descent was found to be compound heterozygous for c.460G>A (p.Gly154Arg) and the deletion of exons 3-9. Additionally, a homozygous exons 4-6 deletion was identified in a consanguineous Middle Eastern Arab family. No homozygotes have been reported for these changes in control databases. Fibroblasts derived from a subject with the recurrent c.460G>A (p.Gly154Arg) mutation showed evidence of increased endoplasmic reticulum stress and a reduction in Golgi volume density in comparison to control. Our results show that the c.460G>A (p.Gly154Arg) mutation and the exons 3-9 heterozygous deletion in TANGO2 are recurrent pathogenic alleles present in the Latino/Hispanic and European populations, respectively, causing considerable morbidity in the homozygotes in these populations.

  19. Psychological Distress and Arrhythmia: Risk Prediction and Potential Modifiers

    OpenAIRE

    Peacock, James; Whang, William

    2013-01-01

    The connection between the heart and the brain has long been anecdotally recognized but systematically studied only relatively recently. Cardiac arrhythmias, especially sudden cardiac death, remain a major public health concern and there is mounting evidence that psychological distress plays a critical role as both a predictor of high-risk cardiac substrate and as an inciting trigger. The transient, unpredictable nature of emotions and cardiac arrhythmias have made their study challenging, bu...

  20. Arrhythmias in the muscular dystrophies.

    Science.gov (United States)

    Rajdev, Archana; Groh, William J

    2015-06-01

    In patients with muscular dystrophies, cardiac involvement leading to cardiomyopathy and arrhythmias occurs with variable prevalence, mirroring the phenotypic variability seen among and within the various hereditary myopathies. Knowledge of the incidence of arrhythmias and predictors of sudden death in the various hereditary myopathies can help guide screening and appropriate management of these patients, thereby improving survival. The noncardiac manifestations can lead to delayed recognition of symptoms, affect the decision to implant a prophylactic device, and once a decision is made to proceed with device implant, increase peri-procedural respiratory and anesthesia-related complications. PMID:26002394

  1. Genetic Basis of Ventricular Arrhythmias

    OpenAIRE

    Pazoki, Raha; Wilde, Arthur A. M.; Connie R Bezzina

    2010-01-01

    Sudden cardiac death (SCD) is a leading cause of total and cardiovascular mortality, and ventricular fibrillation is the underlying arrhythmia in the majority of cases. In the young, where the incidence of SCD is low, a great proportion of SCDs occur in the context of inherited disorders such as cardiomyopathy or primary electrical disease, where a monogenic hereditary component is a strong determinant of risk. Marked advancement has been made over the past 15 years in the understanding of th...

  2. 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

    Directory of Open Access Journals (Sweden)

    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.

  3. Predictors of cardiac arrhythmias in the postoperative period by echocardiography, tissue Doppler and speckle tracking in patients with congenital heart diseases

    Directory of Open Access Journals (Sweden)

    Averina I.I.

    2015-09-01

    Conclusion. The indicators with predictive value for the arrhythmia in the postoperative period reflect the universal process of remodeling with the development of diastolic and systolic dysfunction, damage of longitudinal and circular functions of LV, longitudinal function of left atrium and the mitral valve function.

  4. Arrhythmia risk in liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Ioana Mozos

    2015-01-01

    Interactions between the functioning of the heart andthe liver have been described, with heart diseasesaffecting the liver, liver diseases affecting the heart,and conditions that simultaneously affect both. Theheart is one of the most adversely affected organs inpatients with liver cirrhosis. For example, arrhythmiasand electrocardiographic changes are observed inpatients with liver cirrhosis. The risk for arrhythmia isinfluenced by factors such as cirrhotic cardiomyopathy,cardiac ion channel remodeling, electrolyte imbalances,impaired autonomic function, hepatorenal syndrome, metabolic abnormalities, advanced age, inflammatory syndrome, stressful events, impaired drug metabolism and comorbidities. Close monitoring of cirrhotic patients is needed for arrhythmias, particularly when QT intervalprolonging drugs are given, or if electrolyte imbalances or hepatorenal syndrome appear. Arrhythmia risk may persist after liver transplantation due to possible QT interval prolongation, persistence of the parasympathetic impairment, post-transplant reperfusion and chronic immunosuppression, as well as consideration of the fact that the transplant itself is a stressful event for the cardiovascular system. The aims of the present article were to provide a review of the most important data regarding the epidemiology, pathophysiology, and biomarkers of arrhythmia risk in patients with liver cirrhosis, to elucidate the association with long-term outcome, and to propose future research directions.

  5. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  6. Arrhythmia and exercise intolerance in Fontan patients

    DEFF Research Database (Denmark)

    Idorn, L; Juul, K; Jensen, A S;

    2013-01-01

    BACKGROUND: Long-term survival after the Fontan procedure shows excellent results but is associated with a persistent risk of arrhythmias and exercise intolerance. We aimed to analyze the current burden of clinically relevant arrhythmia and severe exercise intolerance in Danish Fontan patients...... and estimated to 99.1% per year. Prevalence of clinically relevant arrhythmia and severe exercise intolerance increased significantly with age and was found in 32% and 85% of patients ≥20years, respectively. Thus, from survival data and logistic regression models the future prevalence of patients, clinically...... relevant arrhythmia and severe exercise intolerance were estimated, revealing a considerable augmentation. Furthermore, resting and maximum cardiac index, resting stroke volume index and pulmonary diffusing capacity decreased significantly with age while diastolic and systolic ventricular function...

  7. Teaching Cardiac Electrophysiology Modeling to Undergraduate Students: Laboratory Exercises and GPU Programming for the Study of Arrhythmias and Spiral Wave Dynamics

    Science.gov (United States)

    Bartocci, Ezio; Singh, Rupinder; von Stein, Frederick B.; Amedome, Avessie; Caceres, Alan Joseph J.; Castillo, Juan; Closser, Evan; Deards, Gabriel; Goltsev, Andriy; Ines, Roumwelle Sta.; Isbilir, Cem; Marc, Joan K.; Moore, Diquan; Pardi, Dana; Sadhu, Sandeep; Sanchez, Samuel; Sharma, Pooja; Singh, Anoopa; Rogers, Joshua; Wolinetz, Aron; Grosso-Applewhite, Terri; Zhao, Kai; Filipski, Andrew B.; Gilmour, Robert F., Jr.; Grosu, Radu; Glimm, James; Smolka, Scott A.; Cherry, Elizabeth M.; Clarke, Edmund M.; Griffeth, Nancy; Fenton, Flavio H.

    2011-01-01

    As part of a 3-wk intersession workshop funded by a National Science Foundation Expeditions in Computing award, 15 undergraduate students from the City University of New York collaborated on a study aimed at characterizing the voltage dynamics and arrhythmogenic behavior of cardiac cells for a broad range of physiologically relevant conditions…

  8. 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.

  9. Nonrespiratory Sinus Arrhythmia

    Directory of Open Access Journals (Sweden)

    Barbosa Filho José

    2002-01-01

    Full Text Available We report here 2 cases of sinus arrhythmia considered to be a form of nonrespiratory sinus arrhythmia because they did not have variances in the RR interval sequence within the oscillations modulated by respiration. Because the patients had pulsus alternans similar that observed in bigeminy, and because they did not have signs or symptoms of heart failure, we believe the arrhythmias represent intrinsic alterations of the electric activity of the sinus node

  10. Changes in heart rate, arrhythmia frequency, and cardiac biomarker values in horses during recovery after a long-distance endurance ride

    DEFF Research Database (Denmark)

    Madsen, Mette Flethøj; Kanters, Jørgen K.; Haugaard, Maria Mathilde;

    2016-01-01

    and SDNN was decreased during the recovery versus preride period. Frequency of ventricular premature complexes increased during recovery, albeit not significantly, whereas frequency of supraventricular premature complexes was not significantly different between preride and recovery periods. Serum cardiac......-km endurance ride. PROCEDURES: ECG recordings were obtained from each horse before (preride) and after (recovery) an endurance ride to evaluate changes in heart rate and the SD of normal R-R intervals (SDNN) during the initial 12 hours of recovery. Frequencies of supraventricular and ventricular...... premature complexes before and after the ride were evaluated. Blood samples were obtained before the ride and twice during recovery. Hematologic analyses included measurement of serum cardiac troponin I concentration and creatine kinase isoenzyme MB activity. RESULTS: Heart rate was significantly increased...

  11. Computational Modeling of Cardiac Electromechanics

    OpenAIRE

    Krishnamoorthi, Shankarjee

    2013-01-01

    Cardiac arrhythmias are a leading cause of death worldwide. Notably, the electrophysiologiy and microstructural requirements for a fatal ventricular arrhythmia remain incompletely understood, thereby the treatment remains largely empirical. Standard antiarrhythmic drug therapy has failed to reduce, and in some instances has increased, the incidence of Sudden Cardiac Death (SCD). Hence, a more complete understanding of the mechanisms that foment a fatal arrhythmia is needed and computational m...

  12. Age-Related Differences in the Effect of Psychological Distress on Mortality: Type D Personality in Younger versus Older Patients with Cardiac Arrhythmias

    Directory of Open Access Journals (Sweden)

    Johan Denollet

    2013-01-01

    Full Text Available Background. Mixed findings in biobehavioral research on heart disease may partly be attributed to age-related differences in the prognostic value of psychological distress. This study sought to test the hypothesis that Type D (distressed personality contributes to an increased mortality risk following implantable cardioverter defibrillator (ICD treatment in younger patients but not in older patients. Methods. The Type D Scale (DS14 was used to assess general psychological distress in 455 younger (≤70 y,. Cardiac resynchronization therapy (CRT, but not Type D personality, was associated with increased mortality in older patients. Among younger patients, however, Type D personality was associated with an adjusted hazard ratio = 1.91 (95% CI 1.09–3.34 and 2.26 (95% CI 1.16–4.41 for all-cause and cardiac mortality; other predictors were increasing age, CRT, appropriate shocks, ACE-inhibitors, and smoking. Conclusion. Type D personality was independently associated with all-cause and cardiac mortality in younger ICD patients but not in older patients. Cardiovascular research needs to further explore age-related differences in psychosocial risk.

  13. 三维标测系统指导下复杂心律失常的经导管射频消融治疗%Three-dimensional mapping for radiofrequency catheter ablation of complex cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    洪浪; 王洪; 赖珩莉; 尹秋林; 陈章强; 陆林祥; 邱赞; 肖承伟

    2009-01-01

    目的:探讨在三维标测系统指导下,经导管复杂心律失常射频消融治疗的有效性与安全性. 方法:选择2006年2月至2008年9月住院患者98例,其中阵发性房颤50例、持续性或永久性房颤6例、心房扑动9例、房性心动过速(房速)9例、室性心动过速(室速)或频发室性早搏24例.在EnSite NavX或Array系统(72例)或CARTO系统(26例)指导下进行射频消融手术. 结果:84例一次手术成功(85.71%),7例再次导管消融成功,成功率合计92.86%.50例房颤一次手术成功,5例再次消融后3例成功.9例心房扑动患者中7例一次手术成功,1例复发再次消融成功.9例房速中7例一次手术成功,1例复发再次消融成功.24例室速、室早患者中20例一次消融成功,4例行再次消融2例成功.共有并发症6例:心包填塞4例,左前降支远端栓塞1例、术后肺栓塞1例. 结论:三维标测系统可清晰地显示心脏三维立体结构,对复杂疑难心律失常的射频消融治疗具有较好的指导作用,提高消融的成功率并增加手术安全性.%Objective:To explore the validity and safety of radiofrequeney catheter ablation of complex cardiac arrhythmias guided by a three-dimensional mapping system. Methods.. A cohort of 98 consecutive inpatients were registered from February 2006 to September 2008, of which 68 cases were male and 30 cases were female, with an average age of (50.2 ± 19. 7) years ranging from 9 to 88 years of age. These patients suffered from various arrhythmias including paroxysmal atrial fibrillation (50 cases), persistent or permanent atrial fibrillation (6 cases), atrial flutter (9 cases), atrial tachy-cardia (9 cases), ventricular tachycardia or frequent episode ventricular premature beat (24 cases). A total of 72 cases underwent radiofrequency catheter ablation of arrhythmias guided by an En-Site3000/NavX or Array mapping system, and 26 cases guided by a CARTO mapping system. Re-suits:Successful ablation of

  14. 循证护理在急性心肌梗死后心律失常患者中的应用%The application of evidence-based care in acute myocardial infarction patients with cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    胡静; 胡晓娟

    2012-01-01

    目的 探讨循证护理在急性心肌梗死后心律失常患者中的应用效果,以期促进患者尽快康复.方法 选取2010年10月~2011年10月本院住院的符合WHO急性心肌梗死后心律失常标准的患者120例,将其随机分为循证护理组和常规护理组,各60例,常规护理组实施常规护理,循证护理组在常规护理的基础上实施循证护理措施,包括对急性心肌梗死后心律失常的时相分布特征、可控因素、心理干预措施、健康宣教等方面的偱证,用以指导临床护理.比较两组患者心律失常发生率、心功能分级、平均住院时间、平均卧床时间、平均医疗费用、患者健康知识达标率、患者满意度.结果 常规护理组心率失常发生率为66.67%,明显高于循证护理组的13.33%,两组比较差异有高度统计学意义(P < 0.01);常规护理组健康知识达标率为71.67%,循证护理组为96.67%,两组比较差异有统计学意义(χ2=7.43,P < 0.05).两组患者心功能分级比较差异有统计学意义(P < 0.05).循证护理组患者平均住院时间为(11.02±1.01)d、平均住院费用为(5 174.95±612.30)元,均显著低于常规护理组,差异有高度统计学意义(t = 13.98、16.12,P < 0.01);循证护理组平均卧床时间为(2.96±0.73)d,与常规护理组比较差异有统计学意义(t = 7.14,P < 0.05).循证护理组患者满意度为96.67%,高于常规护理组的70.00%,两组比较差异有统计学意义(χ2=7.06,P < 0.05).结论循证护理可有效降低急性心肌梗死后心律失常的发生,提高患者满意度,促进患者尽快康复.%Objective To investigate the application results of evidence-based care in acute myocardial infarction patients with cardiac arrhythmias, and to promote the speedy recovery of patients. Methods 120 patients who were in line with WHO acute myocardial infarction arrhythmia standard were selected from October 2010 to October 2011 and were randomly divided into

  15. Noninvasive prognostic markers for cardiac death and ventricular arrhythmia in long-term follow-up of subjects with chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    P.R. Benchimol-Barbosa

    2007-02-01

    Full Text Available The objective of the present study was to investigate clinical, echocardiographic and electrocardiographic (12-lead resting ECG, 24-h ambulatory ECG monitoring and signal-averaged ECG (SAECG parameters in subjects with chronic Chagas' disease in a long-term follow-up as prognostic markers for adverse outcomes. Fifty adult outpatients (34 to 74 years old, 31 females staged according to Los Andes class I, II or III and complaining of palpitation were enrolled in a longitudinal study. SAECG was analyzed in time and frequency domains and the endpoint was a composite of cardiac death and ventricular tachycardia. During a follow-up of 84.2 ± 39.0 months, 34.0% of the patients developed adverse outcomes (9 cardiac deaths and 11 episodes of ventricular tachycardia. After optimal dichotomization, in a stepwise multivariate Cox-hazard regression model, apical aneurysm (HR = 3.7; 95% CI = 1.2-1.3; P = 0.02, left ventricular ejection fraction 614 per 24 h (hazard ratio = 6.1; 95% CI = 1.7-22.6; P = 0.006 were independent predictors of the composite endpoint. Although a high frequency content in SAECG demonstrated association with the presence of left ventricular dysfunction and myocardial fibrosis, its predictive value for the composite endpoint was not significant. Apical aneurysms, reduced left ventricular function and a high incidence of ventricular ectopic beats over a 24-h period have a strong predictive value for a composite endpoint of cardiac death and ventricular tachycardia in subjects with chronic Chagas' disease.

  16. Neural defects and cardiac arrhythmia in fish larvae following embryonic exposure to 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47).

    Science.gov (United States)

    Lema, Sean C; Schultz, Irvin R; Scholz, Nathaniel L; Incardona, John P; Swanson, Penny

    2007-05-31

    Polybrominated diphenyl ethers (PBDEs) are added to plastics, polyurethane foam, and textiles as a flame retardant. While PBDEs play a key role in reducing loss of human life and property from fires, these flame retardants have become pervasive organic contaminants in the environment and in the tissues of fish, birds, marine mammals, and humans. Levels of PBDEs in wildlife and humans continue to rise, raising concerns about potential ecological and health risks associated with exposure to these chemicals. Nevertheless, there is little currently known about the toxicological effects of PBDE exposure. Here, we examined the developmental toxicity of the PBDE congener 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47) using the zebrafish (Danio rerio) as an ontogenetic model. Zebrafish embryos were exposed continuously to dissolved phase PBDE 47 (100-5000 microg/l) beginning 3-5 h post-fertilization (hpf). Fish treated with the highest concentrations of PBDE 47 delayed hatching, had reduced growth post-hatching, and displayed an abnormal dorsal curvature of the body with flexion at the hindbrain. By 96h post-fertilization larvae exposed to PBDE 47 had significant tachycardia, which progressed into atrioventricular block arrhythmias. Microinjection of fluorescent dye into the hindbrain ventricle revealed that cerebrospinal fluid in the neural tube and brain ventricles flowed more slowly in fish larvae exposed to PBDE 47, a likely etiology for the dorsal curvature. Similar, though much less pronounced, developmental toxicity also occurred in larvae exposed to PBDE 47 only for a 20h period during early embryogenesis (3-23 hpf), suggesting that PBDEs incorporated in lipid of the egg are bioavailable and cause toxicity later in life. Taken together, this work indicates that exposure to PBDE 47 can cause morphological abnormalities, impair cardiovascular function and cerebrospinal fluid flow, and provides a tractable starting point for using the zebrafish model to explore

  17. Types and risk factors of cardiac arrhythmias and its effects on pregnancies in 266 hospitalized pregnancy women%266例妊娠患者合并心律失常的类型、危险因素及对妊娠的影响

    Institute of Scientific and Technical Information of China (English)

    李红; 杜静; 薛倩; 刘元生

    2015-01-01

    Objective To investigate the types and risk factors of cardiac arrhythmias and its influence during pregnancy. Methods A total of 266 cases of pregnancies complicated with arrhythmias admitted and delivered were reviewed from June 1993 to June 2012 in Peking University People's Hospital. Results The most common cardiac arrhythmias during pregnancy was sinus tachycardia ( 41. 4% ) (110 / 266). In all kinds of arrhythmia, gestational hypertension was the most common cause of arrhythmia. Single factor analysis showed that, among all the risk factors and the influence on outcomes during pregnancy complicated with arrhythmias, 74. 8% ( 199 / 266 ) of cases were normal cardiac structure, and 25. 2%(67 / 266) of cases were abnormal cardiac structure. There was no significant difference in maternal mortality between pregnancy with or without abnormal cardiac structure(P ﹥ 0. 05). In addition, 86. 5% (230 / 266) of cases were in NYHA grading Ⅰ-Ⅱ, 13. 5% (36 / 266) were in NYHA grading Ⅲ-Ⅳ. The difference of maternal mortality between pregnancy in NYHA grading Ⅲ-Ⅳ and grading Ⅰ-Ⅱ has significance ( P ﹤0. 01) . Conclusions The most common cardiac arrhythmias during pregnancy is sinus tachycardia. Gestational hypertension is the most common cause of arrhythmia. Pregnancy in NYHA grading Ⅲ-Ⅳ has an obvious bad effect on maternal mortality.%目的:分析妊娠合并心律失常的类型、危险因素及对妊娠的影响。方法入选北京大学人民医院1993年6月至2012年6月间妊娠合并心律失常的266例住院分娩患者的临床病历资料,回顾性分析心律失常的危险因素及其对妊娠的影响。结果妊娠合并心律失常中以窦性心动过速最常见,占41.4%(110/266),其次为室性期前收缩和预激综合征合并的室上性心动过速,分别占18.0%(48/266)和8.3%(22/266)。在各种危险因素中,妊娠期高血压综合征最为常见。所有患者中25.2%(67/266)合并器质性心脏病,74.8

  18. A simple HPLC-fluorescence method for the measurement of R,S-sotalol in the plasma of patients with life-threatening cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    S.R. Santos

    2000-02-01

    Full Text Available R,S-sotalol, a ß-blocker drug with class III antiarrhythmic properties, is prescribed to patients with ventricular, atrial and supraventricular arrhythmias. A simple and sensitive method based on HPLC-fluorescence is described for the quantification of R,S-sotalol racemate in 500 µl of plasma. R,S-sotalol and its internal standard (atenolol were eluted after 5.9 and 8.5 min, respectively, from a 4-micron C18 reverse-phase column using a mobile phase consisting of 80 mM KH2PO4, pH 4.6, and acetonitrile (95:5, v/v at a flow rate of 0.5 ml/min with detection at lex = 235 nm and lem = 310 nm, respectively. This method, validated on the basis of R,S-sotalol measurements in spiked blank plasma, presented 20 ng/ml sensitivity, 20-10,000 ng/ml linearity, and 2.9 and 4.8% intra- and interassay precision, respectively. Plasma sotalol concentrations were determined by applying this method to investigate five high-risk patients with atrial fibrillation admitted to the Emergency Service of the Medical School Hospital, who received sotalol, 160 mg po, as loading dose. Blood samples were collected from a peripheral vein at zero, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12.0 and 24.0 h after drug administration. A two-compartment open model was applied. Data obtained, expressed as mean, were: CMAX = 1230 ng/ml, TMAX = 1.8 h, AUCT = 10645 ng h-1 ml-1, Kab = 1.23 h-1, a = 0.95 h-1, ß = 0.09 h-1, t(1/2ß = 7.8 h, ClT/F = 3.94 ml min-1 kg-1, and Vd/F = 2.53 l/kg. A good systemic availability and a fast absorption were obtained. Drug distribution was reduced to the same extent in terms of total body clearance when patients and healthy volunteers were compared, and consequently elimination half-life remained unchanged. Thus, the method described in the present study is useful for therapeutic drug monitoring purposes, pharmacokinetic investigation and pharmacokinetic-pharmacodynamic sotalol studies in patients with tachyarrhythmias.

  19. The Relationship of Left Ventricular Remodeling and Cardiac Function with Ventricular Arrhythmia in Ischemic Cardiomyopathy%缺血性心肌病左室重构和心功能与室性心律失常的关系

    Institute of Scientific and Technical Information of China (English)

    楚涛

    2012-01-01

    目的:探讨缺血性心肌病(ICM)患者左心室重构和心功能与室性心律失常的关系.方法:120例ICM患者分别按左心功能和左心室舒张末期内径(left ventricle end diastolic dimension,LVEDd)分组,分析各组患者发生室性心律失常的情况.结果:ICM患者的复杂型室性早搏、室内传导阻滞、室性早搏并发室内传导阻滞的发生率与LVEDd有明显相关性,差异有显著性(P<0.05);复杂型室性早搏的发生率与左心功能有关,差异有显著性(P<0.05),而室内传导阻滞以及室性早搏并发室内传导阻滞的发生率与左心功能无关,差异无显著性(P>0.05);简单型室性早搏的发生率与LVEDd和左心功能无关,差异无显著性(P>0.05).结论:ICM患者复杂型室性早搏发生与LVEDd及心功能有明显相关性,LVEDd重度增大者更易发生室性早搏及室内传导阻滞.%Objective: To investigate the relationship of left ventricular remodeling and cardiac function with ventricular arrhythmias in patients with ischemic cardiomyopathy (ICM). Methods; Total 120 cases with ICM were divided into groups according to left ventricle end-diastolic dimension (LVEDd) and left ventricular function, and the occurrence of ventricular arrhythmias in each group was investigated. Results; The occurrence of complex ventricular premature beat, intraventricular block and ventricular premature beat complicated with intraventricular block was related to LVEDd ( P 0. 05). Simple type of ventricular premature beat was not related to LVEDd and left heart function (P > 0. 05). Conclusions: The occurrence of complex ventricular premature beat is related to LVEDd and left heart function. When LVEDd is severe enlargement, ventricular premature beat complicated with intraventricular block is more likely to occur.

  20. Drug-Free Correction of the Tone of the Autonomic Nervous System in the Management of Cardiac Arrhythmia in Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Sergey V. Popov, PhD, ScD

    2013-06-01

    Full Text Available Background: The aim of our study was to examine the possibility of ventricular extrasystole (VES management in CAD (coronary artery disease patients by attenuating the sympathetic activity with a course of electrical stimulation of the vagus nerve. Methods: A decrease in sympathetic tone was achieved via vagus nerve electrical stimulation (VNES. VNES was performed in 48 male CAD patients, mean age 53.5±4.1 years. Antiarrhythmic drug therapy was canceled prior to VNES therapy. The effect of VNES on heart rate variability (HRV and VES were carefully studied. All the patients received a 24-hour ECG monitoring. HRV was calculated for high frequency (HF and low frequency (LF bands and the LF/HF index was determined. Results: Immediately following VNES therapy, 30 patients (group 1 reported alleviation of angina signs and the LF/HF index was significantly decreased (p=0.001. Eighteen patients (group 2 showed no change either in health or the LF/HF index. According to ECG and echocardiography, the VES number did not significantly change immediately after VNES therapy. One month after the VNES course, group 1 reported further improvement in health; the LF/HF index approached normal values. In group 2, the LF/HF significantly decreased (p=0.043. However, in the entire study sample, the VES number significantly decreased overall (p=0.025. Conclusion: VNES attenuated the cardiac effects of hypersympathicotonia decreased the ischemic impact on the myocardium, alleviated the cardiac angina signs, and beneficially influenced the VES number in CAD patients.

  1. Computer assisted optimisation on non-pharmacological treatment of congestive heart failure and supraventricular arrhythmia

    OpenAIRE

    Reumann, Matthias

    2007-01-01

    Heart Failure is the most common cardiac disease worldwide; supraventricular arrhythmia the most common cardiac arrhythmia. The understanding of these diseases advances treatment options. Ablation therapy and atrial antitachycardial pacing are non-pharmacological options in the treatment of atrial fibrillation. Cardiac resynchronization therapy with biventricular pacing devices has been shown successful in patients with severe heart failure. However, an optimization or even individual therapy...

  2. Fully parallel ANN-based arrhythmia classifier on a single-chip FPGA: FPAAC

    OpenAIRE

    ÖZDEMİR, Ahmet Turan; DANIŞMAN, Kenan

    2011-01-01

    Recognition of cardiac arrhythmias by electrocardiogram (ECG) is an important issue for diagnosis of cardiac abnormalities. Many studies on recognition of cardiac arrhythmias by ECG, using various techniques, have been performed in the past 20 years. Artificial neural networks (ANNs) are the most widely used tool in medical diagnosis systems (MDS) because of their powerful prediction characteristics. An ANN model is inspired by real biological neural networks, with a parallel structur...

  3. Arrhythmias in Adult Congenital Heart Disease: Diagnosis and Management.

    Science.gov (United States)

    Kumar, Saurabh; Tedrow, Usha B; Triedman, John K

    2015-11-01

    Cardiac arrhythmias are a major source of morbidity and mortality in adults with CHD. A multidisciplinary approach in a center specializing in the care of ACHD is most likely to have the expertise needed provide this care. Knowledge of the underlying anatomy, mechanism of arrhythmia, and potential management strategies is critical, as well as access and expertise in the use of advanced imaging and ablative technologies. Future challenges in management include refining the underlying mechanism and putative ablation targets for catheter ablation of AF, an arrhythmia rapidly rising in prevalence in this population.

  4. 老年贲门癌术后心律失常的危险因素分析%Analysis of the risky factors for postoperative arrhythmia in elder cardiac carcinoma patients

    Institute of Scientific and Technical Information of China (English)

    张立凡; 许怀宏; 杨敏杰; 张辉标

    2011-01-01

    Objective To analyze the risky factors associated with postoperative arrhythmia in elder cardiac carcmoma patients. Methods Between 1999 and 2009, 189 elder patients undergoing resection of cardiac carcinoma were reviewed retrospectively according to presence or absence of arrhythmia. Multiple preoperative factors were evaluated by univariate and multivariate logistic regression analysis. Results Univariate risk factors included postoperative hypoxemia (P < 0 . 05),postoperative hypokalemia (P < 0.01), preoperative blood viscosity lever increase (P < 0 .05) , incision at chest (P < 0 . 05),myocardial ischemia (P < 0.05), taken epidural analgesia after operation (P < 0.05), low ratio of arterial oxygen tension to inspired oxygen fraction (PaO2/FiO2) (P<0.01), smoking (P<0.05). Multivariate logistic regression analysis identified that low ratio of arterial oxygen tension to inspired oxygen fraction (PaO2/FiO2), postoperative hypokalemia, incision at chest, myocardial ischemia were risk factors. Conclusion These results suggest that the patients with risk factors described above need more careful peri- and post- operative surveillance and management.%目的 探讨老年患者贲门癌根治术后早期心律失常的危险因素.方法 将上海复旦大学附属华东医院胸外科、普外科1999至2009年收治的老年贲门癌术后早期发生心律失常的63例患者的资料,与按1:2比例随机抽取同期老年贲门癌根治术后未发生心律失常的126例患者的资料作对照,进行单因素分析和多因素Logistic回归分析.结果 单因素分析结果显示:是否经胸手术、术后PaO_2/FiO_2,、术后PaO_2、术后低钾血症、吸烟史、术前EKG显示心肌缺血、术前血黏度增高、术后止痛不佳与老年贲门癌术后发生心律失常有关.多因素Logistic回归分析显示:术后PaO_2/FiO_2<300mmHg、术后低钾血症、经胸手术、术前EKG显示心肌缺血为老年贲门癌术后发生心律

  5. Laboratory Markers of Ventricular Arrhythmia Risk in Renal Failure

    Directory of Open Access Journals (Sweden)

    Ioana Mozos

    2014-01-01

    Full Text Available Sudden cardiac death continues to be a major public health problem. Ventricular arrhythmia is a main cause of sudden cardiac death. The present review addresses the links between renal function tests, several laboratory markers, and ventricular arrhythmia risk in patients with renal disease, undergoing or not hemodialysis or renal transplant, focusing on recent clinical studies. Therapy of hypokalemia, hypocalcemia, and hypomagnesemia should be an emergency and performed simultaneously under electrocardiographic monitoring in patients with renal failure. Serum phosphates and iron, PTH level, renal function, hemoglobin and hematocrit, pH, inflammatory markers, proteinuria and microalbuminuria, and osmolarity should be monitored, besides standard 12-lead ECG, in order to prevent ventricular arrhythmia and sudden cardiac death.

  6. Poincare Geometry-Characterized Arrhythmia Identification Scheme in Grid

    Directory of Open Access Journals (Sweden)

    Dong-Hyun Kim

    2009-12-01

    Full Text Available In this paper, we propose a new scheme of Poincare geometry-characterized ECG analysis for cardiac disease identification. Based on reliable P-wave detection we created P-P Poincare plot applying P-P intervals of ECG signal. By the new geometric Poincare plot analysis, which combines R-R intervals and P-P intervals, weidentified geometric differences of normal and arrhythmia ECG databases at PhysioBank in Physionet. Poincare descriptors show that the analysis scheme can classify two ECG signals reliably. Furthermore, we discuss a cardiac disease estimation system that may be applicable to estimate the occurrence of arrhythmia in healthy person.

  7. Loperamide Induced Life Threatening Ventricular Arrhythmia

    Science.gov (United States)

    Bodar, Vijaykumar; Singh, Sharanjit; Frumkin, William; Mangla, Aditya; Doshi, Kaushik

    2016-01-01

    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.

  8. Loperamide Induced Life Threatening Ventricular Arrhythmia.

    Science.gov (United States)

    Upadhyay, Ankit; Bodar, Vijaykumar; Malekzadegan, Mohammad; Singh, Sharanjit; Frumkin, William; Mangla, Aditya; Doshi, Kaushik

    2016-01-01

    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. PMID:27547470

  9. Cardiac arrhythmia classification based on mutiple lead electrocardiogram signals and multivariate autoregressive modeling method%基于多导联心电信号和多变量回归模型的心律失常的分类

    Institute of Scientific and Technical Information of China (English)

    葛丁飞; 李时辉; Krishnan S. M.

    2004-01-01

    心电信号(ECG)智能分析非常有利于严重心脏病人的自动诊断.本文介绍了多变量回归模型(MAR)建模法,利用MAR模型从双导联ECG中提取特征对ECG信号进行分类.在分类时,利用MAR模型系数及其K-L变换(K-L MAR系数)作为信号特征,并采用了树状决策过程和二次判别函数(QDF)分类器.利用文中方法对MIT-BIH标准数据库中的正常窦性心律(NSR)、期收缩(APC)、心室早期收缩(PVC)、心室性心动过速(VT)和心室纤维性颤动(VF)各300个样本信号进行了建模和测试. 结果表明,为了达到分类目的,MAR模型阶数取4是足够的,基于MAR系数的分类取得了比基于K-L MAR系数的分类稍好的结果.基于MAR系数的分类获得了97.3%~98.6%的分类精度.%Artificial-intelligence analysis of electrocardiogram (ECG) signals is great benefit to the automatic diagnosis in critical ill patients. Multivariate autoregressive modeling (MAR) for the purpose of classification of cardiac arrhythmias has been introduced. The MAR coefficients and K-L transformation of MAR coefficients extracted from two-lead ECG signals have been utilized for representing the ECG signals. The ECG data obtained from MIT-BIH database included normal sinus rhythm, atria premature contraction, premature ventricular contraction, ventricular tachycardia, and ventricular fibrillation. The current classification was performed using a stage-by-stage quadratic discriminant function (QDF). The results showed a MAR order of 4 was sufficient for the purpose of classification, and MAR coefficients produced slightly better results than K-L transformation of MAR coefficients. The classification accuracy of 97.3% to 98.6% based on MAR coefficients is obtained in the research.

  10. Effects of Heterogeneous Diffuse Fibrosis on Arrhythmia Dynamics and Mechanism.

    Science.gov (United States)

    Kazbanov, Ivan V; ten Tusscher, Kirsten H W J; Panfilov, Alexander V

    2016-01-01

    Myocardial fibrosis is an important risk factor for cardiac arrhythmias. Previous experimental and numerical studies have shown that the texture and spatial distribution of fibrosis may play an important role in arrhythmia onset. Here, we investigate how spatial heterogeneity of fibrosis affects arrhythmia onset using numerical methods. We generate various tissue textures that differ by the mean amount of fibrosis, the degree of heterogeneity and the characteristic size of heterogeneity. We study the onset of arrhythmias using a burst pacing protocol. We confirm that spatial heterogeneity of fibrosis increases the probability of arrhythmia induction. This effect is more pronounced with the increase of both the spatial size and the degree of heterogeneity. The induced arrhythmias have a regular structure with the period being mostly determined by the maximal local fibrosis level. We perform ablations of the induced fibrillatory patterns to classify their type. We show that in fibrotic tissue fibrillation is usually of the mother rotor type but becomes of the multiple wavelet type with increase in tissue size. Overall, we conclude that the most important factor determining the formation and dynamics of arrhythmia in heterogeneous fibrotic tissue is the value of maximal local fibrosis. PMID:26861111

  11. 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......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...... studies, associating the use of specific drugs with SCD, strongly support the presence of an increased risk. Whereas the absolute risk of drug-induced life-threatening arrhythmia may be relatively low, even small increments in risk of SCD may have a major health impact considering that millions...

  12. Cardiac arrhythmias in adult patients with asthma

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... more common (OR: 12.4 [95% CI: 4.7-32.8] and 3.7 [95% CI: 1.3-10.5], respectively). CONCLUSIONS: The adult patients with asthma more commonly show tachycardia and PVCs on the ECG than those without asthma. The patients with asthma received β2-mimetics; the risk of tachycardia and PVCs is even more...

  13. Identification of Cardiac Arrhythmias using ECG

    OpenAIRE

    Pooja Sharma; Ms.Lakhwinder Kaur

    2012-01-01

    Heart failure is the most common reason of death nowadays, but if the medical help is given directly, the patient’s life may be saved in many cases. Numerous heart diseases can be detected by means of analyzing electrocardiograms (ECG). Artificial Neural Networks (ANN) are computer-based expert systems that have proved to be useful in pattern recognition tasks. ANN can be used in different phases of the decision-making process, from classification to diagnostic procedures. This work concentra...

  14. Identification of Cardiac Arrhythmias using ECG

    Directory of Open Access Journals (Sweden)

    Pooja Sharma

    2012-01-01

    Full Text Available Heart failure is the most common reason of death nowadays, but if the medical help is given directly, the patient’s life may be saved in many cases. Numerous heart diseases can be detected by means of analyzing electrocardiograms (ECG. Artificial Neural Networks (ANN are computer-based expert systems that have proved to be useful in pattern recognition tasks. ANN can be used in different phases of the decision-making process, from classification to diagnostic procedures. This work concentrates on a review followed by a novel method. The purpose of the review is to assess the evidence of healthcare benefits involving the application of artificial neural networks to the clinical functions of diagnosis, prognosis and survival analysis, in ECG signals. The developed method is based on a compound neural network (CNN, to classify ECGs as normal or carrying an Atrio Ventricular heart Block (AVB. This method uses three different feed forward multilayer neural networks. A single output unit encodes the probability of AVB occurrences. A value between 0 and 0.1 is the desired output for a normal ECG; a value between 0.1 and 1 would infer an occurrence of an AVB. The results show that this compound network has a good performance in detecting AVBs, with a sensitivity of 90.7% and a specificity of 86.05%. The accuracy value is 87.9%.

  15. 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.

    2012-01-01

    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

  16. Clinical application of echocardiography in detection of foetal arrhythmia:a retrospective study of 451 foetuses

    Institute of Scientific and Technical Information of China (English)

    赵博文; 张松英; 潘美; 徐海珊; 寿金朵; 吕江红; 汤富刚; 范妙英; 范晓明; 林莎

    2004-01-01

    @@Foetal arrhythmia is defined as any irregular foetal cardiac rhythm or regular rhythm at a rate outside the reference range of 120 to 160 beats/minute. Foetal echocardiography permits accurate determination of the structural characteristics and the nature of the arrhythmia in foetuses. It is particularly indicated for mothers from high-risk groups. Management of diagnosed heart disease, including foetal arrhythmia, leads either to the termination of pregnancy or to optimal postnatal care of baby and mother. This retrospective study examined the application of foetal echocardiography in the diagnosis of foetal arrhythmia and its clinical significance.

  17. Towards a hierarchy of mechanisms in CaMKII-mediated arrhythmia

    Directory of Open Access Journals (Sweden)

    Kevin P Vincent

    2014-05-01

    Full Text Available CaMKII activity has been shown to contribute to arrhythmogenesis in a remarkably broad range of cardiac pathologies. Several of these involve significant structural and electrophysiologic remodeling, whereas others are due to specific channelopathies, and are not typically associated with arrhythmogenic changes to protein expression or cellular and tissue structure. The ability of CaMKII to contribute to arrhythmia across such a broad range of phenotypes suggests one of two interpretations regarding the role of CaMKII in cardiac arrhythmia: (1 some CaMKII-dependent mechanism is a common driver of arrhythmia irrespective of the specific etiology of the disease, or (2 these different etiologies expose different mechanisms by which CaMKII is capable of promoting arrhythmia. In this review, we dissect the available mechanistic evidence to explore these two possibilities and discuss how the various molecular actions of CaMKII promote arrhythmia in different pathophysiologic contexts.

  18. Seizures following hippocampal kindling induce QT interval prolongation and increased susceptibility to arrhythmias in rats.

    Science.gov (United States)

    Bealer, Steven L; Little, Jason G

    2013-07-01

    The prolonged seizures of status epilepticus produce chronic arrhythmogenic changes in cardiac function. This study was designed to determine if repeated, self-limiting seizures administered to kindled rats induce similar cardiac dysfunction. Multiple seizures administered to rats following hippocampal kindling resulted in cardiac QT interval prolongation and increased susceptibility to experimental arrhythmias. These data suggest that multiple, self-limiting seizures of intractable epilepsy may have cardiac effects that can contribute to sudden unexpected death in epilepsy (SUDEP).

  19. [Arrhythmias during pregnancy].

    Science.gov (United States)

    Trappe, H-J

    2008-09-01

    Cardiovascular emergencies are rare during pregnancy with an incidence of 0,2-4,0%. Emergencies include arrhythmias, acute coronary syndrome, peripartum cardiomyopathy and hypertensive disorders. Electrical DC-cardioversion with 50-100 Joules is indicated in the acute treatment of arrhythmias in all patients in an unstable hemodynamic state. If 100 J fails higher energies (up to 360 J) will be necessary. In stable supraventricular tachycardia intravenous adenosine is the first choice drug and may safely terminate the arrhythmia. Ventricular premature beats are frequently present during pregnancy and benign in most patients. However, life-threatening ventricular tachyarrhythmias (sustained ventricular tachycardia [VT], ventricular flutter [VFlt], ventricular fibrillation [VF]) were observed less frequently. Electrical DC-cardioversion is necessary in all pregnant women who are in a hemodynamically unstable state and have a life-threatening ventricular tachyarrhythmias. In hemodynamically stable pregnant women the initial therapy with ajmaline, procainamide or lidocaine is indicated. Implantation of a cardioverter-defibrillator is indicated in patients with syncope caused by VT, VF, VFlt or aborted sudden death. PMID:18767007

  20. Computer-assisted education system for arrhythmia (CAESAR).

    Science.gov (United States)

    Fukushima, M; Inoue, M; Fukunami, M; Ishikawa, K; Inada, H; Abe, H

    1984-08-01

    A computer-assisted education system for arrhythmia (CAESAR) was developed for students to acquire the ability to logically diagnose complicated arrhythmias. This system has a logical simulator of cardiac rhythm using a mathematical model of the impulse formation and conduction system of the heart. A simulated arrhythmia (ECG pattern) is given on a graphic display unit with simulated series of the action potential of five pacemaker centers and the "ladder diagram" of impulse formation and conduction, which show the mechanism of that arrhythmia. For the purpose of the evaluation of this system, 13 medical students were given two types of tests concerning arrhythmias before and after 2-hr learning with this system. The scores they obtained after learning increased significantly from 73.3 +/- 11.9 to 93.2 +/- 3.0 (P less than 0.001) in one test and from 47.2 +/- 17.9 to 64.9 +/- 19.6 (P less than 0.001) in another one. These results proved that this CAI system is useful and effective for training ECG interpretation of arrhythmias.

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

    OpenAIRE

    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 i...

  2. Cardiac tumours in infancy

    OpenAIRE

    Yadava, O.P.

    2012-01-01

    Cardiac tumours in infancy are rare and are mostly benign with rhabdomyomas, fibromas and teratomas accounting for the majority. The presentation depends on size and location of the mass as they tend to cause cavity obstruction or arrhythmias. Most rhabdomyomas tend to regress spontaneously but fibromas and teratomas generally require surgical intervention for severe haemodynamic or arrhythmic complications. Other relatively rare cardiac tumours too are discussed along with an Indian perspect...

  3. Optical mapping system for visualizing arrhythmias in isolated mouse atria.

    Science.gov (United States)

    Schmidt, Robyn; Nygren, Anders

    2006-01-01

    Optical mapping has become an important technique in the study of cardiac electrophysiology, especially in terms of investigating the mechanisms of cardiac arrhythmias. The increasing availability of transgenic mice as models for cardiovascular disease is driving the need for instrumentation suitable for the study of electrical activity in the mouse heart. In this paper we evaluate our optical mapping system's ability to clearly record induced arrhythmic activity in an isolated mouse atrial preparation. Preliminary results indicate that the signal quality is high enough that individual optically recorded action potentials can be discerned in many pixels, even without post-processing for noise removal. The optical mapping video is clear enough for general observations regarding the patterns of electrical propagation during arrhythmic behaviour. The induced arrhythmias appear to have a regular pattern of activity, and are likely best classified as atrial tachycardias.

  4. Treatment of depression in an adolescent with cardiomyopathy and arrhythmia.

    Science.gov (United States)

    Tanidir, Canan; Tanidir, Ibrahim C; Tuzcu, Volkan

    2015-10-01

    Patients with cardiomyopathy have a higher incidence of mood and anxiety disorders, resulting in greater probability for hospitalisation and increased risk for arrhythmia and death. We report a case of a 16-year-old boy with Danon disease, Wolff-Parkinson-White syndrome, and hypertrophic cardiomyopathy, who later developed depression and significant weight loss. The patient was successfully treated for his anxiety and depression with mirtazapine without any adverse cardiac effects. PMID:25400066

  5. Life-threatening ventricular arrhythmia recognition by nonlinear descriptor

    OpenAIRE

    Krishnan Shankar; Chan Kap; Sun Yan

    2005-01-01

    Abstract Background Ventricular tachycardia (VT) and ventricular fibrillation (VF) are ventricular cardiac arrhythmia that could be catastrophic and life threatening. Correct and timely detection of VT or VF can save lives. Methods In this paper, a multiscale-based non-linear descriptor, the Hurst index, is proposed to characterize the ECG episode, so that VT and VF can be recognized as different from normal sinus rhythm (NSR) in the descriptor domain. Results This newly proposed technique wa...

  6. Genetics of inherited primary arrhythmia disorders

    Directory of Open Access Journals (Sweden)

    Spears DA

    2015-09-01

    Full Text Available Danna A Spears, Michael H Gollob Division of Cardiology – Electrophysiology, University Health Network, Toronto General Hospital, Toronto, ON, Canada Abstract: A sudden unexplained death is felt to be due to a primary arrhythmic disorder when no structural heart disease is found on autopsy, and there is no preceding documentation of heart disease. In these cases, death is presumed to be secondary to a lethal and potentially heritable abnormality of cardiac ion channel function. These channelopathies include congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, Brugada syndrome, and short QT syndrome. In certain cases, genetic testing may have an important role in supporting a diagnosis of a primary arrhythmia disorder, and can also provide prognostic information, but by far the greatest strength of genetic testing lies in the screening of family members, who may be at risk. The purpose of this review is to describe the basic genetic and molecular pathophysiology of the primary inherited arrhythmia disorders, and to outline a rational approach to genetic testing, management, and family screening. Keywords: long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, Brugada syndrome, short QT syndrome, genetics

  7. Association between delayed enhancement on cardiac magnetic resonance imaging and arrhythmia in patients with hypertrophic cardiomyopathy%肥厚型心肌病延迟增强磁共振成像与心律失常的相关性

    Institute of Scientific and Technical Information of China (English)

    汪晶; 孔祥泉; 徐海波; 周国锋; 刘芳; 石浩军; 刘定西

    2010-01-01

    Objective To observe the association between myocardial fibrosis,detected by delayed-enhancement(DE) cardiac magnetic resonance imaging (MRI) and arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Methods Forty-eight untreated HCM patients who underwent Cine MR, DE-MRI,24 h ambulatory Holter electrocardiogram and ECG examinations were recruited. Extent of myocardial fibrosis (fibrosis mass/total LV mass) was assessed using DE imaging. Association between arrhythmias including premature ventricular complexes ( PVCS ≥ 200 ), supra-ventricular tachycardia ( SVT ), non-sustained ventricular tachycardia (NSVT), atrio-ventricular block (AVB) and intra-ventricular block (IVB) detected by Holter monitoring and ECG with regard to delayed enhancement (DE) on contrast enhanced CMR was analyzed. Results Myocardial fibrosis was detected in 35 patients. Incidence of arrhythmia was significantly higher in patients with DE than in patients without DE ( P < 0. 05 ). Extent of myocardial fibrosis was significantly associated with the QRS duration ( r = 0. 33, P < 0. 001 ). Conclusion Myocardial fibrosis detected by DE-CMR was associated with arrhythmia in patients with HCM. DE-CMR might be helpful to detect high-risk HCM patients prone to arrhythmia.%目的 探讨肥厚型心肌病延迟增强磁共振成像(MRI)显示的心肌纤维化与心律失常的相关性.方法 对48例未经治疗的肥厚型心肌病患者进行了MRI心功能分析、钆喷替酸葡甲胺(Gd-DTPA)延迟增强MRI、常规心电图和24 b动态心电图检查.分别探讨延迟增强MRI与频发室性期前收缩(PVCS总数≥200个)、阵发性室上性心动过速(SVT)、非持续性室性心动速(NSVT)、房室传导阻滞(AVB)、室内传导阻滞(IVB)之间的关系.计算延迟强化心肌质量、延迟强化心肌质量百分比,并分析其与24 h内PVCS、SVT和NSVT总数,传导阻滞(PR间期、QRS时限)间的相关性.描述肥厚型心肌病延迟强化

  8. Analysis of electrolyte abnormalities and the mechanisms leading to arrhythmias in heart failure. A literature review.

    Science.gov (United States)

    Urso, C; Canino, B; Brucculeri, S; Firenze, A; Caimi, G

    2016-01-01

    About 50% of deaths from heart failure (HF) are sudden, presumably referable to arrhythmias. Electrolyte and acid-base abnormalities are a frequent and potentially dangerous complication in HF patients. Their incidence is almost always correlated with the severity of cardiac dysfunction; furthermore leading to arrhythmias, these imbalances are associated with a poor prognosis. The frequency of ventricular ectopic beats and sudden cardiac death correlate with both plasma and whole body levels of potassium, especially in alkalemia. The early recognition of these alterations and the knowledge of the pathophysiological mechanisms are useful for the management of these HF patients.

  9. [Cardiac amyloidosis].

    Science.gov (United States)

    Hoyer, Caroline; Angermann, Christiane E; Knop, Stefan; Ertl, Georg; Störk, Stefan

    2008-03-15

    Amyloidoses are a heterogeneous group of multisystem disorders, which are characterized by an extracellular deposition of amyloid fibrils. Typically affected are the heart, liver, kidneys, and nervous system. More than half of the patients die due to cardiac involvement. Clinical signs of cardiac amyloidosis are edema of the lower limbs, hepatomegaly, ascites and elevated jugular vein pressure, frequently in combination with dyspnea. There can also be chest pain, probably due to microvessel disease. Dysfunction of the autonomous nervous system or arrhythmias may cause low blood pressure, dizziness, or recurrent syncope. The AL amyloidosis caused by the deposition of immunoglobulin light chains is the most common form. It can be performed by monoclonal gammopathy. The desirable treatment therapy consists of high-dose melphalan therapy twice followed by autologous stem cell transplantation. Due to the high peritransplantation mortality, selection of appropriate patients is mandatory. The ATTR amyloidosis is an autosomal dominant disorder caused by the amyloidogenic form of transthyretin, a plasmaprotein that is synthesized in the liver. Therefore, liver transplantation is the only curative therapy. The symptomatic treatment of cardiac amyloidosis is based on the current guidelines for chronic heart failure according to the patient's New York Heart Association (NYHA) state. Further types of amyloidosis with possible cardiac involvement comprise the senile systemic amyloidosis caused by the wild-type transthyretin, secondary amyloidosis after chronic systemic inflammation, and the beta(2)-microglobulin amyloidosis after long-term dialysis treatment. PMID:18344065

  10. Propofol and arrhythmias: two sides of the coin

    Institute of Scientific and Technical Information of China (English)

    Qiang LIU; Ai-ling KONG; Rong CHEN; Cheng QIAN; Shao-wen LIU; Bao-gui SUN; Le-xin WANG; Long-sheng SONG; Jiang HONG

    2011-01-01

    The hypnotic agent propofol is effective for the induction and maintenance of anesthesia. However, recent studies have shown that propofol administration is related to arrhythmias. Propofol displays both pro- and anti-arrhythmic effects in a concentration-dependent manner. Data indicate that propofol can convert supraventricular tachycardia and ventricular tachycardia and may inhibit the conduction system of the heart. The mechanism of the cardiac effects remains poorly defined and may involve ion channels, the autonomic nervous system and cardiac gap junctions. Specifically, sodium, calcium and potassium currents in cardiac cells are suppressed by clinically relevant concentrations of propofol. Propofol shortens the action potential duration (APD) but lessens the ischemia-induced decrease in the APD. Furthermore, propofol suppresses both sympathetic and parasympathetic tone and preserves gap junctions during ischemia. All of these effects cumulatively contribute to the antiarrhythmic and proarrhythmic properties of propofol.

  11. Induced pluripotent stem cell-derived cardiomyocytes: boutique science or valuable arrhythmia model?

    Science.gov (United States)

    Knollmann, Björn C

    2013-03-15

    This 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 antiarrhythmic 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

  12. Induced pluripotent stem cell-derived cardiomyocytes: boutique science or valuable arrhythmia model?

    Science.gov (United States)

    Knollmann, Björn C

    2013-03-15

    This 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 antiarrhythmic 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.

  13. Improved arrhythmia detection in implantable loop recorders

    DEFF Research Database (Denmark)

    Brignole, M.; Black, C.L.B.; Sutton, R.;

    2008-01-01

    Improved Arrhythmia Detection. Introduction: Implantable loop recorders (ILR) have an automatic arrhythmia detection feature that can be compromised by inappropriately detected episodes. This study evaluated a new ILR sensing and detection scheme for automatically detecting asystole...

  14. Cardioverter-Defibrillator: A Treatment for Arrhythmia

    Science.gov (United States)

    MENU Return to Web version Arrhythmia | Cardioverter-Defibrillator: A Treatment for Arrhythmia What is an implantable cardioverter-defibrillator? An implantable cardioverter-defibrillator (often called an ICD) is a device that keeps ...

  15. Fuzzy Soft System and Arrhythmia Classification

    OpenAIRE

    Pankaj Srivastava; Neeraja Sharma; Aparna, C. S.

    2014-01-01

    An arrhythmia is an irregularity with the speed or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, or with an irregular rhythm. Most arrhythmias are harmless, but some can be serious or even life threatening. The present paper deals with the classification scheme of arrhythmia commonly occurring in human beings of Southeast Asian countries. Medical knowledge used in practice has been closely studied for modelling user friendly referral system to sharpen a...

  16. [Cardiac potassium channels: molecular structure, physiology, pathophysiology and therapeutic implications].

    Science.gov (United States)

    Mironov, N Iu; Golitsyn, S P

    2013-01-01

    Potassium channels and currents play essential roles in cardiac repolarization. Potassium channel blockade by class III antiarrhythmic drugs prolongs cardiac repolarization and results in termination and prevention of cardiac arrhythmias. Excessive inhomogeneous repolarization prolongation may lead to electrical instability and proarrhythmia (Torsade de Pointes tachycardia). This review focuses on molecular structure, physiology, pathophysiology and therapeutic potential of potassium channels of cardiac conduction system and myocardium providing information on recent findings in pathogenesis of cardiac arrhythmias, including inherited genetic abnormalities, and future perspectives. PMID:24654438

  17. Atrial Arrhythmias in Astronauts - Summary of a NASA Summit

    Science.gov (United States)

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

    2010-01-01

    Background and Problem Definition: To evaluate NASA s current standards and practices related to atrial arrhythmias in astronauts, Space Medicine s Advanced Projects Section at the Johnson Space Center was tasked with organizing a summit to discuss the approach to atrial arrhythmias in the astronaut cohort. Since 1959, 11 cases of atrial fibrillation, atrial flutter, or supraventricular tachycardia have been recorded among active corps crewmembers. Most of the cases were paroxysmal, although a few were sustained. While most of the affected crewmembers were asymptomatic, those slated for long-duration space flight underwent radiofrequency ablation treatment to prevent further episodes of the arrhythmia. The summit was convened to solicit expert opinion on screening, diagnosis, and treatment options, to identify gaps in knowledge, and to propose relevant research initiatives. Summit Meeting Objectives: The Atrial Arrhythmia Summit brought together a panel of six cardiologists, including nationally and internationally renowned leaders in cardiac electrophysiology, exercise physiology, and space flight cardiovascular physiology. The primary objectives of the summit discussions were to evaluate cases of atrial arrhythmia in the astronaut population, to understand the factors that may predispose an individual to this condition, to understand NASA s current capabilities for screening, diagnosis, and treatment, to discuss the risks associated with treatment of crewmembers assigned to long-duration missions or extravehicular activities, and to discuss recommendations for prevention or management of future cases. Summary of Recommendations: The summit panel s recommendations were grouped into seven categories: Epidemiology, Screening, Standards and Selection, Treatment of Atrial Fibrillation Manifesting Preflight, Atrial Fibrillation during Flight, Prevention of Atrial Fibrillation, and Future Research

  18. Method and apparatus for the guided ablative therapy of fast ventricular arrhythmia

    Science.gov (United States)

    Cohen, Richard J. (Inventor); Barley, Maya (Inventor)

    2010-01-01

    Method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. The excitation from the previous excitatory wave is significant at the beginning of the next excitation. In particular, it is designed for treatment of fast cardiac arrhythmias. Electrical signals are acquired from recording electrodes, and an inverse dipole method is used to identify the site of origin of an arrhythmia. The location of the tip of an ablation catheter is similarly localized from signals acquired from the recording electrodes while electrical pacing energy is delivered to the tip of the catheter close to or in contact with the cardiac tissue. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.

  19. Arrhythmia risk stratification of patients after myocardial infarction using personalized heart models.

    Science.gov (United States)

    Arevalo, Hermenegild J; Vadakkumpadan, Fijoy; Guallar, Eliseo; Jebb, Alexander; Malamas, Peter; Wu, Katherine C; Trayanova, Natalia A

    2016-01-01

    Sudden cardiac death (SCD) from arrhythmias is a leading cause of mortality. For patients at high SCD risk, prophylactic insertion of implantable cardioverter defibrillators (ICDs) reduces mortality. Current approaches to identify patients at risk for arrhythmia are, however, of low sensitivity and specificity, which results in a low rate of appropriate ICD therapy. Here, we develop a personalized approach to assess SCD risk in post-infarction patients based on cardiac imaging and computational modelling. We construct personalized three-dimensional computer models of post-infarction hearts from patients' clinical magnetic resonance imaging data and assess the propensity of each model to develop arrhythmia. In a proof-of-concept retrospective study, the virtual heart test significantly outperformed several existing clinical metrics in predicting future arrhythmic events. The robust and non-invasive personalized virtual heart risk assessment may have the potential to prevent SCD and avoid unnecessary ICD implantations. PMID:27164184

  20. Arrhythmia in Acute Right Ventricular Infarction

    Directory of Open Access Journals (Sweden)

    Azin Alizadeh Asl

    2007-09-01

    Full Text Available Acute inferior myocardial infarction (MI frequently involves the right ventricle (RV.1-3 We assessed the prognostic impact of RV myocardial involvement in patients with inferior MI. One hundred seventy patients were admitted to the cardiac care unit of Madani Heart Hospital (Tabriz-Iran with the diagnosis of inferior MI with (group1 or without (group2 the simultaneous involvement of RV during the study period (from 2005 to 2006. Patients presenting within 12h of symptom onset were eligible for inclusion. Patients with simultaneous anterior wall MI or renal impairment (creatinine > 2 mg/dl, as well as those undergoing primary percutaneous translational coronary angioplasty, were excluded. Eighty eight percent of the patients with RVMI and 75% of those with isolated inferior MI had some type of arrhythmia. Atrioventricular (AV block occurred in 42% of the infarctions with RV involvement and only in 29% of the control group. Intra-ventricular conduction disturbance (IVCD was also more frequent in RVMI (29.4% vs. 13.1%, p=0.021, especially right bundle branch block (RBBB (20% vs. 7.4%, P=0.003. There was, however, no meaningful difference in the incidence of left bundle branch block (LBBB between the two groups (3.5% vs. 2.35%, P=0.95. Ventricular fibrillation (VF was observed in 5.2% and 1.2% and ventricular tachycardia in 26% and 12.2% of the patients in groups 1 and 2, respectively. In 27% of patients with RVMI, it was necessary to implant a pacemaker as compared to 10% of those in the control group. Mortality was higher in the patients with inferior infarction extended to the RV (15.3% vs. 3.5%, P= 0.0001. Thus, the differences between the findings in the two groups in terms of the occurrence of post-MI arrhythmias and conduction disorders were quite significant, but there was no meaningful difference with respect to the incidence of LBBB between the two groups. Additionally, patients with inferior MI who also had RV myocardial involvement were

  1. Cardiac Vagal Regulation and Early Peer Status

    Science.gov (United States)

    Graziano, Paulo A.; Keane, Susan P.; Calkins, Susan D.

    2007-01-01

    A sample of 341 5 1/2-year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks…

  2. Fever-Induced Life-Threatening Arrhythmias in Children Harboring an SCN5A Mutation

    NARCIS (Netherlands)

    P. Chockalingam; L.A. Rammeloo; P.G. Postema; J. Hruda; S.A.B. Clur; N.A. Blom; A.A. Wilde

    2011-01-01

    Cardiac channelopathies caused by SCN5A mutation are well tolerated by most patients. However, the dramatic presentation of a previously healthy 4-month-old girl with life-threatening arrhythmias and the subsequent findings in the child and her family provide evidence that loss-of-function sodium ch

  3. Relationship of ventricular arrhythmias to the angiographically and scintigraphically estimated extent of ventricular damage late after myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Huikuri, H.V.; Korhonen, U.R.; Linnaluoto, M.K.; Takkunen, J.T.

    1987-03-01

    In order to study the quantitative relationship of ventricular arrhythmias to myocardial damage and ischemia, 61 patients with a previous myocardial infarction (at least 6 months previously) were studied by 24-hour ambulatory ECG monitoring, cardiac catheterization, and thallium-201 scintigraphy. Thirty-five patients (57%) had no ectopic beats or only infrequent, unifocal ones and 26 patients (43%) had complex ventricular arrhythmias. Left ventricular function was lower in the latter, but the number of diseased vessels did not differ in the two groups. The reduction of thallium activity in the infarct area was more marked in patients with complex arrhythmias. Multiple thallium defects were not more common in arrhythmia patients, however. These data support the view that complex ventricular arrhythmias are more closely related to the severity of ventricular damage than the presence of myocardial ischemia remote to the area of previous infarction.

  4. Evaluating the Cancer Therapeutic Potential of Cardiac Glycosides

    OpenAIRE

    José Manuel Calderón-Montaño; Estefanía Burgos-Morón; Manuel Luis Orta; Dolores Maldonado-Navas; Irene García-Domínguez; Miguel López-Lázaro

    2014-01-01

    Cardiac glycosides, also known as cardiotonic steroids, are a group of natural products that share a steroid-like structure with an unsaturated lactone ring and the ability to induce cardiotonic effects mediated by a selective inhibition of the Na+/K+-ATPase. Cardiac glycosides have been used for many years in the treatment of cardiac congestion and some types of cardiac arrhythmias. Recent data suggest that cardiac glycosides may also be useful in the treatment of cancer. These compounds typ...

  5. Proposition of novel classification approach and features for improved real-time arrhythmia monitoring.

    Science.gov (United States)

    Kim, Yoon Jae; Heo, Jeong; Park, Kwang Suk; Kim, Sungwan

    2016-08-01

    Arrhythmia refers to a group of conditions in which the heartbeat is irregular, fast, or slow due to abnormal electrical activity in the heart. Some types of arrhythmia such as ventricular fibrillation may result in cardiac arrest or death. Thus, arrhythmia detection becomes an important issue, and various studies have been conducted. Additionally, an arrhythmia detection algorithm for portable devices such as mobile phones has recently been developed because of increasing interest in e-health care. This paper proposes a novel classification approach and features, which are validated for improved real-time arrhythmia monitoring. The classification approach that was employed for arrhythmia detection is based on the concept of ensemble learning and the Taguchi method and has the advantage of being accurate and computationally efficient. The electrocardiography (ECG) data for arrhythmia detection was obtained from the MIT-BIH Arrhythmia Database (n=48). A novel feature, namely the heart rate variability calculated from 5s segments of ECG, which was not considered previously, was used. The novel classification approach and feature demonstrated arrhythmia detection accuracy of 89.13%. When the same data was classified using the conventional support vector machine (SVM), the obtained accuracy was 91.69%, 88.14%, and 88.74% for Gaussian, linear, and polynomial kernels, respectively. In terms of computation time, the proposed classifier was 5821.7 times faster than conventional SVM. In conclusion, the proposed classifier and feature showed performance comparable to those of previous studies, while the computational complexity and update interval were highly reduced. PMID:27318329

  6. [Emergency treatment of arrhythmias in neonates and infants].

    Science.gov (United States)

    Weber, H; Wesselhoeft, H; Eigster, G

    1983-11-01

    Emergency treatment of cardiac arrhythmias was required in 41 newborn and infants aged two days to 9 months (mean 77 days) from July 1977 until September 1981. Heart defects were present in 27 (65.8%). Invasive electrophysiological studies were performed in all patients. The different types of arrhythmias were: bradyarrhythmias in 9 (21.9%): bradycardia to cardiac arrest (5), congenital complete AV-block (3), postoperative complete AV-block (1). Tachyarrhythmias in 32 patients (78.1%): reentry through accessory connections (21), congenital atrial flutter (6), ventricular flutter/fibrillation (3), and AV-nodal tachycardia (2). Overdrive atrial or ventricular stimulation with a consecutive series of 15-20 impulses of 5-10 Volts abolished arrhythmic attacks in 22 patients including 4 in whom prior digitalization had no effect. In two other patients overdrive pacing achieved sinus rhythm only after i.v. Propafenon. In 4 further patients 36.2 to 63.8 mg/m2 i.v. Propafenon and in 4 other patients DC synchronized cardioversion with 1 to 3 Wsec/kg restored a normal heart rate. The 3 patients with congenital complete heart block died, one despite permanent pacing. Oral Propafenon therapy with 300 mg/m2 die in three divided doses following emergency therapy of tachyarrhythmias was discontinued in patients without arrhythmias after 1 year on drug therapy. There was no relapse after a mean follow-up period of 1.9 years. Only patients with congestive heart failure due to cardiac defects needed additional digitalisation. Thus, in our experience antiarrhythmic drug therapy with Propafenon was more effective in this age group than digitalization. PMID:6664346

  7. Cardiac ablation by transesophageal high intensity focused ultrasound

    Institute of Scientific and Technical Information of China (English)

    JIANG Chen-xi; YU Rong-hui; MA Chang-sheng

    2010-01-01

    @@ Cardiac ablation is an important modality of invasive therapy in modern cardiology, especially in the treatment of arrhythmias, as well as other diseases such as hypertrophic obstructive cardiomyopathy (HOCM). Since Huang et al1 used radiofrequency (RF) to ablate canine atrial ventricular junction, RF has developed into the leading energy source in catheter ablation of arrhythmias.

  8. {sup 123}I-meta-iodobenzylguanidine myocardial scintigraphy in arrhythmia disease; La scintigraphie myocardique a la {sup 123}I-metaiodobenzylguanidine dans les arythmies

    Energy Technology Data Exchange (ETDEWEB)

    Valli, N.; Ducassou, D.; Barat, J.L. [Universite Victor-Segalen, Service de Medecine Nucleaire, Hopital du Haut-Leveque, 33 - Pessac (France)

    2007-12-15

    Meta-iodobenzylguanidine-iodine 123 ({sup 123}I-Mibg) myocardial scintigraphy is one of only the few methods available for the objective evaluation of cardiac sympathetic function at the clinical level. Disorders of cardiac sympathetic function play an important role in a variety of heart diseases and particularly arrhythmia disease. Mibg abnormalities have been described in various arrhythmia diseases. Their signification and their prognostic value are still not clear. This article focuses on reviewing the characteristics of {sup 123}I-Mibg myocardial scintigraphy in different arrhythmia diseases. (authors)

  9. Poincare Geometry-Characterized Arrhythmia Identification Scheme in Grid

    OpenAIRE

    Dong-Hyun Kim; Jin-Ho Kim; Chan-Hyun Youn.

    2009-01-01

    In this paper, we propose a new scheme of Poincare geometry-characterized ECG analysis for cardiac disease identification. Based on reliable P-wave detection we created P-P Poincare plot applying P-P intervals of ECG signal. By the new geometric Poincare plot analysis, which combines R-R intervals and P-P intervals, weidentified geometric differences of normal and arrhythmia ECG databases at PhysioBank in Physionet. Poincare descriptors show that the analysis scheme can classify two ECG signa...

  10. Arrhythmia Management in the Elderly-Implanted Cardioverter Defibrillators and Prevention of Sudden Death.

    Science.gov (United States)

    Manian, Usha; Gula, Lorne J

    2016-09-01

    We present an overview of arrhythmia management in elderly patients as it pertains to implantable cardioverter defibrillator (ICD) therapy and prevention of sudden death. Treatment of arrhythmia in elderly patients is fraught with challenges pertaining to goals of care and patient frailty. With an ever increasing amount of technology available, realistic expectations of therapy need to balance quality and quantity of life. The ICD is an important treatment option for selected patients at risk of ventricular arrhythmia and sudden cardiac death. However, the incidence of sudden death as a percentage of all-cause mortality decreases with age. Studies have reported that 20% of elderly patients might die within 1 year of an episode of life-threatening ventricular arrhythmia, but most because of nonarrhythmic causes. This illustrates the 'sudden cardiac death paradox,' with a great proportion of death in elderly patients, even those at risk for ventricular arrhythmias, attributable to medical conditions that cannot be addressed by an ICD. We discuss current practices in ICD therapy in elderly patients, existing evidence from registries and clinical trials, approaches to risk stratification, and important ethical considerations. Although the decision on whether ICD insertion is appropriate in the elderly population remains an area of uncertainty from an evidence-based and ethical perspective, we offer insight on potential clinical and research strategies for this growing population. PMID:27568872

  11. Ventricular arrhythmias in patients of atrial fibrillation treated with Flecainide: A case report

    Directory of Open Access Journals (Sweden)

    Barman M, Djamel B

    2014-07-01

    Full Text Available Purpose: Flecainide is a class 1C antiarrhythmic drug, especially used for the management of supraventricular arrhythmia. Flecainide also has a recognized proarrhythmic effect in all age groups of adult patients treated for ventricular tachycardia. It is used to treat a variety of cardiac arrhythmias including paroxysmal fibrillation, Paroxysmal Supraventricular tachycardia and ventricular tachycardia. Flecainide works by regulating the flow of sodium in the heart, causing prolongation of the cardiac action potential. The proarrhythmic effects however noted are not widely reported. Case report: We report a case of paroxysmal atrial fibrillation with structurally normal heart who was treated with oral Flecainide. Despite subjective improvement and no adverse events [QTc prolongation] a repeat holter detected him to have multiple short non sustained ventricular arrhythmias. Results: Development of ventricular arrhythmias, salvos &non sustained ventricular tachycardia after a month of initiation of oral Flecainide detected by 24 hours ECG holter lead to discontinuation of Flecainide and subsequent early electro physiological studies and successful ablation. Conclusion: Initiation of oral Flecainide in a case of atrial fibrillation with subjective improvement and regular ECG monitoring, no QTc prolongation can still lead to development of dangerous ventricular arrhythmias. A cautious approach and thorough investigations and follow up are recommended.

  12. Nitric oxide and the autonomic regulation of cardiac excitability. The G.L. Brown Prize Lecture.

    Science.gov (United States)

    Paterson, D

    2001-01-01

    Cardiac sympathetic imbalance and arrhythmia; Nitric oxide-cGMP pathway and the cholinergic modulation of cardiac excitability; Nitric oxide-cGMP pathway and the sympathetic modulation of cardiac excitability; Functional significance of nitric oxide in the autonomic regulation of cardiac excitability; Summary; References. Experimental Physiology (2001) 86.1, 1-12. PMID:11429613

  13. Nitric oxide and the autonomic regulation of cardiac excitability. The G.L. Brown Prize Lecture.

    Science.gov (United States)

    Paterson, D

    2001-01-01

    Cardiac sympathetic imbalance and arrhythmia; Nitric oxide-cGMP pathway and the cholinergic modulation of cardiac excitability; Nitric oxide-cGMP pathway and the sympathetic modulation of cardiac excitability; Functional significance of nitric oxide in the autonomic regulation of cardiac excitability; Summary; References. Experimental Physiology (2001) 86.1, 1-12.

  14. Detection of Shockable Ventricular Arrhythmia using Variational Mode Decomposition.

    Science.gov (United States)

    Tripathy, R K; Sharma, L N; Dandapat, S

    2016-04-01

    Ventricular tachycardia (VT) and ventricular fibrillation (VF) are shockable ventricular cardiac ailments. Detection of VT/VF is one of the important step in both automated external defibrillator (AED) and implantable cardioverter defibrillator (ICD) therapy. In this paper, we propose a new method for detection and classification of shockable ventricular arrhythmia (VT/VF) and non-shockable ventricular arrhythmia (normal sinus rhythm, ventricular bigeminy, ventricular ectopic beats, and ventricular escape rhythm) episodes from Electrocardiogram (ECG) signal. The variational mode decomposition (VMD) is used to decompose the ECG signal into number of modes or sub-signals. The energy, the renyi entropy and the permutation entropy of first three modes are evaluated and these values are used as diagnostic features. The mutual information based feature scoring is employed to select optimal set of diagnostic features. The performance of the diagnostic features is evaluated using random forest (RF) classifier. Experimental results reveal that, the feature subset derived from mutual information based scoring and the RF classifier produces accuracy, sensitivity and specificity values of 97.23 %, 96.54 %, and 97.97 %, respectively. The proposed method is compared with some of the existing techniques for detection of shockable ventricular arrhythmia episodes from ECG. PMID:26798076

  15. Life-threatening ventricular arrhythmia recognition by nonlinear descriptor

    Directory of Open Access Journals (Sweden)

    Krishnan Shankar

    2005-01-01

    Full Text Available Abstract Background Ventricular tachycardia (VT and ventricular fibrillation (VF are ventricular cardiac arrhythmia that could be catastrophic and life threatening. Correct and timely detection of VT or VF can save lives. Methods In this paper, a multiscale-based non-linear descriptor, the Hurst index, is proposed to characterize the ECG episode, so that VT and VF can be recognized as different from normal sinus rhythm (NSR in the descriptor domain. Results This newly proposed technique was tested using MIT-BIH malignant ventricular arrhythmia database. The relationship between the ECG episode length and the corresponding recognition performance was studied. The experiments demonstrated good performance of the proposed descriptor. An accuracy rate as high as 100% was obtained for VT/VF to be recognized from NSR; for VT and VF to be recognized from each other, the recognition accuracy varies from 84.24% to 100%. In addition, the results were compared favorably against those obtained using Complexity measure. Conclusions There is strong potential for using the Hurst index for malignant ventricular arrhythmia recognition in clinical applications.

  16. Phosphodiesterase 4B in the cardiac L-type Ca²⁺ channel complex regulates Ca²⁺ current and protects against ventricular arrhythmias in mice.

    Science.gov (United States)

    Leroy, Jérôme; Richter, Wito; Mika, Delphine; Castro, Liliana R V; Abi-Gerges, Aniella; Xie, Moses; Scheitrum, Colleen; Lefebvre, Florence; Schittl, Julia; Mateo, Philippe; Westenbroek, Ruth; Catterall, William A; Charpentier, Flavien; Conti, Marco; Fischmeister, Rodolphe; Vandecasteele, Grégoire

    2011-07-01

    β-Adrenergic receptors (β-ARs) enhance cardiac contractility by increasing cAMP levels and activating PKA. PKA increases Ca²⁺-induced Ca²⁺ release via phosphorylation of L-type Ca²⁺ channels (LTCCs) and ryanodine receptor 2. Multiple cyclic nucleotide phosphodiesterases (PDEs) regulate local cAMP concentration in cardiomyocytes, with PDE4 being predominant for the control of β-AR-dependent cAMP signals. Three genes encoding PDE4 are expressed in mouse heart: Pde4a, Pde4b, and Pde4d. Here we show that both PDE4B and PDE4D are tethered to the LTCC in the mouse heart but that β-AR stimulation of the L-type Ca²⁺ current (ICa,L) is increased only in Pde4b-/- mice. A fraction of PDE4B colocalized with the LTCC along T-tubules in the mouse heart. Under β-AR stimulation, Ca²⁺ transients, cell contraction, and spontaneous Ca²⁺ release events were increased in Pde4b-/- and Pde4d-/- myocytes compared with those in WT myocytes. In vivo, after intraperitoneal injection of isoprenaline, catheter-mediated burst pacing triggered ventricular tachycardia in Pde4b-/- mice but not in WT mice. These results identify PDE4B in the CaV1.2 complex as a critical regulator of ICa,L during β-AR stimulation and suggest that distinct PDE4 subtypes are important for normal regulation of Ca²⁺-induced Ca²⁺ release in cardiomyocytes.

  17. Indeterminacy of Spatiotemporal Cardiac Alternans

    CERN Document Server

    Zhao, Xiaopeng

    2007-01-01

    Cardiac alternans, a beat-to-beat alternation in action potential duration (at the cellular level) or in ECG morphology (at the whole heart level), is a marker of ventricular fibrillation, a fatal heart rhythm that kills hundreds of thousands of people in the US each year. Investigating cardiac alternans may lead to a better understanding of the mechanisms of cardiac arrhythmias and eventually better algorithms for the prediction and prevention of such dreadful diseases. In paced cardiac tissue, alternans develops under increasingly shorter pacing period. Existing experimental and theoretical studies adopt the assumption that alternans in homogeneous cardiac tissue is exclusively determined by the pacing period. In contrast, we find that, when calcium-driven alternans develops in cardiac fibers, it may take different spatiotemporal patterns depending on the pacing history. Because there coexist multiple alternans solutions for a given pacing period, the alternans pattern on a fiber becomes unpredictable. Usin...

  18. The expression of troponin T in cardiac conduction system after exhaustive exercise and their role in exercise induced arrhythmia%不同力竭运动后大鼠心脏传导系统肌钙蛋白T mRNA和蛋白的变化及其在运动性心律失常发生中的作用

    Institute of Scientific and Technical Information of China (English)

    常芸; 杨红霞

    2012-01-01

    目的 探讨力竭运动后不同时相心脏窦房结、房室结和浦肯野氏纤维细胞骨架因子肌钙蛋白T(cTnT)基因和蛋白水平的表达特点,为运动性心律失常发生机制的阐明提供实验依据.方法 100只健康成年雄性SD大鼠随机分为一次力竭运动、反复力竭组及相应的其对照组,每组10只.分别于力竭运动后0、4、12及24 h应用激光显微切割技术定位并收集窦房结、房室结和浦肯野氏纤维细胞团,进行免疫荧光组织化学及实时荧光定量PCR分析cTnT的mRNA和蛋白表达变化.结果 一次力竭运动后,窦房结cTnT mRNA和蛋白表达变化不大,各时相组间无显著性差异;房室结cTnT mRNA和蛋白表达在运动后12 h显著高于对照组(P<0.01),浦肯野纤维cTnT mRNA和蛋白表达呈逐渐升高趋势,在运动后24 h显著高于对照组(P<0.01).反复力竭运动后窦房结、房室结和浦肯野纤维cTnT mRNA和蛋白表达呈先升高后下降的趋势,在运动后即刻显著高于对照组(P<0.05).结论 力竭运动后心脏传导系统各部位细胞骨架支撑因子cTnT在mRNA和蛋白水平呈异常高表达提示心脏传导系统细胞骨架结构损伤,可能构成运动性心律失常的病理基础.%Objective This paper discusses on the mRNA and protein expression of troponin T on cardiac sinus node,atrioventricular node and Purkinje fibers at different time phrase after exhaustive exercise, and trys to provide experimental evidence for clarifying the mechanism of exercise-induced arrhythmia. Methods 100 health)' adult male SD rats were grouped into the one-time exhaustive swimming group( n = 40 ), the 2-week repeated exhaustive swimming group( n = 40 ), and 2 control groups( 10 rats for each group ). The exercise rats were sacrificed at 0,4,12,and 24 hours after exhaustive swimming, the control groups were sacrificed at the same time with the 0 hour after exhaustive swimming group. The cells of SAN, AVN and Purkinje's fiber were

  19. Arrhythmia

    Science.gov (United States)

    ... travels, it causes the heart to contract and pump blood. Each electrical signal begins in a group of ... atria. This causes the atria to contract and pump blood into the heart's two lower chambers, the ventricles ( ...

  20. Atrial Arrhythmia Summit: Post Summit Report

    Science.gov (United States)

    Barr, Yael

    2010-01-01

    The Atrial Arrhythmia Summit brought together nationally and internationally recognized experts in cardiology, electrophysiology, exercise physiology, and space medicine in an effort to elucidate the mechanisms, risk factors, and management of atrial arrhythmias in the unique occupational cohort of the U.S. astronaut corps.

  1. Risk of arrhythmia induced by psychotropic medications: a proposal for clinical management.

    Science.gov (United States)

    Fanoe, Søren; Kristensen, Diana; Fink-Jensen, Anders; Jensen, Henrik Kjærulf; Toft, Egon; Nielsen, Jimmi; Videbech, Poul; Pehrson, Steen; Bundgaard, Henning

    2014-05-21

    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 studies, associating the use of specific drugs with SCD, strongly support the presence of an increased risk. Whereas the absolute risk of drug-induced life-threatening arrhythmia may be relatively low, even small increments in risk of SCD may have a major health impact considering that millions of patients are treated with psychotropics. In subgroups of pre-disposed patients, e.g. patients with cardiac diseases or other co-morbidities, the elderly or patients treated with other negatively interacting drugs, the absolute risk of drug-induced arrhythmia may be considerable. On the other hand, several 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. In this review, data from various authorities on the risk of arrhythmia associated with psychotropic medications were weighted and categorized into three risk categories. Additionally, we suggest a clinically applicable algorithm to reduce the risk of malignant arrhythmia in patients to be treated 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 patients on psychotropic drugs.

  2. Fractal ventilation enhances respiratory sinus arrhythmia

    Directory of Open Access Journals (Sweden)

    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.

  3. The susceptibility of ventricular arrhythmia to aconitine in conscious Lyon hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    Min LI; Jin WANG; He-hui XIE; Fu-ming SHEN; Ding-feng SU

    2007-01-01

    Aim: The present work was designed to investigate the relationship between hemodynamic parameters and the susceptibility of ventricular arrhythmia to aconitine in conscious Lyon hypertensive rats (LH). Methods: Male LH and Lyon low blood pressure rats (LL) were used. After the determination of baroreflex sensitivity (BRS), ventricular arrhythmia was induced by aconitine infusion inconscious rats. Blood pressure (BP) was recorded during the period of infusion. Results: Compared with the LL rats, the LH rats possessed significantly higher BP, blood pressure variability and lower BRS. The threshold of aconitine required for ventricular fibrillation and cardiac arrest in the LH rats were significantly lower than those in the LL rats. It was found that all the hemodynamic parameters studied were not correlated with the tl~eshold of aconitine required for arrhythmia, with the exception of BRS, which was positively related to the threshold of aconitine required for ventricular premature beat. Conclusion: The LH rats possessed greater susceptibility to aconitine-induced ventricular arrhythmias when compared to the LL rats. This greater susceptibility could not be attributed to anyone of the hemodynamic parameters alone studied in the LH rats. It is proposed that various hypertension-associated abnormalities, including the abnormal hemodynamics, may co-contribute to this vulnerability to ventricular arrhythmias.

  4. Arrhythmia management after device removal.

    Science.gov (United States)

    Nishii, Nobuhiro

    2016-08-01

    Arrhythmic management is needed after removal of cardiac implantable electronic devices (CIEDs). Patients completely dependent on CIEDs need temporary device back-up until new CIEDs are implanted. Various methods are available for device back-up, and the appropriate management varies among patients. The duration from CIED removal to implantation of a new CIED also differs among patients. Temporary pacing is needed for patients with bradycardia, a wearable cardioverter defibrillator (WCD) or catheter ablation is needed for patients with tachyarrhythmia, and sequential pacing is needed for patients dependent on cardiac resynchronization therapy. The present review focuses on arrhythmic management after CIED removal. PMID:27588151

  5. Infarct size and recurrence of ventricular arrhythmias after defibrillator implantation

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, J. de; Tavernier, R.; Kazmierckzak, J.; Buyzere, M. de; Clement, D.L. [Department of Cardiology, University Hospital Gent, Gent (Belgium); Wiele, C. van de; Dierckx, R.A. [Department of Nuclear Medicine, University Hospital Gent (Belgium); Jordaens, L. [Thoraxcenter, University Hospital Rotterdam-Dijkzigt (Netherlands)

    2000-07-01

    Infarct size as determined by perfusion imaging is an independent predictor of mortality after implantable cardioverter defibrillator (ICD) implantation in patients with coronary artery disease (CAD) and life-threatening ventricular arrhythmias (VA). However, its value as a predictor of VA recurrence and hospitalisation after ICD implantation is unknown. Therefore, the objective of this study was to evaluate whether infarct size as determined by perfusion imaging can help to identify patients who are at high risk for recurrence of VA and hospitalisation after ICD implantation. We studied 56 patients with CAD and life-threatening VA. Before ICD implantation, all patients underwent a uniform study protocol including a thallium-201 stress-redistribution perfusion study. A defect score as a measurement of infarct size was calculated using a 17-segment 5-point scoring system. Study endpoints during follow-up were documented episodes of appropriate anti-tachycardia pacing and/or shocks for VA and cardiac hospitalisation for electrical storm (defined as three or more appropriate ICD interventions within 24 h), heart failure or angina. After a mean follow-up of 470{+-}308 days, 22 patients (39%) had recurrences of VA. In univariate analysis, predictors for recurrence were: (a) ventricular tachycardia (VT) as the initial presenting arrhythmia (86% vs 59% for patients without ICD therapy, P=0.04), (b) treatment with {beta}-blockers (36% vs 68%, P=0.03) and (c) a defect score (DS) {>=}20 (64% vs 32%, P=0.03). In multivariate analysis, VT as the presenting arrhythmia ({chi}2=5.51, P=0.02) and a DS {>=}20 ({chi}2=4.22, P=0.04) remained independent predictors. Cardiac hospitalisation was more frequent in patients with a DS {>=}20 (44% vs 13% for patients with DS <20, P=0.015) and this was particularly due to more frequent hospitalisations for electrical storm (24% vs 3% for patients with DS<20, P=0.037). The extent of scarring determined by perfusion imaging can separate

  6. Cardiac applications of optogenetics.

    Science.gov (United States)

    Ambrosi, Christina M; Klimas, Aleksandra; Yu, Jinzhu; Entcheva, Emilia

    2014-08-01

    In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics.

  7. Probing cardiac repolarization reserve in drug safety assessment

    NARCIS (Netherlands)

    Nalos, L.

    2011-01-01

    Excessive prolongation of cardiac repolarization, manifested as QT prolongation on ECG, is common unwanted side effect of many drugs and drug candidates. Prolongation of QT interval may lead to life threatening cardiac arrhythmia – Torsade de Point (TdP). Number of drugs was withdrawn from the marke

  8. Genetic risk factors for common and rare cardiac rhythm disorders

    NARCIS (Netherlands)

    R.F.J. Marsman

    2014-01-01

    Sudden cardiac death (SCD) is defined by abrupt and unexpected death due to a cardiac cause, most often attributed to sustained ventricular arrhythmias. Knowledge about the molecular pathways involved in SCD is necessary in order to develop preventive strategies and novel therapies. Insight into the

  9. Heart Attack or Sudden Cardiac Arrest: How Are They Different?

    Science.gov (United States)

    ... for Heart360 Cardiovascular Conditions • Conditions Home • Arrhythmia and Atrial Fibrillation • Cardiac Arrest • Cardiac Rehab • Cardiomyopathy • Cardiovascular Conditions of Childhood • Cholesterol • Congenital Heart Defects • Diabetes • Heart Attack • Heart Failure (HF) • Heart Valve Problems and Disease • High Blood ...

  10. Hyperkalaemia, cardiac arrhythmias, and cerebral lesions in high risk neonates.

    OpenAIRE

    Shortland, D; Trounce, J Q; Levene, M I

    1987-01-01

    The case notes of 20 infants with hyperkalaemia (defined as two successive serum potassium measurements of greater than 7.5 mmol/l) were reviewed. The incidence of hyperkalaemia was also looked at in an unselected population of 200 low birthweight infants. The mean gestational age of the 20 affected infants was 29 weeks and the mean birth weight 1235 g. The incidence of hyperkalemia in the cohort of 200 infants weighing less than 1500 g at birth was 3.5%. Hyperkalaemia was associated with a h...

  11. Cardiac Arrhythmia Management: Why Women Are Different from Men

    Science.gov (United States)

    ... disorder characterized by inappropriate catecholamine response to orthostatic stress, often triggered by viral illnesses or other physiologic stressors, and with a particular female preponderance. Its confusion with psychiatric disorders has led to incorrect diagnoses including anxiety neurosis ...

  12. Experience of treatment of heart rhabdomyomas in combination with various arrhythmias and conduction disorders

    OpenAIRE

    Bockeria L. A.; Bockeria O. L.; Rubtsov P.P.; Akhobekov A.A.; Alekhina M. A.

    2014-01-01

    Оbjective. Presentation the experience of diagnosis and treatment of heart rhabdomyomas in combination withvarious arrhythmias and conduction disorders.Material and methods. In archival material found 9 records of pediatric patients treated in A.N. BakoulevCenter for Cardiovascular Surgery from June 2004 to September 2013 with cardiac rhabdomyomas. The ageofpatients ranged from 19 days to 17 years. Along with the general clinical studies patients perfomed electro-cardiography (ECG), Holter EC...

  13. Convulsive Syncope Induced by Ventricular Arrhythmia Masquerading as Epileptic Seizures: Case Report and Literature Review

    OpenAIRE

    Sabu, John; Regeti, Kalyani; Mallappallil, Mary; Kassotis, John; Islam, Hamidul; Zafar, Shoaib; Khan, Rafay; Ibrahim, Hiyam; Kanta, Romana; Sen, Shuvendu; Yousif, Abdalla; Nai, Qiang

    2016-01-01

    It is important but difficult to distinguish convulsive syncope from epileptic seizure in many patients. We report a case of a man who presented to emergency department after several witnessed seizure-like episodes. He had a previous medical history of systolic heart failure and automated implantable converter defibrillator (AICD) in situ. The differential diagnoses raised were epileptic seizures and convulsive syncope secondary to cardiac arrhythmia. Subsequent AICD interrogation revealed ve...

  14. Does respiratory sinus arrhythmia serve a buffering role for diastolic pressure fluctuations?

    OpenAIRE

    Tan, Can Ozan; Taylor, J. Andrew

    2010-01-01

    Though many consider the magnitude of respiratory sinus arrhythmia as an index of cardiac vagal control, its physiological origins remain unclear. One influential model postulates that the systolic pressure rise within a given beat stimulates the baroreflex arc to adjust the following heart period such that diastolic pressure is “stabilized” and hence displays lesser fluctuation. Accordingly, the magnitude of diastolic pressure fluctuations with respiration should change reciprocally after au...

  15. Prevalence of arrhythmias among children below 15 years of age with congenital heart diseases attending Mulago National Referral Hospital, Uganda

    OpenAIRE

    Batte, Anthony; Lwabi, Peter; Lubega, Sulaiman; Kiguli, Sarah; Nabatte, Violette; Karamagi, Charles

    2016-01-01

    Background In Uganda, few children with congenital heart diseases (CHD) benefit from early corrective cardiac surgery. These children are at high risk of developing heart failure and electrolyte imbalances; factors which increase their risk of developing arrhythmias. This study aimed to determine the prevalence and factors associated with arrhythmias among children with congenital heart diseases receiving care at Mulago Hospital. Methods This was a cross-sectional study carried out from Augus...

  16. QTc interval in the assessment of cardiac risk

    DEFF Research Database (Denmark)

    Elming, Hanne; Brendorp, Bente; Køber, Lars;

    2002-01-01

    In the United States alone 300,000-400,000 people die of sudden cardiac death every year. Much of this mortality is assumed to be caused by ventricular tachyarrhythmias. Prolonged QTc reflect cardiac repolarization prolongation and/or increased repolarization inhomogenity known to be associated...... with increased risk of arrhythmias. The paper gives a review of the possibilities to assess the risk of ventricular arrhythmia and/or cardiac death from QTc. Prolonged QTc may hold independent prognostic importance for mortality in common diseases as ischemic heart disease and diabetes mellitus where...

  17. 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

  18. Remote monitoring of cardiac implantable electronic devices

    OpenAIRE

    Lappegård, Knut Tore

    2015-01-01

    Seminario desarrollado en la Segunda Conferencia Internacional de Comunicación en Salud, celebrada el 23 de octubre de 2015 en la Universidad Carlos III de Madrid Cardiac implantable electronic devices (CIEDs) are used with increasing frequency for the diagnosis and treatment of cardiac arrhythmias. In Europe, a total number of 550,000 pacemakers and 180,000 defibrillators were implanted in 2014. Follow-up of these patients is a large challenge to the health system and requires a substanti...

  19. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    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

  20. Historical perspectives of cardiac electrophysiology.

    Science.gov (United States)

    Lüderitz, Berndt

    2009-01-01

    The diagnosis and treatment of clinical electrophysiology has a long and fascinating history. From earliest times, no clinical symptom impressed the patient (and the physician) more than an irregular heart beat. Although ancient Chinese pulse theory laid the foundation for the study of arrhythmias and clinical electrophysiology in the 5th century BC, the most significant breakthrough in the identification and treatment of cardiac arrhythmias first occurred in this century. In the last decades, our knowledge of electrophysiology and pharmacology has increased exponentially. The enormous clinical significance of cardiac rhythm disturbances has favored these advances. On the one hand, patients live longer and thus are more likely to experience arrhythmias. On the other hand, circulatory problems of the cardiac vessels have increased enormously, and this has been identified as the primary cause of cardiac rhythm disorders. Coronary heart disease has become not just the most significant disease of all, based on the statistics for cause of death. Arrhythmias are the main complication of ischemic heart disease, and they have been directly linked to the frequently arrhythmogenic sudden death syndrome, which is now presumed to be an avoidable "electrical accident" of the heart. A retrospective look--often charming in its own right--may not only make it easier to sort through the copious details of this field and so become oriented in this universe of important and less important facts: it may also provide the observer with a chronological vantage point from which to view the subject. The study of clinical electrophysiology is no dry compendium of facts and figures, but rather a dynamic field of study evolving out of the competition between various ideas, intentions and theories. PMID:19196616

  1. Cardiac repolarization during hypoglycaemia in type 1 diabetes: Impact of basal renin-angiotensin system activity

    NARCIS (Netherlands)

    R. Due-Andersen (Rikke); T. Høi-Hansen (Thomas); C.E. Larroude; N.V. Olsen; J.K. Kanters; F. Boomsma (Frans); U. Pedersen-Bjergaard (Ullrik); B. Thorsteinsson (Birger)

    2008-01-01

    textabstractAims: Hypoglycaemia-induced cardiac arrhythmias may be involved in the pathogenesis of the 'dead-in-bed syndrome' in patients with type 1 diabetes. Evidence suggests that the renin-angiotensin system (RAS) influences the occurrence of arrhythmias. The aim of this study was to explore if

  2. Cardiac repolarization during hypoglycaemia in type 1 diabetes: impact of basal renin-angiotensin system activity

    DEFF Research Database (Denmark)

    Due-Andersen, Rikke; Høi-Hansen, Thomas; Larroude, Charlotte Ellen;

    2008-01-01

    AIMS: Hypoglycaemia-induced cardiac arrhythmias may be involved in the pathogenesis of the 'dead-in-bed syndrome' in patients with type 1 diabetes. Evidence suggests that the renin-angiotensin system (RAS) influences the occurrence of arrhythmias. The aim of this study was to explore if basal RAS...

  3. Molecular and cellular determinants of cardiac tachyarrhythmias : from trigger to therapy

    NARCIS (Netherlands)

    Bingen, B.O.

    2016-01-01

    Cardiac tachyarrhythmias are a vast contributor to morbidity and mortality worldwide. Still, the mechanisms underlying these arrhythmias are incompletely understood. As a result, many of the treatment options available for these arrhythmias rely on sole alleviation of symptoms or prevention of compl

  4. Flecainide: Current status and perspectives in arrhythmia management

    Institute of Scientific and Technical Information of China (English)

    George; K; Andrikopoulos; Sokratis; Pastromas; Stylianos; Tzeis

    2015-01-01

    Flecainide acetate is a class IC antiarrhythmic agent and its clinical efficacy has been confirmed by the results of several clinical trials. Nowadays, flecainide is recommended as one of the first line therapies for pharmacological conversion as well as maintenance of sinus rhythm in patients with atrial fibrillation and/or supraventricular tachycardias. Based on the Cardiac Arrhythmia Suppression Trial study results, flecainide is not recommended in patients with structural heart disease due to high proarrhythmic risk. Recent data support the role of flecainide in preventing ventricular tachyarrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia associated both with ryanodine receptor and calsequestrin mutations. We herein review the current clinical data related to flecainide use in clinical practice and some concerns about its role in the management of patients with coronary artery disease.

  5. Vernakalant hydrochloride for the rapid conversion of atrial fibrillation after cardiac surgery

    DEFF Research Database (Denmark)

    Kowey, Peter R; Dorian, Paul; Mitchell, L Brent;

    2009-01-01

    Postoperative atrial arrhythmias are common and are associated with considerable morbidity. This study was designed to evaluate the efficacy and safety of vernakalant for the conversion of atrial fibrillation (AF) or atrial flutter (AFL) after cardiac surgery....

  6. A challenging case of ventricular arrhythmia in a patient with myocarditis: ICD yes/no after ablation

    Directory of Open Access Journals (Sweden)

    Maria L Narducci; Teresa Rio; Francesco Perna; Domenico D�Amario; Biagio Merlino; Riccardo Marano; Gianluigi Bencardino; Frediano Inzani; Gemma Pelargonio; Filippo Crea

    2014-10-01

    Full Text Available In patients with myocarditis, early diagnosis and appropriate therapy are mandatory, as well as close clinical and strumental follow-up with particular regard on progression of disease and ventricular arrhythmias relapse. The management of ventricular arrhythmias should follow current guidelines for ICD implantation, but new therapeutic options could be evaluated in these patients as combined epicardial/endocardial ablation and external wereable defibrillator. Particularly, left ventricular ejection fraction (LVEF represented the only risk stratifier for sudden cardiac death currently used in myocarditis, although the use of single risk factor have limited utility. On this regard, combined analysis of structural myocardial tissue definition by cardiac magnetic resonance (CMR and endomyocardial biopsy, in association with resting cardiac systolic function could improve predictive accuracy for sudden death in patients with myocarditis.

  7. The Utility of Ambulatory Electrocardiographic Monitoring for Detecting Silent Arrhythmias and Clarifying Symptom Mechanism in an Elderly Urban Population with Heart Failure and Hypertension: Clinical Implications

    Directory of Open Access Journals (Sweden)

    Kathleen T. Hickey

    2010-06-01

    Full Text Available Background : Atrial and ventriclar tachyarrhythmias, as well as bradyarrhythmias, in the elderly with heart failure (HF and/or hypertension (HTN have been well documented. However, the frequency of these arrhythmias, whether silent or symptomatic, and their association with subsequent cardiac events has not been well defi ned in patients 65 years or older with HF and other cardiovascular risk factors. Objective : To assess the value of 2 weeks of remote, transtelephonic cardiac monitoring for detecting arrhythmias in an elderly, urban population living with HF. Methods : Fi” y-four patients with a history of systolic HF and/or HTN were consented and enrolled. All wore an auto triggered cardiac loop monitor for 2 weeks that captures EKG data and both silent and symptomatic arrhythmias were recorded. Results : Mean age was 73 ± 6 years with 59% of subjects were females, 74% Hispanic, 22% black, and 4% white/other. All patients had HF and 94% had HTN. From the cardiac monitoring, 72% demonstrated ectopic atrial and ventricular activity, and 1 paroxysmal episode of atrial fi brillation was documented. In addition, 3 subjects had signifi cant non-sustained ventricular tachycardia, and 4 individuals had severe bradycardia recorded on cardiac monitoring. These 7 individuals underwent placement of an implantable cardioverter defi brillator (ICD or pacemaker based on the documented arrhythmias which may have otherwise gone undetected. Conclusions : TA substantial proportion of patients exhibited cardiac arrhythmias. Future morbidity was prevented because of the detection of arrhythmias on monitoring that led to specifi c therapies such as pacemaker or ICD implantation which otherwise may not have been implemented.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. 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

  10. Characterization of antiarrhythmic drugs by alternating current induced arrhythmias in isolated heart tissues.

    Science.gov (United States)

    Borchard, U; Bösken, R; Greeff, K

    1982-04-01

    A new method for inducing arrhythmias or asystolia by the application of a 50 HZ alternating current (ac) to electrically driven heart preparations has been developed and applied to isolated left atria and right ventricular papillary muscles of the guinea-pig. An increase in driving frequency from 1 to 3 HZ effects a significant reduction of the threshold of ac-arrhythmia in guinea-pig papillary muscles but no change in atria. A decrease in temperature from 31 degrees C to 25 degrees C and an increase in [Ca2+]0 from 1.25 to 5 mmol/l elevates threshold for ac-arrhythmia and -asystolia. The fast sodium channel inhibitors quinidine, carticaine and benzylamino-5,6-dihydro-8,9-dimethoxy-imidazo-5,1-a-isoquinoline hydrochloride (HE-36) increase threshold of ac-arrhythmia in left atria and papillary muscles, whereas the slow channel inhibitor verapamil is ineffective in concentrations up to 6 mumol/l. Threshold of ac-arrhythmia is elevated by quinidine predominantly in papillary muscles. Carticaine and HE-36 are effective in left atria and papillary muscles to almost the same extent. Threshold of ac-asystolia is increased mainly in papillary muscles by quinidine and HE-36; carticaine produces a similar increase in left atria and papillary muscles. Verapamil even leads to a decrease in threshold predominantly in papillary muscles. It is concluded that model arrhythmias induced by alternating current are brought about mainly by an increase in Na+-conductance of cardiac cell membranes. The negative chronotropic potency in right atria occurs in the sequence verapamil greater than quinidine greater than carticane approximately HE-36. The negative inotropic potency in papillary muscle occurs in the same sequence but HE-36 increases force of contraction.

  11. Noninvasive low-frequency electromagnetic stimulation of the left stellate ganglion reduces myocardial infarction-induced ventricular arrhythmia

    Science.gov (United States)

    Wang, Songyun; Zhou, Xiaoya; Huang, Bing; Wang, Zhuo; Zhou, Liping; Wang, Menglong; Yu, Lilei; Jiang, Hong

    2016-01-01

    Noninvasive magnetic stimulation has been widely used in autonomic disorders in the past few decades, but few studies has been done in cardiac diseases. Recently, studies showed that low-frequency electromagnetic field (LF-EMF) might suppress atrial fibrillation by mediating the cardiac autonomic nervous system. In the present study, the effect of LF-EMF stimulation of left stellate ganglion (LSG) on LSG neural activity and ventricular arrhythmia has been studied in an acute myocardium infarction canine model. It is shown that LF-EMF stimulation leads to a reduction both in the neural activity of LSG and in the incidence of ventricular arrhythmia. The obtained results suggested that inhibition of the LSG neural activity might be the causal of the reduction of ventricular arrhythmia since previous studies have shown that LSG hyperactivity may facilitate the incidence of ventricular arrhythmia. LF-EMF stimulation might be a novel noninvasive substitute for the existing implant device-based electrical stimulation or sympathectomy in the treatment of cardiac disorders. PMID:27470078

  12. Part and Parcel of the Cardiac Autonomic Nerve System: Unravelling Its Cellular Building Blocks during Development

    OpenAIRE

    Végh, Anna M D; Duim, Sjoerd N; Smits, Anke M; Robert E Poelmann; Arend D. J. ten Harkel; DeRuiter, Marco C; Marie José Goumans; Monique R M Jongbloed

    2016-01-01

    The autonomic nervous system (cANS) is essential for proper heart function, and complications such as heart failure, arrhythmias and even sudden cardiac death are associated with an altered cANS function. A changed innervation state may underlie (part of) the atrial and ventricular arrhythmias observed after myocardial infarction. In other cardiac diseases, such as congenital heart disease, autonomic dysfunction may be related to disease outcome. This is also the case after heart transplantat...

  13. The Cause and Mechanism of Cardiac Electrical Instability. Defibrillation Mechanism

    Directory of Open Access Journals (Sweden)

    Rustam G. Habchabov

    2012-06-01

    Full Text Available The reason for the ominous arrhythmias pathway, causing sudden somatic death from cardiovascular diseases is still not clear, cardiological examinations of this phenomenon are conducted throughout the world. Laceration of connective insulating tissue membrane of heart pathway with ectopic nodes oxidation may cause ominous arrhythmias; nobody has considered this cause as a cardiac electrical instability before. Defibrillator electric discharges cannot penetrate into myocardium due to the connective insulating tissue membrane, nobody has considered nervous system, transmitting electricity.

  14. Changes underlying arrhythmia in the transgenic heart overexpressing Refsum disease gene-associated protein.

    Science.gov (United States)

    Koh, Jeong Tae; Jeong, Byung Chul; Kim, Jae Ha; Ahn, Young Keun; Lee, Hyang Sim; Baik, Yung Hong; Kim, Kyung Keun

    2004-01-01

    Previously, we identified a novel neuron-specific protein (PAHX-AP1) that binds to Refsum disease gene product (PAHX), and we developed transgenic (TG) mice that overexpress heart-targeted PAHX-AP1. These mice have atrial tachycardia and increased susceptibility to aconitine-induced arrhythmia. This study was undertaken to elucidate the possible changes in ion channels underlying the susceptibility to arrhythmia in these mice. RT-PCR analyses revealed that the cardiac expression of adrenergic beta(1)-receptor (ADRB1) was markedly lower, whereas voltage-gated potassium channel expression (Kv2.1) was higher in PAHX-AP1 TG mice compared with non-TG mice. However, the expression of voltage-sensitive sodium and calcium channels, and muscarinic receptor was not significantly different. Propranolol pretreatment, a non-specific beta-adrenoceptor antagonist, blocked aconitine-induced arrhythmia in non-TG mice, but not in PAHX-AP1 TG mice. Our results indicate that, in the PAHX-AP1 TG heart, the modulation of voltage-gated potassium channel and ADRB1 expression seem to be important in the electrophysiological changes associated with altered ion channel functions, but ADRB1 is not involved in the greater susceptibility to aconitine-induced arrhythmia.

  15. Disordered myocardial Ca(2+) homeostasis results in substructural alterations that may promote occurrence of malignant arrhythmias.

    Science.gov (United States)

    Tribulova, N; Knezl, V; Szeiffova Bacova, B; Egan Benova, T; Viczenczova, C; Gonçalvesova, E; Slezak, J

    2016-09-19

    We aimed to determine the impact of Ca(2+)-related disorders induced in intact animal hearts on ultrastructure of the cardiomyocytes prior to occurrence of severe arrhythmias. Three types of acute experiments were performed that are known to be accompanied by disturbances in Ca(2+) handling. Langedorff-perfused rat or guinea pig hearts subjected to K(+)-deficient perfusion to induce ventricular fibrillation (VF), burst atrial pacing to induce atrial fibrillation (AF) and open chest pig heart exposed to intramyocardial noradrenaline infusion to induce ventricular tachycardia (VT). Tissue samples for electron microscopic examination were taken during basal condition, prior and during occurrence of malignant arrhythmias. Cardiomyocyte alterations preceding occurrence of arrhythmias consisted of non-uniform sarcomere shortening, disruption of myofilaments and injury of mitochondria that most likely reflected cytosolic Ca(2+) disturbances and Ca(2+) overload. These disorders were linked with non-uniform pattern of neighboring cardiomyocytes and dissociation of adhesive junctions suggesting defects in cardiac cell-to-cell coupling. Our findings identified heterogeneously distributed high [Ca(2+)](i)-induced subcellular injury of the cardiomyocytes and their junctions as a common feature prior occurrence of VT, VF or AF. In conclusion, there is a link between Ca(2+)-related disorders in contractility and coupling of the cardiomyocytes pointing out a novel paradigm implicated in development of severe arrhythmias. PMID:27643936

  16. 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

    2015-01-01

    Background 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. Methods and Results 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. Conclusions 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. PMID:26015324

  17. Elevated Platelet Activating Factor Level in Ischemia-Related Arrhythmia and Its Electrophysiological Effect on Myocardium

    Institute of Scientific and Technical Information of China (English)

    TAO Yong Kang; ZHAO Shui Ping; YU Pu Lin; SHI Jing; GU Cheng Dong; SUN Hong Tao; ZHANG Guo Qiang

    2013-01-01

    Objective The mechanism through which platelet activating factor (PAF) induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction (AMI) and the underlying mechanism. Methods (1) Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram (ECG) was recorded continuously. (2) Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. (3) PAF perfusion and standard microelectrode recording were performed on guinea pig papillary muscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization (APD90)under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.

  18. ECG-Edit function in multidetector-row computed tomography coronary arteriography for patients with arrhythmias

    International Nuclear Information System (INIS)

    Electrocardiogram (ECG)-gating is necessary for cardiac computed tomography, but is not suitable for arrhythmias, so the aim of this study was to evaluate the usefulness of the ECG-edit function for this purpose. Of 1,221 patients undergoing 64-row multidetector-row computed tomography coronary angiography (coronary MDCT), 123 patients (28 atrial fibrillation (Af), 39 premature atrial contractions (PAC), 42 premature ventricular contractions (PVC), 3 PAC+PVC, 10 sinus arrhythmias (SA), and a second-degree atrioventricular block (2deg AVB)) had arrhythmias necessitating the ECG-edit function. Short R-R interval was deleted and mid-diastolic phases were selected from the long R-R intervals using the ''R+absolute time'' method. In the present study, the reconstructed images were evaluated using a triple-grade scale A-C, representing excellent, acceptable, and unacceptable image quality. Image quality, categorized as A, B and C, respectively, was 50%, 36% and 14% for the 28 patients with Af; 56%, 36% and 8% for the 39 PAC patients, and 65%, 33% and 2% in the 42 PVC patients. None of the scans of the PAC+PVC, SA, and 2deg AVB patients was ranked as C. The ECG-edit function is useful for reconstructing coronary MDCT images in many arrhythmias, and provides clinically acceptable images in most cases. (author)

  19. Evaluation of Known or Suspected Cardiac Sarcoidosis.

    Science.gov (United States)

    Blankstein, Ron; Waller, Alfonso H

    2016-03-01

    Sarcoidosis is a multisystem disorder of unknown cause, and cardiac sarcoidosis affects at least 25% of patients and accounts for substantial mortality and morbidity from this disease. Cardiac sarcoidosis may present with heart failure, left ventricular systolic dysfunction, AV block, atrial or ventricular arrhythmias, and sudden cardiac death. Cardiac involvement can be challenging to detect and diagnose because of the focal nature of the disease, as well as the fact that clinical criteria have limited diagnostic accuracy. Nevertheless, the diagnosis of cardiac sarcoidosis can be enhanced by integrating both clinical and imaging findings. This article reviews the various roles that different imaging modalities provide in the evaluation and management of patients with known or suspected cardiac sarcoidosis. PMID:26926267

  20. [On evaluating occupational fitness in railway workers with ventricular arrhythmias after coronary arteries stenting].

    Science.gov (United States)

    Muraseyeva, E V; Gorokhova, S G; Prigorovskaya, T S; Pfaf, V F

    2016-01-01

    The authors studied prospects of work capacity preserving after coronary stenting in IHD and cardiac arrhythmias. Examination covered 158 railway workers underwent complete endovascular revascularization of myocardium for coronary stenosis; all of them had ventricular arrhythmias before coronary surgery. Findings are that in long-term period (in 16 months in average) after coronary stenting, grade I and III ventricular extrasystoles disappeared in 77.8 and 54.5% of cases respectively, but only in 11.9% of grade IV ventricular extrasystoles cases. Ventricular extrasystoles remained unchanged in 44.3% of cases. Reliable relationships were seen between unchanged grade IV ventricular extrasystoles and body weight index (OR = 5.49, 95% CI: 0.87-34.67), general cholesterol level (OR = 1.69; 95% CI: 1.06-2.69), low density lipoproteins (OR = 1.66; 95% CI: 1.00-2.76) and left ventricular ejection function lower 45% (OR = 1.61; 95% CI: 1.14-2.27), exertion ventricular extrasystoles before myocardium revascularization (OR = 3.1; 95% CI: 1.78-5.41). That necessitates correction of the mentioned risk factors of cardiac arrhythmias for restored work capacity.

  1. Exercise-induced protection against reperfusion arrhythmia involves stabilization of mitochondrial energetics.

    Science.gov (United States)

    Alleman, Rick J; Tsang, Alvin M; Ryan, Terence E; Patteson, Daniel J; McClung, Joseph M; Spangenburg, Espen E; Shaikh, Saame Raza; Neufer, P Darrell; Brown, David A

    2016-05-15

    Mitochondria influence cardiac electrophysiology through energy- and redox-sensitive ion channels in the sarcolemma, with the collapse of energetics believed to be centrally involved in arrhythmogenesis. This study was conducted to determine if preservation of mitochondrial membrane potential (ΔΨm) contributes to the antiarrhythmic effect of exercise. We utilized perfused hearts, isolated myocytes, and isolated mitochondria exposed to metabolic challenge to determine the effects of exercise on cardiac mitochondria. Hearts from sedentary (Sed) and exercised (Ex; 10 days of treadmill running) Sprague-Dawley rats were perfused on a two-photon microscope stage for simultaneous measurement of ΔΨm and ECG. After ischemia-reperfusion, the collapse of ΔΨm was commensurate with the onset of arrhythmia. Exercise preserved ΔΨm and decreased the incidence of fibrillation/tachycardia (P hypoxia-reoxygenation, with Ex rats demonstrating enhanced redox control and sustained ΔΨm during reoxygenation. Finally, we induced anoxia-reoxygenation in isolated mitochondria using high-resolution respirometry with simultaneous measurement of respiration and H2O2 Mitochondria from Ex rats sustained respiration with lower rates of H2O2 emission than Sed rats. Exercise helps sustain postischemic mitochondrial bioenergetics and redox homeostasis, which is associated with preserved ΔΨm and protection against reperfusion arrhythmia. The reduction of fatal ventricular arrhythmias through exercise-induced mitochondrial adaptations indicates that mitochondrial therapeutics may be an effective target for the treatment of heart disease. PMID:26945082

  2. 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.

  3. Outcomes among athletes with arrhythmias and electrocardiographic abnormalities: implications for ECG interpretation.

    Science.gov (United States)

    McClaskey, David; Lee, Daniel; Buch, Eric

    2013-10-01

    Electrocardiographic (ECG) aberrations and arrhythmias occur frequently among athletes due to normal variants, subclinical cardiac disease or structural and electrical remodeling in response to training. It is unclear whether these changes are associated with adverse clinical outcomes over time among otherwise asymptomatic, healthy athletes. Consensus guidelines have been developed to guide the clinician regarding further management of these arrhythmias. The purpose of this review is to summarize prospective data regarding cardiovascular outcomes related to ECG changes among athletes and compare these findings with current guidelines. A review of the literature was conducted using the PubMed database (1966--present). Outcomes of interest included documented cardiac symptoms or events, such as episodes of cardiac or cerebral hypoperfusion, sudden death or prophylactic procedural interventions. Studies were included for analysis if they involved (1) athletes with documented, baseline arrhythmias and/or abnormal ECG variations; (2) a study design with longitudinal follow-up (designated as >1 month, to exclude short-term Holter studies); and (3) outcomes that include documented cardiac symptoms or events. A total of 33 studies met the above criteria, encompassing over 4,200 athletes, with follow-up ranging from 2 months to 14.6 years. There were few adverse outcomes among cases of sinus bradycardia >30 bpm, sinus pauses sports eligibility. Findings in this review are limited by a lack of control groups, limited assessment of confounding factors (such as performance-enhancing drugs), and under-representation of women and certain ethnicities. Further prospective studies are needed to better characterize the long-term outcome of ECG abnormalities among athletes and provide evidence for ECG interpretation guidelines. PMID:23852445

  4. [Sudden cardiac death in individuals with normal hearts: an update].

    Science.gov (United States)

    González-Melchor, Laila; Villarreal-Molina, Teresa; Iturralde-Torres, Pedro; Medeiros-Domingo, Argelia

    2014-01-01

    Sudden death (SD) is a tragic event and a world-wide health problem. Every year, near 4-5 million people experience SD. SD is defined as the death occurred in 1h after the onset of symptoms in a person without previous signs of fatality. It can be named "recovered SD" when the case received medical attention, cardiac reanimation effective defibrillation or both, surviving the fatal arrhythmia. Cardiac channelopathies are a group of diseases characterized by abnormal ion channel function due to genetic mutations in ion channel genes, providing increased susceptibility to develop cardiac arrhythmias and SD. Usually the death occurs before 40 years of age and in the autopsy the heart is normal. In this review we discuss the main cardiac channelopathies involved in sudden cardiac death along with current management of cases and family members that have experienced such tragic event.

  5. A Rabbit Ventricular Action Potential Model Replicating Cardiac Dynamics at Rapid Heart Rates

    OpenAIRE

    Mahajan, Aman; Shiferaw, Yohannes; Sato, Daisuke; Baher, Ali; Olcese, Riccardo; Xie, Lai-Hua; Yang, Ming-Jim; Chen, Peng-Sheng; Restrepo, Juan G.; Karma, Alain; Garfinkel, Alan; Qu, Zhilin; Weiss, James N.

    2008-01-01

    Mathematical modeling of the cardiac action potential has proven to be a powerful tool for illuminating various aspects of cardiac function, including cardiac arrhythmias. However, no currently available detailed action potential model accurately reproduces the dynamics of the cardiac action potential and intracellular calcium (Cai) cycling at rapid heart rates relevant to ventricular tachycardia and fibrillation. The aim of this study was to develop such a model. Using an existing rabbit ven...

  6. Successful use of levosimendan as a primary inotrope in pediatric cardiac surgery: An observational study in 110 patients

    Directory of Open Access Journals (Sweden)

    Reena Khantwal Joshi

    2016-01-01

    Conclusions: Levosimendan-based inotropic regime offers optimized cardiac output with a well-controlled heart rate and a low incidence of arrhythmias in patients undergoing all categories of congenital heart surgeries.

  7. Observation of blood B-type natriuretic peptide level changes in different periods and different cardiac pacing modes

    Institute of Scientific and Technical Information of China (English)

    WANG Ru-xing; LI Xiao-rong; JIANG Wen-ping; LIU Zhi-hua; YANG Xiang-jun; XIAO Chun-hui; SHAO Li-zheng; ZHU Jian-qiu

    2005-01-01

    @@ In recent years, the indications of cardiac pacing have extended continuously with the rapid development of pacing technique. Pacemaker treatment has not only limited in arrhythmias of bradycardia and the number of pacemaker treatment has increased year by year.

  8. The cardiomyocyte molecular clock, regulation of Scn5a, and arrhythmia susceptibility.

    Science.gov (United States)

    Schroder, Elizabeth A; Lefta, Mellani; Zhang, Xiping; Bartos, Daniel C; Feng, Han-Zhong; Zhao, Yihua; Patwardhan, Abhijit; Jin, Jian-Ping; Esser, Karyn A; Delisle, Brian P

    2013-05-15

    The molecular clock mechanism underlies circadian rhythms and is defined by a transcription-translation feedback loop. Bmal1 encodes a core molecular clock transcription factor. Germline Bmal1 knockout mice show a loss of circadian variation in heart rate and blood pressure, and they develop dilated cardiomyopathy. We tested the role of the molecular clock in adult cardiomyocytes by generating mice that allow for the inducible cardiomyocyte-specific deletion of Bmal1 (iCSΔBmal1). ECG telemetry showed that cardiomyocyte-specific deletion of Bmal1 (iCSΔBmal1(-/-)) in adult mice slowed heart rate, prolonged RR and QRS intervals, and increased episodes of arrhythmia. Moreover, isolated iCSΔBmal1(-/-) hearts were more susceptible to arrhythmia during electromechanical stimulation. Examination of candidate cardiac ion channel genes showed that Scn5a, which encodes the principle cardiac voltage-gated Na(+) channel (Na(V)1.5), was circadianly expressed in control mouse and rat hearts but not in iCSΔBmal1(-/-) hearts. In vitro studies confirmed circadian expression of a human Scn5a promoter-luciferase reporter construct and determined that overexpression of clock factors transactivated the Scn5a promoter. Loss of Scn5a circadian expression in iCSΔBmal1(-/-) hearts was associated with decreased levels of Na(V)1.5 and Na(+) current in ventricular myocytes. We conclude that disruption of the molecular clock in the adult heart slows heart rate, increases arrhythmias, and decreases the functional expression of Scn5a. These findings suggest a potential link between environmental factors that alter the cardiomyocyte molecular clock and factors that influence arrhythmia susceptibility in humans.

  9. Epicardial radiofrequency ablation for left ventricular aneurysm related ventricular arrhythmias during off-pump coronary artery bypass surgery

    Institute of Scientific and Technical Information of China (English)

    YU Yang; GAO Ming-xin; LI Hai-tao; ZHANG Fan; GU Cheng-xiong

    2012-01-01

    Background Left ventricular aneurysm (LVA) is one of the serious complications after acute myocardial infarction.We attempted to evaluate the preliminary efficacy of LVA repair combined with epicardial radiofrequency ablation for ventricular arrhythmia during off-pump coronary artery bypass grafting (OPCAB).Methods From June 2009 to April 2011,31 patients with LVA had angina symptoms and ventricular arrhythmia.In all patients,circular and cross-shaped radiofrequency epicardial ablations were performed using unipolar ablation pen along the border between the aneurysm wall and normal cardiac tissue and in the central zone of the aneurysms,followed by a linear placation of ventricular aneurysms on beating heart.Results All the patients showed complete recovery.The average number of grafted vessels was 2.7±1.3.Intraoperative examinations revealed that the ventricular arrhythmia was effectively controlled by radiofrequency ablation.All cases had been followed up for one year.Holter monitoring revealed a significant reduction in ventricular arrhythmias (P <0.05).Echocardiography showed significant increase in left ventricular ejection fraction (P <0.05) and decrease in left ventricular end-diastolic diameter (P <0.05).Conclusions For patients with ventricular aneurysm and preoperative malignant arrhythmia,aneurysm repair plus epicardial radiofrequency ablation in OPCAB was found to be an effective and feasible therapeutic technique.However,medium-to long-term therapeutic efficacy of this method remains to be determined by future studies and observations.

  10. Effect of Fish Oil on Ventricular Tachyarrhythmia and Death in Patients With Implantable Cardioverter Defibrillators: The Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) Randomized Trial

    NARCIS (Netherlands)

    Brouwer, I.A.; Zock, P.L.; Camm, A.J.; Bocker, D.; Hauer, R.N.W.; Wever, E.F.D.; Dullemeijer, C.; Ronden, J.E.; Katan, M.B.; Lubinski, A.; Buschler, H.; Schouten, E.G.

    2006-01-01

    Context Very-long-chain n-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish are thought to reduce risk of sudden death, possibly by reducing susceptibility to cardiac arrhythmia. Objective To study the effect of supplemental fish oil vs placebo on ventricular tachyarrhythmia or death. Design,

  11. 心腔内超声指导下消融左心室前组乳头肌起源的室性心律失常%Radiofrequency catheter ablation of ventricular arrhythmias originating from left ventricular anterior papillary muscle guided by intra-cardiac echocardiography

    Institute of Scientific and Technical Information of China (English)

    余金波; 杨兵; 张凤祥; 居维竹; 杨刚; 陈红武; 顾凯; 郦明芳; 陈明龙

    2015-01-01

    目的报道单中心应用心腔内超声( ICE)指导射频导管消融治疗特发性左心室前组乳头肌起源室性心律失常的标测与消融的结果。方法2012年2月至2013年8月在南京医科大学第一附属医院心血管内科行ICE指导下射频导管消融治疗左心室前组乳头肌起源室性心律失常患者6例。其中室性心动过速(室速)合并室性早搏(室早)者3例、频发室早者3例,男4例,女2例,年龄14~52(35.1±15.2)岁,均无器质性心脏病证据,3例患者既往有1~4次消融失败史。结果6例患者室速及室早均即刻消融成功,靶点处双极电图较体表QRS波起始提前20~30(24.8±4.1)ms,分别位于乳头肌尖端2例、中段2例及基底部各2例,其中3例患者在室速或室早时靶点处可记录到提前的高频电位。4例患者经动脉逆行途径消融成功,2例经动脉逆行途径失败后,经穿刺房间隔顺行法消融成功。平均随访(18.9±7.3)个月后,1例患者复发。所有患者均未出现并发症。结论应用ICE指导可提高左心室前组乳头肌起源室性心律失常消融成功率,部分患者需采用穿刺房间隔途径顺行法消融。%Objective To investigate the feasibility and efficacy of mapping and radiofrequency cathe-ter ablation( RFCA) of ventricular arrhythmias( VA) originating from the left ventricular anterior papillary mus-cle(LV-APM)guided by intra-cardiac echocardiography(ICE). Methods Six consecutive patients(4 men, aged from 14 to 52 years) without structural heart disease underwent catheter ablation of VA originating from the LV-APM guided by ICE. Results Three patients had premature ventricular contractions ( PVC ) , two patients had nonsustained ventricular tachycardia(VT)and PVC,the remain patient had sustained VT and PVC. Three patients had one to four times previous failed ablation guided by electroanatomic mapping system. All VA were successfully eliminated by catheter ablation. The earliest site of

  12. Genetically engineered SCN5A mutant pig hearts exhibit conduction defects and arrhythmias.

    Science.gov (United States)

    Park, David S; Cerrone, Marina; Morley, Gregory; Vasquez, Carolina; Fowler, Steven; Liu, Nian; Bernstein, Scott A; Liu, Fang-Yu; Zhang, Jie; Rogers, Christopher S; Priori, Silvia G; Chinitz, Larry A; Fishman, Glenn I

    2015-01-01

    SCN5A encodes the α subunit of the major cardiac sodium channel Na(V)1.5. Mutations in SCN5A are associated with conduction disease and ventricular fibrillation (VF); however, the mechanisms that link loss of sodium channel function to arrhythmic instability remain unresolved. Here, we generated a large-animal model of a human cardiac sodium channelopathy in pigs, which have cardiac structure and function similar to humans, to better define the arrhythmic substrate. We introduced a nonsense mutation originally identified in a child with Brugada syndrome into the orthologous position (E558X) in the pig SCN5A gene. SCN5A(E558X/+) pigs exhibited conduction abnormalities in the absence of cardiac structural defects. Sudden cardiac death was not observed in young pigs; however, Langendorff-perfused SCN5A(E558X/+) hearts had an increased propensity for pacing-induced or spontaneous VF initiated by short-coupled ventricular premature beats. Optical mapping during VF showed that activity often began as an organized focal source or broad wavefront on the right ventricular (RV) free wall. Together, the results from this study demonstrate that the SCN5A(E558X/+) pig model accurately phenocopies many aspects of human cardiac sodium channelopathy, including conduction slowing and increased susceptibility to ventricular arrhythmias.

  13. Cardiac MRI and CT features of inheritable and congenital conditions associated with sudden cardiac death

    Energy Technology Data Exchange (ETDEWEB)

    Sparrow, Patrick; Merchant, Naeem; Provost, Yves; Doyle, Deirdre; Nguyen, Elsie; Paul, Narinder [University Health Network and Mount Sinai Hospital, Division of Cardiothoracic Imaging, Department of Medical Imaging, Toronto, Ontario (Canada)

    2009-02-15

    Cardiac MRI (CMR) and electrocardiogram (ECG)-gated multi-detector computed tomography (MDCT) are increasingly important tools in the identification and assessment of cardiac-related disease processes, including those associated with sudden cardiac death (SCD). While the commonest cause of SCD is coronary artery disease (CAD), in patients under 35 years inheritable cardiomyopathies such as hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy are important aetiologies. CMR in particular offers both accurate delineation of the morphological abnormalities associated with these and other conditions and the possibility for risk stratification for development of ventricular arrhythmias with demonstration of macroscopic scar by delayed enhancement imaging with intravenous gadolinium. (orig.)

  14. Increased Short-Term Variability of the QT Interval in Professional Soccer Players: Possible Implications for Arrhythmia Prediction

    OpenAIRE

    Lengyel, Csaba; Orosz, Andrea; Hegyi, Péter; Komka, Zsolt; Udvardy, Anna; Bosnyák, Edit; Trájer, Emese; Pavlik, Gábor; Tóth, Miklós; Wittmann, Tibor; Papp, Julius Gy; Varró, András; Baczkó, István

    2011-01-01

    Background Sudden cardiac death in competitive athletes is rare but it is significantly more frequent than in the normal population. The exact cause is seldom established and is mostly attributed to ventricular fibrillation. Myocardial hypertrophy and slow heart rate, both characteristic changes in top athletes in response to physical conditioning, could be associated with increased propensity for ventricular arrhythmias. We investigated conventional ECG parameters and temporal short-term bea...

  15. Effects of Org 7797 on early, late and inducible arrhythmias following coronary artery occlusion in rats and dogs.

    OpenAIRE

    Winslow, E.; Campbell, J K; Barron, E; Marshall, R J; Muir, A. W

    1991-01-01

    1. The class Ic steroidal antiarrhythmic agent, Org 7797, was compared with two other Ic agents, flecainide and propafenone for intravenous activity against ischaemia-related cardiac arrhythmias and for electrophysiological actions in vivo. In addition the haemodynamic effects of Org 7797 were assessed in greyhounds. 2. Org 7797 (0.5 mg kg-1) significantly reduced the expected incidence of early ischaemia-induced ventricular fibrillation (VF) in rats and greyhound dogs and at doses of 0.5-1.0...

  16. Life-threatening ventricular arrhythmia due to silent coronary artery spasm: usefulness of I-123 metaiodobenzylguanidine scintigraphy for detecting coronary artery spasm in the era of automated external defibrillators: a case report

    OpenAIRE

    Kaku, Bunji; Katsuda, Shoji; Taguchi, Tomio

    2015-01-01

    Introduction Cardiac arrhythmia is sometimes life-threatening, and automated external defibrillators are presently used in some countries. Coronary artery spasm is one of the primary causes of life-threatening arrhythmia. In general, chest symptoms are key indicators of possible coronary artery spasm; however, if chest symptoms are not present, clinicians may not suspect this disease. We encountered a patient who had recovered from ventricular fibrillation treated by using an automated extern...

  17. Robotic magnetic navigation for ablation of human arrhythmias

    Science.gov (United States)

    Da Costa, Antoine; Guichard, Jean Baptiste; Roméyer-Bouchard, Cécile; Gerbay, Antoine; Isaaz, Karl

    2016-01-01

    Radiofrequency treatment represents the first choice of treatment for arrhythmias, in particular complex arrhythmias and especially atrial fibrillation, due to the greater benefit/risk ratio compared to antiarrhythmic drugs. However, complex arrhythmias such as atrial fibrillation require long procedures with additional risks such as X-ray exposure or serious complications such as tamponade. Given this context, the treatment of arrhythmias using robotic magnetic navigation entails a technique well suited to complex arrhythmias on account of its efficacy, reliability, significant reduction in X-ray exposure for both patient and operator, as well as a very low risk of perforation. As ongoing developments will likely improve results and procedure times, this technology will become one of the most modern technologies for treating arrhythmias. Based on the literature, this review summarizes the advantages and limitations of robotic magnetic navigation for ablation of human arrhythmias. PMID:27698569

  18. 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

  19. Effectiveness of morphological and spectral heartbeat characterization on arrhythmia clustering for Holter recordings

    Science.gov (United States)

    Castro-Hoyos, Cristian; Peluffo-Ordóñez, Diego Hernán.; Rodríguez-Sotelo, Jose Luis; Castellanos-Domínguez, Germán.

    2015-01-01

    Heartbeat characterization is an important issue in cardiac assistance diagnosis systems. In particular, wide sets of features are commonly used in long term electrocardiographic signals. Then, if such a feature space does not represent properly the arrhythmias to be grouped, classification or clustering process may fail. In this work a suitable feature set for different heartbeat types is studied, involving morphology, representation and time-frequency features. To determine what kind of features generate better clusters, feature selection procedure is used and assessed by means clustering validity measures. Then the feature subset is shown to produce fine clustering that yields into high sensitivity and specificity values for a broad range of heartbeat types.

  20. Role of Genetic Testing in Patients with Ventricular Arrhythmias in Apparently Normal Hearts.

    Science.gov (United States)

    Hofman, Nynke; Wilde, Arthur A M

    2016-09-01

    Ventricular arrhythmias without structural heart disease are responsible for ∼35% of patients who have sudden cardiac death before the age of 40 years. Molecular autopsy and/or cardiological investigation of nearby family members often reveals the diagnosis and genetic testing can be helpful in family screening and risk stratification in disease carriers. Extended gene panels can be screened in a short period of time at low cost. A multidisciplinary team of (genetically) specialized clinicians is necessary to judge all the available details and to decide on the significance of the variant and further strategies. PMID:27521086

  1. Cardiac involvement in myotonic dystrophy

    DEFF Research Database (Denmark)

    Lund, Marie; Diaz, Lars Jorge; Ranthe, Mattis Flyvholm;

    2014-01-01

    genetic testing for DM1. Information on incident cardiac diseases was obtained from the NPR. We estimated standardized incidence ratios (SIRs) of cardiac disease compared with the background population, overall and according to selected diagnostic subgroups (cardiomyopathy, heart failure, conduction...... disorders, arrhythmias, and device implantation). In the DM cohort, SIR for any cardiac disease was 3.42 [95% confidence interval (CI) 3.01-3.86]; for a cardiac disease belonging to the selected subgroups 6.91 (95% CI: 5.93-8.01) and for other cardiac disease 2.59 (95% CI: 2.03-3.25). For a cardiac disease...... belonging to the selected subgroups, the risk was particularly high in the first year after DM diagnosis [SIR 15.4 (95% CI: 10.9-21.3)] but remained significantly elevated in subsequent years [SIR 6.07 (95% CI: 5.11-7.16]). The risk was higher in young cohort members [e.g. 20-39 years: SIR 18.1 (95% CI: 12...

  2. Cardiac repolarization during hypoglycaemia and hypoxaemia in healthy males: Impact of renin-angiotensin system activity

    NARCIS (Netherlands)

    R. Due-Andersen (Rikke); T. Høi-Hansen (Thomas); N.V. Olsen; C.E. Larroude; J.K. Kanters; F. Boomsma (Frans); U. Pedersen-Bjergaard (Ullrik); B. Thorsteinsson (Birger)

    2008-01-01

    textabstractAims: Activity in the renin-angiotensin system (RAS) may influence the susceptibility to cardiac arrhythmia. To study the effect of basal RAS activity on cardiac repolarization during myocardial stress induced by hypoglycaemia or hypoxaemia in healthy humans. Methods and results: Ten sub

  3. Cardiac repolarization during hypoglycaemia and hypoxaemia in healthy males: impact of renin-angiotensin system activity

    DEFF Research Database (Denmark)

    Due-Andersen, Rikke; Høi-Hansen, Thomas; Olsen, Niels Vidiendal;

    2008-01-01

    AIMS: Activity in the renin-angiotensin system (RAS) may influence the susceptibility to cardiac arrhythmia. To study the effect of basal RAS activity on cardiac repolarization during myocardial stress induced by hypoglycaemia or hypoxaemia in healthy humans. METHODS AND RESULTS: Ten subjects...

  4. 不同力竭运动后大鼠心脏传导系统PPARα mRNA和蛋白表达的变化及其在运动性心律失常发生中的作用%The mRNA and Protein Expression of PPARα in Cardiac Conduction System after Different Exhaustive Exercise and Their Role in Exercise Induced Arrhythmia

    Institute of Scientific and Technical Information of China (English)

    常芸; 杨红霞; 彭泽胄

    2012-01-01

    目的:探讨大鼠力竭运动后不同时相心脏窦房结、房室结和浦肯野氏纤维代谢因子过氧化体增殖物激活型受体α(PPARα)基因和蛋白水平的表达特点,为阐明运动性心律失常发生机制提供实验依据.方法:100只健康成年雄性SD大鼠随机分为一次力竭组(4组)、2周反复力竭组(4组)及其相应的安静对照组(2组),每组10只.分别于力竭运动后即刻、4、12及24小时,应用激光显微切割技术定位并收集窦房结、房室结和浦肯野氏纤维细胞,采用实时荧光定量PCR和免疫荧光方法检测PPARα mRNA和蛋白表达.结果:一次和反复力竭运动后,心脏传导系统各部位PPARα mRNA 和蛋白表达均在运动后4小时下降至低谷,反复力竭后12小时,房室结PPARα mRNA和蛋白表达显著低于一次力竭后12小时(P<0.01);反复力竭后24小时浦肯野氏纤维PPARα mRNA表达显著低于一次力竭后24小时(P<0.01),其他各时相组间无明显差异(P>0.05).结论:力竭运动后心脏传导系统各部位代谢调节因子PPARα在mRNA和蛋白水平异常低表达,且有时相性规律,易诱发传导系统能量代谢障碍,构成运动性心律失常的病理过程.%Objective This paper discusses the mRNA and protein expression of PPARa on cardiac sinus node (SAN),atrioventricular (AVN) node and Purkinje's fibers at different time phrase after exhaustive exercise, and tries to provide experimental evidence for clarifying the mechanism of exercise -induced arrhythmia. Methods 100 healthy adult male SD rats were grouped into the one-time exhaustive swimming group (n = 40),the 2-week repeated exhaustive swimming group (n = 40),and the control group(n = 20). The exercise rats were sacrificed at 0,4,12,and 24 hours after exhaustive swimming and the control rats were sacrificed at the same time as 0 hour after exhaustive swimming group. The cells of SAN,AVN and Purkinje's fiber were spotted and collected in the approach of

  5. Physics of Cardiac Arrhythmogenesis

    Science.gov (United States)

    Karma, Alain

    2013-04-01

    A normal heartbeat is orchestrated by the stable propagation of an excitation wave that produces an orderly contraction. In contrast, wave turbulence in the ventricles, clinically known as ventricular fibrillation (VF), stops the heart from pumping and is lethal without prompt defibrillation. I review experimental, computational, and theoretical studies that have shed light on complex dynamical phenomena linked to the initiation, maintenance, and control of wave turbulence. I first discuss advances made to understand the precursor state to a reentrant arrhythmia where the refractory period of cardiac tissue becomes spatiotemporally disordered; this is known as an arrhythmogenic tissue substrate. I describe observed patterns of transmembrane voltage and intracellular calcium signaling that can contribute to this substrate, and symmetry breaking instabilities to explain their formation. I then survey mechanisms of wave turbulence and discuss novel methods that exploit electrical pacing stimuli to control precursor patterns and low-energy pulsed electric fields to control turbulence.

  6. Arrhythmia discrimination using a smart phone.

    Science.gov (United States)

    Chong, Jo Woon; Esa, Nada; McManus, David D; Chon, Ki H

    2015-05-01

    We hypothesize that our smartphone-based arrhythmia discrimination algorithm with data acquisition approach reliably differentiates between normal sinus rhythm (NSR), atrial fibrillation (AF), premature ventricular contractions (PVCs) and premature atrial contraction (PACs) in a diverse group of patients having these common arrhythmias. We combine root mean square of successive RR differences and Shannon entropy with Poincare plot (or turning point ratio method) and pulse rise and fall times to increase the sensitivity of AF discrimination and add new capabilities of PVC and PAC identification. To investigate the capability of the smartphone-based algorithm for arrhythmia discrimination, 99 subjects, including 88 study participants with AF at baseline and in NSR after electrical cardioversion, as well as seven participants with PACs and four with PVCs were recruited. Using a smartphone, we collected 2-min pulsatile time series from each recruited subject. This clinical application results show that the proposed method detects NSR with specificity of 0.9886, and discriminates PVCs and PACs from AF with sensitivities of 0.9684 and 0.9783, respectively. PMID:25838530

  7. Cardiac involvement in children with neuro-muscular disorders

    OpenAIRE

    E. N. Arkhipova

    2015-01-01

    Many inherited neuromuscular disorders include cardiac involvement as a typical clinical feature. Among the most common of them is the group of muscular dystrophies. Dilated cardiomyopathy, ventricular arrhythmias, atrial fibrillations, atrioventricular and intraventricular conduction abnormalities, and sudden cardiac death are well known pathological findings in Duchenne muscular dystrophies, myotonic dystrophy type I and 2, Emery-Dreifuss muscular dystrophies and different types of limb-gir...

  8. Cardiac involvement in Duchenne and Becker muscular dystrophy

    OpenAIRE

    Mavrogeni, Sophie; Markousis-Mavrogenis, George; Papavasiliou, Antigoni; Kolovou, Genovefa

    2015-01-01

    Duchenne and Becker muscular dystrophy (DMD/BMD) are X-linked muscular diseases responsible for over 80% of all muscular dystrophies. Cardiac disease is a common manifestation, not necessarily related to the degree of skeletal myopathy; it may be the predominant manifestation with or without any other evidence of muscular disease. Death is usually due to ventricular dysfunction, heart block or malignant arrhythmias. Not only DMD/BMD patients, but also female carriers may present cardiac invol...

  9. Genetic testing and genetic counseling in patients with sudden death risk due to heritable arrhythmias.

    Science.gov (United States)

    Spoonamore, Katherine G; Ware, Stephanie M

    2016-03-01

    Sudden cardiac death due to heritable ventricular arrhythmias is an important cause of mortality, especially in young healthy individuals. The identification of the genetic basis of Mendelian diseases associated with arrhythmia has allowed the integration of this information into the diagnosis and clinical management of patients and at-risk family members. The rapid expansion of genetic testing options and the increasing complexity involved in the interpretation of results creates unique opportunities and challenges. There is a need for competency to incorporate genetics into clinical management and to provide appropriate family-based risk assessment and information. In addition, disease-specific genetic knowledge is required to order and correctly interpret and apply genetic testing results. Importantly, genetic diagnosis has a critical role in the risk stratification and clinical management of family members. This review summarizes the approach to genetic counseling and genetic testing for inherited arrhythmias and highlights specific genetic principles that apply to long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia.

  10. Sudden chest pain and cardiac emergencies in the obstetric patient.

    Science.gov (United States)

    Mabie, W C; Freire, C M

    1995-03-01

    The differential diagnosis and work-up of a patient with chest pain during pregnancy is presented in this article. This is followed by discussions of cardiac emergencies including hypertensive crisis, pulmonary edema, arrhythmias, cardiopulmonary resuscitation, myocardial infarction, and aortic dissection. PMID:7784039

  11. Cardiac morbidity risk and depression and anxiety

    DEFF Research Database (Denmark)

    Tully, Phillip J; Pedersen, Susanne S.; Winefield, Helen R;

    2011-01-01

    Questionnaire and a measure of Type D personality traits. Postoperative cardiac morbidity was confirmed after surgery during the index hospitalization and included stroke,renal failure, ventilation>24 h, deep sternal wound infection, reoperation, arrhythmia and 30-day mortality at any location (n=59, 37.......3% of total). After adjustment for age, recent myocardial infarction, heart failure, hypertension, urgency of surgery and time spent on cardiopulmonary bypass generalized anxiety disorder was associated with cardiac morbidity (odds ratio [OR]=3.26, 95% confidence interval [CI] 1.10-9.67, p=0.03). Adjusted...

  12. Pharmacological modulation of gap junction function with the novel compound rotigaptide: a promising new principle for prevention of arrhythmias.

    Science.gov (United States)

    Kjølbye, Anne Louise; Haugan, Ketil; Hennan, James K; Petersen, Jørgen S

    2007-10-01

    Existing anti-arrhythmic therapy is hampered by lack of efficacy and unacceptable side effects. Thus, ventricular tachycardia and fibrillation remains the strongest predictor of in-hospital mortality in patients with myocardial infarction. In atrial fibrillation, rhythm control with conventional ion channel blockers provide no therapeutic benefit relative to rate control. Several lines of research indicate that impaired gap junctional cell-to-cell coupling between neighbouring cardiomyocytes is critical for the development of cardiac re-entry arrhythmias. Rotigaptide is the first drug that has been developed to prevent arrhythmias by re-establishing gap junctional intercellular communication. During conditions with acute cardiac ischaemia, rotigaptide effectively prevents induction of both ventricular and atrial tachyarrhythmia. Moreover, rotigaptide effectively prevents ischaemia reperfusion arrhythmias. At the cellular level, rotigaptide inhibits ischaemia-induced dephosphorylation of Ser297 and Ser368, which is considered important for the gating of connexin43 gap junction channels. No drug-related toxicity has been demonstrated at plasma concentrations 77,000 times above therapeutic concentrations. In rats and dogs, rotigaptide reduces infarct size following myocardial infarction. A series of phase I trials has been completed in which rotigaptide has been administered intravenously to ~200 healthy persons. No drug-related side effects have been demonstrated in healthy human beings. Clinical safety, tolerability and efficacy in patients with heart disease are being evaluated in ongoing clinical trials. Rotigaptide represents a pioneering pharmacological principle with a highly favourable preclinical and clinical safety profile, which makes this molecule a promising drug candidate for the prevention of cardiac arrhythmias.

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

    Directory of Open Access Journals (Sweden)

    Ali Aydin

    Full Text Available BACKGROUND: Marfan syndrome is associated with ventricular arrhythmia but risk factors including FBN1 mutation characteristics require elucidation. METHODS AND RESULTS: 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. CONCLUSIONS: 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.

  14. Cardiac sympathetic neuronal imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Lautamaeki, Riikka; Tipre, Dnyanesh [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Cardiovascular Nuclear Medicine, Baltimore, MD (United States)

    2007-06-15

    Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed. (orig.)

  15. Cardiac beat-to-beat alternations driven by unusual spiral waves

    OpenAIRE

    Kim, Tae Yun; Woo, Sung-Jae; Hwang, Seong-min; Hong, Jin Hee; Lee, Kyoung J.

    2007-01-01

    Alternans, a beat-to-beat temporal alternation in the sequence of heartbeats, is a known precursor of the development of cardiac fibrillation, leading to sudden cardiac death. The equally important precursor of cardiac arrhythmias is the rotating spiral wave of electro-mechanical activity, or reentry, on the heart tissue. Here, we show that these two seemingly different phenomena can have a remarkable relationship. In well controlled in vitro tissue cultures, isotropic populations of rat vent...

  16. Mesenchymal stem cells improve cardiac conduction by upregulation of connexin 43 through paracrine signaling

    OpenAIRE

    Mureli, Shwetha; Gans, Christopher P.; Bare, Dan J; Geenen, David L.; Kumar, Nalin M.; Banach, Kathrin

    2012-01-01

    Mesenchymal stem cells (MSCs) were shown to improve cell survival and alleviate cardiac arrhythmias when transplanted into cardiac tissue; however, little is known about the mechanism by which MSCs modify the electrophysiological properties of cardiac tissue. We aimed to distinguish the influence of cell-cell coupling between myocytes and MSCs from that of MSC-derived paracrine factors on the spontaneous activity and conduction velocity (θ) of multicellular cardiomyocyte preparations. HL-1 ce...

  17. Connexin43 Cardiac Gap Junction Remodeling: Lessons from Genetically Engineered Murine Models

    OpenAIRE

    Remo, Benjamin F.; Giovannone, Steven; Fishman, Glenn I.

    2012-01-01

    Sudden cardiac death is responsible for several hundred thousand deaths each year in the United States. Multiple lines of evidence suggest that perturbation of gap junction expression and function in the heart, or what has come to be known as cardiac gap junction remodeling, plays a key mechanistic role in the pathophysiology of clinically significant cardiac arrhythmias. Here we review recent studies from our laboratory using genetically engineered murine models to explore mechanisms implica...

  18. Towards Real-Time Computation of Cardiac Electrophysiology for Training Simulator

    OpenAIRE

    Talbot, Hugo; Duriez, Christian; Courtecuisse, Hadrien; Relan, Jatin; Sermesant, Maxime; Cotin, Stéphane; Delingette, Hervé

    2012-01-01

    This work aims at developing a training simulator for interventional radiology and thermo-ablation of cardiac arrhythmias. To achieve this, a real-time model of the cardiac electrophysiology is needed, which is very challenging due to the stiff equations involved. In this paper, we detail our contributions in order to obtain efficient cardiac electrophysiology simulations. First, an adaptive parametrisation of the Mitchell-Schaeffer model as well as numerical optimizations are proposed. An ac...

  19. Cardiac arrest

    Science.gov (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  20. Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

    DEFF Research Database (Denmark)

    Nyegaard, Mette; Overgaard, Michael Toft; Sondergaard, M.T.;

    2012-01-01

    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause...... a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe...... calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac...

  1. Respiratory arrhythmia in the hearts of harbour porpoises (Phocoena phocoena)

    NARCIS (Netherlands)

    Kastelein, R.A.; Meijler, F.L.

    1989-01-01

    The heart rates of 3 Harbour porpoises (recorded for 26 days) showed individual variation. Electrocardiograms of two of these animals, made while they were on land, showed respiratory arrhythmia. The heart rate dropped when the animals were returned to the water, but the arrhythmia remained.

  2. Atrial Arrhythmias and Their Implications for Space Flight - Introduction

    Science.gov (United States)

    Polk, J. D.; Barr, Y. R.; Bauer, P.; Hamilton, D. R.; Kerstman, E.; Tarver, B.

    2010-01-01

    This panel will discuss the implications of atrial arrhythmias in astronauts from a variety of perspectives; including historical data, current practices, and future challenges for exploration class missions. The panelists will present case histories, outline the evolution of current NASA medical standards for atrial arrhythmias, discuss the use of predictive tools, and consider potential challenges for current and future missions.

  3. Molecular and Electrophysiological Mechanisms Underlying Cardiac Arrhythmogenesis in Diabetes Mellitus.

    Science.gov (United States)

    Tse, Gary; Lai, Eric Tsz Him; Tse, Vivian; Yeo, Jie Ming

    2016-01-01

    Diabetes is a common endocrine disorder with an ever increasing prevalence globally, placing significant burdens on our healthcare systems. It is associated with significant cardiovascular morbidities. One of the mechanisms by which it causes death is increasing the risk of cardiac arrhythmias. The aim of this article is to review the cardiac (ion channel abnormalities, electrophysiological and structural remodelling) and extracardiac factors (neural pathway remodelling) responsible for cardiac arrhythmogenesis in diabetes. It is concluded by an outline of molecular targets for future antiarrhythmic therapy for the diabetic population. PMID:27642609

  4. Learning rules from multisource data for cardiac monitoring

    CERN Document Server

    Cordier, Marie-Odile; Quiniou, René

    2009-01-01

    This paper formalises the concept of learning symbolic rules from multisource data in a cardiac monitoring context. Our sources, electrocardiograms and arterial blood pressure measures, describe cardiac behaviours from different viewpoints. To learn interpretable rules, we use an Inductive Logic Programming (ILP) method. We develop an original strategy to cope with the dimensionality issues caused by using this ILP technique on a rich multisource language. The results show that our method greatly improves the feasibility and the efficiency of the process while staying accurate. They also confirm the benefits of using multiple sources to improve the diagnosis of cardiac arrhythmias.

  5. Cardiac involvement in children with neuro-muscular disorders

    Directory of Open Access Journals (Sweden)

    E. N. Arkhipova

    2015-01-01

    Full Text Available Many inherited neuromuscular disorders include cardiac involvement as a typical clinical feature. Among the most common of them is the group of muscular dystrophies. Dilated cardiomyopathy, ventricular arrhythmias, atrial fibrillations, atrioventricular and intraventricular conduction abnormalities, and sudden cardiac death are well known pathological findings in Duchenne muscular dystrophies, myotonic dystrophy type I and 2, Emery-Dreifuss muscular dystrophies and different types of limb-girdle muscular dystrophies and other disorders. Detection of cardiac pathology in patients with different muscular dystrophies is possible with ECG, echocardiography and cardiovascular magnetic resonance imaging, which are recommended for screening and early cardioprotective treatment.

  6. Progress in Investigations of Arrhythmias Originating in the Right Ventricle%右室相关心律失常的临床和基础

    Institute of Scientific and Technical Information of China (English)

    胡金柱; 洪葵

    2011-01-01

    The structural and electrical remodeling in the left ventricle as a result of coronary heart disease and cardiomyopathy is the primary cause of ventricular arrhythmia and sudden cardiac death. However, arrhythmias can also originate in the right ventricle. Ventricular arrhythmias originating in the right ventricle usually affect younger patients, and can also lead to sudden cardiac death. Advances in available research techniques are providing more information about the pathogenesis, diagnosis and prognosis of right ventricular arrhythmias. Arrhyth-mias originating in the right ventricle mostly occur in arrhythmogenic right ventricular cardiomyopathy/dysplasia, Brugada syndrome, right ventricular outflow tract ventricular tachycardia, and congenital heart defects. This article reviews recent research in these diseases and their connection to right ventricular arrhythmias.%冠心病或心肌病所致左室结构和电重构是室性心律失常和心源性猝死发生的主要原因.近20年来,右室相关心律失常已受到工作者重视,其好发于青壮年患者,易导致心源性猝死,基础研究尤其是分子遗传学的发展推动了人们对右室相关心律失常发病机制、诊断和预后的认识和理解.右室相关心律失常多见于致心律失常型右室心肌病、Brugada综合征、右室流出道室性心动过速及先天性心脏病等,现将对其临床与基础研究进行概述.

  7. Neck heart syndrome arrhythmia 16 cases of clinical analysis%颈心综合征16例临床分析

    Institute of Scientific and Technical Information of China (English)

    赵淑萍; 尉双玲; 郎明丽

    2013-01-01

    目的探讨颈心综合征致心律失常的诊断、治疗及病因。方法回顾性分析我科2008年-2012年收治的16例颈椎病引起心律失常的诊断、治疗及病情转归情况。结果本组16例在明确心律失常系颈心综合征引起后,治疗原发病,心律失常均得到控制。结论颈心综合征发作时可导致心律失常的发生,明确诊断后积极治疗颈椎病会提高抗心律失常疗效,临床上要提高对颈椎病导致心律失常的认识,避免延误诊治。%Objective To explore neck heart syndrome to diagnosis, treatment and the causes of arrhythmias. Methods To analyze the I division in 2008-2012 treated 16 cases of cervical spondylosis cause disease diagnosis , treatment and outcome of cardiac arrhythmias. Results Of 16 cases in clear arrhythmia heart syndrome caused by neck, after treatment of primary disease, arrhythmia under control. Conclusion Cervical syndrome of heart attack can cause cardiac arrhythmia occurs, active treatment after diagnosis of cervical spondylosis can improve the anti-arrhythmic effects, so to improve clinical understanding of cervical vertebra disease cause arrhythmia, to avoid delay in diagnosis and treatment.

  8. Effect of Different Pranayamas on Respiratory Sinus Arrhythmia

    Science.gov (United States)

    Raj, Jeneth Berlin; Ramanathan, Meena; Trakroo, Madanmohan

    2016-01-01

    Introduction Respiratory Sinus Arrhythmia (RSA) is the differential change of Heart Rate (HR) in response to inspiration and expiration. This is a noninvasive sensitive index of parasympathetic cardiac control. Aim To evaluate changes in RSA by utilizing a simple and cost-effective analysis of electrocardiographic (ECG) tracings obtained during performance of four pranayama techniques. Materials and Methods Fifty two trained volunteers performed the following pranayamas with different ratios for inspiration and expiration: sukha (1:1), traditional (1:2), pranava (1:3) and savitri (2:1:2:1) and ECG was recorded while performing the techniques with rest period of 5 minutes in-between. HR was calculated and maximum HR during inspiration (Imax), minimum HR during expiration (Emin), differences between Imax and Emin (Δ), percentage differences between Imax and Emin (Δ%) and expiration: inspiration ratio (E:I) calculated by respective formulae. Statistical analysis was carried out using repeated measures of ANOVA with Tukey-Kramer multiple comparisons test. Results There were significant differences between groups in all five aspects namely: p= 0.0093 for mean Imax, p = 0.0009 for mean Emin, and p < 0.0001 for Δ HR (I-E), Δ% HR (I-E) and E:I ratio. Pranava pranayama produced the greatest changes in all five comparisons. Conclusion We suggest that further short and long term studies be undertaken with pranava pranayama in patients to further qualitatively and quantitatively evaluate inherent mechanisms of this simple technique. Addition of these cost-effective techniques to the medical armory will help patients of rhythm disorders and other cardiovascular conditions. PMID:27134863

  9. Sick sinus syndrome in a patient with extensive cardiac lipomatosis (sinus node dysfunction in lipomatosis).

    Science.gov (United States)

    Kadmon, Ehud; Paz, Rami; Kusniec, Jairo; Strasberg, Boris

    2010-04-01

    We present a case of a 45-year-old man with an incidental and longstanding diagnosis of extensive mediastinal and cardiac lipomatosis. Along the years, he had experienced various arrhythmias, mainly bradyarrhythmias, mostly asymptomatic. Recently after documenting a sinus pause of 6 seconds and runs of nonsustained ventricular tachycardias, he underwent an implantation of a cardioverter-defibrillator. There are many reports of cardiac lipomatosis in the literature, including reports of related ventricular arrhythmias, some of which are fatal. (PACE 2010; 513-515).

  10. The mRNA and Protein Expression of KCNQ1 in Cardiac Conduction System after Exhaustive Exercise and Their Role in Exercise-induced Arrhythmia%不同力竭运动后大鼠心脏传导系统 KCNQ1 mRNA 和蛋白的变化及其在运动性心律失常发生中的作用

    Institute of Scientific and Technical Information of China (English)

    薄冰; 常芸; 杨红霞; 温悦萌

    2012-01-01

    Objective This paper presents our study on the mRNA and protein expression of KCNQ1 in sinoatrial node(SAN),atrioventricular node(AVN) and Purkinje's fibers at different time phases after exhaustive exercise,in order to provide the experimental evidence for clarifying the mechanism of exercise-induced arrhythmia. Methods One hundred healthy adult male SD rats were grouped into the acute single exhaustive swimming group (n. = 40), 2-week repeated exhaustive swimming group (n = 40) ,and 2 control groups (10 rats for each group). The exercise rats were sacrificed at 0,4,12,and 24 hours after exhaustive swimming,and rats in the control groups were sacrificed at the same time points as the exercised rats. The cells of SAN.AVN and Purkinje's fiber were spotted and collected with the approach of laser micro dissection. The mRNA and protein expressions of KCNQ1 were analyzed by real-time fluorescent quantitative PCR.immunochemistry and image analysis. Results As compared to control group, the mRNA and protein expression of KCNQ1 in cardiac conduction system increased greatly 4 hours after acute single exhaustive exercise (P < 0.05). The mRNA and protein expression of KCNQ1 in SAN and Purkinje's fiber increased greatly 4 hours and 24 hours after repeated exhaustive exercise when compared to control group (P < 0.05). The mRNA and protein expression of KCNQ1 in AVN increased greatly 12 hours after repeated exhaustive exercise (P < 0.05). Conclusion After exhaustive exercise, the abnormally increased expression of KCNQ1 mRNA and protein could cause the activation of potassium channel on cell membrane,and thus increase the outflow of potassium ion and change the process of action potential,which could be the pathological basis and mechanism of exercise-induced arrhythmia.%目的:探讨力竭运动后不同时相心脏窦房结、房室结和浦肯野氏纤维离子通道相关因子KCNQ1基因和蛋白水平的表达特点,为运动性心律失常发生机制的

  11. Experience of treatment of heart rhabdomyomas in combination with various arrhythmias and conduction disorders

    Directory of Open Access Journals (Sweden)

    Bockeria L. A.

    2014-12-01

    Full Text Available Оbjective. Presentation the experience of diagnosis and treatment of heart rhabdomyomas in combination withvarious arrhythmias and conduction disorders.Material and methods. In archival material found 9 records of pediatric patients treated in A.N. BakoulevCenter for Cardiovascular Surgery from June 2004 to September 2013 with cardiac rhabdomyomas. The ageofpatients ranged from 19 days to 17 years. Along with the general clinical studies patients perfomed electro-cardiography (ECG, Holter ECG, echocardiography with doppler, computed tomography (CT and cardiacmagnetic resonance imaging (MRI with contrast. Rhabdomyomas localized in the left ventricle with3patients, in the right ventricle with 3 patients, in the right atrium – 2 patients and in the left atrium –1patient. Intramural and mixed rhabdomyomas growth was accompanied by a variety of arrhythmias andconduction of the heart, which were observed in 6 patients. Among them one cases were registered: manifesting Wolff–Parkinson–White syndrome, continuous recurrent atrial tachycardia, atrial fibrillation/flutter,full blockade of the right bundle branch, atrioventricular (AV block 3rd degree, a weakness syndrome sinusnode and paroxysmal atrial tachycardia.Results. Surgical care was performed in 5 cases. In 4 cases the tumor was unresectable or surgical treatment has not been shown. These patients were released under the supervision of a cardiologist at the place of residence on drug therapy. The most frequent localization rhabdomyomas of the heart – the ventricles(66.7%. Rhabdomyomas of the heart in combination with disorders of rhythm and conduction was observedin 6 patient (66.7%. Surgery included resection of rhabdomyomas of the heart under conditions of artificialblood circulation and pharmacological cardioplegia. Patient with atrial fibrillation/flutter in 1 cases was performed radiofrequency modification operation Cox Maze. In this group of patients in-hospital mortality is 0

  12. Mechanisms of ventricular arrhythmias: from molecular fluctuations to electrical turbulence.

    Science.gov (United States)

    Qu, Zhilin; Weiss, James N

    2015-01-01

    Ventricular arrhythmias have complex causes and mechanisms. Despite extensive investigation involving many clinical, experimental, and computational studies, effective biological therapeutics are still very limited. In this article, we review our current understanding of the mechanisms of ventricular arrhythmias by summarizing the state of knowledge spanning from the molecular scale to electrical wave behavior at the tissue and organ scales and how the complex nonlinear interactions integrate into the dynamics of arrhythmias in the heart. We discuss the challenges that we face in synthesizing these dynamics to develop safe and effective novel therapeutic approaches. PMID:25340965

  13. Multifocal Ectopic Purkinje-Related Premature Contractions: A New SCN5A-Related Cardiac Channelopathy. : MEPPC: a new SCN5A-related cardiac channelopathy

    OpenAIRE

    Amarouch, Mohamed Yassine; Barc, Julien; Bar, Isabelle; Baron, Estelle; Barthez, Olivier; Bertaux, Geraldine; Béziau, Delphine M.; Charpentier, Flavien; Charron, Philippe; Coudière, Yves; Dina, Christian; Faivre, Laurence; Fressart, Véronique; Kyndt, Florence; Laurent, Gabriel

    2012-01-01

    OBJECTIVES: The aim of this study was to describe a new familial cardiac phenotype and to elucidate the electrophysiological mechanism responsible for the disease. BACKGROUND: Mutations in several genes encoding ion channels, especially SCN5A, have emerged as the basis for a variety of inherited cardiac arrhythmias. METHODS: Three unrelated families comprising 21 individuals affected by multifocal ectopic Purkinje-related premature contractions (MEPPC) characterized by narrow junctional and r...

  14. 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.

  15. Dystrophinopathy presenting with arrhythmia in an asymptomatic 34-year-old man: a case report

    Directory of Open Access Journals (Sweden)

    Wakefield Seth E

    2009-07-01

    Full Text Available Abstract Introduction Important clues in the recognition of individuals with dystrophin gene mutations are illuminated in this case report. In particular, this report seeks to broaden the perspective of early signs and symptoms of a potentially life-limiting genetic disorder. This group of disorders is generally considered to be a pediatric muscular dystrophy when in actual fact, this case report may represent a spectrum of subclinically affected adults. Case presentation We present the diagnostic saga of a 34-year-old Caucasian man who had two liver biopsies for elevated liver enzymes and 16 years later presented with a cardiac arrhythmia amidst an emergent appendectomy which finally led to his specific genetic diagnosis. Conclusions This genetic disorder can affect more than one organ, and in our patient affected both skeletal and cardiac muscle. Furthermore, liver function tests when elevated may erroneously implicate a liver disorder when they actually reflect cardiac and skeletal muscle origin. Presented here is a patient with Becker's muscular dystrophy and cardiomyopathy.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Determination of the vectorelectrogram in isolated rat atria: application to the study of arrhythmias

    International Nuclear Information System (INIS)

    Atrial tachyarrhythmias, the most frequent type of cardiac arrhythmia, are associated with increased stroke risk. Reentry and focal activity are considered as the main mechanisms underlying this dysfunction. In this study, we describe determination of the vectorelectrogram in isolated rat atria as a means to distinguish different patterns of electrical propagation. In all studied right atria beating at sinus rhythm, the mean electric vector (MEV) trajectory was clockwise, and each cycle was preceded by electric diastole (null MEV), either in the absence or presence of muscarinic cholinergic or β-adrenergic receptor stimulation. During cholinergic tachyarrhythmia (induced by high-rate electric stimulation in both atria, plus exposure to carbachol in left atria), vector loops were ellipsoidal and stable, with variable direction, and did not cross the origin, which is consistent with reentrant activation and with findings obtained in vivo by other authors. In contrast, during spontaneous activity induced by rapid pacing in isoproterenol-exposed left atria, vector loops were similar to those in right atria at sinus rhythm, thus suggestive of focal activity. It is concluded that the vectorelectrogram approach allows discrimination of different patterns of propagation during arrhythmia in isolated atria and may be useful for high-output tests of pro- and anti-arrhythmic compounds

  18. Cardiac Malpositions

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Shi Joon; Im, Chung Gie; Yeon, Kyung Mo; Hasn, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    Cardiac Malposition refers to any position of the heart other than a left-sided heart in a situs solitus individual. Associated cardiac malformations are so complex that even angiocardiographic and autopsy studies may not afford an accurate information. Although the terms and classifications used to describe the internal cardiac anatomy and their arterial connections in cardiac malpositions differ and tend to be confusing, common agreement exists on the need for a segmental approach to diagnosis. Authors present 18 cases of cardiac malpositions in which cardiac catheterization and angiocardiography were done at the Department of Radiology, Seoul National University Hospital between 1971 and 1979. Authors analyzed the clinical, radiographic, operative and autopsy findings with the emphasis on the angiocardiographic findings. The results are as follows: 1. Among 18 cases with cardiac malpositions, 6 cases had dextrocardia with situs inversus, 9 cases had dextrocardia with situs solitus and 3 cases had levocardia with situs inversus. 2. There was no genuine exception to visceroatrial concordance rule. 3. Associated cardiac malpositions were variable and complex with a tendency of high association of transposition and double outlet varieties with dextrocardia in situs solitus and levocardia in situs inversus. Only one in 6 cases of dextrocardia with situs inversus had pure transposition. 4. In two cases associated pulmonary atresia was found at surgery which was not predicted by angiocardiography. 5. Because many of the associated complex lesions can be corrected surgically provided the diagnosis is accurate, the selective biplane angiocardiography with or without cineradiography is essential.

  19. [Idiopathic ventricular tachycardia, an arrhythmia with good prognosis].

    NARCIS (Netherlands)

    Camaro, C.; Bos, H.S.; Smeets, J.L.R.M.

    2010-01-01

    Three patients, one experiencing palpitations and two complaining of chest pain in stressful situations, appeared to have monomorphic wide complex tachycardia. After excluding channelopathy, structural abnormalities and ischaemia of the heart, this arrhythmia was classified as idiopathic. Symptoms d

  20. 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.

  1. 3D/2D Registration of Mapping Catheter Images for Arrhythmia Interventional Assistance

    CERN Document Server

    Fallavollita, Pascal

    2009-01-01

    Radiofrequency (RF) catheter ablation has transformed treatment for tachyarrhythmias and has become first-line therapy for some tachycardias. The precise localization of the arrhythmogenic site and the positioning of the RF catheter over that site are problematic: they can impair the efficiency of the procedure and are time consuming (several hours). Electroanatomic mapping technologies are available that enable the display of the cardiac chambers and the relative position of ablation lesions. However, these are expensive and use custom-made catheters. The proposed methodology makes use of standard catheters and inexpensive technology in order to create a 3D volume of the heart chamber affected by the arrhythmia. Further, we propose a novel method that uses a priori 3D information of the mapping catheter in order to estimate the 3D locations of multiple electrodes across single view C-arm images. The monoplane algorithm is tested for feasibility on computer simulations and initial canine data.

  2. 3D/2D Registration of Mapping Catheter Images for Arrhythmia Interventional Assistance

    Directory of Open Access Journals (Sweden)

    Pascal Fallavollita

    2009-09-01

    Full Text Available Radiofrequency (RF catheter ablation has transformed treatment for tachyarrhythmias and has become first-line therapy for some tachycardias. The precise localization of the arrhythmogenic site and the positioning of the RF catheter over that site are problematic: they can impair the efficiency of the procedure and are time consuming (several hours. Electroanatomic mapping technologies are available that enable the display of the cardiac chambers and the relative position of ablation lesions. However, these are expensive and use custom-made catheters. The proposed methodology makes use of standard catheters and inexpensive technology in order to create a 3D volume of the heart chamber affected by the arrhythmia. Further, we propose a novel method that uses a priori 3D information of the mapping catheter in order to estimate the 3D locations of multiple electrodes across single view C-arm images. The monoplane algorithm is tested for feasibility on computer simulations and initial canine data.

  3. Hepatocyte growth factor gene therapy reduces ventricular arrhythmia in animal models of myocardial ischemia.

    Directory of Open Access Journals (Sweden)

    Yumoto,Akihisa

    2005-06-01

    Full Text Available

    It was recently reported that gene therapy using hepatocyte growth factor (HGF has the potential to preserve cardiac function after myocardial ischemia. We speculated that this HGF gene therapy could also prevent ventricular arrhythmia. To investigate this possibility, we examined the antiarrhythmic effect of HGF gene therapy in rat acute and old myocardial infarction models. Myocardial ischemia was induced by ligation of the left descending coronary artery. Hemagglutinating virus of Japan (HVJ-coated liposome containing HGF genes were injected directly into the myocardium fourteen days before programmed pacing. Ventricular fibrillation (VFwas induced by programmed pacing. The VF duration was reduced and the VF threshold increased after HGF gene therapy ( p< 0.01. Histological analyses revealed that the number of vessels in the ischemic border zone was greatly increased after HGF gene injection. These findings revealed that HGF gene therapy has an anti-arrhythmic effect after myocardial ischemia.

  4. Sudden cardiac death in 13 captive chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Lammey, Michael L; Lee, D Rick; Ely, John J; Sleeper, Meg M

    2008-02-01

    Sudden cardiac death (SCD), presumed secondary to fatal arrhythmias, is a common cause of mortality in captive chimpanzees at the Alamogordo Primate Facility. Over the 6-year period at the Alamogordo Primate Facility between 2001 and 2006, 13 animals were defined as sudden cardiac death (11 male and 2 female) on the basis of clinical presentation which was 38% of all deaths. All animals had annual physical exams, including electrocardiograms and serial blood pressures. Six of the 13 animals underwent a complete cardiac evaluation by a veterinary cardiologist and all six of these animals were diagnosed with various degrees of cardiomyopathy. Systemic hypertension was noted in two of the 13 cases and antemortem cardiac arrhythmias were seen in all 13 animals. Histological examination of the hearts revealed myocardial fibrosis in 12 chimpanzees. Most of the animals (10/13) that died of sudden cardiac death had cardiomegaly (increased heart weight/body weight ratio) and some degree of myocardial fibrosis noted. Additional data as well as serial diagnostic evaluations will be needed to identify the possible causes of sudden cardiac death in captive chimpanzees. PMID:18269527

  5. Evaluating the Cancer Therapeutic Potential of Cardiac Glycosides

    Directory of Open Access Journals (Sweden)

    José Manuel Calderón-Montaño

    2014-01-01

    Full Text Available Cardiac glycosides, also known as cardiotonic steroids, are a group of natural products that share a steroid-like structure with an unsaturated lactone ring and the ability to induce cardiotonic effects mediated by a selective inhibition of the Na+/K+-ATPase. Cardiac glycosides have been used for many years in the treatment of cardiac congestion and some types of cardiac arrhythmias. Recent data suggest that cardiac glycosides may also be useful in the treatment of cancer. These compounds typically inhibit cancer cell proliferation at nanomolar concentrations, and recent high-throughput screenings of drug libraries have therefore identified cardiac glycosides as potent inhibitors of cancer cell growth. Cardiac glycosides can also block tumor growth in rodent models, which further supports the idea that they have potential for cancer therapy. Evidence also suggests, however, that cardiac glycosides may not inhibit cancer cell proliferation selectively and the potent inhibition of tumor growth induced by cardiac glycosides in mice xenografted with human cancer cells is probably an experimental artifact caused by their ability to selectively kill human cells versus rodent cells. This paper reviews such evidence and discusses experimental approaches that could be used to reveal the cancer therapeutic potential of cardiac glycosides in preclinical studies.

  6. Cardiovascular profiles of scleroderma patients with arrhythmias and conduction disorders.

    Science.gov (United States)

    Muresan, L; Petcu, A; Pamfil, C; Muresan, C; Rinzis, M; Mada, R O; Gusetu, G N; Pop, D; Zdrenghea, D; Rednic, S

    2016-01-01

    Introduction Arrhythmias and conduction disorders are common among patients with scleroderma. Their early identification is important, since scleroderma patients with arrhythmias have a higher mortality risk compared with scleroderma patients without arrhythmias. The aim of this study was to characterize the cardiovascular profiles of scleroderma patients with different types of arrhythmias and conduction disorders. Methods One hundred and ten consecutive patients with a diagnosis of systemic sclerosis according to the ACR criteria were included in the study. Patients underwent a 12-lead ECG and a 24-hour Holter ECG monitoring for arrhythmias and conduction disorders identification. Blood sample testing, echocardiography, spirometry, chest X-ray and, when considered appropriate, high resolution chest CT were also performed. A subgroup of 21 patients underwent NT-pro BNP level measurements. Patients' clinical and para-clinical characteristics were compared according to the presence or absence of arrhythmias and conduction disorders. Results The prevalence of arrhythmia and conduction disturbances was 60.9%. Patients with such disorders were older (54.4 ± 13.3 vs. 49.7 ± 10.1 years, p=0.05), had a higher prevalence of pulmonary hypertension (p=0.008), valve disease (p < 0.001), especially mitral and tricuspid regurgitation, chamber enlargement on echocardiography (left atrial and right ventricular, p = 0.012 and 0.005, respectively) as well as higher NT-pro BNP levels: 265.5 ± 399.7 vs. 163 ± 264.3 pg/ml, p=0.04. Conclusion Arrhythmias and conduction disorders are common in patients with scleroderma. Patients with such disorders are older, have a higher prevalence of pulmonary hypertension, more severe mitral and tricuspid regurgitation, left atrial and right ventricular dilation on echocardiography. PMID:27115105

  7. Abnormal heart rate turbulence predicts the initiation of ventricular arrhythmias

    OpenAIRE

    Iwasa, Atsushi; Hwa, Michael; Hassankhani, Alborz; Liu, Taylor; Narayan, Sanjiv M.

    2005-01-01

    Background: Abnormal heart rate turbulence (HRT) reflects autonomic derangements predicting all-cause mortality, yet has riot been shown to predict ventriculor arrhythmias in at-risk patients. We hypothesized that HRT at programmed ventricular stimulation (PVS) would predict arrhythmia initiation in patients with left ventriculor dysfunction. Methods: We studied 27 patients with coronary disease, left ventricular ejection fraction (LVEF) 26.7 +/- 9.1%, and plasma B-type natriuretic peptide (B...

  8. Arrhythmias and electrocardiographic changes in systolic heart failure

    OpenAIRE

    Ashok Devkota; Ahmed Bakhit; Alix Dufresne; Aung Naing Oo; Premraj Parajuli; Saveena Manhas

    2016-01-01

    Background: Heart failure is a common condition that that leads to hospitalization. It is associated with various atrial and ventricular arrhythmias. Aim: The aim of this study is to find common arrhythmias and electrocardiographic changes in hospitalized patients who have systolic heart failure. Materials and Methods: This is a retrospective study of medical records, and electrocardiograms (EKGs) of 157 patients admitted to our hospital who had systolic heart failure with ejection fraction (...

  9. Surface Electrocardiogram Predictors of Sudden Cardiac Arrest

    Science.gov (United States)

    Abdelghani, Samy A.; Rosenthal, Todd M.; Morin, Daniel P.

    2016-01-01

    Background: Heart disease is a major cause of death in industrialized nations, with approximately 50% of these deaths attributable to sudden cardiac arrest. If patients at high risk for sudden cardiac arrest can be identified, their odds of surviving fatal arrhythmias can be significantly improved through prophylactic implantable cardioverter defibrillator placement. This review summarizes the current knowledge pertaining to surface electrocardiogram (ECG) predictors of sudden cardiac arrest. Methods: We conducted a literature review focused on methods of predicting sudden cardiac arrest through noninvasive electrocardiographic testing. Results: Several electrocardiographic-based methods of risk stratification of sudden cardiac arrest have been studied, including QT prolongation, QRS duration, fragmented QRS complexes, early repolarization, Holter monitoring, heart rate variability, heart rate turbulence, signal-averaged ECG, T wave alternans, and T-peak to T-end. These ECG findings have shown variable effectiveness as screening tools. Conclusion: At this time, no individual ECG finding has been found to be able to adequately stratify patients with regard to risk for sudden cardiac arrest. However, one or more of these candidate surface ECG parameters may become useful components of future multifactorial risk stratification calculators. PMID:27660578

  10. Troponin not just a simple cardiac marker: prognostic significance of cardiac troponin

    Institute of Scientific and Technical Information of China (English)

    Benny Mulyanto Setiadi; LEI Han; CHANG Jing

    2009-01-01

    Objective The object of this study was to review the role of cardiac troponin as a prognostic factor in acute coronary syndrome patients of varying circumstances.Data sources The data used in this review were obtained mainly from the studies of cardiac troponin reported in pubmed from 1981 to 2006.Study selection Relevant articles on studies of cardiac troponin were selected.Results Elevated cardiac troponin in patients with ST elevation and non ST elevation myocardial infarction was associated with adverse outcomes, including a higher incidence of congestive heart failure, shock, and death. Patients with elevated cardiac troponin value seemed to benefit more from invasive strategies including a percutaneous coronary intervention and bypass surgery, but elevated cardiac troponin was also correlated with adverse outcomes, including a higher degree of failure, shock, and mortality in patients undergoing percutaneous coronary intervention; a higher degree of perioperative myocardial infarction, low cardiac output syndrome, cardiopulmonary resuscitation, and new-onset ventricular arrhythmia in patients undergoing bypass surgery were also observed. Elevated troponin after a percutaneous coronary intervention seemed to be associated with short-term adverse outcomes rather than long-term adverse outcomes, unless the elevation of the troponin post percutaneous coronary intervention was quite high (about 5 times above normal). On the contrary, elevated cardiac troponin after bypass surgery was more confusing to analyze since it happened in almost all patients. Furthermore, differences in cutoff values and time measurements in some studies add more confusion; thus, further research is warranted.Conclusions The prognostic value of cardiac troponin is demonstrated in almost all acute coronary syndrome patients. In addition to its high sensitivity and specificity, the prognostic value of cardiac troponin is another reason to make it the "golden cardiac marker' of this time.

  11. Common Genetic Variation Near the Phospholamban Gene Is Associated with Cardiac Repolarisation : Meta-Analysis of Three Genome-Wide Association Studies

    NARCIS (Netherlands)

    Nolte, Ilja M.; Wallace, Chris; Newhouse, Stephen J.; Waggott, Daryl; Fu, Jingyuan; Soranzo, Nicole; Gwilliam, Rhian; Deloukas, Panos; Savelieva, Irina; Zheng, Dongling; Dalageorgou, Chrysoula; Farrall, Martin; Samani, Nilesh J.; Connell, John; Brown, Morris; Dominiczak, Anna; Lathrop, Mark; Zeggini, Eleftheria; Wain, Louise V.; Newton-Cheh, Christopher; Eijgelsheim, Mark; Rice, Kenneth; de Bakker, Paul I. W.; Pfeufer, Arne; Sanna, Serena; Arking, Dan E.; Asselbergs, Folkert W.; Spector, Tim D.; Carter, Nicholas D.; Jeffery, Steve; Tobin, Martin; Caulfield, Mark; Snieder, Harold; Paterson, Andrew D.; Munroe, Patricia B.; Jamshidi, Yalda

    2009-01-01

    To identify loci affecting the electrocardiographic QT interval, a measure of cardiac repolarisation associated with risk of ventricular arrhythmias and sudden cardiac death, we conducted a meta-analysis of three genome-wide association studies (GWAS) including 3,558 subjects from the TwinsUK and BR

  12. Common genetic variation near the phospholamban gene is associated with cardiac repolarisation : Meta-analysis of three genome-wide association studies

    NARCIS (Netherlands)

    I.M. Nolte (Ilja); C. Wallace (Chris); S.J. Newhouse (Stephen); D. Waggott (Daryl); J. Fu (Jingyuan); N. Soranzo (Nicole); R. Gwilliam (Rhian); S. Demissie (Serkalem); I. Savelieva (Irina); D. Zheng (Dongling); C. Dalageorgou (Chrysoula); M. Farrall (Martin); N.J. Samani (Nilesh); J. Connell (John); M.J. Brown (Morris); A. Dominiczak (Anna); M. Lathrop (Mark); E. Zeggini (Eleftheria); L.V. Wain (Louise); C. Newton-Cheh (Christopher); M. Eijgelsheim (Mark); K. Rice (Kenneth); P.I.W. de Bakker (Paul); A. Pfeufer (Arne); S. Sanna (Serena); D.E. Arking (Dan); F.W. Asselbergs (Folkert); T.D. Spector (Tim); N.D. Carter (Nicholas); S. Jeffery (Steve); M. Tobin (Martin); M. Caulfield (Mark); H. Snieder (Harold); A.D. Paterson (Andrew); P. Munroe (Patricia); Y. Jamshidi (Yalda)

    2009-01-01

    textabstractTo identify loci affecting the electrocardiographic QT interval, a measure of cardiac repolarisation associated with risk of ventricular arrhythmias and sudden cardiac death, we conducted a meta-analysis of three genome-wide association studies (GWAS) including 3,558 subjects from the Tw

  13. Electrocardiographic Patch Devices and Contemporary Wireless Cardiac Monitoring

    Directory of Open Access Journals (Sweden)

    Erik eFung

    2015-05-01

    Full Text Available Cardiac electrophysiologic derangements often coexist with disorders of the circulatory system. Capturing and diagnosing arrhythmias and conduction system disease may lead to a change in diagnosis, clinical management and patient outcomes. Standard 12-lead electrocardiogram (ECG, Holter monitors and event recorders have served as useful diagnostic tools over the last few decades. However, their shortcomings are only recently being addressed by emerging technologies. With advances in device miniaturization and wireless technologies, and changing consumer expectations, wearable ‘on-body’ ECG patch devices have evolved to meet contemporary needs. These devices are unobtrusive and easy to use, leading to increased device wear time and diagnostic yield. While becoming the standard for detecting arrhythmias and conduction system disorders in the outpatient setting where continuous ECG monitoring in the short to medium term (days to weeks is indicated, these cardiac devices and related digital mobile health technologies are reshaping the clinician-patient interface with important implications for future healthcare delivery.

  14. Hypokalemia and sudden cardiac death

    DEFF Research Database (Denmark)

    Kjeldsen, Keld

    2010-01-01

    Worldwide, approximately three million people suffer sudden cardiac death annually. These deaths often emerge from a complex interplay of substrates and triggers. Disturbed potassium homeostasis among heart cells is an example of such a trigger. Thus, hypokalemia and, also, more transient...... was found in 24% of hospitalized patients. Hypokalemia is associated with increased risk of arrhythmia in patients with cardiovascular disease, as well as increased all-cause mortality, cardiovascular mortality and heart failure mortality by up to 10-fold. Long-term potassium homeostasis depends on renal...... capacity for potassium exchange. In cardiovascular patients, hypokalemia is often caused by nonpotassium-sparing diuretics, insufficient potassium intake and a shift of potassium into stores by increased potassium uptake stimulated by catecholamines, beta-adrenoceptor agonists and insulin. Interestingly...

  15. Evolving Cardiac Conduction Phenotypes in Developing Zebrafish Larvae: Implications to Drug Sensitivity

    OpenAIRE

    Yu, Fei; Huang, Jie; Adlerz, Katrina; Jadvar, Hossein; Hamdan, Mohamed H.; Chi, Neil; Chen, Jau-Nian; Hsiai, Tzung K.

    2010-01-01

    Cardiac arrhythmias include problems with impulse formation and/or conduction abnormalities. Zebrafish (Danio rerio) is an emerging model system for studying the cardiac conduction system. However, real-time recording of the electrocardiogram remains a challenge. In the present study, we assessed the feasibility of recording electrical cardiogram (ECG) signals from the zebrafish larvae using the micropipette electrodes, and demonstrated the dynamic changes in ECG signals and their sensitivity...

  16. Capnography during cardiac resuscitation: a clue on mechanisms and a guide to interventions

    OpenAIRE

    Gazmuri, Raúl J.; Kube, Erika

    2003-01-01

    Measurement of the end-tidal partial pressure of carbon dioxide (PETCO2) during cardiac arrest has been shown to reflect the blood flow being generated by external means and to prognosticate outcome. In the present issue of Critical Care, Grmec and colleagues compared the initial and subsequent PETCO2 in patients who had cardiac arrest precipitated by either asphyxia or ventricular arrhythmia. A much higher PETCO2 was found immediately after intubation in instances of asphyxial arrest. Yet, a...

  17. Investigations on different aspects of cardiac ventricular repolarization: repolarization reserve and adaptation to heart rate

    OpenAIRE

    Dr Husti Zoltán

    2015-01-01

    Investigations on different aspects of cardiac ventricular repolarization: repolarization reserve and adaptation to heart rate Introduction 1. The proper assessment of the pro-arrhythmic potential of candidate compounds is a major concern for drug development, since drug-induced arrhythmias, including Torsades de Pointes (TdP), can lead to sudden cardiac death. The prediction of TdP in clinical setting is very difficult since the incidence of drug-induced TdP is very low (1:100 0...

  18. Cardiac rehabilitation

    Science.gov (United States)

    ... attack or other heart problem. You might consider cardiac rehab if you have had: Heart attack Coronary heart disease (CHD) Heart failure Angina (chest pain) Heart or heart valve surgery Heart transplant Procedures such as angioplasty and stenting In some ...

  19. Cardiac ion channels and mechanisms for protection against atrial fibrillation

    DEFF Research Database (Denmark)

    Grunnet, Morten; Bentzen, Bo Hjorth; Sørensen, Ulrik S;

    2011-01-01

    Atrial fibrillation (AF) is recognised as the most common sustained cardiac arrhythmia in clinical practice. Ongoing drug development is aiming at obtaining atrial specific effects in order to prevent pro-arrhythmic, devastating ventricular effects. In principle, this is possible due to a different...... the recent discovery that Ca(2+)-activated small conductance K(+) channels (SK channels) are important for the repolarisation of atrial action potentials. Finally, an overview of current pharmacological treatment of AF is included....

  20. Premature Cardiac Contractions and Risk of Incident Ischemic Stroke

    OpenAIRE

    Ofoma, Uchenna; He, Fan; Michele L. Shaffer; Naccarelli, Gerard V.; Liao, Duanping

    2012-01-01

    Background The etiologies of ischemic stroke remain undetermined in 15% to 40% of patients. Apart from atrial fibrillation, other arrhythmias are less well-characterized as risk factors. Premature cardiac contractions are known to confer long-term cardiovascular risks, like myocardial infarction. Ischemic stroke as cardiovascular risk outcome remains a topic of interest. We examined the prospective relationships in the Atherosclerosis Risk in Communities (ARIC) study, to determine whether pre...

  1. HEART RHYTHM DISORDERS IN NEW-BORNS AND INFANTS: CLINICAL COURSE AND PERINATAL RISK FACTORS OF ARRHYTHMIAS APPEARANCE

    Directory of Open Access Journals (Sweden)

    I. A. Kovalyov

    2013-01-01

    Full Text Available Clinical course, prognosis and mechanisms of separate forms of heart rhythm disorders in children differ from those in adults. Especially, it refers to new-borns and infants whose conduction system differs by functional and morphologic immaturity. In connection with it, the assessment of natural history of heart rhythm disorders, occurred in a perinatal period, and determination of risk factors of arrhythmia appearance in infants are of some interest. 88 newborns took part in the study. The patients were involved by continuous sampling technique. Risk factors, occurred in a perinatal period and potentially influenced on development of heart rhythm disorders, were assessed. In our study we took biological, gynecologic and obstetric history, data of gestation and delivery course, early and late neonatal period, early infancy, Echo, neurosonography, Holter monitoring with determination of heart rhythm variability, and determined thyroid hormonal status. Maximum specific gravity had extrasystoles – 32.4% – in the structure of idiopathic arrhythmias in infants. Heart rhythm disorders with natural history were kept at six months of life only in 5,4% of children. Persistence of arrhythmias was marked during one year only for WPW syndrome. Heart rhythm disorders are often marked significantly in children whose mothers had acute respiratory disease during the pregnancy, or if the children were born from the first pregnancy, had the signs of central nervous system damage syndromes in an early perinatal period (arrest, intracranial hypertension, convulsive disorder. Disorders of autonomic imbalance of cardiac function and peculiarities of hemodynamics of pulmonary circulation contribute significantly into appearance and persistence of all types of arrhythmias. On the whole, the prognosis of heart rhythm disorders, occurred in the perinatal period, without organic and structural changes of myocardium is favorable. The exclusion can be made for

  2. [Differential diagnosis and therapy of bradycardic arrhythmias].

    Science.gov (United States)

    Rausch, P; Jungmair, W; Kaliman, J F

    1994-01-01

    The most important symptoms in bradycardia are vertigo, dizziness and syncopy due to diminished cerebral blood sypply. Cardial symptoms are cardiac insufficiency and angina pectoris. By means of ECG, especially Holter-ECG, carotid sinus massage, atropin test and invasive methods (atrial stimulation, His-bundle ECG) sinu-nodal dysfunction, carotid sinus syndrome, bradyarrhythmia absoluta and AV-block can be diagnosed. Pharmacological treatment is only useful in acute situations. For symptomatic bradyarrhythmias the implantation of a Pacemaker is the therapy of choice. Individual treatment of the various types of bradyarrhythmia and the patients special needs is possible through the evolution of pacemaker technology. PMID:7825327

  3. Cardiac amyloidosis induces up-regulation of Deleted in Malignant Brain Tumors 1 (DMBT1)

    DEFF Research Database (Denmark)

    Müller, Hanna; Renner, Marcus; Bergmann, Frank;

    2013-01-01

    Amyloidosis is a life-threatening protein misfolding disease and affects cardiac tissue, leading to heart failure, myocardial ischemia and arrhythmia. Amyloid deposits result in oxidative stress, inflammation and apoptosis. The purpose of this study was to examine the role of innate defense...

  4. Phenotypical Manifestations of Mutations in the Genes Encoding Subunits of the Cardiac Sodium Channel

    NARCIS (Netherlands)

    Wilde, Arthur A. M.; Brugada, Ramon

    2011-01-01

    Variations in the gene encoding for the major sodium channel (Na(v)1.5) in the heart, SCN5A, has been shown to cause a number of arrhythmia syndromes (with or without structural changes in the myocardium), including the long-QT syndrome (type 3), Brugada syndrome, (progressive) cardiac conduction di

  5. Evaluating the Safety of Intraoperative Antiarrhythmics in Pediatric Cardiac Surgery Patients.

    Science.gov (United States)

    Beaty, Rachel S; Moffett, Brady S; Hall, Stuart; Kim, Jeffrey

    2015-10-01

    Cardiac arrhythmias occurring during the intraoperative period for cardiac surgery have been associated with excess morbidity and mortality. Several antiarrhythmics have been utilized for the management of intraoperative arrhythmias. These antiarrhythmic medications can cause undesirable adverse outcomes in the intensive care setting. The incidence and treatment of adult intraoperative arrhythmias have been studied. In addition, the prevalence, risk factors, and optimal treatment of pediatric postoperative arrhythmias have also been studied. However, the literature has not been published on intraoperative antiarrhythmia treatment during pediatric cardiac surgery. The purpose of this study was to determine the safety of intraoperative antiarrhythmic medications utilized in pediatric cardiac surgery patients. This was a retrospective review of all patients who received an intraoperative antiarrhythmic in the cardiovascular operating room at Texas Children's Hospital. Patients were included if they underwent cardiovascular surgery from November 2008 to July 2013 and were excluded if antiarrhythmics were given intraoperatively for other indications (i.e., esmolol for hypertension) or if patients were older than 18 years of age. Safety of antiarrhythmic treatment was determined by the absence or presence of adverse events. Control or recurrence of the arrhythmia was analyzed as a secondary measure to help determine antiarrhythmic efficacy. A total of 45 patients were identified (53.3 % male). Patients were a median of 0.52 years at the time of surgery. Primary surgery types were tetralogy of Fallot repair (n = 6; 13.3 %) and ventricular septal defect closure (n = 5, 11.1 %). Thirty-one patients (68.9 %) had documented adverse events after the administration of antiarrhythmics. Most of these adverse events occurred after the administration of amiodarone (n = 16; 51.6 %) followed by esmolol (n = 15; 48.4 %). Fifty-one percent of the arrhythmias resolved in the operating

  6. Effects of Chronic Oral Administration of Natural Honey on Ischemia/Reperfusion-induced Arrhythmias in Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Moslem Najafi

    2011-01-01

    Full Text Available Objective(sIn this study, effects of chronic administration of oral natural honey against ischemia/reperfusion (I/R-induced cardiac arrhythmias were investigated in isolated rat heart. Materials and MethodsMale Wistar rats were divided into four groups (n= 10-14 rats in each group and fed with natural honey (1%, 2% and 4% dissolved in the drinking water for 45 days except for the control group. After anesthesia, the rats’ hearts were isolated quickly, mounted on a Langendorff apparatus and perfused with a modified Krebs-Henseleit solution during stabilization, 30 min regional ischemia followed by 30 min reperfusion. The ECGs were recorded throughout the experiments to analyze cardiac arrhythmias based on the Lambeth conventions. ResultsIn the ischemic phase, honey (1% significantly reduced (P<0.05 the number and duration of ventricular tachycardia (VT. Honey (1% and 2% also significantly decreased number of ventricular ectopic beats (VEBs. In addition, incidence and duration of reversible ventricular fibrillation (Rev VF were lowered by honey 2% (P<0.05. During reperfusion time, VT incidence was 73% in the control group, however natural honey (1% decreased it to 22% (P<0.05. Honey also produced significant reduction in the incidences of total VF, Rev VF, duration and number of VT. ConclusionFor the first time, the results of present study demonstrated protective effects of chronic oral honey administration against I/R-induced arrhythmias in isolated rat heart. Antioxidant activity, the existence of energy sources such as glucose and fructose and improvement of some hemodynamic functions might be responsible for these effects.

  7. Glycemic control in cardiac surgery: Rationale and current evidence

    Directory of Open Access Journals (Sweden)

    G Girish

    2014-01-01

    Full Text Available Studies in cardiac surgical patients have shown an association of hyperglycemia with increased incidences of sepsis, mediastinitis, prolonged mechanical ventilation, cardiac arrhythmias and longer intensive care and hospital stay. There is considerable controversy regarding appropriate glycemic management in these patients and in the definition of hyperglycemia and hypoglycemia or the blood sugar levels at which therapy should be initiated. There is also dilemma regarding the usage of "tight glycemic control" with studies showing conflicting evidences. Part of the controversy can be explained by the differing designs of these studies and the variable definitions of hyperglycemia and hypoglycemia.

  8. Curative Effect Observation on Amiodarone in the Treatment of Arrhythmia%胺碘酮治疗心律失常的临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    李光立; 李玲

    2014-01-01

    Objective:To explore the arrhythmia outcomes in patients treated with amiodarone. Method:49 patients were treated with arrhythmia. Result:34 cases were markedly improved(69.4%),effective in 11 cases (accounting for 22.4%),4 cases were ineffective(8.2%),the total effective rate was 91.8%. Conclusion:Oral application of amiodarone in the treatment of arrhythmia in clinical effect is good,and can significantly improve cardiac arrhythmia patients,high security,small side effects,with the value of clinical application and promotion.%目的:探讨心律失常患者采用胺碘酮治疗的疗效。方法:对49例心律失常患者进行胺碘酮治疗。结果:显效34例(69.4%),有效11例(22.4%),无效4例(8.2%),总有效率为91.8%。结论:口服应用胺碘酮在治疗心律失常方面临床效果好,能够明显改善心律失常患者病情,安全性高,副作用小,具有临床应用与推广的价值。

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

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Yasuo; Fukushima, Yoshimitsu; Kumita, Shinichiro (Dept. of Radiology, Nippon Medical School, Tokyo (Japan)), email: yas-amano@nifty.com; Takayama, Morimasa (Dept. of Cardiology, Sakakibara Heart Inst., Tokyo (Japan)); Kitamura, Mitsunobu (Coronary Care Unit, Chiba-Hokuso Hospital of Nippon Medical School, Chiba (Japan))

    2011-07-15

    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

  10. Visualization of cardiac wavefronts using data fusion

    Science.gov (United States)

    Kynor, David B.; Dietz, Anthony; Friets, Eric; Peterson, Jon; Bergstrom, Ursula; Triedman, John; Hammer, Peter

    2002-05-01

    Catheter ablation has emerged as a highly effective treatment for arrhythmias that are constrained by known, easily located, anatomic landmarks. However, this treatment has enjoyed limited success for arrhythmias that are characterized by complex activation patterns or are not anatomically constrained. This class of arrhythmias, which includes atrial fibrillation and ventricular tachycardia resulting from ischemic heart disease, demands improved mapping tools. Current technology forces the cardiologist to view cardiac anatomy independently from the functional information contained in the electrical activation patterns. This leads to difficulties in interpreting the large volumes of data provided by high-density recording catheters and in mapping patients with abnormal anatomy (e.g., patients with congenital heart disease). The goal of this is work is development of new data processing and display algorithms that will permit the clinician to view activation sequences superimposed onto existing fluoroscopic images depicting the location of recording catheters within the heart. In cases where biplane fluoroscopic images and x-ray camera position data are available, the position of the catheters can be reconstructed in three-dimensions.

  11. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-mediated Calcium Signaling and Arrhythmias in the Heart Evoked by β-Adrenergic Stimulation*♦

    Science.gov (United States)

    Nebel, Merle; Schwoerer, Alexander P.; Warszta, Dominik; Siebrands, Cornelia C.; Limbrock, Ann-Christin; Swarbrick, Joanna M.; Fliegert, Ralf; Weber, Karin; Bruhn, Sören; Hohenegger, Martin; Geisler, Anne; Herich, Lena; Schlegel, Susan; Carrier, Lucie; Eschenhagen, Thomas; Potter, Barry V. L.; Ehmke, Heimo; Guse, Andreas H.

    2013-01-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+-releasing second messenger known to date. Here, we report a new role for NAADP in arrhythmogenic Ca2+ release in cardiac myocytes evoked by β-adrenergic stimulation. Infusion of NAADP into intact cardiac myocytes induced global Ca2+ signals sensitive to inhibitors of both acidic Ca2+ stores and ryanodine receptors and to NAADP antagonist BZ194. Furthermore, in electrically paced cardiac myocytes BZ194 blocked spontaneous diastolic Ca2+ transients caused by high concentrations of the β-adrenergic agonist isoproterenol. Ca2+ transients were recorded both as increases of the free cytosolic Ca2+ concentration and as decreases of the sarcoplasmic luminal Ca2+ concentration. Importantly, NAADP antagonist BZ194 largely ameliorated isoproterenol-induced arrhythmias in awake mice. We provide strong evidence that NAADP-mediated modulation of couplon activity plays a role for triggering spontaneous diastolic Ca2+ transients in isolated cardiac myocytes and arrhythmias in the intact animal. Thus, NAADP signaling appears an attractive novel target for antiarrhythmic therapy. PMID:23564460

  12. The spectrum of epidemiology underlying sudden cardiac death.

    Science.gov (United States)

    Hayashi, Meiso; Shimizu, Wataru; Albert, Christine M

    2015-06-01

    Sudden cardiac death (SCD) from cardiac arrest is a major international public health problem accounting for an estimated 15%-20% of all deaths. Although resuscitation rates are generally improving throughout the world, the majority of individuals who experience a sudden cardiac arrest will not survive. SCD most often develops in older adults with acquired structural heart disease, but it also rarely occurs in the young, where it is more commonly because of inherited disorders. Coronary heart disease is known to be the most common pathology underlying SCD, followed by cardiomyopathies, inherited arrhythmia syndromes, and valvular heart disease. During the past 3 decades, declines in SCD rates have not been as steep as for other causes of coronary heart disease deaths, and there is a growing fraction of SCDs not due to coronary heart disease and ventricular arrhythmias, particularly among certain subsets of the population. The growing heterogeneity of the pathologies and mechanisms underlying SCD present major challenges for SCD prevention, which are magnified further by a frequent lack of recognition of the underlying cardiac condition before death. Multifaceted preventative approaches, which address risk factors in seemingly low-risk and known high-risk populations, will be required to decrease the burden of SCD. In this Compendium, we review the wide-ranging spectrum of epidemiology underlying SCD within both the general population and in high-risk subsets with established cardiac disease placing an emphasis on recent global trends, remaining uncertainties, and potential targeted preventive strategies.

  13. Exercise-induced cardiac fatigue in low handicap polo horses

    Directory of Open Access Journals (Sweden)

    CAO Bello

    2014-01-01

    Full Text Available Physical exercise leads to several changes in the cardiovascular system of horses and may induce abnormalities that are not observed at rest. Little is known about the cardiac effects of intense physical exercise performed by horses in polo competitions. This study aimed at identifying if exercise-induced cardiac fatigue is observed in healthy polo ponies. We examined 25 equine athletes before and after a training match. The results demonstrated post-exercise electrocardiographic alteration such as cardiac arrhythmia, QTc prolongation, abnormal T waves and ST-segment elevation. The post-exercise echocardiogram showed interventricular septum and left ventricle free wall thickness reduction, systolic volume decreased and ejection fraction decreased. These results suggest that polo causes exercise-induced cardiac fatigue. It was not possible to establish accurately the etiology of this abnormality, nor its long-term consequences.

  14. Cardiac manifestations of idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Agrawal, Abhinav; Verma, Isha; Shah, Varun; Agarwal, Abhishek; Sikachi, Rutuja R

    2016-05-01

    Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, parenchymal disease of the lung with an estimated prevalence of 14-43 per 100,000. Patient usually presents with coughing and exertional dyspnea, which can lead to acute respiratory failure. IPF has been associated with various co-morbidities such as lung cancer, emphysema, obstructive sleep apnea (OSA), GERD and multiple cardiovascular consequences. The cardiovascular manifestations of IPF include pulmonary hypertension, heart failure, coronary artery disease, cardiac arrhythmias & cardiac manifestations of drugs used to treat IPF. This review will outline evidence of the association between IPF and cardiovascular conditions and attempt to provide insights into the underlying pathophysiology. We also discuss the impact of these cardiovascular diseases on patients with IPF including increased morbidity and mortality. PMID:27195188

  15. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  16. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  17. Circadian arrhythmia dysregulates emotional behaviors in aged Siberian hamsters.

    Science.gov (United States)

    Prendergast, Brian J; Onishi, Kenneth G; Patel, Priyesh N; Stevenson, Tyler J

    2014-03-15

    Emotional behaviors are influenced by the circadian timing system. Circadian disruptions are associated with depressive-like symptoms in clinical and preclinical populations. Circadian rhythm robustness declines markedly with aging and may contribute to susceptibility to emotional dysregulation in aged individuals. The present experiments used a model of chronic circadian arrhythmia generated noninvasively, via a series of circadian-disruptive light treatments, to investigate interactions between circadian desynchrony and aging on depressive- and anxiety-like behaviors, and on limbic neuroinflammatory gene expression that has been linked with emotionality. We also examined whether a social manipulation (group housing) would attenuate effects of arrhythmia on emotionality. In aged (14-18 months of age) male Siberian hamsters, circadian arrhythmia increased behavioral despair and decreased social motivation, but decreased exploratory anxiety. These effects were not evident in younger (5-9 months of age) hamsters. Social housing (3-5 hamsters/cage) abolished the effects of circadian arrhythmia on emotionality. Circadian arrhythmia alone was without effect on hippocampal or cortical interleukin-1β (IL-1β) and indoleamine 2,3-dioxygenase (Ido) mRNA expression in aged hamsters, but social housing decreased hippocampal IL-1β and Ido mRNAs. The data demonstrate that circadian disruption can negatively impact affective state, and that this effect is pronounced in older individuals. Although clear associations between circadian arrhythmia and constitutive limbic proinflammatory activity were not evident, the present data suggest that social housing markedly inhibits constitutive hippocampal IL-1β and Ido activity, which may contribute to the ameliorating effects of social housing on a number of emotional behaviors.

  18. A novel mutation in the RYR2 gene leading to catecholaminergic polymorphic ventricular tachycardia and paroxysmal atrial fibrillation: dose-dependent arrhythmia-event suppression by β-blocker therapy.

    Science.gov (United States)

    Kazemian, Pedram; Gollob, Michael H; Pantano, Alfredo; Oudit, Gavin Y

    2011-01-01

    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic condition that presents with exercise-induced polymorphic arrhythmias. We describe a case report of a 25-year-old woman who had a cardiac arrest due to ventricular fibrillation. Genetic analysis revealed a novel missense mutation in exon 90 of the ryanodine receptor (RyR2) gene resulting in substitution of arginine for serine at residue 4153 (S4153R). The patient received an implantable cardioverter-defibrillator and low-dose β-blocker therapy. She had recurrent polymorphic ventricular arrhythmias treated with appropriate cardioverter-defibrillator shocks and paroxysmal atrial fibrillation. Titration of β-blocker to a much higher dose suppressed further episodes of ventricular arrhythmia and paroxysmal atrial fibrillation, resulting in reduction in device therapies.

  19. Cardiac involvement in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    V. De Gennaro Colonna

    2011-06-01

    Full Text Available Rheumatoid arthritis (RA is a systemic disease of unknown etiology characterized by a chronic inflammatory process mainly leading to destruction of synovial membrane of small and major diarthrodial joints. The prevalence of RA within the general adult population is about 1% and female subjects in fertile age result mostly involved. It’s an invalidating disease, associated with changes in life quality and a reduced life expectancy. Moreover, we can observe an increased mortality rate in this population early after the onset of the disease. The mortality excess can be partially due to infective, gastrointestinal, renal or pulmonary complications and malignancy (mainly lung cancer and non- Hodgkin lymphoma. Among extra-articular complications, cardiovascular (CV involvement represents one of the leading causes of morbidity and mortality. Every cardiac structure can be affected by different pathogenic pathways: heart valves, conduction system, myocardium, endocardium, pericardium and coronary arteries. Consequently, different clinical manifestations can be detected, including: pericarditis, myocarditis, myocardial fibrosis, arrhythmias, alterations of conduction system, coronaropathies and ischemic cardiopathy, valvular disease, pulmonary hypertension and heart failure. Considering that early cardiac involvement negatively affects the prognosis, it is mandatory to identify high CV risk RA patients to better define long-term management of this population.

  20. Marshall束电生理特性及相关的房性心律失常%Electrophysiological Characteristics of Marshall Bundle and Its Related Atrial Arrhythmia

    Institute of Scientific and Technical Information of China (English)

    李蕾; 刘书旺(综述)

    2016-01-01

    Although the ligament of Marshall ( LOM) has been implicated in the genesis of atrial arrhythmia , the important cardiac muscle fibers ( Marshall bundles , MB) within this LOM is not well concerned .The paper reviews the anatomy of MB and its electrophysio-logical characteristics and mechanism in atrial arrhythmia .%已知Marshall韧带参与了房性心律失常的发生和维持,然而,其中起关键作用的肌性结构———Marshall束尚无详细报道。现就Marshall束的解剖及其在房性心律失常中的电生理特性、折返机制和研究进展做一综述。

  1. Inherited Cardiac Diseases Caused by Mutations in the Nav1.5 Sodium Channel

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Jacob; Winkel, Bo Gregers; Grunnet, Morten;

    2009-01-01

    Cardiac Diseases Caused by SCN5A Mutations. A prerequisite for a normal cardiac function is a proper generation and propagation of electrical impulses. Contraction of the heart is obtained through a delicate matched transmission of the electrical impulses. A pivotal element of the impulse...... propagation is the depolarizing sodium current, responsible for the initial depolarization of the cardiomyocytes. Recent research has shown that mutations in the SCN5A gene, encoding the cardiac sodium channel Nav1.5, are associated with both rare forms of ventricular arrhythmia, as well as the most frequent...... form of arrhythmia, atrial fibrillation (AF). In this comprehensive review, we describe the functional role of Nav1.5 and its associated proteins in propagation and depolarization both in a normal- and in a pathophysiological setting. Furthermore, several of the arrhythmogenic diseases, such as long...

  2. In-Hospital Cardiac Arrest: An Update on Pulseless Electrical Activity and Asystole.

    Science.gov (United States)

    Attin, Mina; Tucker, Rebecca G; Carey, Mary G

    2016-09-01

    Nonshockable rhythms, including pulseless electrical activity (PEA) and asystole, precede more than 70% of in-hospital cardiac arrests (I-HCA). Compared with shockable rhythms (ventricular fibrillation and ventricular tachycardia), nonshockable rhythms have higher mortality and morbidity. Therefore, investigating the underlying mechanisms of these arrhythmias to improve the quality of care and outcome for patients who suffer cardiac arrest is a priority. As the first responders to I-HCA, nurses must have the proper knowledge and training to provide timely and efficient cardiopulmonary resuscitation therapy. This article provides an overview of nonshockable cardiac arrhythmias preceding I-HCA as a means of addressing the gap between science and clinical practice. PMID:27484665

  3. Reduction of false arrhythmia alarms using signal selection and machine learning.

    Science.gov (United States)

    Eerikäinen, Linda M; Vanschoren, Joaquin; Rooijakkers, Michael J; Vullings, Rik; Aarts, Ronald M

    2016-08-01

    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 fatigue. In addition, patient safety is compromised because reaction time of the caregivers to true alarms is reduced. The data for the algorithm development consisted of records of electrocardiogram (ECG), arterial blood pressure, and photoplethysmogram signals in which an alarm for either asystole, extreme bradycardia, extreme tachycardia, ventricular fibrillation or flutter, or ventricular tachycardia occurs. First, heart beats are extracted from every signal. Next, the algorithm selects the most reliable signal pair from the available signals by comparing how well the detected beats match between different signals based on [Formula: see text]-score and selecting the best match. From the selected signal pair, arrhythmia specific features, such as heart rate features and signal purity index are computed for the alarm classification. The classification is performed with five separate Random Forest models. In addition, information on the local noise level of the selected ECG lead is added to the classification. The algorithm was trained and evaluated with the PhysioNet/Computing in Cardiology Challenge 2015 data set. In the test set the overall true positive rates were 93 and 95% and true negative rates 80 and 83%, respectively for events with no information and events with information after the alarm. The overall challenge scores were 77.39 and 81.58. PMID:27454128

  4. Macro-micro imaging of cardiac-neural circuits in co-cultures from normal and diseased hearts.

    Science.gov (United States)

    Bub, Gil; Burton, Rebecca-Ann B

    2015-07-15

    The autonomic nervous system plays an important role in the modulation of normal cardiac rhythm, but is also implicated in modulating the heart's susceptibility to re-entrant ventricular and atrial arrhythmias. The mechanisms by which the autonomic nervous system is pro-arrhythmic or anti-arrhythmic is multifaceted and varies for different types of arrhythmia and their cardiac substrates. Despite decades of research in this area, fundamental questions related to how neuron density and spatial organization modulate cardiac wave dynamics remain unanswered. These questions may be ill-posed in intact tissues where the activity of individual cells is often experimentally inaccessible. Development of simplified biological models that would allow us to better understand the influence of neural activation on cardiac activity can be beneficial. This Symposium Review summarizes the development of in vitro cardiomyocyte cell culture models of re-entrant activity, as well as challenges associated with extending these models to include the effects of neural activation.

  5. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective

    Science.gov (United States)

    Klimas, Aleksandra; Entcheva, Emilia

    2014-08-01

    The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.

  6. Comparison of Arrhythmias among Different Left Ventricular Geometric Patterns in Essential Hypertension

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The differences of arrhythmias among distinct left ventricular geometric patterns in the patients with essential hypertension were studied. 179 patients with essential hypertension received 24 h dynamic ECG recording, ambulatory blood pressure monitoring, echocardiography examination, etc. According to the examinations, left ventricular geometric patterns and arrhythmias were identified. The comparison of morbidity of arrhythmias between the left ventricular remodeling group and the normal geometric pattern group was performed. The multiple stepwise regression analysis was carried out to identify the independent determinants of arrhythmias. After these predictors were controlled or adjusted, the severity of arrhythmias among different left ventricular geometric patterns was compared. It was found that the morbidity of atrial arrhythmia, ventricular arrhythmia and complex ventricular arrhythmias in the left ventricular remodeling group was significantly higher than in the normal geometric pattern group respectively. There were many independent factors influencing on arrhythmias in essential hypertension. Of all these factors, some indices of left ventricular anatomic structure, grade of hypertension, left atrial inner dimension, E/A, diastolic blood pressure load value at night and day average heart rate and so on were very important. After the above-mentioned factors were adjusted, the differences of the orders of arrhythmias between partial geometric patterns were reserved, which resulted from the differences of the geometric patterns. Many factors contributed to arrhythmias of essential hypertension, such as grade of hypertension, LVMI, LA, PWT and so on. The severity of arrhythmias was different in different left ventricular geometric patterns.

  7. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  8. Cardiac Characteristics of Transgenic Mice Overexpressing Refsum Disease Gene-Associated Protein within the Heart.

    Science.gov (United States)

    Koh, J T; Choi, H H; Ahn, K Y; Kim, J U; Kim, J H; Chun, J Y; Baik, Y H; Kim, K K

    2001-09-01

    Arrhythmia is a common cardiac symptom of Refsum disease. Recently, we identified a novel neuron-specific PAHX-associated protein (PAHX-AP1), which binds to the Refsum disease gene (PAHX). In this report, we developed heart-targeted transgenic (TG) mice under the control of alpha-myosin heavy chain promoter to determine whether cardiac overexpression of PAHX-AP1 provokes cardiac involvement symptoms. Northern and in situ hybridization analyses revealed PAHX-AP1 transcript was overexpressed in TG atrium, especially in the sinoatrial node. TG mice showed tachycardia, and tachyarrhythmia was observed in 20% of TG mice. Isolated TG atria showed higher frequency beating and were more sensitive to aconitine-induced tachyarrhythmia than the wild-type, and 40% of the TG atria showed irregular beating. Action potential duration in TG atrial fiber was shortened much more than the wild-type. Systemic administration of arrhythmogenic agents induced arrhythmia in TG mice, while no arrhythmia with the same dose in nonTG mice. Our results indicate that the chronic atrial tachycardia by overexpressed neuron-specific PAHX-AP1 transgene in atrium may be responsible for the increased susceptibility to arrhythmia.

  9. Autonomic Dysfunction Predicts Early Cardiac Affection in Patients with Systemic Sclerosis

    Directory of Open Access Journals (Sweden)

    Khaled M. Othman

    2010-05-01

    Full Text Available Objective: To detect the early preclinical alterations in cardiac autonomic control as well as altered cardiac function in systemic sclerosis (SSc patients and their relevance to the clinical features of the disease using noninvasive methods. Methods: 30 SSc patients and 15 healthy controls matched for age and sex underwent clinical examination, serological analysis, and echocardiographic assessment including Doppler flow imaging to evaluate cardiac function, and 24-hour Holter monitoring analyzed for arrhythmia and heart rate variability (HRV in the time and frequency domains. Results: The trans-mitral Doppler of early to atrial wave (E/A ratio was reversed in five patients (16.6% and the tricuspid E/A ratio was reversed in 10 patients (33.3%. Holter analysis for SSc patients revealed an increased prevalence of premature ventricular contractions (PVC $ 10/h (P = 0.02, supra-ventricular tachycardias (SVTs (P = 0.2, and total PVC count (P = 0.0000. Highly significant (P = 0.000 impairment in all HRV parameters was demonstrated in the SSc patients. Total skin thickness score (TSS, Raynaud’s phenomenon and anti-scleroderma 70 (anti-SCL70 showed significant positive correlations with all arrhythmia parameters, while showing a significant negative correlation with the impaired ventricular diastolic function and various HRV parameters. No correlation was found between arrhythmia and HRV parameters and disease duration, disease type, or presence of anti-centromere antibodies. Conclusion: Low heart rate variability, increased TSS and the presence of anti-SCL70 are correlated with preclinical cardiac involvement in SSc patients and may predict the likelihood of malignant arrhythmia and sudden cardiac death. Therefore, noninvasive HRV evaluation before clinical cardiac involvement in these patients might be beneficial when added to the clinical and laboratory assessments in detecting high-risk patients, and may allow for implementation of preventive

  10. Unpinning of rotating spiral waves in cardiac tissues by circularly polarized electric fields

    Science.gov (United States)

    Feng, Xia; Gao, Xiang; Pan, De-Bei; Li, Bing-Wei; Zhang, Hong

    2014-04-01

    Spiral waves anchored to obstacles in cardiac tissues may cause lethal arrhythmia. To unpin these anchored spirals, comparing to high-voltage side-effect traditional therapies, wave emission from heterogeneities (WEH) induced by the uniform electric field (UEF) has provided a low-voltage alternative. Here we provide a new approach using WEH induced by the circularly polarized electric field (CPEF), which has higher success rate and larger application scope than UEF, even with a lower voltage. And we also study the distribution of the membrane potential near an obstacle induced by CPEF to analyze its mechanism of unpinning. We hope this promising approach may provide a better alternative to terminate arrhythmia.

  11. Arrhythmias and electrocardiographic changes in systolic heart failure

    Directory of Open Access Journals (Sweden)

    Ashok Devkota

    2016-01-01

    Full Text Available Background: Heart failure is a common condition that that leads to hospitalization. It is associated with various atrial and ventricular arrhythmias. Aim: The aim of this study is to find common arrhythmias and electrocardiographic changes in hospitalized patients who have systolic heart failure. Materials and Methods: This is a retrospective study of medical records, and electrocardiograms (EKGs of 157 patients admitted to our hospital who had systolic heart failure with ejection fraction (EF 35%. Twelve-lead EKG of these patients was studied to identify common arrhythmia and demographic variables; laboratory results were compared to identify the differences. Results: A total of 157 patients with systolic heart failure, 63.7% had an EF ≤ 35%. Hypertension 82.8%, diabetes 49%, coronary artery disease 40.8%, chronic obstructive pulmonary disease or bronchial asthma 22.3%, and stroke 12.1% were common associated co-morbidities. On analysis of EKG, 28.6% had tachycardia, 21.9% had prolonged PR > 200 ms, 16.3% had wide QRS > 120 ms, 70.7% had prolonged corrected QT (QTc, and 42.2% had left axis deviation. The most common arrhythmias were sinus tachycardia and atrial fibrillation/flutter which were found in 14.6% and 13.4%, respectively. The left ventricular hypertrophy was a common abnormality found in 22.4% followed by ventricular premature contractions 18.4%, atrial premature contractions 9.5%, and left bundle branch block 6.1%. Patients with severe systolic heart failure had prolonged QRS (P = 0.02 and prolonged QTc (P = 0.01 as compared to the other group. Conclusions: Sinus tachycardia and atrial fibrillation/flutter were common arrhythmias in patients with systolic heart failure. Patients with severe systolic heart failure had statistically significant prolongation of the QRS duration and QTc interval.

  12. An improved method for discriminating ECG signals using typical nonlinear dynamic parameters and recurrence quantification analysis in cardiac disease therapy

    OpenAIRE

    Chang, CQ; Chau, KT; Tang, M; Fung, PCW; Chan, FHY

    2005-01-01

    The discrimination of ECG signals using nonlinear dynamic parameters is of crucial importance in the cardiac disease therapy and chaos control for arrhythmia defibrillation in the cardiac system. However, the discrimination results of previous studies using features such as maximal Lyapunov exponent (λ max) and correlation dimension (D 2) alone are somewhat limited in recognition rate. In this paper, improved methods for computing λ max and D 2 are purposed. Another parameter from recurrence ...

  13. Diagnosis and treatment of cardiac sarcoidosis.

    Science.gov (United States)

    Kusano, Kengo F; Satomi, Kazuhiro

    2016-02-01

    Sarcoidosis is a systemic granulomatous disease of unknown aetiology. The frequency of cardiac involvement (cardiac sarcoidosis (CS)) varies in the different geographical regions, but it has been reported that it is an absolutely important prognostic factor in this disease. Complete atrioventricular block is the most common, and ventricular tachycardia/ventricular fibrillation the second most common arrhythmia in this disease, both of which are associated with cardiac sudden death. Diagnosing CS is sometimes difficult because of the non-specific ECG and echocardiographic findings, and CS is sometimes misdiagnosed as dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy or an idiopathic ventricular aneurysm, and therefore, endomyocardial biopsy is important, but has a low sensitivity. Another problem is the recognition of isolated types of CS. Recently, MRI and (18)F-fluorodeoxyglucose positron emission tomography have been demonstrated to be useful tools for the non-invasive diagnosis of CS as well as therapeutic evaluation tools, but are still unsatisfactory. Treatment of CS is usually done by corticosteroid therapy to control inflammation, prevent fibrosis and protect from any deterioration of the cardiac function, but the long-term outcome is still in debate. Despite the advancement of non-pharmacological approaches for CS (pacing, defibrillators and catheter ablation) to improve the prognosis, there are still many issues remaining to resolve diagnosing and managing CS. Here, we attempt a review of the clinical evidence, with special focus on the current understanding of this disease and showing the current strategies and remaining problems of diagnosing and managing CS. PMID:26643814

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

    International Nuclear Information System (INIS)

    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 Ca2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca2+ 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 Ca2+ handling proteins demonstrated that aconitine promoted Ca2+ overload through the expression regulation of Ca2+ 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 Ca2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca2+ overload causes arrhythmia in rats.

  15. Cardiac rhabdomyosarcoma

    OpenAIRE

    Chlumský, Jaromír; Holá, Dana; Hlaváček, Karel; Michal, Michal; Švec, Alexander; Špatenka, Jaroslav; Dušek, Jan

    2001-01-01

    Cardiac sarcoma is a very rare neoplasm and is difficult to diagnose. The case of a 51-year-old man with a left atrial tumour, locally recurrent three months after its surgical removal, is presented. Computed tomography showed metastatic spread to the lung parenchyma. On revised histology, the mass extirpated was a sarcoma. Because of the metastatic spread, further therapy was symptomatic only; the patient died 15 months after the first manifestation of his problems. Immunohistochemical stain...

  16. Gender-specific differences in major cardiac events and mortality in lamin A/C mutation carriers

    NARCIS (Netherlands)

    van Rijsingen, Ingrid A. W.; Nannenberg, Eline A.; Arbustini, Eloisa; Elliott, Perry M.; Mogensen, Jens; Hermans-van Ast, Johanna F.; van der Kooi, Anneke J.; van Tintelen, J. Peter; van den Berg, Maarten P.; Grasso, Maurizia; Serio, Alessandra; Jenkins, Sharon; Rowland, Camilla; Richard, Pascale; Wilde, Arthur A. M.; Perrot, Andreas; Pankuweit, Sabine; Zwinderman, Aeilko H.; Charron, Philippe; Christiaans, Imke; Pinto, Yigal M.

    2013-01-01

    Mutations in the lamin A/C gene (LMNA) cause a variety of clinical phenotypes, including dilated cardiomyopathy. LMNA is one of the most prevalent mutated genes in dilated cardiomyopathy, and is associated with a high risk of arrhythmias, sudden cardiac death, and heart failure. There are few data o

  17. The prognosis of implantable defibrillator patients treated with cardiac resynchronization therapy: Comorbidity burden as predictor of mortality

    NARCIS (Netherlands)

    D.A.M.J. Theuns (Dominic); B. Schaer (Beat); O.I.I. Soliman (Osama Ibrahim Ibrahim); D. Altmann (David); C. Sticherling (Christian); M.L. Geleijnse (Marcel); S. Osswald (Stefan); L.J.L.M. Jordaens (Luc)

    2011-01-01

    textabstractAimsComorbidity, such as myocardial infarction, diabetes, and renal failure, plays a pivotal role in the prognosis of a patient with arrhythmias. However, data on the prognostic impact of comorbiditiy in heart failure patients with cardiac resynchronization therapy and defibrillation (CR

  18. Familial Evaluation in Catecholaminergic Polymorphic Ventricular Tachycardia Disease Penetrance and Expression in Cardiac Ryanodine Receptor Mutation-Carrying Relatives

    NARCIS (Netherlands)

    van der Werf, Christian; Nederend, Ineke; Hofman, Nynke; van Geloven, Nan; Ebink, Corne; Frohn-Mulder, Ingrid M. E.; Alings, A. Marco W.; Bosker, Hans A.; Bracke, Frank A.; van den Heuvel, Freek; Waalewijn, Reinier A.; Bikker, Hennie; van Tintelen, J. Peter; Bhuiyan, Zahurul A.; van den Berg, Maarten P.; Wilde, Arthur A. M.

    2012-01-01

    Background-Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome associated with mutations in the cardiac ryanodine receptor gene (RYR2) in the majority of patients. Previous studies of CPVT patients mainly involved probands, so current insight into disease

  19. Nicorandil prevents Gαq-induced progressive heart failure and ventricular arrhythmias in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Masamichi Hirose

    Full Text Available BACKGROUND: Beneficial effects of nicorandil on the treatment of hypertensive heart failure (HF and ischemic heart disease have been suggested. However, whether nicorandil has inhibitory effects on HF and ventricular arrhythmias caused by the activation of G protein alpha q (Gα(q -coupled receptor (GPCR signaling still remains unknown. We investigated these inhibitory effects of nicorandil in transgenic mice with transient cardiac expression of activated Gα(q (Gα(q-TG. METHODOLOGY/PRINCIPAL FINDINGS: Nicorandil (6 mg/kg/day or vehicle was chronically administered to Gα(q-TG from 8 to 32 weeks of age, and all experiments were performed in mice at the age of 32 weeks. Chronic nicorandil administration prevented the severe reduction of left ventricular fractional shortening and inhibited ventricular interstitial fibrosis in Gα(q-TG. SUR-2B and SERCA2 gene expression was decreased in vehicle-treated Gα(q-TG but not in nicorandil-treated Gα(q-TG. eNOS gene expression was also increased in nicorandil-treated Gα(q-TG compared with vehicle-treated Gα(q-TG. Electrocardiogram demonstrated that premature ventricular contraction (PVC was frequently (more than 20 beats/min observed in 7 of 10 vehicle-treated Gα(q-TG but in none of 10 nicorandil-treated Gα(q-TG. The QT interval was significantly shorter in nicorandil-treated Gα(q-TG than vehicle-treated Gα(q-TG. Acute nicorandil administration shortened ventricular monophasic action potential duration and reduced the number of PVCs in Langendorff-perfused Gα(q-TG mouse hearts. Moreover, HMR1098, a blocker of cardiac sarcolemmal K(ATP channels, significantly attenuated the shortening of MAP duration induced by nicorandil in the Gα(q-TG heart. CONCLUSIONS/SIGNIFICANCE: These findings suggest that nicorandil can prevent the development of HF and ventricular arrhythmia caused by the activation of GPCR signaling through the shortening of the QT interval, action potential duration, the normalization

  20. Cardiac-Specific Overexpression of SCN5A Gene Leads to Shorter P Wave Duration and PR Interval in Transgenic Mice

    OpenAIRE

    Zhang, Teng; Yong, Sandro L.; Tian, Xiao-Li; Wang, Qing K.

    2007-01-01

    SCN5A plays a critical role in cardiac electrophysiology and its mutations, either gain- or loss-of-functions, are associated with lethal arrhythmias. In this study we investigated the effect of overexpression of SCN5A on the cardiac phenotype in a transgenic mouse model (TG-WT L10). Compared to NTG mice, heart rate, QRS duration and QT intervals remained unchanged in TG-WT mice. Moreover, no spontaneous ventricular arrhythmias were detected in TG-WT hearts. Despite these results, a mild, irr...

  1. Cancer treatment-related cardiac toxicity: prevention, assessment and management.

    Science.gov (United States)

    Fanous, Ibrahim; Dillon, Patrick

    2016-08-01

    Cancer therapies, especially anthracyclines and monoclonal antibodies, have been linked with increased rates of cardiotoxicity. The development of some cardiac side effects happens over several months, and changes in ejection fraction can be detected long before permanent damage or disability occurs. Advanced heart failure could be averted with better and earlier detection. Methodologies for early detection of cardiac changes include stress echocardiograms, cardiac velocity measurements, radionuclide imaging, cardiac MRI and several potential biomarkers. Many agents have been described for prophylaxis of cardiac events precipitated by cancer therapy. Prophylactic use of beta-blockers and ACE inhibitors may be considered for use with trastuzumab in breast cancer as tolerated. Recovery of cardiac function is possible early after the injury from a cancer therapy. Late complications for coronary artery disease, hypertension and arrhythmia are underappreciated. Treatments for severe cancer therapy-related cardiac complications follow the existing paradigms for congestive heart failure and coronary artery disease, although outcomes for cancer patients differ from outcomes for non-cancer patients. PMID:27372782

  2. A Case Report of Primary Cardiac Tumor in A Neonate

    Directory of Open Access Journals (Sweden)

    Sh. Rejaei

    2008-04-01

    Full Text Available Introduction: Primary cardiac tumors are extremely rare in infants and children . Most primary cardiac tumors in pediatric age group are benign, and less than 10% of such tumors are malignant. Many of these tumors are asymptomatic and incidentally diagnosed. The clinical manifestations are very different and includes direct cardiac effect, systemic effect , and embolic phenomena. Every infant or child with an unusual cardiac murmur, unexplained congestive heart failure, or arrhythmia should be evaluated for cardiac tumors. Echocardiography has contributed significantly to the evaluation of these patients. Surgery is the only treatment for primary cardiac tumors that require intervention with a relatively good prognosis. Case Report: The patient was a 20 days old neonate presented with severe congestive heart failure. Evaluation of the patient showed primary cardiac tumor in the left atrium and ventricle. We recommended surgical removal of the tumor but her parents denied surgical intervention at all. Conclusion: After about one year follow up, congestive heart failure symptoms were controlled and the tumor size was decreased.

  3. Major rapid weight loss induces changes in cardiac repolarization

    DEFF Research Database (Denmark)

    Vedel-Larsen, Esben; Iepsen, Eva Winning; Lundgren, Julie;

    2016-01-01

    INTRODUCTION: Obesity is associated with increased all-cause mortality, but weight loss may not decrease cardiovascular events. In fact, very low calorie diets have been linked to arrhythmias and sudden death. The QT interval is the standard marker for cardiac repolarization, but T-wave morphology...... analysis has been suggested as a more sensitive method to identify changes in cardiac repolarization. We examined the effect of a major and rapid weight loss on T-wave morphology. METHODS AND RESULTS: Twenty-six individuals had electrocardiograms (ECG) taken before and after eight weeks of weight loss......A1c (pweight loss induces changes in cardiac repolarization. Monitoring of MCS during calorie restriction makes it possible to detect repolarization changes with higher discriminative power than the QT-interval during major rapid weight...

  4. Dynamics of wave fronts and filaments in anisotropic cardiac tissue

    CERN Document Server

    Dierckx, Hans J F M

    2015-01-01

    The heartbeat is mediated between cardiac cells by waves of electrical depolarisation. During cardiac arrhythmias, electrical activity was found to be organised in scroll waves which rotate around a dynamical filament curve. In this thesis, a curved-space approach is used to mathematically capture anisotropy of wave propagation. We derive for the first time the covariant laws of motion for traveling wave fronts and scroll wave filaments in anisotropic excitable media such as cardiac tissue. We show that locally varying anisotropy yields non-zero Riemann tensor components, which may alter the stability of scroll wave filaments. The instability of scroll wave filaments has been linked to transition from ventricular tachycardia to fibrillation.

  5. T-wave Alternans and Arrhythmogenesis in Cardiac Diseases

    Directory of Open Access Journals (Sweden)

    Zhilin eQu

    2010-11-01

    Full Text Available T-wave alternans, a manifestation of repolarization alternans at the cellular level, is associated with lethal cardiac arrhythmias and sudden cardiac death. At the cellular level, several mechanisms can produce repolarization alternans, including: 1 electrical restitution resulting from collective ion channel recovery, which usually occurs at fast heart rates but can also occur at normal heart rates when action potential is prolonged resulting in a short diastolic interval; 2 the transient outward current, which tends to occur at normal or slow heart rates; 3 the dynamics of early afterdepolarizations, which tends to occur during bradycardia; and 4 intracellular calcium cycling alternans through its interaction with membrane voltage. In this review, we summarize the cellular mechanisms of alternans arising from these different mechanisms, and discuss their roles in arrhythmogenesis in the setting of cardiac disease.

  6. Severe Hypoglycemia–Induced Lethal Cardiac Arrhythmias Are Mediated by Sympathoadrenal Activation

    OpenAIRE

    Reno, Candace M.; Daphna-Iken, Dorit; Chen, Y. Stefanie; VanderWeele, Jennifer; Jethi, Krishan; Fisher, Simon J.

    2013-01-01

    For people with insulin-treated diabetes, severe hypoglycemia can be lethal, though potential mechanisms involved are poorly understood. To investigate how severe hypoglycemia can be fatal, hyperinsulinemic, severe hypoglycemic (10–15 mg/dL) clamps were performed in Sprague-Dawley rats with simultaneous electrocardiogram monitoring. With goals of reducing hypoglycemia-induced mortality, the hypotheses tested were that: 1) antecedent glycemic control impacts mortality associated with severe hy...

  7. Cardiac electrophysiological effects of selective adrenoceptor stimulation and their possible roles in arrhythmias.

    Science.gov (United States)

    Vaughan Williams, E M

    1985-01-01

    The selective alpha 1- and alpha 2-adrenoceptor agonists St 587 and BHT 933, respectively, and the antagonists prazosin (alpha 1) and WY 25309 (alpha 2) have been used in combination with the selective beta 2-adrenoceptor agonist pirbuterol, and the antagonists atenolol (beta 1) and ICI 118551 (beta 2), to analyse the effects of individual types of adrenoceptor stimulation in various parts of the rabbit heart. In the sinus node, beta 1-, but not beta 2-adrenoceptor stimulation increased the fast phase of depolarisation. Both beta 1- and beta 2-adrenoceptor stimulation increased the slope of the slow diastolic depolarisation, accelerated repolarisation, and increased maximum diastolic potential. Beta 1- and beta 2-adrenoceptor stimulation also accelerated repolarisation in Purkinje cells and papillary muscle. After blockade of both beta 1- and beta 2-adrenoceptors, alpha 1-adrenoceptor stimulation caused bradycardia, owing exclusively to delayed repolarisation. Alpha 2-adrenoceptor stimulation had no effect. Beta 1-, but not beta 2-adrenoceptor stimulation augmented peak contractions three- to fivefold, and reduced the time-to-peak tension. In contrast, alpha 1-adrenoceptor stimulation only moderately (up to 47%) increased peak tension, but increased time-to-peak and duration of contractions. The results would be consistent with beta 1-adrenoceptor stimulation increasing inward calcium current, and with stimulation of alpha 1-adrenoceptors delaying the decline of [Ca]i rather than increasing its magnitude. Both beta 1- and beta 2-stimulation increased repolarising current, but alpha 1-stimulation decreased it.

  8. ST Depression, Arrhythmia, Vagal Dominance, and Reduced Cardiac MicroRNA in Particulate-exposed Rats

    Science.gov (United States)

    Recently, investigators demonstrated associations between fine particulate matter (PM)-associated metals and adverse health effects. Residual oil fly ash (ROFA), a waste product of fossil fuel combustion from boilers, is rich in the transition metals Fe, Ni, and V, and when relea...

  9. Image-based modeling and characterization of RF ablation lesions in cardiac arrhythmia therapy

    Science.gov (United States)

    Linte, Cristian A.; Camp, Jon J.; Rettmann, Maryam E.; Holmes, David R.; Robb, Richard A.

    2013-03-01

    In spite of significant efforts to enhance guidance for catheter navigation, limited research has been conducted to consider the changes that occur in the tissue during ablation as means to provide useful feedback on the progression of therapy delivery. We propose a technique to visualize lesion progression and monitor the effects of the RF energy delivery using a surrogate thermal ablation model. The model incorporates both physical and physiological tissue parameters, and uses heat transfer principles to estimate temperature distribution in the tissue and geometry of the generated lesion in near real time. The ablation model has been calibrated and evaluated using ex vivo beef muscle tissue in a clinically relevant ablation protocol. To validate the model, the predicted temperature distribution was assessed against that measured directly using fiberoptic temperature probes inserted in the tissue. Moreover, the model-predicted lesions were compared to the lesions observed in the post-ablation digital images. Results showed an agreement within 5°C between the model-predicted and experimentally measured tissue temperatures, as well as comparable predicted and observed lesion characteristics and geometry. These results suggest that the proposed technique is capable of providing reasonably accurate and sufficiently fast representations of the created RF ablation lesions, to generate lesion maps in near real time. These maps can be used to guide the placement of successive lesions to ensure continuous and enduring suppression of the arrhythmic pathway.

  10. A critical analysis of the scientific evidence behind international guidelines related to cardiac arrhythmias

    NARCIS (Netherlands)

    Roos, M.; Brodbeck, J.; Sarkozy, A.; Chierchia, G.B.; Asmundis, C. de; Brugada, P.

    2011-01-01

    BACKGROUND: Guidelines have become very important in assisting with decision making in clinical practice. However, few studies have analyzed the level of evidence (LOE) underlying guidelines critically. This study aims to assess the accuracy of the referenced literature that has led to recommendatio

  11. Cardiac arrhythmias the first month after acute traumatic spinal cord injury

    DEFF Research Database (Denmark)

    Bartholdy, Kim; Biering-Sørensen, Tor; Malmqvist, Lasse;

    2014-01-01

    . Furthermore, 12-lead electrocardiograms (ECGs) were obtained shortly after SCI and at 4 weeks. RESULTS: Thirty patients were included. Bradycardia (heart rate (HR) b.p.m.) was present in 17-35% of the patients with cervical (C1-C8) SCI (n = 24) within the first 14 days. In the following 14 days...

  12. Complexity-Measure-Based Sequential Hypothesis Testing for Real-Time Detection of Lethal Cardiac Arrhythmias

    OpenAIRE

    Szi-Wen Chen

    2007-01-01

    A novel approach that employs a complexity-based sequential hypothesis testing (SHT) technique for real-time detection of ventricular fibrillation (VF) and ventricular tachycardia (VT) is presented. A dataset consisting of a number of VF and VT electrocardiogram (ECG) recordings drawn from the MIT-BIH database was adopted for such an analysis. It was split into two smaller datasets for algorithm training and testing, respectively. Each ECG recording was measured in a 10-second interval. For ...

  13. Potential proarrhythmic effect of cardiac resynchronization therapy during perioperative period: data from a single cardiac center

    Institute of Scientific and Technical Information of China (English)

    LUO Nian-sang; YUAN Wo-liang; LIN Yong-qing; CHEN Yang-xin; MAO Xiao-qun; XIE Shuang-lun; KONG Min-yi; ZHOU Shu-xian; WANG Jing-feng

    2010-01-01

    Background Cardiac resynchronization therapy (CRT) could improve heart function, symptom status, quality of life and reduce hospitalization and mortality in patients with severe heart failure (HF) with optimal medical management. However,the possible adverse effects of CRT are often ignored by clinicians.Method A retrospective analysis of CRT over a 6-year period was made in a single cardiac center.Results Fifty-four patients were treated with CRT(D) device, aged (57±11) years, with left ventricular ejection fraction of (32.1±9.8)%, of which 4 (7%) developed ventricular tachycardia/ventricular fibrillation (VT/VF) or junctional tachycardia after operation. Except for one with frequent ventricular premature beat before operation, the others had no previous history of ventricular arrhythmia. Of the 4 patients, 3 had dilated cardiomyopathy and 1 had ischemic cardiomyopathy,and tachycardia occurred within 3 days after operation. Sustained, refractory VT and subsequent VF occurred in one patient, frequent nonsustained VT in two patients and nonparoxysmal atrioventricular junctional tachycardia in one patient. VT was managed by amiodarone in two patients, amiodarone together with beta-blocker in one patient, and junctional tachycardia was terminated by overdrive pacing. During over 12-month follow-up, except for one patient's death due to refractory heart and respiratory failure in hospital, the others remain alive and arrhythmia-free.Conclusions New-onset VT/VF or junctional tachycardia may occur in a minority of patients with or without prior history of tachycardia after biventricular pacing. Arrhythmia can be managed by conventional therapy, but may require temporary discontinuation of pacing. More observational studies should be performed to determine the potential proarrhythmic effect of CRT.

  14. Marine omega-3 highly unsaturated fatty acids: From mechanisms to clinical implications in heart failure and arrhythmias.

    Science.gov (United States)

    Glück, Tobias; Alter, Peter

    2016-07-01

    Therapeutic implications of marine omega-3 highly unsaturated fatty acids (HUFA) in cardiovascular disease are still discussed controversially. Several clinical trials report divergent findings and thus leave ambiguity on the meaning of oral omega-3 therapy. Potential prognostic indications of HUFA treatment have been predominantly studied in coronary artery disease, sudden cardiac death, ventricular arrhythmias, atrial fibrillation and heart failure of various origin. It is suspected that increased ventricular wall stress is crucially involved in the prognosis of heart failure. Increased wall stress and an unfavorable myocardial remodeling is associated with an increased risk of arrhythmias by stretch-activated membrane ion channels. Integration of HUFA into the microenvironment of cardiomyocyte ion channels lead to allosteric changes and increase the electrical stability. Increased ventricular wall stress appears to be involved in the local myocardial as well as in the hepatic fatty acid metabolism, i.e. a cardio-hepatic syndrome. Influences of an altered endogenous HUFA metabolism and an inverse shift of the fatty acid profile was underrated in the past. A better understanding of these interacting endogenous mechanisms appears to be required for interpreting the findings of recent experimental and clinical studies. The present article critically reviews major studies on basic pathophysiological mechanisms and treatment effects in clinical trials. PMID:27080538

  15. Disritmias cardíacas e alterações do segmento ST em idosos no perioperatório de ressecção transuretral da próstata sob raquianestesia: estudo comparativo Disritmias cardíacas y alteraciones del segmento ST en ancianos en el perioperatorio de resección transuretral de la próstata sobre raquianestesia: estudio comparativo Cardiac arrhythmias and ST changes in the perioperative period of elderly patients submitted to transurethral prostatectomy under spinal anesthesia: comparative study

    Directory of Open Access Journals (Sweden)

    Beatriz Lemos da Silva Mandim

    2004-04-01

    ón transuretral de la próstata, bien como por la herniorrafia inguinal, en los períodos intra y pos-operatorio.BACKGROUND AND OBJECTIVES: Elderly account for 25% of surgical patients. Several patients with arterial heart disease have normal preoperative ECG and a high incidence of silent myocardial acute infarction in the first postoperative week. Arrhythmias increase with age and supraventricular and ventricular premature complexes, atrial fibrillation and intraventricular conduction abnormalities are observed. This study aimed at evaluating the prevalence of perioperative arrhythmias and ST changes through Holter System in elderly patients submitted to transurethral prostatectomy and inguinal hernia repair under spinal anesthesia. METHODS: Participated in this study 21 patients aged 65 to 84 years submitted to transurethral prostatectomy (TUP and 16 patients aged 63 to 86 years submitted to inguinal hernia repair under spinal anesthesia. Monitoring with Holter System was performed in the preoperative (12 hours, intraoperative (3 hours and postoperative (12 hours periods. RESULTS: The prevalence of supraventricular premature complex was 85.7% vs. 93.7% in the preoperative period, 85.7% vs. 81.2% in the intraoperative and 76.2% vs. 100% in the postoperative period, respectively for groups TUP and control. The prevalence of ventricular premature complex was 76.2% vs. 81.2% in the preoperative period, 80.9% vs. 68.7% in the intraoperative period, and 80.9% vs. 81.2% in the postoperative period, respectively for groups TUP and control. The prevalence of ST changes was 19% vs. 18.7% in the preoperative period, 4.7% vs. 18.7% in the in the intraoperative period, and 14.3% vs. 18.7% in the postoperative period between groups TUP and control, without statistical significance. CONCLUSIONS: Elderly patients have a high prevalence of supraventricular and ventricular cardiac arrhythmias. The total number of preoperative arrhythmias and ST changes was not changed as a function of

  16. An unusual case of cardiac syncope and acute coronary syndrome – a case report

    Directory of Open Access Journals (Sweden)

    Chitu Monica

    2014-12-01

    Full Text Available Introduction: We aimed to present a case of acute coronary syndrome with unexpected etiology complicated by syncope and arrhythmias, confirmed by imagistic examinations as cardiac parasitosis. Cardiac parasitic diseases are rare diseases, whose diagnosis and therapy should be adapted to each case. Imaging techniques allow precise diagnosis of cardiac echinococcosis, providing essential structural details on the damage degree of heart structures, allowing optimization of complex treatment in these cases. Case presentation: A 67-year old, obese and diabetic woman presented with cardiac syncope, arrhythmias and acute chest pain. Imagistic examinations excluded intracoronary thrombosis and confirmed a severe structural damage of myocardial tissue, consisting in replacement of the myocardial structure by many cysts caused by parasitic infestation with echinococcus multilocularis and echinoccocus granulosus originating from the liver. CT scan confirmed severe distruction of the left ventricular myocardium by policysts, that led to thinning of inferior and apical left ventricle wall without any possibility of surgical excision. Therefore a specific chemotherapy with albendazole was initiated. Follow up at 2 months indicated a favorable evolution, with serological decrease of echinococcal antibodies and reduction of cysts volume. Conclusion: In cases of angina and arrhythmias with non-atherosclerotic etiology, imaging techniques can diagnose the anatomopathological substrate of the disease and represent a valuable tool for the follow up.

  17. False Alarm Reduction in BSN-Based Cardiac Monitoring Using Signal Quality and Activity Type Information

    Directory of Open Access Journals (Sweden)

    Tanatorn Tanantong

    2015-02-01

    Full Text Available False alarms in cardiac monitoring affect the quality of medical care, impacting on both patients and healthcare providers. In continuous cardiac monitoring using wireless Body Sensor Networks (BSNs, the quality of ECG signals can be deteriorated owing to several factors, e.g., noises, low battery power, and network transmission problems, often resulting in high false alarm rates. In addition, body movements occurring from activities of daily living (ADLs can also create false alarms. This paper presents a two-phase framework for false arrhythmia alarm reduction in continuous cardiac monitoring, using signals from an ECG sensor and a 3D accelerometer. In the first phase, classification models constructed using machine learning algorithms are used for labeling input signals. ECG signals are labeled with heartbeat types and signal quality levels, while 3D acceleration signals are labeled with ADL types. In the second phase, a rule-based expert system is used for combining classification results in order to determine whether arrhythmia alarms should be accepted or suppressed. The proposed framework was validated on datasets acquired using BSNs and the MIT-BIH arrhythmia database. For the BSN dataset, acceleration and ECG signals were collected from 10 young and 10 elderly subjects while they were performing ADLs. The framework reduced the false alarm rate from 9.58% to 1.43% in our experimental study, showing that it can potentially assist physicians in diagnosing a vast amount of data acquired from wireless sensors and enhance the performance of continuous cardiac monitoring.

  18. 320-detector row CT coronary angiography in patients with arrhythmia

    International Nuclear Information System (INIS)

    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)

  19. ECG Signal Analysis and Arrhythmia Detection using Wavelet Transform

    Science.gov (United States)

    Kaur, Inderbir; Rajni, Rajni; Marwaha, Anupma

    2016-06-01

    Electrocardiogram (ECG) is used to record the electrical activity of the heart. The ECG signal being non-stationary in nature, makes the analysis and interpretation of the signal very difficult. Hence accurate analysis of ECG signal with a powerful tool like discrete wavelet transform (DWT) becomes imperative. In this paper, ECG signal is denoised to remove the artifacts and analyzed using Wavelet Transform to detect the QRS complex and arrhythmia. This work is implemented in MATLAB software for MIT/BIH Arrhythmia database and yields the sensitivity of 99.85 %, positive predictivity of 99.92 % and detection error rate of 0.221 % with wavelet transform. It is also inferred that DWT outperforms principle component analysis technique in detection of ECG signal.

  20. Preoperative Arrhythmias Such as Atrial Fibrillation: Cardiovascular Surgery Risk Factor

    OpenAIRE

    Diana Anghel; Radu Anghel; Flavia Corciova; Mihail Enache; Grigore Tinica

    2014-01-01

    Atrial fibrillation is still the most common arrhythmia that occurs in heart surgery. However, there is few literature data on the manner in which preoperative atrial fibrillation may influence the postoperative outcome of various heart surgery procedures. The purpose of our research is to assess the effects of preoperative atrial fibrillation on patients having undergone different heart surgery procedures. The results of our research are a review of clinical data which were collected prospec...

  1. Developmental trajectories of respiratory sinus arrhythmia: Associations with social responsiveness

    OpenAIRE

    Patriquin, Michelle A.; Lorenzi, Jill; Scarpa, Angela; Bell, Martha Ann

    2013-01-01

    The present longitudinal study examined relations between respiratory sinus arrhythmia (RSA) development and social responsiveness characteristics associated with autism spectrum disorders. Group-based developmental trajectory modeling was used to characterize RSA development patterns in 106 typically developing children across 5, 10, 24, 36, and 48 months of age. A two-group model fit of RSA development was found: a “typically” and “atypically” developing group. The typical group gradually i...

  2. Methodological Issues in the Quantification of Respiratory Sinus Arrhythmia

    OpenAIRE

    Denver, John W.; Reed, Shawn F.; Porges, Stephen W.

    2006-01-01

    Although respiratory sinus arrhythmia (RSA) is a commonly quantified physiological variable, the methods for quantification are not consistent. This manuscript questions the assumption that respiration frequency needs to be manipulated or monitored to generate an accurate measure of RSA amplitude. A review of recent papers is presented that contrast RSA amplitude with measures that use respiratory parameters to adjust RSA amplitude. In addition, data from two studies are presented to evaluate...

  3. Exploiting periodicity to extract the atrial activity in atrial arrhythmias

    OpenAIRE

    Llinares Llopis, Raúl; Igual García, Jorge

    2011-01-01

    [EN] Atrial fibrillation disorders are one of the main arrhythmias of the elderly. The atrial and ventricular activities are decoupled during an atrial fibrillation episode, and very rapid and irregular waves replace the usual atrial P-wave in a normal sinus rhythm electrocardiogram (ECG). The estimation of these wavelets is a must for clinical analysis. We propose a new approach to this problem focused on the quasiperiodicity of these wavelets. Atrial activity is characterized by...

  4. Artifact versus arrhythmia in pseudo-polymorphic tachycardia; case report

    OpenAIRE

    Ahmed V; Patel A; Sharma A; Bloomfield D

    2015-01-01

    Vaseem Ahmed, Anish Patel, Abhishek Sharma, Dennis Bloomfield Department of Medicine, Richmond University Medical Center, Staten Island, NY, USA Abstract: We present the case of a young male patient in sinus rhythm whose electrocardiogram (ECG) was initially misinterpreted as ventricular tachycardia. Electrocardiographic artifact appearing to be ventricular tachycardia commonly occurs and ECG criteria have been described to aid in the discrimination between artifact and true arrhythmia. Ther...

  5. Prolonged QTc interval and risk of sudden cardiac death in a population of older adults

    DEFF Research Database (Denmark)

    Straus, Sabine M J M; Kors, Jan A; De Bruin, Marie L;

    2006-01-01

    OBJECTIVES: This study sought to investigate whether prolongation of the heart rate-corrected QT (QTc) interval is a risk factor for sudden cardiac death in the general population. BACKGROUND: In developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation...... of the QTc interval has been associated with ventricular arrhythmias, but in most population-based studies no consistent association was found between QTc prolongation and total or cardiovascular mortality. Only very few of these studies specifically addressed sudden cardiac death. METHODS: This study......). The association between a prolonged QTc interval and sudden cardiac death was estimated using Cox proportional hazards analysis. RESULTS: During an average follow-up period of 6.7 years (standard deviation, 2.3 years) 125 patients died of sudden cardiac death. An abnormally prolonged QTc interval (>450 ms in men...

  6. Intramyocardial activation in early ventricular arrhythmias following coronary artery ligation.

    Science.gov (United States)

    Kaplinsky, E; Ogawa, S; Kmetzo, J; Balke, C W; Dreifus, L S

    1980-01-01

    Subendocardial, subepicardial and intramyocardial activation in the ischemic zone was investigated in 20 anesthetized open chest dogs 0-30 minutes after the ligation of the left anterior descending coronary artery. Single and composite electrograms and lead 2 of the ECG were recorded. Coronary artery ligation produced marked delay, fragmentation, and reduction in amplitude in the electrical activity of the subepicardial and intramyocardial muscle layers. The activation remained synchronous in the subendocardial muscle layers. Extension of electrical activity in the ischemic subepicardium and intramyocardium beyond the T wave of the surface ECG preceded the onset of immediate ventricular arrhythmias (IVA) during the initial ten minute period after coronary artery ligation. However, a second surge of delayed ventricular arrhythmias (DVA), 10-30 minutes after ligation, was not associated with the appearance of diastolic electrical activity in any of the subepicardial or myocardial layers. It appears that subepicardial as well as intramyocardial reentry could play an important role in the genesis of the immediate ventricular arrhythmias (1-10 minutes after ligation). In contrast, no obvious reentrant activity as evidenced by delayed and fragmented electrical activity could be observed in the electrogram from any of the myocardial electrical activity could be observed in the electrogram from any of the myocardial layers with the appearance of delayed ventricular ectopic activity 10-30 minutes after ligation.

  7. Improving Managers' Psychophysical Well-Being: Effectiveness of Respiratory Sinus Arrhythmia Biofeedback.

    Science.gov (United States)

    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. PMID:26446978

  8. The risk of life-threatening ventricular arrhythmias in presence of high-intensity endurance exercise along with chronic administration of nandrolone decanoate.

    Science.gov (United States)

    Abdollahi, Farzane; Joukar, Siyavash; Najafipour, Hamid; Karimi, Abdolah; Masumi, Yaser; Binayi, Fateme

    2016-01-01

    Anabolic steroids used to improve muscular strength and performance in athletics. Its long-term consumption may induce cardiovascular adverse effects. We assessed the risk of ventricular arrhythmias in rats which subjected to chronic nandrolone plus high-intensity endurance exercise. Animals were grouped as; control (CTL), exercise (Ex): 8 weeks under exercise, vehicle group (Arach): received arachis oil, and Nan group: received nandrolone decanoate 5 mg/kg twice a week for 8 weeks, Arach+Ex group, and Nan+Ex. Finally, under anesthesia, arrhythmia was induced by infusion of 1.5 μg/0.1 mL/min of aconitine IV and ventricular arrhythmias were recorded for 15 min. Then, animals' hearts were excised and tissue samples were taken. Nandrolone plus exercise had no significant effect on blood pressure but decreased the heart rate (Pventricular fibrillation (VF) frequency and also decreased the VF latency (P<0.05 versus CTL group). Combination of exercise and nandrolone could not recover the decreasing effects of nandrolone on animals weight gain but, it enhanced the heart hypertrophy index (P<0.05). In addition, nandrolone increased the level of hydroxyproline (HYP) and malondialdehyde (MDA) but had not significant effect on glutathione peroxidase of heart. Exercise only prevented the effect of nandrolone on HYP. Nandrolone plus severe exercise increases the risk of VF that cannot be explained only by the changes in redox system. The intensification of cardiac hypertrophy and prolongation of JT interval may be a part of involved mechanisms.

  9. Classification of Arrhythmias Using Linear Predictive Coefficients and Probabilistic Neural Network

    Directory of Open Access Journals (Sweden)

    Hossein EBRAHIMNEZHAD

    2013-09-01

    Full Text Available Cardiac arrhythmia, which means abnormality of heart rhythm, in fact refers to disorder in electrical conduction system of the heart. The aim of this paper is to present a classifier system based on Probabilistic Neural Networks in order to detect and classify abnormal heart rates, where besides its simplicity, has high resolution capability. The proposed algorithm has three stages. At first, the electrocardiogram signals impose into preprocessing block. After preprocessing and noise elimination, the exact position of R peak is detected by multi resolution wavelet analysis. In the next step, the extracted linear predictive coefficients (LPC of QRS complex will enter in to the classification block as an input. A Support Vector Machine classifier is developed in parallel to verify and measure the PNN classifier’s success. The experiments were conducted on the ECG data from the MIT-BIH database to classify four kinds of abnormal waveforms and normal beats such as Normal sinus rhythm, Atrial premature contraction (APC, Right bundle branch block (RBBB and Left bundle branch block (LBBB. The results show 92.9% accuracy and 93.17% sensitivity

  10. Respiratory sinus arrhythmia: opposite effects on systolic and mean arterial pressure in supine humans

    Science.gov (United States)

    Elstad, M.; Toska, K.; Chon, K. H.; Raeder, E. A.; Cohen, R. J.

    2001-01-01

    1. Are arterial blood pressure fluctuations buffered or reinforced by respiratory sinus arrhythmia (RSA)? There is still considerable debate about this simple question. Different results have been obtained, triggering a discussion as to whether or not the baroreflexes are responsible for RSA. We suspected that the measurements of different aspects of arterial pressure (mean arterial pressure (MAP) and systolic pressure (SP)) can explain the conflicting results. 2. Simultaneous recordings of beat-to-beat MAP, SP, left cardiac stroke volume (SV, pulsed ultrasound Doppler), heart rate (HR) and respiration (RE) were obtained in 10 healthy young adults during spontaneous respiration. In order to eliminate HR variations at respiratory frequency we used propranolol and atropine administration in the supine and tilted positions. Respiration-synchronous variation in the recorded variables was quantified by spectral analysis of the recordings of each of these variables, and the phase relations between them were determined by cross-spectral analysis. 3. MAP fluctuations increased after removing heart rate variations in both supine and tilted position, whereas SP fluctuations decreased in the supine position and increased in the head-up tilted position. 4. RSA buffers respiration-synchronous fluctuations in MAP in both positions. However, fluctuations in SP were reinforced by RSA in the supine and buffered in the tilted position.

  11. 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. PMID:26681648

  12. Arrhythmia detection in single- and dual-chamber implantable cardioverter defibrillators: the more leads, the better?

    Science.gov (United States)

    Francia, Pietro; Balla, Cristina; Uccellini, Arianna; Cappato, Riccardo

    2009-09-01

    The implantable cardioverter defibrillator (ICD) offers life-saving therapies for primary and secondary prevention of sudden cardiac death in high-risk patients. However, ICD detection algorithms consistently misclassify a substantial proportion of supraventricular rhythms, thus carrying the risk for inappropriate therapies. Although single-chamber ICD (Sc-ICD) discrimination tools have been reported to provide high specificity in rejecting sinus tachycardia and atrial fibrillation with a relatively low ventricular rate, accurate recognition of atrial fibrillation with faster ventricular rates, atrial tachycardias, atrial flutter, and some reentrant tachycardias is still an issue. Dual-chamber ICDs (Dc-ICDs) are supposed to overcome specificity issues by enhancing detection algorithms with information derived from the atrial and ventricular timing relationship. The initial promise of Dc-ICDs was to improve detection specificity without compromising sensitivity, and to translate this advantage over Sc-ICDs in a more selective use of aggressive therapies. Despite this solid background, superiority of Dc- over Sc-ICDs has never been convincingly demonstrated. The present review focuses on the efficacy of contemporary ICD arrhythmia discrimination tools and appraises the so far reported evidence supporting the superiority of Dc-ICDs in preventing inappropriate therapies.

  13. Correlation between 24-hour profile of blood pressure and ventricular arrhythmias and their prognostic significance in patients with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Đorđević Dragan

    2008-01-01

    Full Text Available Background/Aim. Left ventricular hypertrophy (LVH, apart from arterial hypertension, is a risk factor for electrophysiologic heart condition disorder and sudden cardiac death. The aim of this study was to examine a relationship between complex ventricular arrhythmias and parameters of 24-hour ambulatory blood pressure monitoring in the patients with arterial hypertension and left ventricular hypertrophy (LVH, as well as their prognostic significance during a five-year follow-up. Methods. Ninety patients with arterial hypertension and LVH were included in this study (mean age 55.2±8.3 years. There were 35 healthy people in the control group (mean age 54.5±7.1 years. Left ventricular mass index was 171.9±32.4 g/m2 in the LVH group and 102.4±13.3 g/m2 in the control group. Clinical examination, echocardiogram, 24-hour ambulatory blood pressure monitoring and 24-hour holter monitoring were done in all of the examined persons. Ventricular arrhythmias were classified by the Lown classification. Results. In the LVH group there were 54 (60.0% of the patients with ≥ III Lown class. The best predictor of a Lown class were left ventricular mass index by using multivariate stepwise regression analyses (β = 0.212; p < 0.05 and small decrease of diastolic blood pressure during the night (β = -0.293; p < 0.01. The main predictor of bad prognosis was left ventricular mass index during a five year follow-up (β = 0.302; p < 0.01, for stepwise regression model: F = 8.828; p < 0.01, adjusted R2 = 0.091. Conclusion. Left ventricular arrhythmias are frequent in patients with lower decrease of blood pressure during the night. There was no correlation between the degree of ventricular arrhythmias and parameters from 24-hour blood pressure monitoring and a five-year prognosis in the patients with arterial hypertension and LVH. A bad five-year follow-up outcome of hypertensive disease depends on left ventricular mass index.

  14. Effects of antiarrhythmic peptide 10 on acute ventricular arrhythmia

    Institute of Scientific and Technical Information of China (English)

    Bing Sun; Jin-Fa Jiang; Cui-Mei Zhao; Chao-Hui Hu

    2015-01-01

    Objective:To observe the effects antiarrhythmic peptide 10 (AAP10) aon acute ventricular arrhythmia and the phosphorylation state of ischemic myocardium connexin.Methods:Acute total ischemia and partial ischemia models were established by ceasing perfusion and ligating the left anterior descending coronary artery in SD rats. The effects of AAP10 (1 mg/L) on the incidence rate of ischemia-induced ventricular arrhythmia were observed. The ischemic myocardium was sampled to detect total-Cx43 and NP-Cx43 by immunofluorescent staining and western blotting. the total-Cx43 expression was detected through image analysis system by semi-quantitative analysis.Results: AAP10 could significantly decrease the incidence of ischemia-induced ventricular tachycardia and ventricular fibrillation. During ischemic stage, total ischemia (TI) and AAP10 total ischemia (ATI) groups were compared with partial ischemia (PI) and AAP10 partial ischemia (API) groups. The rates of incidence for arrhythmia in the ATI and API groups (10% and 0%) were lower than those in the TI and PI groups (60% and 45%). The difference between the two groups was statistically significant (P=0.019, P=0.020). The semi-quantitative analysis results of the ischemic myocardium showed that the total-Cx43 protein expression distribution areas for TI, ATI, PI and API groups were significantly decreased compared with the control group. On the other hand, the NP-Cx43 distribution areas of TI, ATI, PI and API groups were significantly increased compared with the control group (P>0.05). AAP10 could increase the total-Cx43 expression in the ischemic area and decrease the NP-Cx43 expression. Western blot results were consistent with the results of immunofluorescence staining.Conclusions:AAP10 can significantly decrease the rate of incidence of acute ischemia-induced ventricular tachycardia and ventricular fibrillation. Acute ischemic ventricular arrhythmias may have a relationship with the decreased phosphorylation of Cx43

  15. Cardiac involvement in Duchenne and Becker muscular dystrophy

    Institute of Scientific and Technical Information of China (English)

    Sophie; Mavrogeni; George; Markousis-Mavrogenis; Antigoni; Papavasiliou; Genovefa; Kolovou

    2015-01-01

    Duchenne and Becker muscular dystrophy(DMD/BMD) are X-linked muscular diseases responsible for over 80% of all muscular dystrophies. Cardiac disease is a common manifestation,not necessarily related to the degree of skeletal myopathy; it may be the predominant manifestation with or without any other evidence of muscular disease. Death is usually due to ventricular dysfunction,heart block or malignant arrhythmias. Not only DMD/BMD patients,but also female carriers may present cardiac involvement. Clinically overt heart failure in dystrophinopathies may be delayed or absent,due to relative physical inactivity. The commonest electrocardiographic findings include conduction defects,arrhythmias(supraventricular or ventricular),hypertrophy and evidence of myocardial necrosis. Echocardiography can assess a marked variability of left ventricular dysfunction,independently of age of onset or mutation groups. Cardiovascular magnetic resonance(CMR) has documented a pattern of epicardial fibrosis in both dystrophinopathies’ patients and carriers that can be observed even if overt muscular disease is absent. Recently,new CMR techniques,such as postcontrast myocardial T1 mapping,have been used in Duchenne muscular dystrophy to detect diffuse myocardial fibrosis. A combined approach using clinical assessment and CMR evaluation may motivate early cardioprotective treatment in both patients and asymptomatic carriers and delay the development of serious cardiac complications.

  16. Spiral wave drift and complex-oscillatory spiral waves caused by heterogeneities in two-dimensional in vitro cardiac tissues

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sung-Jae; Hong, Jin Hee; Kim, Tae Yun; Bae, Byung Wook; Lee, Kyoung J [CRI Center for Neurodynamics and Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of)], E-mail: kyoung@nld.korea.ac.kr

    2008-01-15

    Understanding spiral reentry wave dynamics in cardiac systems is important since it underlies various cardiac arrhythmia including cardiac fibrillation. Primary cultures of dissociated cardiac cells have been a convenient and useful system for studying cardiac wave dynamics, since one can carry out systematic and quantitative studies with them under well-controlled environments. One key drawback of the dissociated cell culture is that, inevitably, some spatial inhomogeneities in terms of cell types and density, and/or the degree of gap junction connectivity, are introduced to the system during the preparation. These unintentional spatial inhomogeneities can cause some non-trivial wave dynamics, for example, the entrainment dynamics among different spiral waves and the generation of complex-oscillatory spiral waves. The aim of this paper is to quantify these general phenomena in an in vitro cardiac system and provide explanations for them with a simple physiological model having some realistic spatial inhomogeneities incorporated.

  17. Are Electronic Cardiac Devices Still Evolving?

    Science.gov (United States)

    Mabo, P.

    2014-01-01

    Summary Objectives The goal of this paper is to review some important issues occurring during the past year in Implantable devices. Methods First cardiac implantable device was proposed to maintain an adequate heart rate, either because the heart’s natural pacemaker is not fast enough, or there is a block in the heart’s electrical conduction system. During the last forty years, pacemakers have evolved considerably and become programmable and allow to configure specific patient optimum pacing modes. Various technological aspects (electrodes, connectors, algorithms diagnosis, therapies, …) have been progressed and cardiac implants address several clinical applications: management of arrhythmias, cardioversion / defibrillation and cardiac resynchronization therapy. Results Observed progress was the miniaturization of device, increased longevity, coupled with efficient pacing functions, multisite pacing modes, leadless pacing and also a better recognition of supraventricular or ventricular tachycardia’s in order to deliver appropriate therapy. Subcutaneous implant, new modes of stimulation (leadless implant or ultrasound lead), quadripolar lead and new sensor or new algorithm for the hemodynamic management are introduced and briefly described. Each times, the main result occurring during the two past years are underlined and repositioned from the history, remaining limitations are also addressed. Conclusion Some important technological improvements were described. Nevertheless, news trends for the future are also considered in a specific session such as the remote follow-up of the patient or the treatment of heart failure by neuromodulation. PMID:25123732

  18. STUDY OF CARDIAC INVOLVEMENT IN DIPHTHERIA

    Directory of Open Access Journals (Sweden)

    Bala Raju Gundam

    2016-07-01

    Full Text Available BACKGROUND Diphtheria still endemic in many developing countries and is responsible for high case fatality. Myocardial involvement is a serious complication of diphtheria and diphtheria myocarditis frequently complicated by arrhythmias causes sudden death if not managed properly. So, early and adequate administration of Anti-Diphtheritic Serum (ADS and frequent monitoring particularly 24 hrs. ECG monitoring is helpful to detect any serious cardiac arrhythmias. METHODS A prospective study on patients who were culture positive diagnosed on the basis of WHO definition were treated and analysed in respect to homographic details, immunisation strategy, and clinical features with particular attention to myocarditis. RESULTS In the study, common age group affected by diphtheria was 5 to 10 years. Incidence of myocarditis more in same age group. Out of 64 patients with myocarditis, 23 patients died. CONCLUSION Incidence of diphtheria has increased in the recent years. Commonly effected age group is 5 to 10 years and most of them are presented with asymptomatic myocarditis. Symptomatic diphtheritic myocarditis has high mortality rate even with aggressive management. Patient who presented with either LBBB alone are with combination of other conduction of abnormalities has high mortality rate.

  19. Role of His-Purkinje System in Ventricular Arrhythmias%希氏-浦肯野系统和室性心律失常

    Institute of Scientific and Technical Information of China (English)

    周旭; 杨新春

    2011-01-01

    Recently the His-Purkinje system has been found to play an important role in the genesis of ventricular arrhythmias. The anatomic and cellular electrophysiologic complexity of the left ventricular conduction system appears to favor reentrant ventricular tachycardia in both diseased and healthy hearts. Newer discoveries strongly suggest the Purkinje system as the cause of ventricular arrhythmias in patients with short-coupled premature ventricular complexes and in those with catecholaminergic polymorphous ventricular tachycardia. With understanding of mechanisms related to His-Purkinje system and ventricular arrhythmias, many cardiac arrhythmias appears to involve the ventricular specialized conduction system and may be treated with catheter ablation.%近期研究提示希氏-浦肯野系统与室性心律失常的发生关系密切.作为左室的特殊传导组织,希氏-浦肯野系统的解剖与电生理特点,使其在正常或病理情况下易于参与折返型心律失常形成.目前资料提示浦肯野系统病变是短联律间期室性早搏相关心律失常和儿茶酚胺敏感性多形性室性心动过速的原因.随着对希氏-浦肯野系统与室性心律失常关系的认识,导管消融可作为此类心律失常的治疗途径.

  20. 47. A cardiac center experience with Brugada syndrome who survived sudden cardiac death

    Directory of Open Access Journals (Sweden)

    I. Suliman

    2016-07-01

    Full Text Available Brugada syndrome is a heritable arrhythmia syndrome that is characterized by an electrocardiographic pattern consisting of coved-type ST-segment elevation (2 mm followed by a negative T wave in the right precordial leads, V1 through V3 (often referred to as type 1 Brugada electrocardiographic pattern, here we describe 3 cases of Brugada who survived sudden cardiac death (SCD cardiac center experience with survived Brugada syndrome patients – case series. First Case: The Father 45 years old male, presented in 2005 after involvement in unprovoked motor vehicle accident, the patient was the driver who lost consciousness and rushed to the hospital. On arrival to our ER and putting the patient on the bed, the ER doctor observed a brief episode of VF on the monitor. The patient was taken to the catheterization Lab , his coronaries were normal. The diagnosis of Brugada was established and the patient received a defibrillator. At That Time all family members were screened and were negative. Second Case: The Son of the first patient 5 years later his 23 years old male rushed to our ER after he lost consciousness, he was passenger in the car of his friend. Third Case: The pilot A military pilot aged a male 35 years old was in very good health when he lost consciousness and brought to the hospital after resuscitation in 2005. He had full invasive cardiac evaluation, subsequently he received a defibrillator in the same admission period, till 2015 he is doing fine. Brugada syndrome is associated with high tendency for sudden cardiac death. In our three cases the first clinical presentation was survived sudden cardiac death (SCD and all three male patients survived. We did not encounter a female patient who survived sudden cardiac death.

  1. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  2. Surveillance of fetal arrhythmias in the outpatient setting: current limitations and call for action.

    Science.gov (United States)

    Freire, Grace

    2015-12-01

    Surveillance of fetal arrhythmias in the outpatient setting remains limited by lack of monitoring modalities. Despite technological advances made in the field of obstetrics, existing devices are not currently suitable to monitor fetal arrhythmias. In this report, the author describes the current and developing fetal heart rate monitoring technologies including the recent introduction of hand-held Doppler monitors for outpatient surveillance of fetal arrhythmias.

  3. Left Ventricular Dilatation Increases the Risk of Ventricular Arrhythmias in Patients With Reduced Systolic Function

    OpenAIRE

    Aleong, Ryan G.; Mulvahill, Matthew J; Halder, Indrani; Carlson, Nichole E; Singh, Madhurmeet; Bloom, Heather L.; Dudley, Samuel C.; Ellinor, Patrick T.; Shalaby, Alaa; Weiss, Raul; Gutmann, Rebecca; Sauer, William H.; Narayanan, Kumar; Chugh, Sumeet S.; Saba, Samir

    2015-01-01

    Background Reduced left ventricular (LV) ejection fraction increases the risk of ventricular arrhythmias; however, LV ejection fraction has a low sensitivity to predict ventricular arrhythmias. LV dilatation and mass may be useful to further risk-stratify for ventricular arrhythmias. Methods and Results Patients from the Genetic Risk of Assessment of Defibrillator Events (GRADE) study (N =930), a study of heart failure subjects with defibrillators, were assessed for appropriate implantable ca...

  4. The Effect of Opium Addiction on Arrhythmia Following Acute Myocardial Infarction

    OpenAIRE

    Mostafa Shokoohi; Hamid Najafipour; Afsaneh Forood; Morvarid Dadras; Fatemeh Mirzaiepour

    2012-01-01

    The effect of opium addiction on the appearance of different types of arrhythmias after acute myocardial infarction (AMI) has been assessed in few studies. This study is aimed to determine the effect of opium on post-MI arrhythmia and also to address the differences in the appearance of different types of arrhythmias after AMI between opium addicted and non-addicted patients. In this comparative study, participants were classified into two groups with opium addiction (n=94) and without opium ...

  5. Role of Pre-incision, Intravenous Prophylactic Amiodarone to Control Arrhythmias in Patients with Rheumatic Valvular Heart Disease undergoing Mitral Valve Replacement

    International Nuclear Information System (INIS)

    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)

  6. 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.)

  7. 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

  8. Cardiac vagal control and children’s adaptive functioning: A meta-analysis

    OpenAIRE

    Graziano, Paulo; Derefinko, Karen

    2013-01-01

    Polyvagal theory has influenced research on the role of cardiac vagal control, indexed by respiratory sinus arrhythmia withdrawal (RSA-W) during challenging states, in children’s self-regulation. However, it remains unclear how well RSA-W predicts adaptive functioning (AF) outcomes and whether certain caveats of measuring RSA (e.g., respiration) significantly impact these associations. A meta-analysis of 44 studies (n = 4,996 children) revealed small effect sizes such that greater levels of R...

  9. Inhibition of the Cardiac Na+ Channel Nav1.5 by Carbon Monoxide*

    OpenAIRE

    Elies, J; Dallas, M.; Boyle, JP; Scragg, JL; Duke, A; Steele, DS; Peers, C

    2014-01-01

    Sublethal carbon monoxide (CO) exposure is frequently associated with myocardial arrhythmias, and our recent studies have demonstrated that these may be attributable to modulation of cardiac Na(+) channels, causing an increase in the late current and an inhibition of the peak current. Using a recombinant expression system, we demonstrate that CO inhibits peak human Nav1.5 current amplitude without activation of the late Na(+) current observed in native tissue. Inhibition was associated with a...

  10. High cardiac vagal control protects against future depressive symptoms under conditions of high social support

    OpenAIRE

    Hopp, Henrik; Shallcross, Amanda J.; Ford, Brett Q.; Troy, Allison S.; Wilhelm, Frank H.; Mauss, Iris B.

    2013-01-01

    High cardiac vagal control (as measured by respiratory sinus arrhythmia; RSA) is associated with lower depression. Recent theories argue that people’s responsiveness to social resources is a key mechanism in this association. This argument implies two hypotheses: first, high RSA should be related to decreased depressive symptoms only when social resources (social support) are available; second, utilization of available social resources (social engagement) should serve as a mechanism for the p...

  11. Atrial and ventricular function in thalassemic patients with supraventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Vitantonio Di Bello

    2009-04-01

    Full Text Available The aims of this study were to evaluate through Color Doppler Myocardial Imaging (CDMI echocardiography if atrial or ventricular myocardial alterations could be detectable in patients with thalassemia major (THAL and if these alterations could be considered as predictive elements for supra-ventricular arrhythmic events. Twenty-three patients with THAL underwent clinical and electrocardiographic evaluation; patients were grouped in THAL1 (9 with supra-ventricular arrhythmias and THAL2 (14 without arrhythmias; 12 healthy subjects were considered as control group (C. We examined through conventional 2D Color Doppler echocardiography some morphological and functional parameters regarding left ventricular (LV systolic and diastolic function, and through CDMI the velocities at mitral annulus level, the regional LV and left atrial (LA strain and strain rate. All THAL patients had LV dimension (pless than 0.05, LA area (p less than 0.01 and E/Em ratio (pless than 0.001 to be significantly higher than controls. The mitral annulus longitudinal velocities were significantly lower in THAL1 than in THAL2 (pless than 0.001; the E/Em ratio was higher in THAL1 than THAL2 (pless than 0.001. The THAL1 showed a lower systolic strain rate of atrial wall than THAL2 and C (pless than 0.05. The multiple regression highlighted a significantly inverse correlation among E/Em and atrial strain (pless than 0.02. CDMI showed both THAL subgroups had subtle systolic and diastolic left ventricular myocardial alterations, which could represent the onset of developing “iron cardiomyopathy” and are related to supra-ventricular arrhythmia. Monitoring these parameters in the THAL patients could contribute to decisions about follow-up and therapy.

  12. Artifact versus arrhythmia in pseudo-polymorphic tachycardia; case report

    Directory of Open Access Journals (Sweden)

    Ahmed V

    2015-04-01

    Full Text Available Vaseem Ahmed, Anish Patel, Abhishek Sharma, Dennis Bloomfield Department of Medicine, Richmond University Medical Center, Staten Island, NY, USA Abstract: We present the case of a young male patient in sinus rhythm whose electrocardiogram (ECG was initially misinterpreted as ventricular tachycardia. Electrocardiographic artifact appearing to be ventricular tachycardia commonly occurs and ECG criteria have been described to aid in the discrimination between artifact and true arrhythmia. There are many causes of artifacts and prompt recognition is important to prevent unnecessary interventions. Keywords: artifact, ventricular tachycardia, pseudo-ventricular tachycardia, notch sign, sinus sign

  13. Pregnancy-Related Human Leukocyte Antigen Sensitization Leading to Cardiac Allograft Vasculopathy and Graft Failure in a Heart Transplant Recipient: A Case Report

    OpenAIRE

    Ginwalla, M.; Pando, M.J.; Khush, K. K.

    2013-01-01

    In this report, we present a heart transplant recipient who developed cross-reactive paternal and donor-specific human leukocyte antigen (HLA) class II antibodies during pregnancy, leading to accelerated cardiac allograft vasculopathy and severe allograft dysfunction 17 years after transplantation. This resulted in acute heart failure and ventricular arrhythmias requiring repeat heart transplantation.

  14. Cardiac hypertrophy, arrhythmogenicity and the new myocardial phenotype. II. The cellular adaptational process.

    Science.gov (United States)

    Swynghedauw, B; Chevalier, B; Charlemagne, D; Mansier, P; Carré, F

    1997-07-01

    Ventricular fibrosis is not the only structural determinant of arrhythmias in left ventricular hypertrophy. In an experimental model of compensatory cardiac hypertrophy (CCH) the degree of cardiac hypertrophy is also independently linked to ventricular arrhythmias. Cardiac hypertrophy reflects the level of adaptation, and matches the adaptational modifications of the myocardial phenotype. We suggest that these modifications have detrimental aspects. The increased action potential (AP) and QT duration and the prolonged calcium transient both favour spontaneous calcium oscillations, and both are potentially arrhythmogenic and linked to phenotypic changes in membrane proteins. To date, only two ionic currents have been studied in detail: Ito is depressed (likely the main determinant in AP durations), and If, the pacemaker current, is induced in the overloaded ventricular myocytes. In rat CCH, the two components of the sarcoplasmic reticulum, namely Ca(2+)-ATPase and ryanodine receptors, are down-regulated in parallel. Nevertheless, while the inward calcium current is unchanged, the functionally linked duo composed of the Na+/Ca2+ exchanged and (Na+, K+)-ATPase, is less active. Such an imbalance may explain the prolonged calcium transient. The changes in heart rate variability provide information about the state of the autonomic nervous system and has prognostic value even in CCH. Transgenic studies have demonstrated that the myocardial adrenergic and muscarinic receptor content is also a determining factor. During CCH, several phenotypic membrane changes participate in the slowing of contraction velocity and are thus adaptational. They also have a detrimental counterpart and, together with fibrosis, favour arrhythmias. PMID:9302342

  15. Respiratory Sinus Arrhythmia as an Index of Vagal Activity during Stress in Infants: Respiratory Influences and Their Control

    Science.gov (United States)

    Ritz, Thomas; Bosquet Enlow, Michelle; Schulz, Stefan M.; Kitts, Robert; Staudenmayer, John; Wright, Rosalind J.

    2012-01-01

    Respiratory sinus arrhythmia (RSA) is related to cardiac vagal outflow and the respiratory pattern. Prior infant studies have not systematically examined respiration rate and tidal volume influences on infant RSA or the extent to which infants' breathing is too fast to extract a valid RSA. We therefore monitored cardiac activity, respiration, and physical activity in 23 six-month old infants during a standardized laboratory stressor protocol. On average, 12.6% (range 0–58.2%) of analyzed breaths were too short for RSA extraction. Higher respiration rate was associated with lower RSA amplitude in most infants, and lower tidal volume was associated with lower RSA amplitude in some infants. RSA amplitude corrected for respiration rate and tidal volume influences showed theoretically expected strong reductions during stress, whereas performance of uncorrected RSA was less consistent. We conclude that stress-induced changes of peak-valley RSA and effects of variations in breathing patterns on RSA can be determined for a representative percentage of infant breaths. As expected, breathing substantially affects infant RSA and needs to be considered in studies of infant psychophysiology. PMID:23300753

  16. Respiratory sinus arrhythmia as an index of vagal activity during stress in infants: respiratory influences and their control.

    Directory of Open Access Journals (Sweden)

    Thomas Ritz

    Full Text Available Respiratory sinus arrhythmia (RSA is related to cardiac vagal outflow and the respiratory pattern. Prior infant studies have not systematically examined respiration rate and tidal volume influences on infant RSA or the extent to which infants' breathing is too fast to extract a valid RSA. We therefore monitored cardiac activity, respiration, and physical activity in 23 six-month old infants during a standardized laboratory stressor protocol. On average, 12.6% (range 0-58.2% of analyzed breaths were too short for RSA extraction. Higher respiration rate was associated with lower RSA amplitude in most infants, and lower tidal volume was associated with lower RSA amplitude in some infants. RSA amplitude corrected for respiration rate and tidal volume influences showed theoretically expected strong reductions during stress, whereas performance of uncorrected RSA was less consistent. We conclude that stress-induced changes of peak-valley RSA and effects of variations in breathing patterns on RSA can be determined for a representative percentage of infant breaths. As expected, breathing substantially affects infant RSA and needs to be considered in studies of infant psychophysiology.

  17. Fatal secondary pulmonary hypertension due to cardiac involvement in AIDS-associated Burkitt′s lymphoma

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    Singh Ashutosh

    2006-09-01

    Full Text Available Primary cardiac lymphomas are rare lesions in children with acquired immunodeficiency syndrome (AIDS. Most of them are high-grade Burkitt′s or Burkitt-like lymphomas. They usually present with congestive cardiac failure, pericardial effusion or tamponade, arrhythmias, with predominant systemic ′B′ symptoms and often with widespread extranodal involvement. The clinical profile and operative and pathological findings of a 4-year-old boy with AIDS-associated Burkitt′s lymphoma of the heart presenting with acute right heart failure and fatal secondary pulmonary hypertension is reported.

  18. A Psychological Factor Affecting a Cardiac Condition in a Psychotherapist

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    R Waxman

    2009-03-01

    Full Text Available It has been established that intense emotions can affect the development and course of cardiac arrhythmias. This study sought to convey that a lack of expression of emotion can also have an effect on arrhythmias. A psychotherapist with Idiopathic Ventricular Fibrillation and an Implantable Cardioverter Defibrillator measured his rate of Premature Ventricular Contractions using a Holter monitor during three separate six-week periods and in three domains: A work days vs. off days, B a 27 hour work week vs. 22 hour work week, and C in 5 different modalities including 1 Meeting with department head 2 Individual psychotherapy with patients 3 Group therapy with patients 4 Supervision of residents 5 Personal psychoanalysis. The results showed more than a 3-fold increase of arrhythmogenic activity during the 27-hour work week vs. 22 and a 5-fold increase in arrhythmogenic activity on work days compared to days off. Department Head meetings were found to be most arrhythmogenic and personal psychoanalysis was least. The data suggest that the psychiatrist’s lack of emotional expression in his clinical work has been demonstrated to markedly worsen his arrhythmia. The results also point to the potential ameliorating effects of the therapist’s own psychotherapy.

  19. Evaluation and management of arrhythmia in the athletic patient.

    Science.gov (United States)

    Lampert, Rachel

    2012-01-01

    Athletes may present with palpitations, syncope, or arrest resulting in the diagnosis of arrhythmia, or screening may result in diagnosis of conditions with predisposition to arrhythmia. This chapter focuses on 3 common arrhythmic conditions in athletes-atrial fibrillation, premature ventricular contractions (PVCs), and the athlete with an implanted device. (1) Atrial fibrillation: most studies show that atrial fibrillation is more common in competitive athletes, particularly those participating in long-term endurance sports. Postulated mechanisms include morphologic changes such as atrial dilatation, autonomic changes such as increased vagal tone, or inflammatory changes due to sports participation. Treatment options include long-term antiarrhythmic agents, "pill in the pocket" medications, or radiofrequency ablation, a highly successful procedure in athletes. (2) Premature ventricular contractions: data conflict on whether the incidence of PVCs is increased in highly trained individuals. Very frequent PVCs in athletes, however, can be a manifestation of underlying heart disease, and athletes presenting with PVCs should undergo evaluation. In the absence of underlying heart disease, PVCs do not carry a poor prognosis, and US guidelines do not recommend restriction from sports. (3) Implanted devices: the safety of sports for the athlete with an implanted device is unknown, and current guidelines recommend against participation in vigorous competitive sports, based on postulated risks including failure to defibrillate and risk of injury. Many athletes with defibrillators and pacemakers do participate in sports. Ongoing research will better delineate the risks of sports for the athlete with an implanted device. PMID:22386293

  20. Disruption of Epac1 protects the heart from adenylyl cyclase type 5-mediated cardiac dysfunction.

    Science.gov (United States)

    Cai, Wenqian; Fujita, Takayuki; Hidaka, Yuko; Jin, Huiling; Suita, Kenji; Prajapati, Rajesh; Liang, Chen; Umemura, Masanari; Yokoyama, Utako; Sato, Motohiko; Okumura, Satoshi; Ishikawa, Yoshihiro

    2016-06-17

    Type 5 adenylyl cyclase (AC5) plays an important role in the development of chronic catecholamine stress-induced heart failure and arrhythmia in mice. Epac (exchange protein activated by cAMP), which is directly activated by cAMP independent of protein kinase A, has been recently identified as a novel mediator of cAMP signaling in the heart. However, the role of Epac in AC5-mediated cardiac dysfunction and arrhythmias remains poorly understood. We therefore generated AC5 transgenic mice (AC5TG) with selective disruption of the Epac1 gene (AC5TG-Epac1KO), and compared their phenotypes with those of AC5TG after chronic isoproterenol (ISO) infusion. Decreased cardiac function as well as increased susceptibility to pacing-induced atrial fibrillation (AF) in response to ISO were significantly attenuated in AC5TG-Epac1KO mice, compared to AC5TG mice. Increased cardiac apoptosis and cardiac fibrosis were also concomitantly attenuated in AC5TG-Epac1KO mice compared to AC5TG mice. These findings indicate that Epac1 plays an important role in AC5-mediated cardiac dysfunction and AF susceptibility. PMID:27117748

  1. Cardiac perception and cardiac control. A review.

    Science.gov (United States)

    Carroll, D

    1977-12-01

    The evidence regarding specific cardiac perception and discrimination, and its relationship to voluntary cardiac control, is critically reviewed. Studies are considered in three sections, depending on the method used to assess cardiac perception: questionnaire assessment, discrimination procedures, and heartbeat tracking. The heartbeat tracking procedure would appear to suffer least from interpretative difficulties. Recommendations are made regarding the style of analysis used to assess heartbeat perception in such tracking tasks. PMID:348240

  2. Development of the cardiac conduction system in zebrafish.

    Science.gov (United States)

    Poon, Kar-Lai; Liebling, Michael; Kondrychyn, Igor; Brand, Thomas; Korzh, Vladimir

    2016-07-01

    The cardiac conduction system (CCS) propagates and coordinates the electrical excitation that originates from the pacemaker cells, throughout the heart, resulting in rhythmic heartbeat. Its defects result in life-threatening arrhythmias and sudden cardiac death. Understanding of the factors involved in the formation and function of the CCS remains incomplete. By transposon assisted transgenesis, we have developed enhancer trap (ET) lines of zebrafish that express fluorescent protein in the pacemaker cells at the sino-atrial node (SAN) and the atrio-ventricular region (AVR), termed CCS transgenics. This expression pattern begins at the stage when the heart undergoes looping morphogenesis at 36 h post fertilization (hpf) and is maintained into adulthood. Using the CCS transgenics, we investigated the effects of perturbation of cardiac function, as simulated by either the absence of endothelium or hemodynamic stimulation, on the cardiac conduction cells, which resulted in abnormal compaction of the SAN. To uncover the identity of the gene represented by the EGFP expression in the CCS transgenics, we mapped the transposon integration sites on the zebrafish genome to positions in close proximity to the gene encoding fibroblast growth homologous factor 2a (fhf2a). Fhf2a is represented by three transcripts, one of which is expressed in the developing heart. These transgenics are useful tools for studies of development of the CCS and cardiac disease. PMID:27593944

  3. Missense mutations in desmin associated with familial cardiac and skeletal myopathy.

    Science.gov (United States)

    Goldfarb, L G; Park, K Y; Cervenáková, L; Gorokhova, S; Lee, H S; Vasconcelos, O; Nagle, J W; Semino-Mora, C; Sivakumar, K; Dalakas, M C

    1998-08-01

    Desmin-related myopathy (OMIM 601419) is a familial disorder characterized by skeletal muscle weakness associated with cardiac conduction blocks, arrhythmias and restrictive heart failure, and by intracytoplasmic accumulation of desmin-reactive deposits in cardiac and skeletal muscle cells. The underlying molecular mechanisms are unknown. Involvement of the desmin gene (DES) has been excluded in three families diagnosed with desmin-related myopathy. We report two new families with desmin-related cardioskeletal myopathy associated with mutations in the highly conserved carboxy-terminal end of the desmin rod domain. A heterozygous A337P mutation was identified in a family with an adult-onset skeletal myopathy and mild cardiac involvement. Compound heterozygosity for two other mutations, A360P and N393I, was detected in a second family characterized by childhood-onset aggressive course of cardiac and skeletal myopathy.

  4. Reentry Near the Percolation Threshold in a Heterogeneous Discrete Model for Cardiac Tissue

    Science.gov (United States)

    Alonso, Sergio; Bär, Markus

    2013-04-01

    Arrhythmias in cardiac tissue are related to irregular electrical wave propagation in the heart. Cardiac tissue is formed by a discrete cell network, which is often heterogeneous. A localized region with a fraction of nonconducting links surrounded by homogeneous conducting tissue can become a source of reentry and ectopic beats. Extensive simulations in a discrete model of cardiac tissue show that a wave crossing a heterogeneous region of cardiac tissue can disintegrate into irregular patterns, provided the fraction of nonconducting links is close to the percolation threshold of the cell network. The dependence of the reentry probability on this fraction, the system size, and the degree of excitability can be inferred from the size distribution of nonconducting clusters near the percolation threshold.

  5. Polyunsaturated fatty acid analogs act antiarrhythmically on the cardiac IKs channel

    DEFF Research Database (Denmark)

    Liin, Sara I.; Silverå Ejneby, Malin; Barro-Soria, Rene;

    2015-01-01

    Polyunsaturated fatty acids (PUFAs) affect cardiac excitability. Kv7.1 and the β-subunit KCNE1 form the cardiac IKs channel that is central for cardiac repolarization. In this study, we explore the prospects of PUFAs as IKs channel modulators. We report that PUFAs open Kv7.1 via an electrostatic...... charge at neutral pH, restore the sensitivity to open IKs channels. PUFA analogs with a positively charged head group inhibit IKs channels. These different PUFA analogs could be developed into drugs to treat cardiac arrhythmias. In support of this possibility, we show that PUFA analogs act...... mechanism. Both the polyunsaturated acyl tail and the negatively charged carboxyl head group are required for PUFAs to open Kv7.1. We further show that KCNE1 coexpression abolishes the PUFA effect on Kv7.1 by promoting PUFA protonation. PUFA analogs with a decreased pKa value, to preserve their negative...

  6. Macaque cardiac physiology is sensitive to the valence of passively viewed sensory stimuli.

    Directory of Open Access Journals (Sweden)

    Eliza Bliss-Moreau

    Full Text Available Autonomic nervous system activity is an important component of affective experience. We demonstrate in the rhesus monkey that both the sympathetic and parasympathetic branches of the autonomic nervous system respond differentially to the affective valence of passively viewed video stimuli. We recorded cardiac impedance and an electrocardiogram while adult macaques watched a series of 300 30-second videos that varied in their affective content. We found that sympathetic activity (as measured by cardiac pre-ejection period increased and parasympathetic activity (as measured by respiratory sinus arrhythmia decreased as video content changes from positive to negative. These findings parallel the relationship between autonomic nervous system responsivity and valence of stimuli in humans. Given the relationship between human cardiac physiology and affective processing, these findings suggest that macaque cardiac physiology may be an index of affect in nonverbal animals.

  7. 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...

  8. 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.

  9. Motivation to pursue genetic testing in individuals with a personal or family history of cardiac events or sudden cardiac death.

    Science.gov (United States)

    Erskine, Kathleen E; Hidayatallah, Nadia Z; Walsh, Christine A; McDonald, Thomas V; Cohen, Lilian; Marion, Robert W; Dolan, Siobhan M

    2014-10-01

    Genetic testing is becoming increasingly available for cardiac channelopathies, such as long QT syndrome and Brugada syndrome, which can lead to sudden cardiac death. Test results can be used to shape an individual's medical management and to identify at-risk family members. In our qualitative study, all participants had a personal or family history of a diagnosed cardiac arrhythmia syndrome or sudden cardiac death. Open-ended interviews were conducted individually and in focus groups. Interviews were audio recorded, transcribed verbatim, and analyzed using a qualitative grounded-theory approach. Of 50 participants, 37 described their motivations for pursuing genetic testing for long QT syndrome or another cardiac channelopathy. Participants' motivations included: to find an explanation for a family member's sudden death, to relieve uncertainty regarding a diagnosis, to guide future medical management, to allay concern about children or other family members, and to comply with recommendations of physicians or family members. Perceived reasons not to pursue genetic testing included denial, fear, and lack of information. The genetic counseling and informed consent process can be enhanced by understanding and addressing an individual's internal and external motivations either for or against pursuing genetic testing.

  10. Cardiac Implantable Electronic Device Infection: From an Infection Prevention Perspective

    Science.gov (United States)

    Sastry, Sangeeta; Rahman, Riaz; Yassin, Mohamed H.

    2015-01-01

    A cardiac implantable electronic device (CIED) is indicated for patients with severely reduced ejection fraction or with life-threatening cardiac arrhythmias. Infection related to a CIED is one of the most feared complications of this life-saving device. The rate of CIED infection has been estimated to be between 2 and 25; though evidence shows that this rate continues to rise with increasing expenditure to the patient as well as healthcare systems. Multiple risk factors have been attributed to the increased rates of CIED infection and host comorbidities as well as procedure related risks. Infection prevention efforts are being developed as defined bundles in numerous hospitals around the country given the increased morbidity and mortality from CIED related infections. This paper aims at reviewing the various infection prevention measures employed at hospitals and also highlights the areas that have relatively less established evidence for efficacy. PMID:26550494

  11. 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.

  12. Predicting the onset of period-doubling bifurcations in noisy cardiac systems.

    Science.gov (United States)

    Quail, Thomas; Shrier, Alvin; Glass, Leon

    2015-07-28

    Biological, physical, and social systems often display qualitative changes in dynamics. Developing early warning signals to predict the onset of these transitions is an important goal. The current work is motivated by transitions of cardiac rhythms, where the appearance of alternating features in the timing of cardiac events is often a precursor to the initiation of serious cardiac arrhythmias. We treat embryonic chick cardiac cells with a potassium channel blocker, which leads to the initiation of alternating rhythms. We associate this transition with a mathematical instability, called a period-doubling bifurcation, in a model of the cardiac cells. Period-doubling bifurcations have been linked to the onset of abnormal alternating cardiac rhythms, which have been implicated in cardiac arrhythmias such as T-wave alternans and various tachycardias. Theory predicts that in the neighborhood of the transition, the system's dynamics slow down, leading to noise amplification and the manifestation of oscillations in the autocorrelation function. Examining the aggregates' interbeat intervals, we observe the oscillations in the autocorrelation function and noise amplification preceding the bifurcation. We analyze plots--termed return maps--that relate the current interbeat interval with the following interbeat interval. Based on these plots, we develop a quantitative measure using the slope of the return map to assess how close the system is to the bifurcation. Furthermore, the slope of the return map and the lag-1 autocorrelation coefficient are equal. Our results suggest that the slope and the lag-1 autocorrelation coefficient represent quantitative measures to predict the onset of abnormal alternating cardiac rhythms.

  13. Ventricular arrhythmias in competitive athletes: risk stratification with T-wave alternans

    Directory of Open Access Journals (Sweden)

    Rita Pizzi

    2009-08-01

    Full Text Available Introduction: Aim of our study is to evaluate the role of TWA to stratify the risk of sudden cardiac death in athletes (Ath with complex ventricular arrhythmias (VA, and to document a possible correlation between TWA and electrophysiological testing (EES results. Methods: We studied 43 Ath with VA (31 M, mean age 34 ± 12 years. In all cases a cardiological evaluation was performed, including TWA and EES. The patients were evaluated during a followup of 25 ± 22 months. The end-point was the occurrence of sudden death or malignant ventricular tachyarrhythmias (VT. Results: TWA was negative in 28 Ath (65%, positive in 8 (19% and indeterminate in 7 (16%. All subjects with negative TWA did not show induction of VT at EES, with significant correlation between negative TWA and negative EES (p<0.001. All Ath with positive TWA also had VT induced by a EES, but without significant correlation between positive TWA and positive EES. In 2 Ath with undetermined TWA (29% VT were induced at EES. Our data did not show significant correlation between indeterminate TWA and positive or negative EES. However, logistic regression analysis showed significant correlation between abnormal TWA test (positive or indeterminate and inducibility of VT at EES (p<0.001. During follow-up we observed a significant difference in end-point occurrence between Ath with negative or positive TWA and between Ath with negative or positive EES. Conclusion: TWA confirm its role as a simple and non-invasive test, and it seems useful for prognostic stratification of Ath with VA. (Heart International 2007; 3: 58-67

  14. Long-term Arrhythmia Monitoring in Cryptogenic Stroke: Who, How, and for How Long?

    Science.gov (United States)

    Montalvo, Mayra; Ali, Rushna; Silver, Brian; Khan, Muhib

    2016-01-01

    Cryptogenic stroke and transient ischemic attack (TIA) account for approximately one-third of stroke patients [1]. Paroxys-mal atrial fibrillation (PAF) has been suggested as a major etiology of these cryptogenic strokes [2, 3]. PAF can be difficult to diagnose because it is intermittent, often brief, and asymptomatic. PAF might be more prevalent than persistent atrial fibrillation in stroke and TIA patients, especially in younger populations [4, 5]. In patients with atrial fibrillation, anticoagulation provides significant risk reduction [6]. A new generation of oral anticoagulants has been approved for non-valvular atrial fibrillation, providing a variety of therapeutic options for patients with atrial fibrillation and risk of stroke [7]. Prior practice included an admission electrocardiogram (ECG) and continuous telemetry monitoring while in hospital [8]. However, this approach can lead to under-detection of brief asymptomatic events, which can occur at variable intervals, often outside of the hospital setting. Technological advancements have led to devices that can monitor cardiac rhythms outside of the hospital for longer durations resulting in higher yield of detection of atrial fibrillation events. Moreover, recent studies show that the normal monitoring time for arrhythmias may be shorter than ideal in order to detect atrial fibrillation, and increasing this interval could significantly improve detection of atrial fibrillation in these patients [9, 10]. The aim of this study is to review the literature in order to define what subgroup of patients, with what methodologies, and for how long monitoring for atrial fibrillation should occur in patients presenting with cryptogenic stroke. PMID:27347225

  15. Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias.

    Directory of Open Access Journals (Sweden)

    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.

  16. Cardiac sarcoplasmic reticulum calcium leak: basis and roles in cardiac dysfunction.

    Science.gov (United States)

    Bers, Donald M

    2014-01-01

    Synchronized SR calcium (Ca) release is critical to normal cardiac myocyte excitation-contraction coupling, and ideally this release shuts off completely between heartbeats. However, other SR Ca release events are referred to collectively as SR Ca leak (which includes Ca sparks and waves as well as smaller events not detectable as Ca sparks). Much, but not all, of the SR Ca leak occurs via ryanodine receptors and can be exacerbated in pathological states such as heart failure. The extent of SR Ca leak is important because it can (a) reduce SR Ca available for release, causing systolic dysfunction; (b) elevate diastolic [Ca]i, contributing to diastolic dysfunction; (c) cause triggered arrhythmias; and (d) be energetically costly because of extra ATP used to repump Ca. This review addresses quantitative aspects and manifestations of SR Ca leak and its measurement, and how leak is modulated by Ca, associated proteins, and posttranslational modifications in health and disease. PMID:24245942

  17. Increased short-term variability of the QT interval in professional soccer players: possible implications for arrhythmia prediction.

    Directory of Open Access Journals (Sweden)

    Csaba Lengyel

    Full Text Available BACKGROUND: Sudden cardiac death in competitive athletes is rare but it is significantly more frequent than in the normal population. The exact cause is seldom established and is mostly attributed to ventricular fibrillation. Myocardial hypertrophy and slow heart rate, both characteristic changes in top athletes in response to physical conditioning, could be associated with increased propensity for ventricular arrhythmias. We investigated conventional ECG parameters and temporal short-term beat-to-beat variability of repolarization (STV(QT, a presumptive novel parameter for arrhythmia prediction, in professional soccer players. METHODS: Five-minute 12-lead electrocardiograms were recorded from professional soccer players (n = 76, all males, age 22.0±0.61 years and age-matched healthy volunteers who do not participate in competitive sports (n = 76, all males, age 22.0±0.54 years. The ECGs were digitized and evaluated off-line. The temporal instability of beat-to-beat heart rate and repolarization were characterized by the calculation of short-term variability of the RR and QT intervals. RESULTS: Heart rate was significantly lower in professional soccer players at rest (61±1.2 vs. 72±1.5/min in controls. The QT interval was prolonged in players at rest (419±3.1 vs. 390±3.6 in controls, p<0.001. QTc was significantly longer in players compared to controls calculated with Fridericia and Hodges correction formulas. Importantly, STV(QT was significantly higher in players both at rest and immediately after the game compared to controls (4.8±0.14 and 4.3±0.14 vs. 3.5±0.10 ms, both p<0.001, respectively. CONCLUSIONS: STV(QT is significantly higher in professional soccer players compared to age-matched controls, however, further studies are needed to relate this finding to increased arrhythmia propensity in this population.

  18. Assessment of cardiac conduction: basic principles of optical mapping.

    Science.gov (United States)

    Ding, Chunhua; Everett, Thomas H

    2010-01-01

    Extracellular recordings acquired from electrodes placed on the surface of cardiac tissue have traditionally been used to study the electrophysiological properties of the tissue. While this technique has been used in several studies that have increased our understanding of cardiac arrhythmias and action potential propagation, there are several limitations that have prevented us from seeing a bigger picture of arrhythmia mechanisms. These limitations include the limited number of electrodes and unstable recordings. Optical mapping was developed to increase the temporal and spatial resolution over traditional electrode recordings and ultimately the accuracy of the data analysis. This technology involves using a voltage-sensitive dye that binds to the cell membrane. The fluorescence changes of the dye have a linear relationship to the action potential changes of the cell membrane. These fluorescent changes can then be detected by a photodiode array, a CCD camera or a CMOS camera. This will allow the recording of the action potential in hundreds to thousands of different sites simultaneously. Presented in this chapter are the materials and hardware needed along with step-by-step instructions on setup and techniques used in optical mapping for larger tissue preparations. PMID:20680823

  19. Early repolarization syndrome: A cause of sudden cardiac death

    Institute of Scientific and Technical Information of China (English)

    Abdi; Ali; Nida; Butt; Azeem; S; Sheikh

    2015-01-01

    Early repolarization syndrome(ERS), demonstrated as J-point elevation on an electrocardiograph, was formerly thought to be a benign entity, but the recent studies have demonstrated that it can be linked to a considerable risk of life- threatening arrhythmias and sudden cardiac death(SCD). Early repolarization characteristics associated with SCD include high-amplitude J-point elevation, horizontal and/or downslopping ST segments, and inferior and/or lateral leads location. The prevalence of ERS varies between 3% and 24%, depending on age, sex and J-point elevation(0.05 m V vs 0.1 m V) being the main determinants.ERS patients are sporadic and they are at a higher risk of having recurrent cardiac events. Implantable cardioverter-defibrillator implantation and isoproterenol are the suggested therapies in this set of patients. On the other hand, asymptomatic patients with ERS are common and have a better prognosis. The risk stratification in asymptomatic patients with ERS still remains a grey area. This review provides an outline of the up-to-date evidence associated with ERS and the risk of life- threatening arrhythmias. Further prospective studies are required to elucidate the mechanisms of ventricular arrhythmogenesis in patients with ERS.

  20. Optogenetic control of the cardiac conduction system (Conference Presentation)

    Science.gov (United States)

    Crocini, Claudia; Ferrantini, Cecilia; Coppini, Raffaele; Loew, Leslie M.; Cerbai, Elisabetta; Poggesi, Corrado; Pavone, Francesco S.; Sacconi, Leonardo

    2016-03-01

    Fatal cardiac arrhythmias are a major medical and social issue in Western countries. Current implantable pacemaker/defibrillators have limited effectiveness and are plagued by frequent malfunctions and complications. Here, we aim at setting up a new method to map and control the electrical activity of whole isolated mouse hearts. We employ a transgenic mouse model expressing Channel Rhodopsin-2 (ChR2) in the heart coupled with voltage optical mapping to monitor and control action potential propagation. The whole heart is loaded with the fluorinated red-shifted voltage sensitive dye (di-4-ANBDQPQ) and imaged with the central portion (128 x 128 pixel) of sCMOS camera operating at frame rate of 1.6 kHz. The wide-field imaging system is implemented with a random access ChR2 activation developed using two orthogonally-mounted acousto-optical deflectors (AODs). AODs rapidly scan different sites of the sample with a commutation time of 4 μs, allowing us to design ad hoc ChR2-stimulation pattern. First, we demonstrate the capability of our system in manipulating the conduction system of the whole mouse heart by changing the electrical propagation features. Then, we explore the efficacy of the random access ChR2 stimulation in inducing arrhythmias as well as to restore the cardiac sinus rhythm during an arrhythmic event. This work shows the potentiality of this new method for studying the mechanisms of arrhythmias and reentry in healthy and diseased hearts, as well as the basis of intra-ventricular dyssynchrony.