Sample records for arrhythmia

  1. Arrhythmia (United States)

    An arrhythmia is a problem with the rate or rhythm of your heartbeat. It means that your heart beats ... is called bradycardia. The most common type of arrhythmia is atrial fibrillation, which causes an irregular and ...

  2. Arrhythmias

    Directory of Open Access Journals (Sweden)

    Hanan Zaghla


    Conclusion: Our results rule out the electropathy hypothesis and underline autonomic neuropathy as the most possible mechanism of arrhythmias in hypoxaemic, non-respiratory failure, and COPD patients.

  3. About Arrhythmia (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More About Arrhythmia Updated:Oct 26,2016 The term "arrhythmia" refers ... damaged. View an animation of arrhythmia . Types of Arrhythmias Atrial Fibrillation = upper heart chambers contract irregularly Bradycardia = ...

  4. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)


    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).

  5. Why Arrhythmia Matters (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Why Arrhythmia Matters Updated:Dec 21,2016 When the heart's ... fibrillation. This content was last reviewed September 2016. Arrhythmia • Home • About Arrhythmia • Why Arrhythmia Matters • Understand Your ...

  6. Treating Arrhythmias in Children (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Treating Arrhythmias in Children Updated:Dec 21,2016 Many options ... card This content was last reviewed September 2016. Arrhythmia • Home • About Arrhythmia • Why Arrhythmia Matters • Understand Your ...

  7. Children and Arrhythmia (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Children and Arrhythmia Updated:Dec 21,2016 If your child has ... options This content was last reviewed September 2016. Arrhythmia • Home • About Arrhythmia • Why Arrhythmia Matters • Understand Your ...

  8. Common Tests for Arrhythmia (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Common Tests for Arrhythmia Updated:Dec 21,2016 Several tests can help ... View an animation of arrhythmia . Common Tests for Arrhythmia Holter monitor (continuous ambulatory electrocardiographic monitor) Suspected arrhythmias ...

  9. How Are Arrhythmias Treated? (United States)

    ... page from the NHLBI on Twitter. How Are Arrhythmias Treated? Common arrhythmia treatments include medicines, medical procedures, and surgery. Your doctor may recommend treatment if your arrhythmia causes serious symptoms, such as dizziness, chest pain, ...

  10. Living with an Arrhythmia (United States)

    ... from the NHLBI on Twitter. Living With an Arrhythmia Many arrhythmias are harmless. It's common to have an occasional ... heartbeat or mild palpitations . People who have harmless arrhythmias can live healthy lives. They usually don't ...

  11. How Are Arrhythmias Diagnosed? (United States)

    ... page from the NHLBI on Twitter. How Are Arrhythmias Diagnosed? Arrhythmias can be hard to diagnose, especially the types ... symptoms every once in a while. Doctors diagnose arrhythmias based on medical and family histories, a physical ...

  12. Cardiac arrhythmias in pregnancy. (United States)

    Knotts, Robert J; Garan, Hasan


    As more women with repaired congenital heart disease survive to their reproductive years and many other women are delaying pregnancy until later in life, a rising concern is the risk of cardiac arrhythmias during pregnancy. Naturally occurring cardiovascular changes during pregnancy increase the likelihood that a recurrence of a previously experienced cardiac arrhythmia or a de novo arrhythmia will occur. Arrhythmias should be thoroughly investigated to determine if there is a reversible etiology, and risks/benefits of treatment options should be fully explored. We discuss the approach to working up and treating various arrhythmias during pregnancy with attention to fetal and maternal risks as well as treatment of fetal arrhythmias. Acute management in stable patients includes close monitoring and intravenous pharmacologic therapy, while DC cardioversion should be used to terminate arrhythmias in hemodynamically unstable patients. Long-term management may require continued oral antiarrhythmic therapy, with particular attention to fetal safety, to prevent complications associated with arrhythmias.

  13. Nonrespiratory Sinus Arrhythmia

    Directory of Open Access Journals (Sweden)

    Barbosa Filho José


    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

  14. Arrhythmias in peripartum cardiomyopathy. (United States)

    Honigberg, Michael C; Givertz, Michael M


    Peripartum cardiomyopathy (PPCM) is a complication of late pregnancy and the early postpartum period characterized by dilated cardiomyopathy and heart failure with reduced ejection fraction. Approximately half of women fail to recover left ventricular function. Standard management of heart failure is indicated, with some exceptions for women who are predelivery or breastfeeding. Atrial and ventricular arrhythmias are reported in PPCM, but the frequency of arrhythmias in this condition is not well characterized. Management of PPCM-associated arrhythmias may include antiarrhythmic drugs, catheter ablation, and wearable or implantable cardioverter-defibrillators. Further research is needed on the prevalence, natural history, and optimal management of arrhythmias in PPCM.

  15. Devices for Arrhythmia (United States)

    ... High Blood Pressure Know Your Numbers Understand Symptoms & Risks ... In a medical emergency, life-threatening arrhythmias may be stopped by giving the heart an electric shock (as with a defibrillator ). For people with ...

  16. [Arrhythmia and sport]. (United States)

    Saoudi, N; Yaici, K; Zarkane, N; Darmon, J P; Rinaldi, J P; Brunner, P; Ricard, P; Mourou, M Y


    Sports arrhythmia has gained wide attention with the mediatization of the death of famous sports stars. Sport strongly modifies the structure of the heart with the development of left ventricular hypertrophy which may be difficult to differentiate from that due to doping. Intense training modifies also the resting electrocardiogram with appearance of signs of left ventricular hypertrophy whereas resting sinus bradycardia and atrioventricular conduction disturbances usually reverts upon exertion. Accordingly, arrhythmia may develop ranging from extrasystoles to atrial fibrillation and even sudden death. Recent data suggest that if benign arrhythmia may be the result of the sole intense training and are reversible, malignant ventricular arrhythmia and sudden death mostly occur in unknown structural heart disease. Hypertrophic cardiomyopathy is amongst the most frequent post mortem diagnosis in this situation. Doping is now present in many sports and further threatens the athlete in the safe practice of sport.

  17. Arrhythmias (For Parents) (United States)

    ... Child If Your Child Has a Heart Defect Coarctation of the Aorta Cardiac Catheterization Mitral Valve Prolapse ... Atrial Septal Defect Arrhythmias Cardiac Catheterization EKG (Video) Coarctation of the Aorta Atrial Septal Defect Ventricular Septal ...

  18. Types of Arrhythmia (United States)

    ... for children who have arrhythmias include medicines, defibrillation (electric shock), surgically implanted devices that control the heartbeat, and other procedures that fix abnormal electrical signals in the heart. Rate This Content: NEXT >> Updated: ...

  19. Sports and arrhythmias. (United States)

    Giada, F; Conte, R; Pescatore, V; Brugin, E


    Rhythm disorders represent the main challenge for the sport physician and cardiologist to grant the certificate of sports eligibility to the athletes. Arrhythmias that occur in athletes can be divided into two types. The most common are generally an expression of morphofunctional changes in the athlete's heart and are represented by certain forms of non-complex tachyarrhythmias and bradyarrhythmias. On the other hand you may encounter less frequently more complex arrhythmias that may be an epiphenomenon of cardiomyopathy can cause sudden death during sports activities. By collection of detailed medical history, careful examination, and in particular by the 12-lead electrocardiogram is already possible to understand the arrhythmic risk sporting population. After an analysis of main types of arrhythmias encountered in the athlete and the main diagnostic methods, this study focuses on the interplay between forms of arrhythmias, arrhythmogenic heart diseases and activity sports. Surely the increased adrenergic tone and anatomical and functional alterations sports-related favor the development of arrhythmia and sudden death risk in structural cardiomyopathies. But this is not yet resolved the question of whether sport is able to increase the incidence of ventricular arrhythmias in a normal heart. Dangerousness of the arrhythmia is variable depending on the sport is practiced with high intensity or not. Even if it is important considering the possibility of syncope in hazardous environments. Arrhythmias at risk impose the exclusion of the athlete from the practice of sport. In some cases it may be considered a drug treatment, ablation, and in rare and selected cases, the implantation of a pacemaker or an implantable defibrillator.

  20. Computers and clinical arrhythmias. (United States)

    Knoebel, S B; Lovelace, D E


    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

  1. [Arrhythmias from swallowing]. (United States)

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


    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.

  2. Behavioral influences on cardiac arrhythmias. (United States)

    Lampert, Rachel


    Stress can trigger both ventricular and atrial arrhythmias, as evidenced by epidemiological, clinical, and laboratory studies, through its impact on autonomic activity. Chronic stress also increases vulnerability to arrhythmias. Novel therapies aimed at decreasing the psychological and physiological response to stress may decrease arrhythmia frequency and improve quality of life.

  3. Fibrosis and Cardiac Arrhythmias

    NARCIS (Netherlands)

    de Jong, Sanne; van Veen, Toon A. B.; van Rijen, Harold V. M.; de Bakker, Jacques M. T.


    In this review article about fibrosis and arrhythmias, we show that the amount of collagen, a normal element of the heart muscle, increases with age and in heart disease. The relation between fibrosis and electrophysiological parameters such as conduction, fractionation of electrograms, abnormal imp

  4. [Psychosomatic aspects of cardiac arrhythmias]. (United States)

    Siepmann, Martin; Kirch, Wilhelm


    Emotional stress facilitates the occurrence of cardiac arrhythmias including sudden cardiac death. The prevalence of anxiety and depression is increased in cardiac patients as compared to the normal population. The risk of cardiovascular mortality is enhanced in patients suffering from depression. Comorbid anxiety disorders worsen the course of cardiac arrhythmias. Disturbance of neurocardiac regulation with predominance of the sympathetic tone is hypothesized to be causative for this. The emotional reaction to cardiac arrhythmias is differing to a large extent between individuals. Emotional stress may result from coping with treatment of cardiac arrhythmias. Emotional stress and cardiac arrhythmias may influence each other in the sense of a vicious circle. Somatoform cardiac arrhythmias are predominantly of psychogenic origin. Instrumental measures and frequent contacts between physicians and patients may facilitate disease chronification. The present review is dealing with the multifaceted relationships between cardiac arrhythmias and emotional stress. The underlying mechanisms and corresponding treatment modalities are discussed.

  5. Systems biology and cardiac arrhythmias. (United States)

    Grace, Andrew A; Roden, Dan M


    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence.

  6. Chaos control of cardiac arrhythmias. (United States)

    Garfinkel, A; Weiss, J N; Ditto, W L; Spano, M L


    Chaos theory has shown that many disordered and erratic phenomena are in fact deterministic, and can be understood causally and controlled. The prospect that cardiac arrhythmias might be instances of deterministic chaos is therefore intriguing. We used a recently developed method of chaos control to stabilize a ouabain-induced arrhythmia in rabbit ventricular tissue in vitro. Extension of these results to clinically significant arrhythmias such as fibrillation will require overcoming the additional obstacles of spatiotemporal complexity.

  7. Who Is at Risk for Arrhythmia? (United States)

    ... on Twitter. Who Is at Risk for an Arrhythmia? Arrhythmias are very common in older adults. Atrial fibrillation (a common type of arrhythmia that can cause problems) affects millions of people, ...

  8. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa


    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.

  9. Data analysis in cardiac arrhythmias. (United States)

    Rodrigo, Miguel; Pedrón-Torecilla, Jorge; Hernández, Ismael; Liberos, Alejandro; Climent, Andreu M; Guillem, María S


    Cardiac arrhythmias are an increasingly present in developed countries and represent a major health and economic burden. The occurrence of cardiac arrhythmias is closely linked to the electrical function of the heart. Consequently, the analysis of the electrical signal generated by the heart tissue, either recorded invasively or noninvasively, provides valuable information for the study of cardiac arrhythmias. In this chapter, novel cardiac signal analysis techniques that allow the study and diagnosis of cardiac arrhythmias are described, with emphasis on cardiac mapping which allows for spatiotemporal analysis of cardiac signals.Cardiac mapping can serve as a diagnostic tool by recording cardiac signals either in close contact to the heart tissue or noninvasively from the body surface, and allows the identification of cardiac sites responsible of the development or maintenance of arrhythmias. Cardiac mapping can also be used for research in cardiac arrhythmias in order to understand their mechanisms. For this purpose, both synthetic signals generated by computer simulations and animal experimental models allow for more controlled physiological conditions and complete access to the organ.

  10. Pharmacological management of arrhythmias in the elderly

    NARCIS (Netherlands)

    VanGelder, IC; Brugemann, J; Crijns, HJGM


    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

  11. Arrhythmia risk in liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Ioana Mozos


    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.

  12. Molecular therapies for cardiac arrhythmias

    NARCIS (Netherlands)

    Boink, G.J.J.


    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

  13. [Maternal arrhythmias during pregnancy. Practical review]. (United States)

    Kornacewicz-Jach, Zdzisława; Peregud-Pogorzelska, Małgorzata


    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.

  14. Cardiac Arrhythmias: Diagnosis, Symptoms, and Treatments. (United States)

    Fu, Du-Guan


    The cardiac arrhythmia is characterized by irregular rhythm of heartbeat which could be either too slow (100 beats/min) and can happen at any age. The use of pacemaker and defibrillators devices has been suggested for heart arrhythmias patients. The antiarrhythmic medications have been reported for the treatment of cardiac arrhythmias or irregular heartbeats. The diagnosis, symptoms, and treatments of cardiac arrhythmias as well as the radiofrequency ablation, tachycardia, Brugada syndrome, arterial fibrillation, and recent research on the genetics of cardiac arrhythmias have been described here.

  15. Common cardiac arrhythmias: recognition and treatment. (United States)

    Talmers, F N; Kinhal, V; Sabharwal, S; Weissler, A M


    Cardiac arrhythmias are commonly seen in the everyday practice of medicine by the physician. Although certain arrhythmias may be suspected clinically, precise diagnosis is made by electrocardiographic recording of the abnormal rhythm. Once the arrhythmia has been recorded, the next steps are proper electrocardiographic diagnosis and selection of proper treatment. The specific mode of therapy and the speed with which it is delivered will depend not only on the type of arrhythmia, but also on the hemodynamic consequences of the rhythm abnormality on the patient's cardiovascular system. The purpose of this paper is to discuss the electrocardiographic criteria of common cardiac arrhythmias as well as current concepts regarding therapy.

  16. New theory of arrhythmia. Conceptual substantiation of arrhythmia mechanisms

    Directory of Open Access Journals (Sweden)

    Vladimir I. Ermoshkin


    Full Text Available Aims A new attempt is made to substantiate the concept of the mechanism of arrhythmia and sudden cardiac death. Methods The paper is based on a theoretical analysis of special literature, personal experience of participation in conferences and discussions with leading Russian cardiologists. Results We have succeeded in demonstrating the fact that researchers ignore the fact that cardiomyocytes can be excited by mechanical pulses, when considering the arrhythmia mechanisms. We have conducted trials using the Cardiocode device. Under stress in a human, opened may be large and small arteriovenous anastomoses, via which blood under high pressure is ejected into veins. It leads to pressure surges in arteries and veins. The vena cava dilates, its tonus increases. In some cases, the pulse waves travel via anastomoses along the vena cava walls to the atria and the ventricles. An above-threshold concentration of tensions from mechanical pulses may excite cardiomyocytes from different points of the myocardium, disturbing the sinus rhythm. As a result, extrasystoles, tachycardia attacks, blocking of blood circulation in the peripheral segments of the venous arterial networks, edemata, thrombosis and metabolism disorders appear. Arrhythmia, tachycardia attacks and concomitant myocardial ischemia lead to progression of heart fibrosis. Such changes increase the probability of fibrillations and sudden cardiac death. Conclusion Unhealthy lifestyle, the presence of opening and not properly closing anastomoses may provoke a number of diseases. To avoid the cardiac arrhythmia attacks and prevent SCD, it is necessary to suppress travel of the mechanical waves within the following circuitry: aorta – artery – anastomosis – vein – vena cava – atria – ventricles. The travel of the mechanical waves within the same vessel circuitry explains the fact that the fixed couplings under extrasystoles are observed, and the beat-to-beat RR intervals under tachycardia

  17. 10.2.Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)


    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-

  18. Arrhythmias (United States)

    ... when to contract and pump blood around the body. The electrical signals start in a group of cells, called the ... a small battery-operated device implanted into the body (near the collarbone) through ... signals to speed up the heartbeat. Defibrillators. A small ...

  19. Atrial Arrhythmia Summit: Post Summit Report (United States)

    Barr, Yael


    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.

  20. Drug-induced arrhythmias, quantifying the problem

    NARCIS (Netherlands)

    Bruin, M.L. de


    Cardiac arrhythmias as an adverse reaction to the use of non-antiarrhythmic drugs have attracted much attention during recent years. It has become the single most common reason for regulatory action regarding the marketing of drugs. Although drug-induced arrhythmias are very rare (approximately 1 pe

  1. Update in cardiac arrhythmias and pacing. (United States)

    García-Bolao, Ignacio; Ruiz-Mateas, Francisco; Bazan, Victor; Berruezo, Antonio; Alcalde, Oscar; Leal del Ojo, Juan; Acosta, Juan; Martínez Sellés, Manuel; Mosquera, Ignacio


    This article discusses the main advances in cardiac arrhythmias and pacing published between 2013 and 2014. Special attention is given to the interventional treatment of atrial fibrillation and ventricular arrhythmias, and on advances in cardiac pacing and implantable cardioverter defibrillators, with particular reference to the elderly patient.

  2. Cardiac arrhythmias during or after epileptic seizures. (United States)

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


    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.

  3. Effect of female sex on cardiac arrhythmias. (United States)

    Gowd, B M Pampana; Thompson, Paul D


    We performed a systematic literature review to examine the effect of female sex on cardiac electrophysiology and arrhythmias. Women have faster resting heart rates yet longer QTc intervals. Women also have shorter PR and QRS intervals; these are presumed to be due to the small heart size of women and hormonal effects on ion channels. Women are two times more likely to experience atrioventricular nodal re-entry tachycardia than men. In contrast to atrioventricular nodal re-entry tachycardia, accessory-pathway-mediated atrial arrhythmias are less common in women, and women have more concealed and fewer manifest accessory pathways. Supraventricular tachycardia in women varies with the menstrual cycle and is more frequent in the luteal phase and inversely correlated with estrogen levels. Atrial fibrillation (AF) is less prevalent in women, but the absolute number of women with AF is higher because AF prevalence increases with age and women live longer. Also, complications of AF are greater in women. Women are generally less prone to ventricular arrhythmias, but they comprise a higher percentage of symptomatic subjects with congenital long QT syndrome and are more often affected by drugs that prolong the QT. Women are less prone to arrhythmias during pregnancy although they commonly complain of palpitations, which are sometimes related to the increase in heart rate during pregnancy. Clinicians should explore the relationship of arrhythmias to the menstrual cycle in female patients and should know that the menstrual cycle may affect the induction of arrhythmias during electrophysiological testing. Clinicians should also be aware that the arrhythmia and the result of clinical trials examining arrhythmia treatment may have different implications in women than in men.

  4. Inherited arrhythmias: The cardiac channelopathies

    Directory of Open Access Journals (Sweden)

    Shashank P Behere


    Full Text Available Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information′s website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years and age (birth-18 years, yielding 47 results. The second search using the medical subject headings (MeSH database with the search terms "Long QT Syndrome" (MeSH and "Short QT Syndrome" (MeSH and "Brugada Syndrome" (MeSH and "Catecholaminergic Polymorphic Ventricular Tachycardia" (MeSH, applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full.


    Institute of Scientific and Technical Information of China (English)

    Qing-bo Fan; Ming-ying Gai; Jian-qiu Yang; Fei-fei Xing


    Objective To explore fetal arrhythmia clinical significance and its correlation with fetal prognosis.Methods Twenty-six cases of fetal arrhythmia detected among 12 799 pregnant women recorded over a ten-year period in Peking Uinon Medical College (PUMC) Hospital were reviewed retrospectively. Fetal arrhythmia was diagnosed by fetal auscultation, ultrasonography, electric fetal heart monitoring, and fetal echocardiography.Results Twenty-six fetuses were documented with fetal arrhythmia (3 tachycardia, 4 bradycardia, 19 normal heart rate with irregular fetal cardiac rhythm). The incidence of fetal arrhythmia in our hospital was 0.2%. They were diagnosed at the average of 35 weeks' gestation (15 to 41 weeks). Twenty-two cases were diagnosed by antenatal fetal auscultation, 1 case was diagnosed by ultrasonography, and 3 cases were diagnosed by electric fetal heart monitoring. Fetal echocardiograms were performed on 17 fetuses, 6 cases (35.3%) of which showed that ventricular premature beats with normal structure of fetal heart.All neonates survived postnatally and 24 of them (92.3%) were followed up. Echocardiograms were performed for 16 neonates and 2 of them were identified as atrial septal defects with normal heart rhythms. The results of follow-up showed that the two patients had no apparent clinical manifestation. The echocardiogram showed that atrial septal defect obliterated already.Conclusion The prognosis is well for most of the fetuses with arrhythmias, with low incidence of heart deformation.

  6. Cardiac arrhythmias during or after epileptic seizures (United States)

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


    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

  7. Gene therapy to treat cardiac arrhythmias. (United States)

    Bongianino, Rossana; Priori, Silvia G


    Gene therapy to treat electrical dysfunction of the heart is an appealing strategy because of the limited therapeutic options available to manage the most-severe cardiac arrhythmias, such as ventricular tachycardia, ventricular fibrillation, and asystole. However, cardiac genetic manipulation is challenging, given the complex mechanisms underlying arrhythmias. Nevertheless, the growing understanding of the molecular basis of these diseases, and the development of sophisticated vectors and delivery strategies, are providing researchers with adequate means to target specific genes and pathways involved in disorders of heart rhythm. Data from preclinical studies have demonstrated that gene therapy can be successfully used to modify the arrhythmogenic substrate and prevent life-threatening arrhythmias. Therefore, gene therapy might plausibly become a treatment option for patients with difficult-to-manage acquired arrhythmias and for those with inherited arrhythmias. In this Review, we summarize the preclinical studies into gene therapy for acquired and inherited arrhythmias of the atria or ventricles. We also provide an overview of the technical advances in the design of constructs and viral vectors to increase the efficiency and safety of gene therapy and to improve selective delivery to target organs.

  8. Arrhythmia and exercise intolerance in Fontan patients

    DEFF Research Database (Denmark)

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


    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......, and blood sampling and medical history was retrieved from medical records. RESULTS: Twenty-six (11%) patients died or had heart transplantation (HTx) after a mean (±SD) post-Fontan follow-up of 8.3±5.7years. Excluding perioperative deaths (n=8), a linear probability of HTx-free survival was observed......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...

  9. Cardiac arrhythmias associated with spinal cord injury

    DEFF Research Database (Denmark)

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


    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...... as during procedures such as penile vibro-stimulation and tracheal suction. These episodes of bradycardia were seen more often in individuals with cervical injuries. Longitudinal studies with continuous electrocardiogram recordings are needed to uncover the true relation between cardiac arrhythmias and SCI....

  10. Repolarization reserve, arrhythmia and new drug development

    Directory of Open Access Journals (Sweden)

    Yang Li


    Full Text Available Repolarization-related lethal arrhythmias have led to the concept of “repolarization reserve”, which may help elucidate the relationship between K+ currents and other components of repolarization. Pharmacological manipulation as well as congenital and cardiac disease may affect repolarization and alter the repolarization reserve, leading to the development of arrhythmias. Pharmacological enhancement of outward currents or suppression of inward currents has been shown to be of therapeutic value. A number of newly found selective ion channel inhibitors or agonists have been investigated for their ability to enhance repolarization reserve and decrease the incidence of arrhythmia. In this paper we review the development, potential mechanisms, clinical application, and pharmacological significance of repolarization reserve in order to better understand, predict and prevent unexplained adverse cardiac events.

  11. Arrhythmias in viral myocarditis and pericarditis. (United States)

    Baksi, A John; Kanaganayagam, G Sunthar; Prasad, Sanjay K


    Acute viral myocarditis and acute pericarditis are self-limiting conditions that run a benign course and that may not involve symptoms that lead to medical assessment. However, ventricular arrhythmia is frequent in viral myocarditis. Myocarditis is thought to account for a large proportion of sudden cardiac deaths in young people without prior structural heart disease. Identification of acute myocarditis either with or without pericarditis is therefore important. However, therapeutic interventions are limited and nonspecific. Identifying those at greatest risk of a life-threatening arrhythmia is critical to reducing the mortality. This review summarizes current understanding of this challenging area in which many questions remain.

  12. Pharmacogenetics of drug-induced arrhythmias

    DEFF Research Database (Denmark)

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


    of a spontaneous reporting system for ADRs, using drug-induced arrhythmias as an example. METHODS: Reports of drug-induced arrhythmias to proarrhythmic drugs were selected from the database of the Netherlands Pharmacovigilance Centre (1996-2003). Information on the patient's general practitioner (GP) was obtained...... were screened for 10 missense mutations in 5 genes associated with the congenital long-QT (LQT) syndrome (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2). RESULTS: We identified 45 eligible cases, 29 GPs could be contacted of which seven were willing to participate. Four cases and five matched controls could...

  13. [Effect of anti-arrhythmia drugs on mouse arrhythmia induced by Bufonis Venenum]. (United States)

    Lu, Wen-juan; Zhou, Jing; Ma, Hong-yue; Lü, Gao-hong; You, Fen-qiang; Ding, An-wei; Duan, Jin-ao


    This study is to investigate the effects of phenytoin sodium, lidocaine (sodium channel blockers), propranolol (beta-adrenergic receptor antagonist), amiodarone (drugs prolonging the action potential duration) and verapamil (calcium channel blockers) on arrhythmia of mice induced by Bufonis Venenum (Chansu) and isolated mouse hearts lethal dose of Chansu. Arrhythmia of mice were induced by Chansu and then electrocardiograms (ECGs) were recorded. The changes of P-R interval, QRS complex, Q-T interval, T wave amplitude, heart rate (HR) were observed. Moreover, arrhythmia rate, survival rate and arrhythmia score were counted. Isolated mouse hearts were prefused, and the lethal dose of Chansu was recorded. Compared with control group, after pretreatment with phenytoin sodium, broadening of QRS complex and HR were inhibited, and the incidence of ventricular arrhythmia was reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with lidocaine, the prolongation of P-R interval and broadening of QRS complex were inhibited, and the incidences of ventricular arrhythmia were reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with propranolol, prolongation of P-R interval, broadening of QRS complex, prolongation of Q-T interval and HR were inhibited, and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically, while survival rate was improved. After pretreatment with amiodarone, HR was inhibited, the incidences of ventricular tachycardia were reduced dramatically. Lastly, after pretreatment with verapamil, the prolongation of P-R interval and Q-T interval were inhibited and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically; the isolated mouse hearts lethal dose of Chansu was reduced significantly. In in

  14. Noninvasive diagnostic mapping of supraventricular arrhythmias (Wolf-Parkinson-White syndrome and atrial arrhythmias). (United States)

    Cakulev, Ivan; Sahadevan, Jayakumar; Waldo, Albert L


    The 12-lead electrocardiogram has limited value in precisely identifying the origin of focal or critical component of reentrant arrhythmias during supraventricular arrhythmias, as well as precisely locating accessory atrioventricular conduction pathways. Because of these limitations, efforts have been made to reconstruct epicardial activation sequences from body surface measurements obtained noninvasively. The last decade has registered significant progress in obtaining clinically useful data from the attempts to noninvasively map the epicardial electrical activity. This article summarizes the recent advances made in this area, specifically addressing the clinical outcomes of such efforts relating to atrial arrhythmias and Wolf-Parkinson-White syndrome.

  15. A vertical approach to cardiac arrhythmias. (United States)

    Vaughan Williams, E M


    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. Cardiac arrhythmias in adult patients with asthma

    DEFF Research Database (Denmark)

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


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

  17. Risk of arrhythmia induced by psychotropic medications

    DEFF Research Database (Denmark)

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


    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...

  18. Cardiac Arrhythmias and Abnormal Electrocardiograms After Acute Stroke. (United States)

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


    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.

  19. Robotic magnetic navigation for ablation of human arrhythmias (United States)

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


    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

  20. Non-invasive Mapping of Cardiac Arrhythmias. (United States)

    Shah, Ashok; Hocini, Meleze; Haissaguerre, Michel; Jaïs, Pierre


    Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism, and the likely site of origin. Several decades of research has led to the development of a 252-lead ECG and computed tomography (CT) scan-based three-dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats), and ventricular pre-excitation (Wolff-Parkinson-White syndrome).

  1. 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


    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

  2. Cardiac Arrhythmia Classification by Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Hadji Salah


    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.

  3. Heart-brain interactions in cardiac arrhythmia. (United States)

    Taggart, P; Critchley, H; Lambiase, P D


    This review examines current knowledge of the effects of higher brain centres and autonomic control loops on the heart with particular relevance to arrhythmogenesis. There is now substantial evidence that higher brain function (cortex), the brain stem and autonomic nerves affect cardiac electrophysiology and arrhythmia, and that these may function as an interactive system. The roles of mental stress and emotion in arrhythmogenesis and sudden cardiac death are no longer confined to the realms of anecdote. Advances in molecular cardiology have identified cardiac cellular ion channel mutations conferring vulnerability to arrhythmic death at the myocardial level. Indeed, specific channelopathies such as long QT syndrome and Brugada syndrome are selectively sensitive to either sympathetic or vagal stimulation. There is increasing evidence that afferent feedback from the heart to the higher centres may affect efferent input to the heart and modulate the cardiac electrophysiology. The new era of functional neuroimaging has identified the central neural circuitry in this brain-heart axis. Since precipitants of sudden fatal arrhythmia are frequently environmental and behavioural, central pathways translating stress into autonomic effects on the heart might be considered as therapeutic targets. These brain-heart interactions help explain the apparent randomness of sudden cardiac events and provide new insights into future novel therapies to prevent sudden death.

  4. Cancer chemotherapy and cardiac arrhythmias: a review. (United States)

    Tamargo, Juan; Caballero, Ricardo; Delpón, Eva


    Cardiovascular toxicity is a potential complication of cancer chemotherapy (CC) that increases the morbidity and mortality of cancer patients. Cardiac arrhythmias have been reported as an adverse effect of many chemotherapeutic drugs, including novel targeted therapies. The relationship between chemotherapy and arrhythmias has not been well-established and the proarrhythmogenic mechanisms remain uncertain as they can be the result of a direct electrophysiological effect or of changes in cardiac structure and function, including myocardial ischaemia and heart failure, which create an arrhythmogenic substrate. In this review we summarise available evidence of proarrhythmia induced by CC, discuss the possible mechanisms involved in this adverse effect and emphasise the importance of cardiac monitoring for the early diagnosis, intervention and surveillance of those patients more susceptible to develop proarrhythmia in an attempt to reduce the morbidity and mortality. Oncologists should be fully aware of proarrhythmia and the close collaboration between cardiologists and oncologists would result in a better cardiovascular assessment, risk stratification, cardiac monitoring and treatment during CC and during the follow-up. The final objective is to understand the mechanisms of proarrhythmia and evaluate its real incidence and clinical relevance so as to select the safest and most effective treatment for cancer patients.

  5. Almanac 2013: cardiac arrhythmias and pacing. (United States)

    Liew, Reginald


    Important advances have been made in the past few years in the fields of clinical cardiac electrophysiology and pacing. Researchers and clinicians have a greater understanding of the pathophysiological mechanisms underlying atrial fibrillation (AF), which has transpired into improved methods of detection, risk stratification, and treatments. The introduction of novel oral anticoagulants has provided clinicians with alternative options in managing patients with AF at moderate to high thromboembolic risk and further data has been emerging on the use of catheter ablation for the treatment of symptomatic AF. Another area of intense research in the field of cardiac arrhythmias and pacing is in the use of cardiac resynchronisation therapy (CRT) for the treatment of patients with heart failure. Following the publication of major landmark randomised controlled trials reporting that CRT confers a survival advantage in patients with severe heart failure and improves symptoms, many subsequent studies have been performed to further refine the selection of patients for CRT and determine the clinical characteristics associated with a favourable response. The field of sudden cardiac death and implantable cardioverter defibrillators also continues to be actively researched, with important new epidemiological and clinical data emerging on improved methods for patient selection, risk stratification, and management. This review covers the major recent advances in these areas related to cardiac arrhythmias and pacing.

  6. Genetics of inherited primary arrhythmia disorders

    Directory of Open Access Journals (Sweden)

    Spears DA


    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. Atrial Arrhythmias and Their Implications for Space Flight - Introduction (United States)

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


    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.

  8. Cardiac arrhythmias in hypokalemic periodic paralysis: Hypokalemia as only cause?

    NARCIS (Netherlands)

    Stunnenberg, B.C.; Deinum, J.; Links, T.P.; Wilde, A.A.; Franssen, H.; Drost, G.


    It is unknown how often cardiac arrhythmias occur in hypokalemic periodic paralysis (HypoPP) and if they are caused by hypokalemia alone or other factors. This systematic review shows that cardiac arrhythmias were reported in 27 HypoPP patients. Cases were confirmed genetically (13 with an R528H mut


    NARCIS (Netherlands)

    Stunnenberg, Bas C.; Deinum, Jaap; Links, Thera P.; Wilde, Arthur A.; Franssen, Hessel; Drost, Gea


    It is unknown how often cardiac arrhythmias occur in hypokalemic periodic paralysis (HypoPP) and if they are caused by hypokalemia alone or other factors. This systematic review shows that cardiac arrhythmias were reported in 27 HypoPP patients. Cases were confirmed genetically (13 with an R528H mut

  10. Arrhythmia in Acute Right Ventricular Infarction

    Directory of Open Access Journals (Sweden)

    Azin Alizadeh Asl


    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

  11. Nonlinear-dynamical arrhythmia control in humans. (United States)

    Christini, D J; Stein, K M; Markowitz, S M; Mittal, S; Slotwiner, D J; Scheiner, M A; Iwai, S; Lerman, B B


    Nonlinear-dynamical control techniques, also known as chaos control, have been used with great success to control a wide range of physical systems. Such techniques have been used to control the behavior of in vitro excitable biological tissue, suggesting their potential for clinical utility. However, the feasibility of using such techniques to control physiological processes has not been demonstrated in humans. Here we show that nonlinear-dynamical control can modulate human cardiac electrophysiological dynamics by rapidly stabilizing an unstable target rhythm. Specifically, in 52/54 control attempts in five patients, we successfully terminated pacing-induced period-2 atrioventricular-nodal conduction alternans by stabilizing the underlying unstable steady-state conduction. This proof-of-concept demonstration shows that nonlinear-dynamical control techniques are clinically feasible and provides a foundation for developing such techniques for more complex forms of clinical arrhythmia.

  12. Arrhythmias in the setting of hematopoietic cell transplants. (United States)

    Tonorezos, E S; Stillwell, E E; Calloway, J J; Glew, T; Wessler, J D; Rebolledo, B J; Pham, A; Steingart, R M; Lazarus, H; Gale, R P; Jakubowski, A A; Schaffer, W L


    Prior studies report that 9-27% of persons receiving a hematopoietic cell transplant develop arrhythmias, but the effect on outcomes is largely unknown. We reviewed data from 1177 consecutive patients ⩾40 years old receiving a hematopoietic cell transplant at one center during 1999-2009. Transplant indication was predominately leukemia, lymphoma and multiple myeloma. Overall, 104 patients were found to have clinically significant arrhythmia: 43 before and 61 after transplant. Post-transplant arrhythmias were most frequently atrial fibrillation (N=30), atrial flutter (N=7) and supraventricular tachycardia (N=11). Subjects with an arrhythmia post transplant were more likely to have longer median hospital stays (32 days vs 23, P=transplant (41% vs 15%; Ptransplant, diagnosis, history of pretransplant arrhythmia, and transplant-related variables, post-transplant arrhythmia was associated with a greater risk for death within a year of transplant (odds ratio 3.5, 95% confidence interval: 2.1, 5.9; Ptransplants are associated with significant morbidity and mortality. A prospective study of arrhythmia in the transplant setting is warranted.

  13. Role of the autonomic nervous system in modulating cardiac arrhythmias. (United States)

    Shen, Mark J; Zipes, Douglas P


    The autonomic nervous system plays an important role in the modulation of cardiac electrophysiology and arrhythmogenesis. Decades of research has contributed to a better understanding of the anatomy and physiology of cardiac autonomic nervous system and provided evidence supporting the relationship of autonomic tone to clinically significant arrhythmias. The mechanisms by which autonomic activation is arrhythmogenic or antiarrhythmic are complex and different for specific arrhythmias. In atrial fibrillation, simultaneous sympathetic and parasympathetic activations are the most common trigger. In contrast, in ventricular fibrillation in the setting of cardiac ischemia, sympathetic activation is proarrhythmic, whereas parasympathetic activation is antiarrhythmic. In inherited arrhythmia syndromes, sympathetic stimulation precipitates ventricular tachyarrhythmias and sudden cardiac death except in Brugada and J-wave syndromes where it can prevent them. The identification of specific autonomic triggers in different arrhythmias has brought the idea of modulating autonomic activities for both preventing and treating these arrhythmias. This has been achieved by either neural ablation or stimulation. Neural modulation as a treatment for arrhythmias has been well established in certain diseases, such as long QT syndrome. However, in most other arrhythmia diseases, it is still an emerging modality and under investigation. Recent preliminary trials have yielded encouraging results. Further larger-scale clinical studies are necessary before widespread application can be recommended.

  14. Cardiac arrhythmias during exercise testing in healthy men. (United States)

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


    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.

  15. Arrhythmias in Adult Congenital Heart Disease: Diagnosis and Management. (United States)

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


    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.

  16. An update on risk factors for drug-induced arrhythmias. (United States)

    Vlachos, Konstantinos; Georgopoulos, Stamatis; Efremidis, Michael; Sideris, Antonios; Letsas, Konstantinos P


    A variety of drugs, either anti-arrhythmics or non-antiarrhythmics, have been associated with drug-induced arrhythmias. Drug-induced arrhythmias are usually observed in the presence of long QT interval or Brugada electrocardiographic pattern. Clinical risk factors, such as female gender, structural heart disease, metabolic and electrolyte abnormalities, bradycardia and conduction disease, increased drug bioavailability, and silent channelopathies act as ''effect amplifiers'' which can make an otherwise relatively safe drug dangerous with regard to risk for polymorphic ventricular tachycardia in the setting of QT interval prolongation. A drug-induced type 1 electrocardiographic pattern of Brugada syndrome is considered highly proarrhythmic. Specific electrocardiographic markers including the corrected QT interval, QRS duration, Tpeak-Tend/QT ratio, and others may predict the risk of arrhythmias in both situations. The present review highlights on the current clinical and electrocardiographic risk factors for prediction of drug-induced arrhythmias.

  17. Atrial Arrhythmias in Astronauts. Summary of a NASA Summit (United States)

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


    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.

  18. Therapy with conventional antiarrhythmic drugs for ventricular arrhythmias. (United States)

    Nestico, P F; DePace, N L; Morganroth, J


    Conventional antiarrhythmic drugs are an important tool for the clinical cardiologist for the treatment of ventricular arrhythmias. Knowledge of the different properties of these drugs will help decrease the incidence of adverse effects and increase the frequency of successful therapy.

  19. QTc-prolonging drugs and hospitalizations for cardiac arrhythmias

    DEFF Research Database (Denmark)

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


    , and subsequently focused on several specific groups of patients who could be extremely vulnerable for drug-induced arrhythmias. We performed a case-control study in which patients (cases), hospitalized for nonatrial cardiac arrhythmias from 1987 to 1998, were compared with their matched controls regarding current...... use of QTc-prolonging drugs. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate conditional logistic regression, adjusting for potential confounding factors. Data were obtained from the PHARMO record linkage system. We identified 501 cases, 39 of whom used QTc......-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...

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

    NARCIS (Netherlands)

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


    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

  1. Controlled exposures to air pollutants and risk of cardiac arrhythmia

    NARCIS (Netherlands)

    Langrish, Jeremy P; Watts, Simon J; Hunter, Amanda J; Shah, Anoop S V; Bosson, Jenny A; Unosson, Jon; Barath, Stefan; Lundbäck, Magnus; Cassee, Flemming R; Donaldson, Ken; Sandström, Thomas; Blomberg, Anders; Newby, David E; Mills, Nicholas L


    BACKGROUND: Epidemiological studies have reported associations between air pollution exposure and increases in cardiovascular morbidity and mortality. Exposure to air pollutants can influence cardiac autonomic tone and reduce heart rate variability, and may increase the risk of cardiac arrhythmias,

  2. Sleep Apnea and Nocturnal Cardiac Arrhythmia: A Populational Study

    Directory of Open Access Journals (Sweden)

    Fatima Dumas Cintra


    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.

  3. Respiratory Sinus Arrhythmia and Emotional Reactions

    Directory of Open Access Journals (Sweden)

    Asmir Gračanin


    Full Text Available Respiratory sinus arrhythmia (RSA, which is considered to reflect parasympathetic activity, has received an increased scientific interest during the last several decades. Research on RSA in psychophysiology was especially focused on its relationship with the emotional process and related individual differences. This contribution starts with a short description of parasympathetic nervous system function and its influences on heart activity. This is followed by the description of the Polyvagal Theory and the model of neurovisceral integration, which represent a broad framework for an understanding of the relations between parasympathetic activity, workings of the central nervous system functions, cognitive processes, and emotional reactions. After a brief explanation of the way the RSA is typically measured, a short overview of experimental research directed to RSA changes that accompany emotional reactions and correlational research of the relations between baseline measures of RSA and emotional traits is presented. This research shows that different hypotheses derived from the Polyvagal theory and the Model of neurovisceral integration are confirmed primarily in the context of vagal withdrawal and decreased vagal tone that are related to stress reactions, emotion of fear and trait anxiety, and to a lesser extent to trait hostility. The final section includes a brief discussion on the sources of inconsistency in the results of experimental research of relations between basic emotions and RSA changes, such as the neglected role of cognitive processes and somatic activity.

  4. Computer-assisted education system for arrhythmia (CAESAR). (United States)

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


    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.

  5. Cardiac arrhythmias induced by chloral hydrate in rhesus monkeys. (United States)

    Han, Pengfei; Song, Haibo; Yang, Pingliang; Xie, Huiqi; Kang, Y James


    Chloral hydrate has been long used as a safe sedative and hypnotic drug in humans. However, reports on its cardiovascular adverse effects have been published from time to time. The present study was undertaken to use Rhesus monkeys as a model to define the dose regiment of chloral hydrate at which cardiac arrhythmias can be induced and the consequences of the cardiac events. Male Rhesus monkeys of 2-3 years old were intravenously infused with chloral hydrate starting at 50 mg/kg with an increasing increment of 25 mg/kg until the occurrence of cardiac arrhythmias. In addition, a traditional up-and-down dosing procedure was applied to define a single dose level at which cardiac arrhythmias can be induced. The data obtained showed that when the sequentially escaladed dose reached 125 mg/kg, cardiac arrhythmias occurred in all monkeys tested. The single effective dose to cause cardiac arrhythmias calculated from the crossover analysis was 143 ± 4 mg/kg. This value would be equivalent to 68.6 ± 1.9 mg/kg for children and 46.4 ± 1.3 mg/kg for adults in humans. Under either multiple or single dose condition, cardiac arrhythmias did not occur before 40 min after the onset of anesthesia induced by chloral hydrate. Cardiac arrhythmias were recovered without help at the end of the anesthesia in most cases, but also continued after the regain of consciousness in some cases. The cardiac arrhythmias were accompanied with compromised cardiac function including suppressed fractional shortening and ejection fraction. This study thus suggests that cautions need to be taken when chloral hydrate is used above certain levels and beyond a certain period of anesthesia, and cardiac arrhythmias induced by chloral hydrate need to be closely monitored because compromised cardiac function may occur simultaneously. In addition, patients with cardiac arrhythmias induced by chloral hydrate should be monitored even after they are recovered from the anesthesia.

  6. Fractal ventilation enhances respiratory sinus arrhythmia

    Directory of Open Access Journals (Sweden)

    Girling Linda G


    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.

  7. Reduced incidence of cardiac arrhythmias in walkers and runners.

    Directory of Open Access Journals (Sweden)

    Paul T Williams

    Full Text Available PURPOSE: Walking is purported to reduce the risk of atrial fibrillation by 48%, whereas jogging is purported to increase its risk by 53%, suggesting a strong anti-arrhythmic benefit of walking over running. The purpose of these analyses is to compare incident self-reported physician-diagnosed cardiac arrhythmia to baseline energy expenditure (metabolic equivalent hours per day, METhr/d from walking, running and other exercise. METHODS: Proportional hazards analysis of 14,734 walkers and 32,073 runners. RESULTS: There were 1,060 incident cardiac arrhythmias (412 walkers, 648 runners during 6.2 years of follow-up. The risk for incident cardiac arrhythmias declined 4.4% per baseline METhr/d walked by the walkers, or running in the runners (P = 0.0001. Specifically, the risk declined 14.2% (hazard ratio: 0.858 for 1.8 to 3.6 METhr/d, 26.5% for 3.6 to 5.4 METhr/d, and 31.7% for ≥5.4 METhr/d, relative to <1.8 METhr/d. The risk reduction per METhr/d was significantly greater for walking than running (P<0.01, but only because walkers were at 34% greater risk than runners who fell below contemporary physical activity guideline recommendations; otherwise the walkers and runners had similar risks for cardiac arrhythmias. Cardiac arrhythmias were unrelated to walking and running intensity, and unrelated to marathon participation and performance. CONCLUSIONS: The risk for cardiac arrhythmias was similar in walkers and runners who expended comparable METhr/d during structured exercise. We found no significant risk increase for self-reported cardiac arrhythmias associated with running distance, exercise intensity, or marathon participation. Rhythm abnormalities were based on self-report, precluding definitive categorization of the nature of the rhythm disturbance. However, even if the runners' arrhythmias include sinus bradycardia due to running itself, there was no increase in arrhythmias with greater running distance.

  8. Ventricular assist device support for management of sustained ventricular arrhythmias. (United States)

    Fasseas, Panayotis; Kutalek, Steven P; Samuels, Fania L; Holmes, Elena C; Samuels, Louis E


    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias.

  9. Cardiac arrhythmias in hypokalemic periodic paralysis: Hypokalemia as only cause? (United States)

    Stunnenberg, Bas C; Deinum, Jaap; Links, Thera P; Wilde, Arthur A; Franssen, Hessel; Drost, Gea


    It is unknown how often cardiac arrhythmias occur in hypokalemic periodic paralysis (HypoPP) and if they are caused by hypokalemia alone or other factors. This systematic review shows that cardiac arrhythmias were reported in 27 HypoPP patients. Cases were confirmed genetically (13 with an R528H mutation in CACNA1S, 1 an R669H mutation in SCN4A) or had a convincing clinical diagnosis of HypoPP (13 genetically undetermined) if reported prior to the availability of genetic testing. Arrhythmias occurred during severe hypokalemia (11 patients), between attacks at normokalemia (4 patients), were treatment-dependent (2 patients), or unspecified (10 patients). Nine patients died from arrhythmia. Convincing evidence for a pro-arrhythmogenic factor other than hypokalemia is still lacking. The role of cardiac expression of defective skeletal muscle channels in the heart of HypoPP patients remains unclear. Clinicians should be aware of and prevent treatment-induced cardiac arrhythmia in HypoPP.

  10. Macrolide antibiotics and the risk of cardiac arrhythmias. (United States)

    Albert, Richard K; Schuller, Joseph L


    Randomized, controlled trials have demonstrated that chronic therapy with macrolide antibiotics reduces the morbidity of patients with cystic fibrosis, non-cystic fibrosis bronchiectasis, chronic obstructive pulmonary disease, and nontuberculous mycobacterial infections. Lower levels of evidence indicate that chronic macrolides are also effective in treating patients with panbronchiolitis, bronchiolitis obliterans, and rejection after lung transplant. Macrolides are known to cause torsade des pointes and other ventricular arrhythmias, and a recent observational study prompted the FDA to strengthen the Warnings and Precautions section of azithromycin drug labels. This summary describes the electrophysiological effects of macrolides, reviews literature indicating that the large majority of subjects experiencing cardiac arrhythmias from macrolides have coexisting risk factors and that the incidence of arrhythmias in absence of coexisting risk factors is very low, examines recently published studies describing the relative risk of arrhythmias from macrolides, and concludes that this risk has been overestimated and suggests an approach to patient evaluation that should reduce the relative risk and the incidence of arrhythmias to the point that chronic macrolides can be used safely in the majority of subjects for whom they are recommended.

  11. Laboratory Markers of Ventricular Arrhythmia Risk in Renal Failure

    Directory of Open Access Journals (Sweden)

    Ioana Mozos


    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.

  12. 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:; Du, Y.-C.; Chen Tainsong [Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)


    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.

  13. Ion channelopathy and hyperphosphorylation contributing to cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    De-zai DAI; Feng YU


    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.

  14. Role of adipose tissue in the pathogenesis of cardiac arrhythmias. (United States)

    Samanta, Rahul; Pouliopoulos, Jim; Thiagalingam, Aravinda; Kovoor, Pramesh


    Epicardial adipose tissue is present in normal healthy individuals. It is a unique fat depot that, under physiologic conditions, plays a cardioprotective role. However, excess epicardial adipose tissue has been shown to be associated with prevalence and severity of atrial fibrillation. In arrhythmogenic right ventricular cardiomyopathy and myotonic dystrophy, fibrofatty infiltration of the myocardium is associated with ventricular arrhythmias. In the ovine model of ischemic cardiomyopathy, the presence of intramyocardial adipose or lipomatous metaplasia has been associated with increased propensity to ventricular tachycardia. These observations suggest a role of adipose tissue in the pathogenesis of cardiac arrhythmias. In this article, we review the role of cardiac adipose tissue in various cardiac arrhythmias and discuss the possible pathophysiologic mechanisms.

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

    Directory of Open Access Journals (Sweden)

    Schwartz Andrei


    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.

  16. Controlled Exposures to Air Pollutants and Risk of Cardiac Arrhythmia (United States)

    Watts, Simon J.; Hunter, Amanda J.; Shah, Anoop S.V.; Bosson, Jenny A.; Unosson, Jon; Barath, Stefan; Lundbäck, Magnus; Cassee, Flemming R.; Donaldson, Ken; Sandström, Thomas; Blomberg, Anders; Newby, David E.; Mills, Nicholas L.


    Background: Epidemiological studies have reported associations between air pollution exposure and increases in cardiovascular morbidity and mortality. Exposure to air pollutants can influence cardiac autonomic tone and reduce heart rate variability, and may increase the risk of cardiac arrhythmias, particularly in susceptible patient groups. Objectives: We investigated the incidence of cardiac arrhythmias during and after controlled exposure to air pollutants in healthy volunteers and patients with coronary heart disease. Methods: We analyzed data from 13 double-blind randomized crossover studies including 282 participants (140 healthy volunteers and 142 patients with stable coronary heart disease) from whom continuous electrocardiograms were available. The incidence of cardiac arrhythmias was recorded for each exposure and study population. Results: There were no increases in any cardiac arrhythmia during or after exposure to dilute diesel exhaust, wood smoke, ozone, concentrated ambient particles, engineered carbon nanoparticles, or high ambient levels of air pollution in either healthy volunteers or patients with coronary heart disease. Conclusions: Acute controlled exposure to air pollutants did not increase the short-term risk of arrhythmia in participants. Research employing these techniques remains crucial in identifying the important pathophysiological pathways involved in the adverse effects of air pollution, and is vital to inform environmental and public health policy decisions. Citation: Langrish JP, Watts SJ, Hunter AJ, Shah AS, Bosson JA, Unosson J, Barath S, Lundbäck M, Cassee FR, Donaldson K, Sandström T, Blomberg A, Newby DE, Mills NL. 2014. Controlled exposures to air pollutants and risk of cardiac arrhythmia. Environ Health Perspect 122:747–753; PMID:24667535

  17. Circadian arrhythmia dysregulates emotional behaviors in aged Siberian hamsters. (United States)

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


    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. Sinoatrial node dysfunction induces cardiac arrhythmias in diabetic mice

    DEFF Research Database (Denmark)

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


    and electrophysiological characteristics were investigated in diabetic db/db and control db/+mice.ResultsWe found improved contractile function and impaired filling dynamics of the heart in db/db mice, relative to db/+controls. Electrophysiologically, we observed comparable heart rates in the two mouse groups, but SAN...... 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...

  19. Cardiac arrhythmias and conduction defects in systemic sclerosis. (United States)

    Vacca, Alessandra; Meune, Christophe; Gordon, Jessica; Chung, Lorinda; Proudman, Susanna; Assassi, Shervin; Nikpour, Mandana; Rodriguez-Reyna, Tatiana S; Khanna, Dinesh; Lafyatis, Robert; Matucci-Cerinic, Marco; Distler, Oliver; Allanore, Yannick


    Signs and symptoms of arrhythmias or conduction defects are frequently reported in patients with SSc. These rhythm disorders may have several origins (i.e., related to primary heart involvement, pericardial disease, valvular regurgitation or pulmonary arterial hypertension) and may negatively affect the overall prognosis of these patients. It is therefore important to identify patients at high risk for cardiac arrhythmias with a complete cardiological evaluation and to identify the underlying heart disease, including SSc-related myocardial involvement. In addition, some therapeutic options in SSc patients may differ from those recommended in other populations.

  20. An Unusual Cause of Cardiac Arrhythmias; Mediastinal Schwannoma

    Directory of Open Access Journals (Sweden)

    Serdar Ozkan


    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.

  1. Acute cardiac arrhythmias following surgery for congenital heart disease: mechanisms, diagnostic tools, and management. (United States)

    Payne, Linda; Zeigler, Vicki L; Gillette, Paul C


    This article focuses on the management of those cardiac arrhythmias most commonly seen in the immediate postoperative period. They include ventricular tachycardia, ventricular fibrillation, atrial flutter, junctional ectopic tachycardia, bradycardia, and atrioventricular block. The mechanisms of cardiac arrhythmias are reviewed followed by a brief overview of the predominant acute arrhythmias, tools used for the diagnostic evaluation of these arrhythmias, management strategies, and, finally, nursing considerations.

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

    Institute of Scientific and Technical Information of China (English)


    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.

  3. Dofetilide: a new drug to control cardiac arrhythmia

    DEFF Research Database (Denmark)

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


    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...

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

    NARCIS (Netherlands)

    Varkevisser, R.


    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

  5. Reduction in dynamin-2 is implicated in ischaemic cardiac arrhythmias. (United States)

    Shi, Dan; Xie, Duanyang; Zhang, Hong; Zhao, Hong; Huang, Jian; Li, Changming; Liu, Yi; Lv, Fei; The, Erlinda; Liu, Yuan; Yuan, Tianyou; Wang, Shiyi; Chen, Jinjin; Pan, Lei; Yu, Zuoren; Liang, Dandan; Zhu, Weidong; Zhang, Yuzhen; Li, Li; Peng, Luying; Li, Jun; Chen, Yi-Han


    Ischaemic cardiac arrhythmias cause a large proportion of sudden cardiac deaths worldwide. The ischaemic arrhythmogenesis is primarily because of the dysfunction and adverse remodelling of sarcolemma ion channels. However, the potential regulators of sarcolemma ion channel turnover and function in ischaemic cardiac arrhythmias remains unknown. Our previous studies indicate that dynamin-2 (DNM2), a cardiac membrane-remodelling GTPase, modulates ion channels membrane trafficking in the cardiomyocytes. Here, we have found that DNM2 plays an important role in acute ischaemic arrhythmias. In rat ventricular tissues and primary cardiomyocytes subjected to acute ischaemic stress, the DNM2 protein and transcription levels were markedly down-regulated. This DNM2 reduction was coupled with severe ventricular arrhythmias. Moreover, we identified that the down-regulation of DNM2 within cardiomyocytes increases the action potential amplitude and prolongs the re-polarization duration by depressing the retrograde trafficking of Nav1.5 and Kir2.1 channels. These effects are likely to account for the DNM2 defect-induced arrhythmogenic potentials. These results suggest that DNM2, with its multi-ion channel targeting properties, could be a promising target for novel antiarrhythmic therapies.

  6. Electrocardiographic abnormalities and cardiac arrhythmias in structural brain lesions. (United States)

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


    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.

  7. Atrial Arrhythmias in Astronauts - Summary of a NASA Summit (United States)

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


    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

  8. Association between Hypophosphatemia and Cardiac Arrhythmias in the Early Stage of Sepsis: Could Phosphorus Replacement Treatment Reduce the Incidence of Arrhythmias? (United States)

    Schwartz, Andrei; Brotfain, Evgeni; Koyfman, Leonid; Kutz, Ruslan; Gruenbaum, Shaun E; Klein, Moti; Zlotnik, Alexander


    It is well known that new-onset arrhythmias are common in septic patients. It is thought that hypophosphatemia in the early stages of sepsis may contribute to the development of new arrhythmias. In this study, we hypothesized that intravenous (IV) phosphorus replacement may reduce the incidence of arrhythmias in critically ill patients. 34 adult septic patients with hypophosphatemia admitted to the general intensive care unit were treated with IV phosphorus replacement per ICU protocol, and the incidence of new arrhythmias were compared with 16 patients from previously published data. IV phosphorus replacement was associated with a significantly reduced incidence of arrhythmias (38% vs. 63%, p=0.04). There were no differences in observed mortality between subgroups, which may be due to the small sample size. This study demonstrated that IV phosphorus replacement might be effective in reducing the incidence of new arrhythmias in septic patients.

  9. Optical mapping system for visualizing arrhythmias in isolated mouse atria. (United States)

    Schmidt, Robyn; Nygren, Anders


    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.

  10. ECG Signal Analysis and Arrhythmia Detection using Wavelet Transform (United States)

    Kaur, Inderbir; Rajni, Rajni; Marwaha, Anupma


    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.

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

    CERN Document Server

    Mora, Luis A


    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.

  12. Arrhythmia as a cardiac manifestation in MELAS syndrome. (United States)

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


    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.

  13. Ventricular Assist Device Support: for Management of Sustained Ventricular Arrhythmias



    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the s...

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

    Institute of Scientific and Technical Information of China (English)

    Yong-Fu Xiao


    @@ 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.

  15. Effect of fish oil on arrhythmias and mortality: systematic review


    León, Hernando; Shibata, Marcelo C; Sivakumaran, Soori; Dorgan, Marlene; Chatterley, Trish; Ross T Tsuyuki


    Objective To synthesise the literature on the effects of fish oil—docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)—on mortality and arrhythmias and to explore dose response and formulation effects. Design Systematic review and meta-analysis. Data sources Medline, Embase, the Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, Allied and Complementary Medicine, Academic OneFile, ProQuest Dissertations and Theses, Evidence-Based Complementary Medicine, and LILACS. S...

  16. Arrhythmia as a cardiac manifestation in MELAS syndrome

    Directory of Open Access Journals (Sweden)

    Tamara Thomas


    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.

  17. Pseudohypoaldosteronism in a neonate presenting as life-threatening arrhythmia


    Rajpoot, Sudeep K.; Maggi, Carlos; Bhangoo, Amrit


    Summary Neonatal hyperkalemia and hyponatremia are medical conditions that require an emergent diagnosis and treatment to avoid morbidity and mortality. Here, we describe the case of a 10-day-old female baby presenting with life-threatening hyperkalemia, hyponatremia, and metabolic acidosis diagnosed as autosomal dominant pseudohypoaldosteronism type 1 (PHA1). This report aims to recognize that PHA1 may present with a life-threatening arrhythmia due to severe hyperkalemia and describes the ma...

  18. Effect of Electroacupuncture on Reperfusion Ventricular Arrhythmia in Rat

    Institute of Scientific and Technical Information of China (English)

    ZENG Qing; LI Man; OUYANG Xingbiao; NONG Yi; LIU Xiaochun; SHI Jing; GUAN Xinmin


    Protective effect and mechanism of electroacupuncture (EA) on acute reperfusion ventricular arrhthmia was investigated. Ventricular arrhythmia was induced by occlusion of the proximal left anterior descend (LAD) branch of coronary artery for 5 min and followed with 15 min reperfusion . EA on acupoint "Neiguan", "Jianshi" was performed at 30 min before ligation and continued another 5 min during ischemia. Isoprenaline (20, 30 and 50 μg/kg) or atropine (1 mg/kg) was intravenously injected at 5min before ischemia. The results showed that EA significantly decreased the incidence of ischemia/reperfusion (I/R) induced ventricular tachycardia (VT), ventricular fibrillation (VF) and mortality as compared to I/R group. Atropine partially suppressed the EA's effect of antiarrhythmia; Isoprenaline increased the incidence and severity of reperfusion arrhythmia, which was inhibited by EA, but this inhibition of EA was blocked with increasing dose of isoprenaline. The results indicated that EA treatment could prevent the occurrence of reperfusion ventricular arrhythmia in rats with myocardial ischemia, and its mechanism might be related to the regulation of EA on the β-adrenoceptors and M-cholinergic receptor activation in myocardium.

  19. Intramyocardial activation in early ventricular arrhythmias following coronary artery ligation. (United States)

    Kaplinsky, E; Ogawa, S; Kmetzo, J; Balke, C W; Dreifus, L S


    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.

  20. Computational approaches to understand cardiac electrophysiology and arrhythmias (United States)

    Roberts, Byron N.; Yang, Pei-Chi; Behrens, Steven B.; Moreno, Jonathan D.


    Cardiac rhythms arise from electrical activity generated by precisely timed opening and closing of ion channels in individual cardiac myocytes. These impulses spread throughout the cardiac muscle to manifest as electrical waves in the whole heart. Regularity of electrical waves is critically important since they signal the heart muscle to contract, driving the primary function of the heart to act as a pump and deliver blood to the brain and vital organs. When electrical activity goes awry during a cardiac arrhythmia, the pump does not function, the brain does not receive oxygenated blood, and death ensues. For more than 50 years, mathematically based models of cardiac electrical activity have been used to improve understanding of basic mechanisms of normal and abnormal cardiac electrical function. Computer-based modeling approaches to understand cardiac activity are uniquely helpful because they allow for distillation of complex emergent behaviors into the key contributing components underlying them. Here we review the latest advances and novel concepts in the field as they relate to understanding the complex interplay between electrical, mechanical, structural, and genetic mechanisms during arrhythmia development at the level of ion channels, cells, and tissues. We also discuss the latest computational approaches to guiding arrhythmia therapy. PMID:22886409

  1. Rescue of mutated cardiac ion channels in inherited arrhythmia syndromes. (United States)

    Balijepalli, Sadguna Y; Anderson, Corey L; Lin, Eric C; January, Craig T


    Inherited arrhythmia syndromes comprise an increasingly complex group of diseases involving mutations in multiple genes encoding ion channels, ion channel accessory subunits and channel interacting proteins, and various regulatory elements. These mutations serve to disrupt normal electrophysiology in the heart, leading to increased arrhythmogenic risk and death. These diseases have added impact as they often affect young people, sometimes without warning. Although originally thought to alter ion channel function, it is now increasingly recognized that mutations may alter ion channel protein and messenger RNA processing, to reduce the number of channels reaching the surface membrane. For many of these mutations, it is also known that several interventions may restore protein processing of mutant channels to increase their surface membrane expression toward normal. In this article, we reviewed inherited arrhythmia syndromes, focusing on long QT syndrome type 2, and discuss the complex biology of ion channel trafficking and pharmacological rescue of disease-causing mutant channels. Pharmacological rescue of misprocessed mutant channel proteins, or their transcripts providing appropriate small molecule drugs can be developed, has the potential for novel clinical therapies in some patients with inherited arrhythmia syndromes.

  2. Cardiac arrhythmias and sudden unexpected death in epilepsy (SUDEP). (United States)

    Velagapudi, Poonam; Turagam, Mohit; Laurence, Thomas; Kocheril, Abraham


    Sudden unexpected death in epilepsy (SUDEP) is a major clinical problem in epilepsy patients in the United States, especially those with chronic, uncontrolled epilepsy. Several pathophysiological events contributing to SUDEP include cardiac arrhythmias, respiratory dysfunction, and dysregulation of systemic or cerebral circulation. There is a significant body of literature suggesting the prominent role of cardiac arrhythmias in the pathogenesis of SUDEP. There is evidence to say that long-standing epilepsy can cause physiological and anatomical autonomic instability resulting in life-threatening arrhythmias. Tachyarrhythmias, bradyarrhythmias, and asystole are commonly seen during ictal, interictal, and postictal phase in epilepsy patients. It is unclear if these rhythm disturbances need attention as some of them may be just benign findings. Evidence regarding prolonged cardiovascular monitoring or the benefit of pacemaker/defibrillator implantation for primary or secondary prevention in epilepsy patients is limited. Awareness regarding pathophysiology, cardiac effects, and management options of SUDEP will become useful in guiding more individualized treatment in the near future. (PACE 2011; 1-8).

  3. The role of the Arrhythmia Team, an integrated, multidisciplinary approach to treatment of patients with cardiac arrhythmias: results of the European Heart Rhythm Association survey. (United States)

    Fumagalli, Stefano; Chen, Jian; Dobreanu, Dan; Madrid, Antonio Hernandez; Tilz, Roland; Dagres, Nikolaos


    Management of patients with cardiac arrhythmias is increasingly complex because of continuous technological advance and multifaceted clinical conditions associated with ageing of the population, the presence of co-morbidities and the need for polypharmacy. The aim of this European Heart Rhythm Association Scientific Initiatives Committee survey was to provide an insight into the role of the Arrhythmia Team, an integrated, multidisciplinary approach to management of patients with cardiac arrhythmias. Forty-eight centres from 18 European countries replied to the Web-based questionnaire. The presence of an Arrhythmia Team was reported by 44% of the respondents, whereas 17% were not familiar with this term. Apart from the electrophysiologist, health professionals who should belong to such teams, according to the majority of the respondents, include a clinical cardiologist, a nurse, a cardiac surgeon, a heart failure specialist, a geneticist, and a geriatrician. Its main activity should be dedicated to the management of patients with complex clinical conditions or refractory or inherited forms of arrhythmias. When present, the Arrhythmia Team was considered helpful by 95% of respondents; the majority of centres (79%) agreed that it should be implemented. The Arrhythmia Team seems to be connected to important expectations in the management of cardiac arrhythmias. The efficacy of such an integrated and multidisciplinary approach should be encouraged and tested in clinical practice.

  4. 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


    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

  5. Interventional and surgical treatment of cardiac arrhythmias in adults with congenital heart disease. (United States)

    Koyak, Zeliha; de Groot, Joris R; Mulder, Barbara J M


    Arrhythmias are a major cause of morbidity, mortality and hospital admission in adults with congenital heart disease (CHD). The etiology of arrhythmias in this population is often multifactorial and includes electrical disturbances as part of the underlying defect, surgical intervention or hemodynamic abnormalities. Despite the numerous existing arrhythmia management tools including drug therapy, pacing and ablation, management of arrhythmias in adults with CHD remains difficult and challenging. Owing to improvement in mapping and ablation techniques, ablation and arrhythmia surgery are being performed more frequently in adults with CHD. However, there is little information on the long-term results of these treatment strategies. The purpose of this article is therefore to review the available data on nonpharmacological treatment of cardiac arrhythmias in adult patients with CHD and to give an overview of the available data on the early and late outcomes of these treatment strategies.

  6. Covert lung abscess as a cause of atrial arrhythmia: case report

    Institute of Scientific and Technical Information of China (English)

    LI Mei; LIAO De-ning; ZHANG Jia-you; YIN Ren-fu; WU Zong-gui


    @@ Atrial arrhythmia is common in clinic. Recently, it was revealed that ectopic impulses originating in sleeve muscles around the orifices of pulmonary veins (PVs) were deemed to be one of the most important reasons that trigger or drive atrial arrhythmia, which was called myocardial sleeve related arrhythmia. Electrical isolation by radiofrequency ablation is becoming highlight and proved to be an effective method for the arrhythmia. We report a 55-year-old man with paroxysmal atrial tachy-arrhythmias admitted for PV electrical isolation. An abscess was discovered in right inferior lung before the operation. The arrhythmia was disappeared after resection of the abscess. It implies that for such sufferer and recidivist after ablation, the factors outside the pulmonary veins should be excluded or treated as far as possible, especially before radiofrequency ablation therapy.

  7. Surveillance of fetal arrhythmias in the outpatient setting: current limitations and call for action. (United States)

    Freire, Grace


    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.

  8. 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


    @@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.

  9. Atrial and ventricular function in thalassemic patients with supraventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Vitantonio Di Bello


    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.

  10. Optogenetic Light Crafting Tools for the Control of Cardiac Arrhythmias. (United States)

    Richter, Claudia; Christoph, Jan; Lehnart, Stephan E; Luther, Stefan


    The control of spatiotemporal dynamics in biological systems is a fundamental problem in nonlinear sciences and has important applications in engineering and medicine. Optogenetic tools combined with advanced optical technologies provide unique opportunities to develop and validate novel approaches to control spatiotemporal complexity in neuronal and cardiac systems. Understanding of the mechanisms and instabilities underlying the onset, perpetuation, and control of cardiac arrhythmias will enable the development and translation of novel therapeutic approaches. Here we describe in detail the preparation and optical mapping of transgenic channelrhodopsin-2 (ChR2) mouse hearts, cardiac cell cultures, and the optical setup for photostimulation using digital light processing.

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

    Directory of Open Access Journals (Sweden)

    Hassan G


    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.

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

    Directory of Open Access Journals (Sweden)

    Diego Tarricone


    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

  13. Discriminative sparse coding of ECG during ventricular arrhythmias using LC-K-SVD approach. (United States)

    Kalaji, I; Balasundaram, K; Umapathy, K


    Ventricular tachycardia (VT) and ventricular fibrillation (VF) are two major types of ventricular arrhythmias that results due to abnormalities in the electrical activation in the ventricles of the heart. VF is the lethal of the two arrhythmias, which may lead to sudden cardiac death. The treatment options for the two arrhythmias are different. Therefore, detection and characterization of the two arrhythmias is critical to choose appropriate therapy options. Due to the time-varying nature of the signal content during cardiac arrhythmias, modeling and extracting information from them using time and frequency localized functions would be ideal. To this effect, in this work, we perform discriminative sparse coding of the ECG during ventricular arrhythmia with hybrid time-frequency dictionaries using the recently introduced Label consistent K-SVD (LC-K-SVD) approach. Using 944 segments of ventricular arrhythmias extracted from 23 patients in the Malignant Ventricular Ectopy and Creighton University Tachy-Arrhythmia databases, an overall classification accuracy of 71.55% was attained with a hybrid dictionary of Gabor and symlet4 atoms. In comparison, for the same database and non-trained dictionary (i.e the original dictionary) the classification accuracy was found to be 62.71%. In addition, the modeling error using the trained dictionary from LC-K-SVD approach was found to be significantly lower to the one using the non-trained dictionary.

  14. Cardiac arrhythmias in recently diagnosed hypertensive patients at first presentation: an electrocardiographic-based study. (United States)

    Ejim, E C; Ike, S O; Anisiuba, B C; Essien, I O; Onwubere, B J; Ikeh, V O


    Various forms of cardiac arrhythmias have been documented in hypertensive subjects, and hypertension is an important risk factor for the development of atrial and ventricular arrhythmias and sudden death. Electrocardiography at rest easily documents significant arrhythmias in patients, and this study was carried out to determine the types and frequency of arrhythmias in hypertensive subjects at first presentation in the Hypertension Clinics of the University of Nigeria Teaching Hospital (UNTH) Enugu, Nigeria. The study was hospitalbased and retrospective in nature. The resting 12lead ECG reports of 346 consecutive hypertensive subjects seen at the Hypertension clinics of the UNTH Enugu over a 14 month period were retrieved from the case files and studied. Other information obtained from the case files included the age and gender of the subjects. The mean age of the subjects was 57.3 years. Ninety-five of the subjects had arrhythmias representing 27% of the study population, out of which fifty-five were males (57.9%) and forty were females (42.1%). However 26.9% of all the male subjects had arrhythmias while 28.2% of all the females had arrhythmias. Multiple ventricular ectopics, sinus tachycardia, sinus bradycardia and atrial fibrillation were the most prevalent arrhythmias. This study showed that a significant proportion of hypertensive subjects present initially with significant rhythm disturbances.

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

    NARCIS (Netherlands)

    Neven, K.G.E.J.


    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

  16. 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;


    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...

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

    LENUS (Irish Health Repository)

    Al-Sarraf, Nael


    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.

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

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

    Directory of Open Access Journals (Sweden)

    Bohui Zhu


    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.

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

    Directory of Open Access Journals (Sweden)

    Donald Scheiber


    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.

  1. 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)


    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

  2. 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


    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.

  3. Coregulation of respiratory sinus arrhythmia in adult romantic partners. (United States)

    Helm, Jonathan L; Sbarra, David A; Ferrer, Emilio


    Questions surrounding physiological interdependence in romantic relationships are gaining increased attention in the research literature. One specific form of interdependence, coregulation, can be defined as the bidirectional linkage of oscillating signals within optimal bounds. Conceptual and theoretical work suggests that physiological coregulation should be instantiated in romantic couples. Although these ideas are appealing, the central tenets of most coregulatory models await empirical evaluation. In the current study, we evaluate the covariation of respiratory sinus arrhythmia (RSA) in 32 romantic couples during a series of laboratory tasks using a cross-lagged panel model. During the tasks, men's and women's RSA were associated with their partners' previous RSA responses, and this pattern was stronger for those couples with higher relationship satisfaction. The findings are discussed in terms of their implications for attachment theory, as well as the association between relationships and health.

  4. Disruption of cardiac cholinergic neurons enhances susceptibility to ventricular arrhythmias (United States)

    Jungen, Christiane; Scherschel, Katharina; Eickholt, Christian; Kuklik, Pawel; Klatt, Niklas; Bork, Nadja; Salzbrunn, Tim; Alken, Fares; Angendohr, Stephan; Klene, Christiane; Mester, Janos; Klöcker, Nikolaj; Veldkamp, Marieke W.; Schumacher, Udo; Willems, Stephan; Nikolaev, Viacheslav O.; Meyer, Christian


    The parasympathetic nervous system plays an important role in the pathophysiology of atrial fibrillation. Catheter ablation, a minimally invasive procedure deactivating abnormal firing cardiac tissue, is increasingly becoming the therapy of choice for atrial fibrillation. This is inevitably associated with the obliteration of cardiac cholinergic neurons. However, the impact on ventricular electrophysiology is unclear. Here we show that cardiac cholinergic neurons modulate ventricular electrophysiology. Mechanical disruption or pharmacological blockade of parasympathetic innervation shortens ventricular refractory periods, increases the incidence of ventricular arrhythmia and decreases ventricular cAMP levels in murine hearts. Immunohistochemistry confirmed ventricular cholinergic innervation, revealing parasympathetic fibres running from the atria to the ventricles parallel to sympathetic fibres. In humans, catheter ablation of atrial fibrillation, which is accompanied by accidental parasympathetic and concomitant sympathetic denervation, raises the burden of premature ventricular complexes. In summary, our results demonstrate an influence of cardiac cholinergic neurons on the regulation of ventricular function and arrhythmogenesis. PMID:28128201

  5. Flecainide: Current status and perspectives in arrhythmia management

    Institute of Scientific and Technical Information of China (English)

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


    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.

  6. Anatomical Consideration in Catheter Ablation of Idiopathic Ventricular Arrhythmias. (United States)

    Yamada, Takumi; Kay, G Neal


    Idiopathic ventricular arrhythmias (VAs) are ventricular tachycardias (VTs) or premature ventricular contractions (PVCs) with a mechanism that is not related to myocardial scar. The sites of successful catheter ablation of idiopathic VA origins have been progressively elucidated and include both the endocardium and, less commonly, the epicardium. Idiopathic VAs usually originate from specific anatomical structures such as the ventricular outflow tracts, aortic root, atrioventricular (AV) annuli, papillary muscles, Purkinje network and so on, and exhibit characteristic electrocardiograms based on their anatomical background. Catheter ablation of idiopathic VAs is usually safe and highly successful, but can sometimes be challenging because of the anatomical obstacles such as the coronary arteries, epicardial fat pads, intramural and epicardial origins, AV conduction system and so on. Therefore, understanding the relevant anatomy is important to achieve a safe and successful catheter ablation of idiopathic VAs. This review describes the anatomical consideration in the catheter ablation of idiopathic VAs.

  7. Serious arrhythmias in patients with apical hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

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


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

  8. Myocardial perfusion/metabolism mismatch and ventricular arrhythmias in the chronic post infarction state

    Energy Technology Data Exchange (ETDEWEB)

    Krause, B.J.; Poeppel, T.D.; Vosberg, H.; Mueller, H.W. [Dept. of Nuclear Medicine, Heinrich Heine Univ., Duesseldorf (Germany); Reinhardt, M. [Praxis fuer Radiologie und Nuklearmedizin, Dorsten (Germany); Vester, E.G. [Dept. of Cardiology, Evangelisches Krankenhaus, Duesseldorf (Germany); Yong, M.; Mau, J. [Dept. of Statistics in Medicine, Heinrich Heine Univ., Duesseldorf (Germany); Strauer, B.E. [Dept. of Medicine, Div. of Cardiology, Angiology and Pulmonary Disease, Heinrich Heine Univ., Duesseldorf (Germany)


    Aim: Ventricular arrhythmias have been shown to originate in the myocardial peri-infarct region due to irregular heterotopic conduction. Hypoperfused but viable myocardium is often localised in those areas and may be involved in the pathogenesis of arrhythmias. We tested the hypothesis that these myocardial perfusion/metabolism mismatches (MM) are significantly associated with ventricular arrhythmias in the chronic post infarction state. Patients, methods: 47 post infarction patients were included in the study. 33 suffered from ventricular arrhythmia whereas 14 did not. All patients underwent {sup 99m}Tc tetrofosmin SPECT and {sup 18}F-FDG PET. A region-of-interest(ROI)-analysis was used to assess viable myocardium based on predefined MM-criteria. Univariate analyses as well as a logistic regression model for the multivariate analysis were carried out. Results: 94% of the arrhythmic patients displayed at least one MM-segment as compared to 64% of the non-arrhythmic patients. MM-segments and arrhythmia showed a statistically significant relation (p=0.018). The logistic regression model predicted the occurrence or absence of arrhythmia in 85% of all cases. Multivariate analysis gave consistent results, after adjusting for symptomatic chronic heart failure (CHF), aneurysms and age. Conclusion: Our results support the hypothesis that hypoperfused but viable myocardium represents an arrhyhmogenic substrate and is a relevant risk factor for developing ventricular arrhythmias following myocardial infarction. Therefore, the detection of MM-segments allows the identification of patients with a higher risk for future cardiac events. (orig.)

  9. Proposition of novel classification approach and features for improved real-time arrhythmia monitoring. (United States)

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


    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.

  10. Double hazards of ischemia and reperfusion arrhythmias in a patient with variant angina pectoris. (United States)

    Xu, Mingzhu; Yang, Xiangjun


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

  11. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator? (United States)

    Tan, Alex Y; Ellenbogen, Kenneth


    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.

  12. Non-invasive cardiac mapping in clinical practice: Application to the ablation of cardiac arrhythmias. (United States)

    Dubois, Rémi; Shah, Ashok J; Hocini, Mélèze; Denis, Arnaud; Derval, Nicolas; Cochet, Hubert; Sacher, Frédéric; Bear, Laura; Duchateau, Josselin; Jais, Pierre; Haissaguerre, Michel


    Ten years ago, electrocardiographic imaging (ECGI) started to demonstrate its efficiency in clinical settings. The initial application to localize focal ventricular arrhythmias such as ventricular premature beats was probably the easiest to challenge and validates the concept. Our clinical experience in using this non-invasive mapping technique to identify the sources of electrical disorders and guide catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome) is described here.

  13. Influence of calcium preconditioning and streptomycin on ventricular dilation-induced arrhythmias in isolated rat hearts

    Institute of Scientific and Technical Information of China (English)


    Objective To investigate the mechanism of ventricular dilation-induced arrhythmias by dilating isolated rat hearts. Methods Isolated rat hearts were perfused by Langerdorff method. After equilibration, 80 hearts were randomly divided into four groups as follows: (1) control group (n=20), (2) Ca2+ preconditioning (CPC) group (n=20), (3) streptomycin group (n=20), and (4) CPC + streptomycin group (n=20). A latex balloon which can be filled with fluid was anchored in the left ventricle through the left atrium and mitral valve. Epicardial ECG of the left ventricle, left ventricular pressure, coronary flow and heart rate were recorded before and during ventricular dilation by injecting fluid into the latex balloon. The rate and duration of ventricular dilation-induced arrhythmias were recorded. Results Under the same increase in ventricular end-diastolic pressure made by inflation of the balloon, the rate of arrhythmias was 100% and duration of arrhythmias was 2.56±0.46 s in the control group. Both the rates of premature ventricular beat (90 %) and ventricular tachycardia 70 % ) were high. Compared with the control group, the total rate (60 % ) of arrhythmias was lower, and duration (1.67±0.61 s ) of arrhythmias was shorter in the CPC group. Both the rates of premature ventricular beat (60%) and ventricular tachycardia (40%) were low comparatively. The rate of arrhythmias (45 %) was lower and duration ( 1.64±0.42 s)of arrhythmias was shorter, and the rates of premature ventricular beat (30 % ) or ventricular tachycardia (35 %) were lower in the streptomycin group than in the control one. The least ventricular dilation-induced arrhythmias occurred in the CPC + streptomycin group. The rate of arrhythmias (10%) was the lowest and duration (1.01±0.37s) of arrhythmias was the shortest; both the rates of premature ventricular beat (5%) and ventricular tachycardia (10%) were the lowest. Conclusions Ventricular dilation may induce arrhythmias in isolated rat hearts. Stretch

  14. 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.


    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

  15. Respiratory sinus arrhythmia: A marker of deceased parasympathetic modulation after short duration spaceflight (United States)

    Migeotte, P. F.; Sa, R. C.; Prisk, Kim G.; Paiva, M.


    We investigated the hypothesis that the effects of a short duration spaceflight on the autonomic nervous system can be reflected in the respiratory component of heart rate variability (HRV), the respiratory sinus arrhythmia (RSA).

  16. [Magnesium deficiency and therapy in cardiac arrhythmias: recommendations of the German Society for Magnesium Research]. (United States)

    Vierling, W; Liebscher, D-H; Micke, O; von Ehrlich, B; Kisters, K


    Aim of the recommendations of the German Society for Magnesium Research: Recognition and compensation of magnesium deficiency in patients with risk factors for cardiac arrhythmias or manifest rhythm disturbances. Prevention of arrhythmias by administration of magnesium. Therapeutic administration of magnesium in patients with arrhythmias with and without magnesium deficiency. The current state of knowledge claims for considering the status of magnesium and the possibility of a therapeutic intervention with magnesium within the concept of the treatment of cardiovascular diseases. The use of magnesium as single agent or as an adjunct to other therapeutic actions in the prevention and therapy of cardiac arrhythmias can be effective and, in case of oral administration, very safe. In case of parenteral administration, it is important to use adequate doses, monitor cardiovascular and neuromuscular parameters and to consider contraindications.

  17. Induced pluripotent stem cell-derived cardiomyocytes: boutique science or valuable arrhythmia model? (United States)

    Knollmann, Björn C


    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.

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

    DEFF Research Database (Denmark)

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


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

  19. Catheter Ablation of Ventricular Arrhythmias Arising from the Distal Great Cardiac Vein. (United States)

    Letsas, Konstantinos P; Efremidis, Michael; Vlachos, Konstantinos; Georgopoulos, Stamatis; Xydonas, Sotirios; Valkanas, Kosmas; Sideris, Antonios


    Catheter ablation of idiopathic ventricular arrhythmias arising from the distal great cardiac vein represents a great challenge. We report data regarding the electrocardiographic and electrophysiologic characteristics in two patients with ventricular arrhythmias arising from the distal great cardiac vein. The technical difficulties to advance and navigate the ablation catheter within the coronary venous system as well as the close proximity to the major coronary vessels are discussed.

  20. 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;


    of the International Classification of Diseases, 9th revision, clinical modification (ICD-9-CM). The validity of ICD codes for ventricular arrhythmias and cardiac arrest (427.1, 427.4, 427.41, 427.42, 427.5, 427.69) and ICD codes for unspecified cardiac arrhythmias (427.2, 427.60, 427.8, 427.89, 427.9) was ascertained...

  1. Beyond pure parasystole: promises and problems in modeling complex arrhythmias. (United States)

    Courtemanche, M; Glass, L; Rosengarten, M D; Goldberger, A L


    The dynamics of pure parasystole, a cardiac arrhythmia in which two competing pacemakers fire independently, have recently been fully characterized. This model is now extended in an attempt to account for the more complex dynamics occurring with modulated parasystole, in which there exists nonlinear interaction between the sinus node and the ectopic ventricular focus. Theoretical analysis of modulated parasystole reveals three types of dynamics: entrainment, quasiperiodicity, and chaos. Rhythms associated with quasiperiodicity obey a set of rules derived from pure parasystole. This model is applied to the interpretation of continuous electrocardiographic data sets from three patients with complicated patterns of ventricular ectopic activity. We describe several new statistical properties of these records, related to the number of intervening sinus beats between ectopic events, that are essential in characterizing the dynamics and testing mathematical models. Detailed comparison between data and theory in these cases show substantial areas of agreement as well as potentially important discrepancies. These findings have implications for understanding the dynamics of the heartbeat in normal and pathological conditions.

  2. Real-Time Analytics for the Healthcare Industry: Arrhythmia Detection. (United States)

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


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

  3. Cardiac arrhythmia in Wilson's disease: An oversighted and overlooked entity! (United States)

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


    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

  4. Risk of cardiac arrhythmias during hypoglycemia in patients with type 2 diabetes and cardiovascular risk. (United States)

    Chow, Elaine; Bernjak, Alan; Williams, Scott; Fawdry, Robert A; Hibbert, Steve; Freeman, Jenny; Sheridan, Paul J; Heller, Simon R


    Recent trials of intensive glycemic control suggest a possible link between hypoglycemia and excess cardiovascular mortality in patients with type 2 diabetes. Hypoglycemia might cause arrhythmias through effects on cardiac repolarization and changes in cardiac autonomic activity. Our aim was to study the risk of arrhythmias during spontaneous hypoglycemia in type 2 diabetic patients with cardiovascular risk. Twenty-five insulin-treated patients with type 2 diabetes and a history of cardiovascular disease or two or more risk factors underwent simultaneous continuous interstitial glucose and ambulatory electrocardiogram monitoring. Frequency of arrhythmias, heart rate variability, and markers of cardiac repolarization were compared between hypoglycemia and euglycemia and between hyperglycemia and euglycemia matched for time of day. There were 134 h of recording at hypoglycemia, 65 h at hyperglycemia, and 1,258 h at euglycemia. Bradycardia and atrial and ventricular ectopic counts were significantly higher during nocturnal hypoglycemia compared with euglycemia. Arrhythmias were more frequent during nocturnal versus daytime hypoglycemia. Excessive compensatory vagal activation after the counterregulatory phase may account for bradycardia and associated arrhythmias. QT intervals, corrected for heart rate, >500 ms and abnormal T-wave morphology were observed during hypoglycemia in some participants. Hypoglycemia, frequently asymptomatic and prolonged, may increase the risk of arrhythmias in patients with type 2 diabetes and high cardiovascular risk. This is a plausible mechanism that could contribute to increased cardiovascular mortality during intensive glycemic therapy.

  5. Toluene and benzene inhalation influences on ventricular arrhythmias in the rat. (United States)

    Magos, G A; Lorenzana-Jiménez, M; Vidrio, H


    We have previously found that toluene did not share the capacity of benzene for increasing the arrhythmogenic action of epinephrine in the rat, but appeared to elicit the opposite effect. The present experiments were carried out to verify this observation in rats subjected to more severe ventricular arrhythmias. In animals previously inhaling either air, toluene or benzene and anesthetized with pentobarbital, arrhythmias were produced by coronary ligation or aconitine. In both models, toluene decreased and benzene increased the number of ectopic ventricular beats in the 30 min following induction of arrhythmia. Gas chromatographic measurement of toluene levels in the heart during and after inhalation revealed essentially constant concentrations at the time of arrhythmia evaluation, equivalent to approximately one-third the peak levels observed at the end of inhalation. Although the mechanism of the effect of toluene on arrhythmia could not be ascertained, nonspecific membrane stabilization or central serotonergic stimulation were considered as possible explanations. Since both mechanisms could be operant also in the case of benzene, the opposite effects of the solvents on arrhythmia could not be readily accounted for.

  6. Clinical evaluation of a wireless ECG sensor system for arrhythmia diagnostic purposes. (United States)

    Fensli, Rune; Gundersen, Torstein; Snaprud, Tormod; Hejlesen, Ole


    In a clinical study, a novel wireless electrocardiogram (ECG) recorder has been evaluated with regard to its ability to perform arrhythmia diagnostics. As the ECG recorder will detect a "non-standard" ECG signal, it has been necessary to compare those signals to "standard" ECG recording signals in order to evaluate the arrhythmia detection ability of the new system. Simultaneous recording of ECG signals from both the new wireless ECG recorder and a conventional Holter recorder was compared by two independent cardiology specialists with regard to signal quality for performing arrhythmia diagnosis. In addition, calculated R-R intervals from the two systems were correlated. A total number of 16 patients participated in the study. It can be considered that recorded ECG signals obtained from the wireless ECG system had an acceptable quality for arrhythmia diagnosis. Some of the patients used the wireless sensor while doing physical sport activities, and the quality of the recorded ECG signals made it possible to perform arrhythmia diagnostics even under such conditions. Consequently, this makes possible improvements in correlating arrhythmias to physical activities.

  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 Huth; Gang, Uffe; Thomsen, Poul Erik Bloch;


    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. Detection of Rapid Atrial Arrhythmias in SQUID Magnetocardiography

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


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

  9. Effect of Different Pranayamas on Respiratory Sinus Arrhythmia (United States)

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


    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

  10. Relation between QT dispersion, left ventricle systolic function and frequency of ventricular arrhythmias in coronary patients

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    Stoičkov Viktor


    Full Text Available Introduction QT dispersion (QTd is a measure of non-homogeneous repolarisation of the myocardium and is used as an indicator of arrhythmogenicity. Objective The aim of this study was to assess the relation between QT dispersion, left ventricle systolic function and frequency of ventricular arrhythmias in coronary patients. Method We studied 290 coronary patients, 72 with angina pectoris and 218 after myocardial infarction. Eighty-one coronary patients had frequent and complex ventricular arrhythmias (out of them 19 had ventricular tachycardia and 209 were without arrhythmias or with infrequent ventricular premature contractions (VPC≤10/h. In all patients, QT dispersion, exercise test, 24-hour Holter monitoring and echocardiographic examination were performed. Results Patients with frequent and complex ventricular arrhythmias had significantly higher values of QTd (71.8±25.5 vs 55.6±21.7 ms; p<0.001, corrected QT dispersion (QTdc: 81.3±31.5 vs. 60.3±26.1 ms; p<0.001, left ventricular end-diastolic diameter (LVEDd: 56.2±6.9 vs. 53.4±6.2 mm; p<0.001 and left ventricular end-systolic diameter (LVESd: 39.5±6.2 vs. 36.0±6.3 mm; p<0.001, and significantly lower values of left ventricular ejection fraction (LVEF: 47.7±13.9 vs. 55.9±11.6%; p<0.001 in comparison to those without arrhythmias or with infrequent VPC. Patients with VT had significantly higher values of QTd and QTdc in comparison to other patients with frequent and complex ventricular arrhythmias (83.8±17.1 vs. 69.4±26.2 ms; p<0.02 for QTd; 101.1±23.9:77.6±31.4 ms; p<0.005 for QTdc. There is a significant negative correlation of QTd and QTdc with LVEF, and a significant positive correlation of QTd and QTdc with inside dimensions of the left ventricle, in patients with frequent and complex ventricular arrhythmias. Conclusion The study demonstrated that patients with frequent and complex ventricular arrhythmias had significantly higher values of QTd and QTdc, as well as a higher

  11. MS-551 and KCB-328, two class III drugs aggravated adrenaline-induced arrhythmias. (United States)

    Xue, Y; Yamada, C; Aye, N N; Hashimoto, K


    We investigated the proarrhythmic effects of MS-551 and KCB-328, class III antiarrhythmic drugs using adrenaline-induced arrhythmia models in halothane anaesthetized, closed-chest dogs. In the control period, adrenaline, starting from a low dose of 0.25 to up to 1.0 microg/kg/50 s i.v., was injected to determine the arrhythmia inducing dose and the non-inducing dose. After MS-551 or KCB-328 administration, the adrenaline injection was repeated and the interval between the injection and the occurrence of arrhythmia (latent interval), the changes in arrhythmic ratio (as calculated by dividing the number of ventricular premature contraction by the number of the total heart rate) and the severity of arrhythmia were observed. MS-551 infusion, 1 mg/kg/30 min, decreased the heart rate (HR) by 16% (Platent interval of the adrenaline arrhythmias produced by the inducing dose (30+/-2 s compared with 43+/-3 s of the control interval, P latent interval of the adrenaline arrhythmias produced by the inducing doses (31+/-3 s compared with 49+/-7 s of the control period, P<0.05), but did not significantly alter the arrhythmic ratio. Adrenaline induced TdP only after MS-551 or KCB-328 was administered, i.e. after MS-551, 1 mg/kg/30 min, 3/7 versus 0/7 in the control; KCB, 0.3 mg/kg/30 min, 3/7 versus 0/7 in the control. To examine the direct arrhythmogenic effect of MS-551 and whether an adrenergic mechanism plays some role on this arrhythmogenesis, a bolus injection of MS-551, 3 mg/kg, was injected either without pre-treatment or after pre-treatment with propranolol 0.3 mg/kg. MS-551 induced arrhythmias in five out of seven dogs (TdP in one dog). Also in the propranolol pre-treated dogs, MS-551 induced arrhythmias in five out of seven dogs (TdP in 1 dog). In conclusion, these observations indicate that MS-551 and KCB-328 induced arrhythmias and intensified proarrhythmic effects of adrenaline, MS-551 being stronger than KCB-328 at the same QTc prolonging doses. The direct

  12. 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


    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.

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

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    Barman M, Djamel B


    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.

  14. Protective effects of isorhynchophylline on cardiac arrhythmias in rats and guinea pigs. (United States)

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


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

  15. Severe hypoglycemia-induced lethal cardiac arrhythmias are mediated by sympathoadrenal activation. (United States)

    Reno, Candace M; Daphna-Iken, Dorit; Chen, Y Stefanie; VanderWeele, Jennifer; Jethi, Krishan; Fisher, Simon J


    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 hypoglycemia; 2) with limitation of hypokalemia, potassium supplementation could limit hypoglycemia-associated deaths; 3) with prevention of central neuroglycopenia, brain glucose infusion could prevent hypoglycemia-associated arrhythmias and deaths; and 4) with limitation of sympathoadrenal activation, adrenergic blockers could prevent hypoglycemia-induced arrhythmic deaths. Severe hypoglycemia-induced mortality was noted to be worsened by diabetes, but recurrent antecedent hypoglycemia markedly improved the ability to survive an episode of severe hypoglycemia. Potassium supplementation tended to reduce mortality. Severe hypoglycemia caused numerous cardiac arrhythmias including premature ventricular contractions, tachycardia, and high-degree heart block. Intracerebroventricular glucose infusion reduced severe hypoglycemia-induced arrhythmias and overall mortality. β-Adrenergic blockade markedly reduced cardiac arrhythmias and completely abrogated deaths due to severe hypoglycemia. Under conditions studied, sudden deaths caused by insulin-induced severe hypoglycemia were mediated by lethal cardiac arrhythmias triggered by brain neuroglycopenia and the marked sympathoadrenal response.

  16. Cardiac Arrhythmias in Patients with Chronic Kidney Disease: Implications of Renal Failure for Antiarrhythmic Drug Therapy. (United States)

    Potpara, Tatjana S; Jokic, Vera; Dagres, Nikolaos; Marin, Francisco; Prostran, Milica S; Blomstrom-Lundqvist, Carina; Lip, Gregory Y H


    The kidney has numerous complex interactions with the heart, including shared risk factors (e.g., hypertension, dyslipidemia, etc.) and mutual amplification of morbidity and mortality. Both cardiovascular diseases and chronic kidney disease (CKD) may cause various alterations in cardiovascular system, metabolic homeostasis and autonomic nervous system that may facilitate the occurrence of cardiac arrhythmias. Also, pre-existent or incident cardiac arrhythmias such as atrial fibrillation (AF) may accelerate the progression of CKD. Patients with CKD may experience various cardiac rhythm disturbances including sudden cardiac death. Contemporary management of cardiac arrhythmias includes the use of antiarrhythmic drugs (AADs), catheter ablation and cardiac implantable electronic devices (CIEDs). Importantly, AADs are not used only as the principal treatment strategy, but also as an adjunct therapy in combination with CIEDs, to facilitate their effects or to minimize inappropriate device activation in selected patients. Along with their principal antiarrhythmic effect, AADs may also induce cardiac arrhythmias and the risk for such proarrhythmic effect(s) is particularly increased in patients with reduced left ventricular systolic function or in the setting of electrolyte imbalance. Moreover, CKD itself can induce profound alterations in the pharmacokinetics and pharmacodynamics of many drugs including AADs, thus facilitating the drug accumulation and increased exposure. Hence, the use of AADs in patients with CKD may be challenging. In this review article, we provide an overview of the characteristics of arrhythmogenesis in patients with CKD with special emphasis on the complexity of pharmacokinetics and risk for proarrhythmias when using AADs in patients with cardiac arrhythmias and CKD.

  17. Arrhythmia Management in the Elderly-Implanted Cardioverter Defibrillators and Prevention of Sudden Death. (United States)

    Manian, Usha; Gula, Lorne J


    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.

  18. Metabolic Syndrome Remodels Electrical Activity of the Sinoatrial Node and Produces Arrhythmias in Rats (United States)

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


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

  19. [Myocardial infarct after the acute phase--the risk of arrhythmia]. (United States)

    de Azevedo, S G


    Upon the development, divulgation and improvement of the Ambulatory Electrocardiographic Monitoring (AEM) techniques, the problem of the arrhythmias after an acute myocardial infarction (AMI) has acquired a new acuteness. Its importance becomes clearly evident from the fact today recognized that about 10% of the patients die within the first year after AMI and that the great majority of them dies suddenly. The prognostic value of certain types of ventricular arrhythmias is now well proved to be an independent risk factor respecting to the late complications of AMI, namely the sudden death issue. In this paper, after referring the prognostic criteria for the ventricular arrhythmias, the Author proposes an AEM execution calendar for the AMI patients, since the late hospital phase (hospital discharge). Afterwards, the controversial therapeutic problem of the ventricular arrhythmias is approached, quoting the pharmacological set-backs and pointing out the AEM limitations in regard to the selection and efficacy confirmation of the anti-arrhythmic drugs. At last, a few conclusions of the "Cardiac Arrhythmia Pilot Study" (CAPS, 1986) are mentioned and an other ongoing multicenter study is referred, whose conclusions will be of capital importance to define the anti-arrhythmic therapy utility in the setting of the post-AMI patients.


    Directory of Open Access Journals (Sweden)



    Full Text Available Cardiac arrhythmias are common heart diseases. Electrocardiography (ECG is an important measure for diagnosing arrhythmias. Researchers use the ECG signals in order to train artificial neural networks (ANN. In previous studies the ECG signals of males and females were analysed together. We know that there are some differences between male and female ECG signals. This paper suggests that classifying the arrhythmias according to gender differences gives more accurate results. In this study we classify the subjects as normal and right bundle branch block (RBBB using cascade forward back algorithm in MATLAB. The accuracy of network simulations are as follow: 81.25% only male, 80% only female, 40% male and female together.

  1. 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


    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....... 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....

  2. Ubiquitous health monitoring and real-time cardiac arrhythmias detection: a case study. (United States)

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


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

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

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


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

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

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    Tassi, Eduardo Marinho, E-mail: [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)


    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.

  5. Characterization of antiarrhythmic drugs by alternating current induced arrhythmias in isolated heart tissues. (United States)

    Borchard, U; Bösken, R; Greeff, K


    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.

  6. Risk of Ventricular Arrhythmia with Citalopram and Escitalopram: A Population-Based Study (United States)

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


    Background The risk of ventricular arrhythmia with citalopram and escitalopram is controversial. In this study we investigated the association between these two drugs and the risk of ventricular arrhythmia. Methods We conducted a population-based retrospective cohort study of older adults (mean age 76 years) from 2002 to 2012 in Ontario, Canada, newly prescribed citalopram (n = 137 701) or escitalopram (n = 38 436), compared to those prescribed referent antidepressants sertraline or paroxetine (n = 96 620). After inverse probability of treatment weighting using a propensity score, the baseline characteristics of the comparison groups were similar. The primary outcome was a hospital encounter with ventricular arrhythmia within 90 days of a new prescription, assessed using hospital diagnostic codes. The secondary outcome was all-cause mortality within 90 days. Results Citalopram was associated with a higher risk of a hospital encounter with ventricular arrhythmia compared with referent antidepressants (0.06% vs. 0.04%, relative risk [RR] 1.53, 95% confidence intervals [CI]1.03 to 2.29), and a higher risk of mortality (3.49% vs. 3.12%, RR 1.12, 95% CI 1.06 to 1.18). Escitalopram was not associated with a higher risk of ventricular arrhythmia compared with the referent antidepressants (0.03% vs. 0.04%, RR 0.84, 95% CI 0.42 to 1.68), but was associated with a higher risk of mortality (2.86% vs. 2.63%, RR 1.09, 95% CI 1.01 to 1.18). Conclusion Among older adults, initiation of citalopram compared to two referent antidepressants was associated with a small but statistically significant increase in the 90-day risk of a hospital encounter for ventricular arrhythmia. PMID:27513855

  7. QT dispersion on ECG Holter monitoring and risk of ventricular arrhythmias in patients with dilated cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Polyxeni Garyfallidis


    Full Text Available Background. QT dispersion (QTd is increased in patients with dilated cardiomyopathy. Increased QTd has been associated with the risk of sudden death. We studied: a the relation between QTd on 12-lead ECG and QTd-ECG Holter; b the relation between QTd apex (QTda and QTd end (QTde on ECG Holter and the risk of ventricular arrhythmias in patients with dilated cardiomyopathy. Methods and Results. 65 patients with dilated cardiomyopathy (33 idiopathic and 32 post-ischemic etiology; NYHA II-III were studied. We divided the patients into: Group A -patients with not-sustained ventricular arrhythmias-; and Group B -patients without arrhythmias-. A significant direct correlation between QTd calculated from 12-lead ECG and from ECG Holter was found in all patients. QTda/24h was not significantly different in the two groups (Gr.A 59.9±7.8 msec vs Gr.B 53.6±8.4 msec p=ns while QTde/24h was significantly higher in Group A (Gr.A 81.9±5.9 msec vs Gr.B 44.5±6.8 msec; p<0.005. In post-ischemic etiology (32 pts; 17 with arrhythmias the correlation between QTde/24h and ventricular arrhythmias was confirmed (Gr.A 81.4±7.8 msec vs Gr.B 42.6±6.2 msec p<0.002. Conclusions. ECG Holter recordings can evaluate QTd as well as the QTd on 12-lead ECG. An increased QTde/24h seems to be correlated with the occurence of ventricular arrhythmias in patients with dilated cardiomyopathy and can then be a useful tool to select patients at high risk for sudden death.

  8. Risk of arrhythmia induced by psychotropic medications: a proposal for clinical management. (United States)

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


    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.

  9. 3D X-ray imaging methods in support catheter ablations of cardiac arrhythmias. (United States)

    Stárek, Zdeněk; Lehar, František; Jež, Jiří; Wolf, Jiří; Novák, Miroslav


    Cardiac arrhythmias are a very frequent illness. Pharmacotherapy is not very effective in persistent arrhythmias and brings along a number of risks. Catheter ablation has became an effective and curative treatment method over the past 20 years. To support complex arrhythmia ablations, the 3D X-ray cardiac cavities imaging is used, most frequently the 3D reconstruction of CT images. The 3D cardiac rotational angiography (3DRA) represents a modern method enabling to create CT like 3D images on a standard X-ray machine equipped with special software. Its advantage lies in the possibility to obtain images during the procedure, decreased radiation dose and reduction of amount of the contrast agent. The left atrium model is the one most frequently used for complex atrial arrhythmia ablations, particularly for atrial fibrillation. CT data allow for creation and segmentation of 3D models of all cardiac cavities. Recently, a research has been made proving the use of 3DRA to create 3D models of other cardiac (right ventricle, left ventricle, aorta) and non-cardiac structures (oesophagus). They can be used during catheter ablation of complex arrhythmias to improve orientation during the construction of 3D electroanatomic maps, directly fused with 3D electroanatomic systems and/or fused with fluoroscopy. An intensive development in the 3D model creation and use has taken place over the past years and they became routinely used during catheter ablations of arrhythmias, mainly atrial fibrillation ablation procedures. Further development may be anticipated in the future in both the creation and use of these models.

  10. Carbon Monoxide Induces Cardiac Arrhythmia via Induction of the Late Na+ Current (United States)

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


    Rationale: Clinical reports describe life-threatening cardiac arrhythmias after environmental exposure to carbon monoxide (CO) or accidental CO poisoning. Numerous case studies describe disruption of repolarization and prolongation of the QT interval, yet the mechanisms underlying CO-induced arrhythmias are unknown. Objectives: To understand the cellular basis of CO-induced arrhythmias and to indentify an effective therapeutic approach. Methods: Patch-clamp electrophysiology and confocal Ca2+ and nitric oxide (NO) imaging in isolated ventricular myocytes was performed together with protein S-nitrosylation to investigate the effects of CO at the cellular and molecular levels, whereas telemetry was used to investigate effects of CO on electrocardiogram recordings in vivo. Measurements and Main Results: CO increased the sustained (late) component of the inward Na+ current, resulting in prolongation of the action potential and the associated intracellular Ca2+ transient. In more than 50% of myocytes these changes progressed to early after-depolarization–like arrhythmias. CO elevated NO levels in myocytes and caused S-nitrosylation of the Na+ channel, Nav1.5. All proarrhythmic effects of CO were abolished by the NO synthase inhibitor l-NAME, and reversed by ranolazine, an inhibitor of the late Na+ current. Ranolazine also corrected QT variability and arrhythmias induced by CO in vivo, as monitored by telemetry. Conclusions: Our data indicate that the proarrhythmic effects of CO arise from activation of NO synthase, leading to NO-mediated nitrosylation of NaV1.5 and to induction of the late Na+ current. We also show that the antianginal drug ranolazine can abolish CO-induced early after-depolarizations, highlighting a novel approach to the treatment of CO-induced arrhythmias. PMID:22822026

  11. Arrhythmia recognition and classification using combined linear and nonlinear features of ECG signals. (United States)

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


    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

  12. Analysis of electrolyte abnormalities and the mechanisms leading to arrhythmias in heart failure. A literature review. (United States)

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


    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.

  13. Actual expertise issues of professional suitability of patients with highly curable heart arrhythmias

    Directory of Open Access Journals (Sweden)

    Krainyukov P.E.


    Conclusion. The concept of highly curable heart arrhythmia is introduced. A significant proportion of patients with these arrhythmias are young and of working age, they do not have organic heart disease. High efficiency of RFA for paroxysmal disorders of rhythm, small percentage of complications and recurrences, fast professional and social rehabilitation of these patients allow to revise the existing categories of fitness in respect of persons who underwent RFA. Follow-up medical examination including endo-EFI and subsequent medical examination to determine the category of fitness for military service should be carried out not earlier than 3 months after RFA.

  14. Late sodium current: A mechanism for angina, heart failure, and arrhythmia. (United States)

    Makielski, Jonathan C


    The peak sodium current underlies excitability and conduction in heart muscle, but a late sodium current flowing after the peak contributes to maintaining and prolonging the action potential plateau, and also to intracellular sodium loading, which in turn increases intracellular calcium with consequent effects on arrhythmia and diastolic function. Late sodium current is pathologically increased in both genetic and acquired heart disease, making it an attractive target for therapy to treat arrhythmia, heart failure, and angina. This review provides an overview of the underlying bases for the clinical implications of late sodium current block.

  15. GPU based cloud system for high-performance arrhythmia detection with parallel k-NN algorithm. (United States)

    Tae Joon Jun; Hyun Ji Park; Hyuk Yoo; Young-Hak Kim; Daeyoung Kim


    In this paper, we propose an GPU based Cloud system for high-performance arrhythmia detection. Pan-Tompkins algorithm is used for QRS detection and we optimized beat classification algorithm with K-Nearest Neighbor (K-NN). To support high performance beat classification on the system, we parallelized beat classification algorithm with CUDA to execute the algorithm on virtualized GPU devices on the Cloud system. MIT-BIH Arrhythmia database is used for validation of the algorithm. The system achieved about 93.5% of detection rate which is comparable to previous researches while our algorithm shows 2.5 times faster execution time compared to CPU only detection algorithm.

  16. Tedisamil and lidocaine enhance each other's antiarrhythmic activity against ischaemia-induced arrhythmias in rats


    Sarraf, Guilda; Barrett, Terrance D; Walker, Michael J A


    Combinations of the action potential-widening drug tedisamil (Class III antiarrhythmic activity), and the inactivated state sodium channel blocker lidocaine (Class Ib antiarrhythmic activity) were assessed for antiarrhythmic actions in a rat model of ischaemia-induced arrhythmias and for electrophysiological actions in normal rat myocardial tissue.Both tedisamil and lidocaine dose-dependently suppressed ischaemia-induced arrhythmias. The ED50 values were 3.0±1.3 and 4.9±0.6 μmol kg−1 min−1, r...

  17. MS-551 and KCB-328, two class III drugs aggravated adrenaline-induced arrhythmias


    Xue, Yixue; Yamada, Chikaomi; Nu Aye, Nu; Hashimoto, Keitaro


    We investigated the proarrhythmic effects of MS-551 and KCB-328, class III antiarrhythmic drugs using adrenaline-induced arrhythmia models in halothane anaesthetized, closed-chest dogs. In the control period, adrenaline, starting from a low dose of 0.25 to up to 1.0 μg/kg/50 s i.v., was injected to determine the arrhythmia inducing dose and the non-inducing dose. After MS-551 or KCB-328 administration, the adrenaline injection was repeated and the interval between the injection and the occurr...

  18. The role of viruses, inflammation and myocardial macrophages in the development of idiopathic arrhythmia (United States)

    Rebenkova, M.; Gombozhapova, A.; Shurupov, V.; Rogovskaya, Yu.; Botalov, R.; Ryabov, V.; Popov, S.; Karpov, R.


    We studied viral antigens, inflammation, and macrophages in the endomyocardial biopsies of patients with idiopathic arrhythmias. Immunohistological study was performed to identify the antigens of cardiotropic viruses and the types of lymphocytes and macrophages. We observed the presence of viral antigens in the myocardium of patients with and without histological criteria of myocarditis. Heart failure and ventricular arrhythmias were associated with small focal infiltration of the myocardium with macrophages. The presence of viral antigens in the myocardium was associated with fewer number of myocardial M2 macrophages. Severity of myocardial interstitial fibrosis correlated with small-focal infiltration of M2 macrophages.

  19. [The anti-arrhythmia action of an extract of Rhodiola rosea and of n-tyrosol in models of experimental arrhythmias]. (United States)

    Maĭmeskulova, L A; Maslov, L N


    A daily 8-day course of Rhodiolae fluidum extract (1 ml/kg; ED50 = 0.43 ml/kg)--a preparation from the group of adaptogens caused a marked preventive antiarrhythmic effect on models of adrenaline and CaCl2-induced, but not acontine, arrhythmias. Aglycone--n-tyrosol demonstrated a lower antiarrhythmic activity (ED50 = 16 mg/kg) than that of Rhodiola extract.

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

    Institute of Scientific and Technical Information of China (English)



    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

  1. The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress (United States)

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


    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.

  2. Immediate postoperative digitalization in the prophylaxis of supraventricular arrhythmias following coronary artery bypass. (United States)

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


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

  3. Inhibition of sodium current by taurine magnesium coordination compound prevents cesium chloride-induced arrhythmias. (United States)

    Yin, Yongqiang; Wen, Ke; Wu, Yanna; Kang, Yi; Lou, Jianshi


    The mechanism(s) by which taurine magnesium coordination compound (TMCC) inhibits experimental arrhythmias remains poorly understood. The purpose of this study was to observe the effects of TMCC against cesium chloride-induced arrhythmia in the rabbit heart and find whether the antiarrhythmic activity is related to inhibition of sodium current. Early afterdepolarization was induced by 1.5 mM cesium chloride (1 ml kg(-1)) through intravenous injection. The monophasic action potentials (MAP) and electrocardiograms were simultaneously recorded. The effect of TMCC on functional refractory periods (FRPs) in the left atrium was also observed in vitro. Arrhythmias onset was significantly retarded by TMCC. The number of ventricular premature contractions and incidence of monophasic ventricular tachycardia and polyphasic ventricular tachycardia in 10 min were decreased by TMCC. These effects can be abolished by veratridine (10 μg kg(-1)). MAP duration at 90% repolarization was significantly prolonged by TMCC, which can be prolonged even longer by veratridine (10 μg kg(-1)). In vitro experiments showed that FRPs was prolonged by TMCC which can be cancelled by veratridine (10 μg kg(-1)). TMCC prevents cesium chloride-induced arrhythmias, and inhibition of sodium current, in part, contributes to the antiarrhythmic effect of TMCC.

  4. Arrhythmia detection after atrial fibrillation ablation: value of incremental monitoring time

    NARCIS (Netherlands)

    Mulder, A.A.W.; Wijffels, M.C.; Wever, E.F.; Kelder, J.C.; Boersma, L.V.


    BACKGROUND: After pulmonary vein isolation (PVI), patients need to be followed to analyze the effect of the treatment. We evaluated the influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after a single PVI at 12 months. METHODS: Consecutive patients with paroxy

  5. 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


    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.

  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


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

    NARCIS (Netherlands)

    Geelen, A.


    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

  8. [Infrequent arrhythmia episodes diagnosed by a smartphone-based event recorder]. (United States)

    Pontoppidan, Jacob; Sandgaard, Niels Christian; Brandes, Axel; Johansen, Jens Brock


    Smartphone-based ECG monitor devices are a new promising tool for rhythm detection in patients with palpitations. We present a case where a young patient with infrequent arrhythmia episodes was diagnosed with atrial fibrillation using this novel smartphone-based event recorder.

  9. Use of Whole Exome Sequencing for the Identification of Ito-Based Arrhythmia Mechanism and Therapy (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


    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


    Directory of Open Access Journals (Sweden)

    A. O. Malygin


    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.

  11. Changes underlying arrhythmia in the transgenic heart overexpressing Refsum disease gene-associated protein. (United States)

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


    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.

  12. Central Sympathetic Inhibition: a Neglected Approach for Treatment of Cardiac Arrhythmias? (United States)

    Cagnoni, Francesca; Destro, Maurizio; Bontempelli, Erika; Locatelli, Giovanni; Hering, Dagmara; Schlaich, Markus P


    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Overactivation of the sympathetic nervous system (SNS) plays an important role in the pathogenesis of comorbidities related to AF such as hypertension, congestive heart failure, obesity, insulin resistance, and obstructive sleep apnea. Methods that reduce sympathetic drive, such as centrally acting sympatho-inhibitory agents, have been shown to reduce the incidence of spontaneous or induced atrial arrhythmias, suggesting that neuromodulation may be helpful in controlling AF. Moxonidine acts centrally to reduce activity of the SNS, and clinical trials indicate that this is associated with a decreased AF burden in hypertensive patients with paroxysmal AF and reduced post-ablation recurrence of AF in patients with hypertension who underwent pulmonary vein isolation (PVI). Furthermore, device-based approaches to reduce sympathetic drive, such as renal denervation, have yielded promising results in the prevention and treatment of cardiac arrhythmias. In light of these recent findings, targeting elevated sympathetic drive with either pharmacological or device-based approaches has become a focus of clinical research. Here, we review the data currently available to explore the potential utility of sympatho-inhibitory therapies in the prevention and treatment of cardiac arrhythmias.

  13. Simulation of Cardiac Arrhythmias Using a 2D Heterogeneous Whole Heart Model. (United States)

    Balakrishnan, Minimol; Chakravarthy, V Srinivasa; Guhathakurta, Soma


    Simulation studies of cardiac arrhythmias at the whole heart level with electrocardiogram (ECG) gives an understanding of how the underlying cell and tissue level changes manifest as rhythm disturbances in the ECG. We present a 2D whole heart model (WHM2D) which can accommodate variations at the cellular level and can generate the ECG waveform. It is shown that, by varying cellular-level parameters like the gap junction conductance (GJC), excitability, action potential duration (APD) and frequency of oscillations of the auto-rhythmic cell in WHM2D a large variety of cardiac arrhythmias can be generated including sinus tachycardia, sinus bradycardia, sinus arrhythmia, sinus pause, junctional rhythm, Wolf Parkinson White syndrome and all types of AV conduction blocks. WHM2D includes key components of the electrical conduction system of the heart like the SA (Sino atrial) node cells, fast conducting intranodal pathways, slow conducting atriovenctricular (AV) node, bundle of His cells, Purkinje network, atrial, and ventricular myocardial cells. SA nodal cells, AV nodal cells, bundle of His cells, and Purkinje cells are represented by the Fitzhugh-Nagumo (FN) model which is a reduced model of the Hodgkin-Huxley neuron model. The atrial and ventricular myocardial cells are modeled by the Aliev-Panfilov (AP) two-variable model proposed for cardiac excitation. WHM2D can prove to be a valuable clinical tool for understanding cardiac arrhythmias.

  14. Cardiorenal axis and arrhythmias: Will renal sympathetic denervation provide additive value to the therapeutic arsenal? (United States)

    van Brussel, Peter M; Lieve, Krystien V V; de Winter, Robbert J; Wilde, Arthur A M


    Disruption of sympathetic tone may result in the occurrence or maintenance of cardiac arrhythmias. Multiple arrhythmic therapies that intervene by influencing cardiac sympathetic tone are common in clinical practice. These vary from pharmaceutical (β-blockers, angiotensin-converting enzyme inhibitors, and calcium antagonists) to percutaneous/surgical (cardiac sympathetic denervation) interventions. In some patients, however, these therapies have insufficient prophylactic and therapeutic capabilities. A safe and effective additional therapy wherein sympathetic drive is further attenuated would be expedient. Recently, renal sympathetic denervation (RSD) has been subject of research for various sympathetic nervous system-related diseases. By its presumed afferent and efferent sympatholytic effects, RSD might indirectly attenuate sympathetic outflow via the brain to the heart but might also reduce systemic catecholamine excretion and might therefore reduce catecholamine-sensitive arrhythmias. RSD is subject of research for various sympathetically driven arrhythmias, both supraventricular and ventricular. In this review, we give an overview of the rationale behind RSD as potential therapy in mediating arrhythmias that are triggered by a disrupted sympathetic nervous system and discuss the presently available results from animal and human studies.

  15. Dietary n-3 fatty acids promote arrhythmias during acute regional myocardial ischemia in isolated pig hearts

    NARCIS (Netherlands)

    Coronel, R.; Wilms-Schopman, F.J.G.; Ruijter, den H.M.; Belterman, C.N.; Schumacher, C.A.; Opthof, T.; Hovernier, R.; Lemmens, A.G.; Terpstra, A.H.M.; Katan, M.B.; Zock, P.L.


    Objective Dietary supplementation with fish oil-derived n-3 fatty acids reduces mortality in patients with myocardial infarction, but may have adverse effects in angina patients. The underlying electrophysiologic mechanisms are poorly understood. We studied the arrhythmias and the electrophysiologic

  16. Interrogation of Patient Smartphone Activity Tracker to Assist Arrhythmia Management. (United States)

    Rudner, Joshua; McDougall, Carol; Sailam, Vivek; Smith, Monika; Sacchetti, Alfred


    A 42-year-old man presented to the emergency department (ED) with newly diagnosed atrial fibrillation of unknown duration. Interrogation of the patient's wrist-worn activity tracker and smartphone application identified the onset of the arrhythmia as within the previous 3 hours, permitting electrocardioversion and discharge of the patient from the ED.

  17. Yield of molecular and clinical testing for arrhythmia syndromes: Report of 15 years' experience

    NARCIS (Netherlands)

    Hofman, Nynke; Tan, Hanno L.; Alders, Mariëlle; Kolder, Iris; De Haij, Simone; Mannens, Marcel M.A.M.; Lombardi, Maria Paola; Dit Deprez, Ronald H. Lekanne; Van Langen, Irene; Wilde, Arthur A.M.


    BACKGROUND-: Sudden cardiac death is often caused by inherited arrhythmia syndromes, particularly if it occurs at a young age. In 1996, we started a cardiogenetics clinic aimed at diagnosing such syndromes and providing timely (often presymptomatic) treatment to families in which such syndromes or s

  18. Molecular genetic diagnostics of the cause of ventricular arrhythmias in children

    DEFF Research Database (Denmark)

    Brøndberg, Anders Krogh; Bjerre, Jesper Vandborg; Nielsen, Jens Cosedis;


    Andersen-Tawil syndrome (ATS) is a rare hereditary multi--system disorder consisting of a triad of symptoms, ventricular arrhythmias, periodic paralysis and dysmorphic features. The syndrome is associated with a loss of function mutation in the gene KCNJ2, which encodes the Kir2.1 inward rectifier...

  19. Ellagic acid improved arrhythmias induced by CaCL2 in the rat stress model

    Directory of Open Access Journals (Sweden)

    Mahin Dianat


    Full Text Available Objective: In ventricular arrhythmias, due to their free radical scavenging action, antioxidant agents are usually used in the treatment of cardiovascular disease. Since stress is considered as risk factor for increased mortality by causing malignant arrhythmias, the study was designed to evaluate the cardioprotective effects of ellagic acid (EA on CaCl2-induced arrhythmias in rat stress model. Materials and Methods: Male Sprague-Dawley rats (200-250 g were divided into four groups: Group I: Control rats (2 ml of saline by gavage, Group II: Rats treated with EA (15 mg/kg, gavage, Group III: stress group, Group IV: received EA plus stress. Stress was applied in a restrainer box (6 hour/day, 21 days. After induction of anesthesia, lead II electrocardiogram was recorded for calculating heart rate and QRS complex. The arrhythmia was produced by injection of CaCl2 solution (140 mg/kg, iv and incidences of Ventricular fibrillation, Ventricular premature beats and Ventricular tachycardia were recorded. Results were analyzed by using one-way ANOVA and Fisher`s exact test. pResults: The results showed a positive inotropic effect and negative chronotropic effect for the EA group in comparison with the control group. Incidence rates (% of premature beats, ventricular fibrillation and ventricular tachycardia in stress group and all the arrhythmia parameters decreased in groups which received EA. Conclusions:  By decreasing the incidence rates of premature beats, fibrillation and ventricular tachycardia in groups which received EA, ellagic acid probably acted as an anti-arrhythmic agent which showed to have aprotective functionin heart.

  20. Incidence of cardiac arrhythmias in asymptomatic hereditary hemochromatosis subjects with C282Y homozygosity. (United States)

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


    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 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.

  1. Influence of ambient temperature and diurnal temperature range on incidence of cardiac arrhythmias (United States)

    Kim, Jayeun; Kim, Ho


    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 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.

  2. Hindlimb unloading results in increased predisposition to cardiac arrhythmias and alters left ventricular connexin 43 expression. (United States)

    Moffitt, Julia A; Henry, Matthew K; Welliver, Kathryn C; Jepson, Amanda J; Garnett, Emily R


    Hindlimb unloading (HU) is a well-established animal model of cardiovascular deconditioning. Previous data indicate that HU results in cardiac sympathovagal imbalance. It is well established that cardiac sympathovagal imbalance increases the risk for developing cardiac arrhythmias. The cardiac gap junction protein connexin 43 (Cx43) is predominately expressed in the left ventricle (LV) and ensures efficient cell-to-cell electrical coupling. In the current study we wanted to test the hypothesis that HU would result in increased predisposition to cardiac arrhythmias and alter the expression and/or phosphorylation of LV-Cx43. Electrocardiographic data using implantable telemetry were obtained over a 10- to 14-day HU or casted control (CC) condition and in response to a sympathetic stressor using isoproterenol administration and brief restraint. The arrhythmic burden was calculated using a modified scoring system to quantify spontaneous and provoked arrhythmias. In addition, Western blot analysis was used to measure LV-Cx43 expression in lysates probed with antibodies directed against the total and an unphosphorylated form of Cx43 in CC and HU rats. HU resulted in a significantly greater total arrhythmic burden during the sympathetic stressor with significantly more ventricular arrhythmias occurring. In addition, there was increased expression of total LV-Cx43 observed with no difference in the expression of unphosphorylated LV-Cx43. Specifically, the increased expression of LV-Cx43 was consistent with the phosphorylated form. These data taken together indicate that cardiovascular deconditioning produced through HU results in increased predisposition to cardiac arrhythmias and increased expression of phosphorylated LV-Cx43.

  3. The role of acute hyperinsulinemia in the development of cardiac arrhythmias. (United States)

    Drimba, László; Döbrönte, Róbert; Hegedüs, Csaba; Sári, Réka; Di, Yin; Németh, Joseph; Szilvássy, Zoltán; Peitl, Barna


    Patients with perturbed metabolic control are more prone to develop cardiac rhythm disturbances. The main purpose of the present preclinical study was to investigate the possible role of euglycemic hyperinsulinemia in development of cardiac arrhythmias. Euglycemic hyperinsulinemia was induced in conscious rabbits equipped with a right ventricular pacemaker electrode catheter by hyperinsulinemic euglycemic glucose clamp (HEGC) applying two different rates of insulin infusion (5 and 10 mIU/kg/min) and variable rate of glucose infusion to maintain euglycemia (5.5 ± 0.5 mmol/l). The effect of hyperinsulinemia on cardiac electrophysiological parameters was continuously monitored by means of 12-lead surface ECG recording. Arrhythmia incidence was determined by means of programmed electrical stimulation (PES). The possible role of adrenergic activation was investigated by determination of plasma catecholamine levels and intravenous administration of a beta adrenergic blocking agent, metoprolol. All of the measurements were performed during the steady-state period of HEGC and subsequent to metoprolol administration. Both 5 and 10 mIU/kg/min insulin infusion prolonged significantly QTend, QTc, and Tpeak-Tend intervals. The incidence of ventricular arrhythmias generated by PES was increased significantly by euglycemic hyperinsulinemia and exhibited linear relationship to plasma levels of insulin. No alteration on plasma catecholamine levels could be observed; however, metoprolol treatment restored the prolonged QTend, QTc, and Tpeak-Tend intervals and significantly reduced the hyperinsulinemia-induced increase of arrhythmia incidence. Euglycemic hyperinsulinemia can exert proarrhythmic effect presumably due to the enhancement of transmural dispersion of repolarization. Metoprolol treatment may be of benefit in hyperinsulinemia associated with increased incidence of cardiac arrhythmias.

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

    NARCIS (Netherlands)

    Marsman, Roos F; Bezzina, Connie R; Freiberg, Fabian; Verkerk, Arie O; Adriaens, Michiel E; Podliesna, Svitlana; Chen, Chen; Purfürst, Bettina; Spallek, Bastian; Koopmann, Tamara T; Baczko, Istvan; Dos Remedios, Cristobal G; George, Alfred L; Bishopric, Nanette H; Lodder, Elisabeth M; de Bakker, Jacques M; Fischer, Robert; Coronel, Ruben; Wilde, Arthur A; Gotthardt, Michael; Remme, Carol A


    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.

  5. 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.

  6. Use of an implantable loop recorder in the investigation of arrhythmias in adult captive chimpanzees (Pan troglodytes). (United States)

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


    Cardiovascular disease in general, and cardiac arrhythmias specifically, is common in great apes. However, the clinical significance of arrhythmias detected on short-duration electrocardiograms is often unclear. Here we describe the use of an implantable loop recorder to evaluate cardiac rhythms in 4 unanesthetized adult chimpanzees (Pan troglodytes), 1 with a history of possible syncope and 3 with the diagnosis of multiform ventricular ectopy (ventricular premature complexes) and cardiomyopathy. The clinical significance of ventricular ectopy was defined further by using the implantable loop recorder. Arrhythmia was ruled out as a cause of collapse in the chimpanzee that presented with possible syncope because the implantable loop recorder demonstrated normal sinus rhythm during a so-called syncopal event. This description is the first report of the use of an implantable loop recorder to diagnose cardiac arrhythmias in an unanesthetized great ape species.

  7. [Identification of paroxysmal, transient arrhythmias: Intermittent registration more efficient than the 24-hour Holter monitoring]. (United States)

    Hendrikx, Tijn; Rosenqvist, Mårten; Sandström, Herbert; Persson, Mats; Hörnsten, Rolf


    Many patients suffer from palpitations or dizziness/presyncope. These patients are often referred for Holter ECG (24 hour), although the sensitivity for detecting arrhythmias is low. A new method, short intermittent regular and symptomatic ECG registrations at home, might be a convenient and more sensitive alternative also suitable for primary health care. In this case report we present a patient who had contacted health care several times during a seven year period for paroxysmal palpitations. Routine examination with 24 hour Holter ECG and event recorder did not result in a diagnosis. Using intermittent handheld ECG registration at home, a paroxysmal supraventricular arrhythmia was diagnosed. Further investigation revealed that the patient had a concealed Wolff-Parkinson-White (WPW) syndrome.

  8. Cardiac arrhythmias the first month after acute traumatic spinal cord injury

    DEFF Research Database (Denmark)

    Bartholdy, Kim; Biering-Sørensen, Tor; Malmqvist, Lasse


    of this prospective observational study was to investigate the occurrence of cardiac arrhythmias and cardiac arrests in patients with acute traumatic SCI. METHODS: As early as possible after SCI 24-hour Holter monitoring was performed. Additional Holter recordings were performed 1, 2, 3, and 4 weeks after SCI....... Furthermore, 12-lead electrocardiograms (ECGs) were obtained shortly after SCI and at 4 weeks. RESULTS: Thirty patients were included. Bradycardia (heart rate (HR) ... both on 12-lead ECGs obtained shortly after SCI (P = 0.030) and at 4 weeks (P = 0.041). CONCLUSION: Many patients with cervical SCI experience arrhythmias such as bradycardia, sinus node arrest, supraventricular tachycardia, and more rarely cardiac arrest the first month after SCI. Apart from sinus...

  9. Efficient Fine Arrhythmia Detection Based on DCG P-T Features. (United States)

    Bie, Rongfang; Xu, Shuaijing; Zhang, Guangzhi; Zhang, Meng; Ma, Xianlin; Zhang, Xialin


    Due to the high mortality associated with heart disease, there is an urgent demand for advanced detection of abnormal heart beats. The use of dynamic electrocardiogram (DCG) provides a useful indicator of heart condition from long-term monitoring techniques commonly used in the clinic. However, accurately distinguishing sparse abnormal heart beats from large DCG data sets remains difficult. Herein, we propose an efficient fine solution based on 11 geometrical features of the DCG PQRST(P-T) waves and an improved hierarchical clustering method for arrhythmia detection. Data sets selected from MIT-BIH are used to validate the effectiveness of this approach. Experimental results show that the detection procedure of arrhythmia is fast and with accurate clustering.

  10. Intra-beat Scaling Properties of Cardiac Arrhythmias and Sudden Cardiac Death (United States)

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


    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.

  11. Studies on magnesium's mechanism of action in digitalis-induced arrhythmias. (United States)

    Specter, M J; Schweizer, E; Goldman, R H


    The mechanism by which magnesium affects digitalis-induced arrhythmias was studied in dogs with and without beta-receptor blockade. Digoxin was infused at a rate of 2.5mug/kg/min until ventricular tachycardia developed, then half the animals were given MgSO4, the other half saline. In animals given MgSO4, sinus rhythm was immediately re-established; in animals given saline, ventricular tachycardia persisted. In animals with beta-receptor blockade, MgSO4 was as effective in abolishing ventricular tachycardia as in those without beta-receptor blockade. We found no evidence that magnesium re-activated digoxin-inhibited (Na+, K+)-ATPase, altered myocardial or microsomal digoxin binding, or acted via the autonomic nervous system. Magnesium's direct effect on calcium and potassium fluxes across the myocardial cell membrane may be the mechanism of its antiarrhythmic action in digitalis-toxic arrhythmias.

  12. Renal denervation for treatment of cardiac arrhythmias: state of the art and future directions. (United States)

    Kosiuk, Jedrzej; Hilbert, Sebastian; Pokushalov, Evgeny; Hindricks, Gerhard; Steinberg, Jonathan S; Bollmann, Andreas


    It has now been more than a quarter of a century since modulation of the sympathetic nervous system was proposed for the treatment of cardiac arrhythmias of different origins. But it has also been some time since some of the early surgical attempts have been abandoned. With the development of ablation techniques, however, new approaches and targets have been recently introduced that have revolutionized our way of thinking about sympathetic modulation. Renal nerve ablation technology is now being successfully used for the treatment of resistant hypertension, but the indication spectrum might broaden and new therapeutic options might arise in the near future. This review focuses on the possible impact of renal sympathetic system modulation on cardiac arrhythmias, the current evidence supporting this approach, and the ongoing trials of this method in electrophysiological laboratories. We will discuss the potential roles that sympathetic modulation may play in the future.

  13. Determining conduction patterns on a sparse electrode grid: Implications for the analysis of clinical arrhythmias (United States)

    Vidmar, David; Narayan, Sanjiv M.; Krummen, David E.; Rappel, Wouter-Jan


    We present a general method of utilizing bioelectric recordings from a spatially sparse electrode grid to compute a dynamic vector field describing the underlying propagation of electrical activity. This vector field, termed the wave-front flow field, permits quantitative analysis of the magnitude of rotational activity (vorticity) and focal activity (divergence) at each spatial point. We apply this method to signals recorded during arrhythmias in human atria and ventricles using a multipolar contact catheter and show that the flow fields correlate with corresponding activation maps. Further, regions of elevated vorticity and divergence correspond to sites identified as clinically significant rotors and focal sources where therapeutic intervention can be effective. These flow fields can provide quantitative insights into the dynamics of normal and abnormal conduction in humans and could potentially be used to enhance therapies for cardiac arrhythmias.

  14. Ranolazine: Electrophysiologic Effect, Efficacy, and Safety in Patients with Cardiac Arrhythmias. (United States)

    Shenasa, Mohammad; Assadi, Hamid; Heidary, Shahriar; Shenasa, Hossein


    Ranolazine is currently approved as an antianginal agent in patients with chronic angina (class IIA). Ranolazine exhibits antiarrhythmic effects that are related to its multichannel blocking effect, predominantly inhibition of late sodium (late INa) current and the rapid potassium rectifier current (IKr), as well as ICa, late ICa, and INa-Ca. It also suppresses the early and delayed after depolarizations. Ranolazine is effective in the suppression of atrial and ventricular arrhythmias (off-label use) without significant proarrhythmic effect. Currently, ongoing trials are evaluating the efficacy and safety of ranolazine in patients with cardiac arrhythmias; preliminary results suggest that ranolazine, when used alone or in combination with dronedarone, is safe and effective in reducing atrial fibrillation. Ranolazine is not currently approved by the US Food and Drug Administration as an antiarrhythmic agent.

  15. Mitral valve prolapse and electrolyte abnormality: a dangerous combination for ventricular arrhythmias. (United States)

    Rajani, Ali Raza; Murugesan, Vagishwari; Baslaib, Fahad Omar; Rafiq, Muhammad Anwer


    A 27-year-old woman with a history of bileaflet mitral valve prolapse and moderate mitral regurgitation presented to our emergency with untractable polymorphic wide complex tachycardia and unstable haemodynamics. After cardiopulmonary resuscitation, return of spontaneous circulation was achieved 30 min later. Her post-resuscitation ECG showed a prolonged QT interval which progressively normalised over the same day. Her laboratory investigations revealed hypocalcaemia while other electrolytes were within normal limits. A diagnosis of ventricular arrhythmia secondary to structural heart disease further precipitated by hypocalcaemia was made. Further hospital stay did not reveal a recurrence of prolonged QT interval or other arrhythmias except for an episode of non-sustained ventricular tachycardia. However, the patient suffered diffuse hypoxic brain encephalopathy secondary to prolonged cardiopulmonary resuscitation.

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

    Directory of Open Access Journals (Sweden)

    David Filgueiras-Rama


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

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


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


    Intoxication with Aconitum napellus is rare in our regions. Aconite alkaloids can cause ventricular arrhythmia by a prolonged activation of sodium channels. Because the margin of safety is low between the analgesic and toxic dose, intoxication is not rare when Aconite is used in herbal medicine. We present a case in which a 39-year-old male was accidentally intoxicated with Aconite. Even though no antidote or adequate therapy is available he was successfully resuscitated. (Neth Heart J 2008;1...

  18. Robust algorithm for arrhythmia classification in ECG using extreme learning machine

    Directory of Open Access Journals (Sweden)

    Shin Kwangsoo


    Full Text Available Abstract Background Recently, extensive studies have been carried out on arrhythmia classification algorithms using artificial intelligence pattern recognition methods such as neural network. To improve practicality, many studies have focused on learning speed and the accuracy of neural networks. However, algorithms based on neural networks still have some problems concerning practical application, such as slow learning speeds and unstable performance caused by local minima. Methods In this paper we propose a novel arrhythmia classification algorithm which has a fast learning speed and high accuracy, and uses Morphology Filtering, Principal Component Analysis and Extreme Learning Machine (ELM. The proposed algorithm can classify six beat types: normal beat, left bundle branch block, right bundle branch block, premature ventricular contraction, atrial premature beat, and paced beat. Results The experimental results of the entire MIT-BIH arrhythmia database demonstrate that the performances of the proposed algorithm are 98.00% in terms of average sensitivity, 97.95% in terms of average specificity, and 98.72% in terms of average accuracy. These accuracy levels are higher than or comparable with those of existing methods. We make a comparative study of algorithm using an ELM, back propagation neural network (BPNN, radial basis function network (RBFN, or support vector machine (SVM. Concerning the aspect of learning time, the proposed algorithm using ELM is about 290, 70, and 3 times faster than an algorithm using a BPNN, RBFN, and SVM, respectively. Conclusion The proposed algorithm shows effective accuracy performance with a short learning time. In addition we ascertained the robustness of the proposed algorithm by evaluating the entire MIT-BIH arrhythmia database.

  19. Cardiac Arrhythmia: In vivo screening in the zebrafish to overcome complexity in drug discovery (United States)

    MacRae, Calum A.


    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

  20. Predictors of Atrial Arrhythmias for Patients Undergoing Coronary Artery Bypass Grafting (United States)


    history of preoperative COPD documented on their history and/or physical . History of smoking: classified as a nonsmoker, past smoker, or current smoker. A...term anticoagulant therapy (Leitch et al., 1990; Lowe, Hendry, Hendrickson, & Wells, 1991; Frost et al., 1992; Nystrom, Edvardsson, Berggren, 2...and chronic obstructive pulmonary disease ( COPD ) as predictors of postoperative atrial arrhythmias for CABG patients. Cigarette smoking was a

  1. 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.

  2. Seizures following hippocampal kindling induce QT interval prolongation and increased susceptibility to arrhythmias in rats. (United States)

    Bealer, Steven L; Little, Jason G


    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).

  3. Comparison of real-time classification systems for arrhythmia detection on Android-based mobile devices. (United States)

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


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

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


    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.

  5. [Treatment of arrhythmia in coronary patients and hypertensives with beta blockers and Depasan retard]. (United States)

    Kandziora, J


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

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


    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.

  7. [On evaluating occupational fitness in railway workers with ventricular arrhythmias after coronary arteries stenting]. (United States)

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


    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.

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

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    Afshin Jafari Dehkordi


    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.

  9. [Pertinence of animal and human models in the evaluation of ventricular anti-arrhythmia agents]. (United States)

    Funck-Brentano, C; Le Heuzey, J Y


    The development of antiarrhythmic agents for the treatment of ventricular arrhythmias depends to a large extent on their effects in different animal and human models. The clinical relevance of the data so obtained is debatable. Firstly, in vitro animal models of arrhythmias are not very predictive of the multiple clinical forms of ventricular arrhythmias. Secondly, the intermediary criteria of evaluation of the effects of antiarrhythmic drugs in humans are generally not valid in terms of criteria of substitution for the evaluation of therapeutic effects. Nevertheless, cellular and hemodynamic studies of the electrophysiological properties of drugs are essential for correct clinical usage of antiarrhythmics. They help predict the principal clinical electrocardiographic changes and their modulation with respect to parameters such as ischemia or heart rate, their hemodynamic tolerance and certain undesirable, especially proarrhythmic, effects. However, the clinical pertinence of these studies remains limited for a number of reasons. In particular, most antiarrhythmic agents have multiple electrophysiological effects, the resultant of which is difficult to predict in the clinical situation. In addition, many of these drugs have active metabolites, the formation of which varies from person to person, which also reduces the clinical relevance of studies of the parent molecule alone. Clinical trials in appropriate patient populations should therefore be preferred to the multiplication of studies on experimental models of uncertain relevance.

  10. Mechanism of escape, extrasystolic, and parasystolic arrhythmias. Study on an electrical analogue. (United States)

    Sideris, D A


    A simple analogue of the heart consisting of a system of neon relaxation oscillators is presented. The analogue may display rhythm patterns similar to sinus rhythm, escape rhythm, isorrhythmic dissociation with synchronization, atrial extrasystoles, ventricular extrasystoles, and parasystole. The strict rules followed by these arrhythmias, as well as the deviations from the rules commonly followed by the equivalent heart arrhythmias, may be easily reproduced on the analogue. Such features are the Treppe phenomenon and captured beats in escape rhythm, fixed coupling intervals in extrasystoles, partial or complete atrioventricular block in very premature atrial extrasystoles, prolongation of the period following an atrial extrasystole, interpolated premature beats, complete compensatory pause and the rule of bigeminy in ventricular extrasystoles, slight instability of the parasystolic period, multiple length parasystolic periods slightly different from the exact multiples of the parasystolic idioperiod, preference of the parasystoles for certain phase in the sinus cycle, synchronization at a phase difference and fluctuation repeatedly and without interruption from a parasystolic to an extrasystolic rhythm and synchronization in escape rhythm with isorrhythmic dissociation. The mechanisms involved in these phenomena are discussed in detail. The striking similarity between the properties of the cardiac pacemakers and those of the relaxation oscillators on the one hand and betwen the rhythm patterns of the heart and those of the analogue on the other may permit the hypothesis that the mechanisms operating in the analogue may be used in analyzing and understanding heart arrhythmias.

  11. Genetic testing and genetic counseling in patients with sudden death risk due to heritable arrhythmias. (United States)

    Spoonamore, Katherine G; Ware, Stephanie M


    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.

  12. Efficient ECG signal analysis using wavelet technique for arrhythmia detection: an ANFIS approach (United States)

    Khandait, P. D.; Bawane, N. G.; Limaye, S. S.


    This paper deals with improved ECG signal analysis using Wavelet Transform Techniques and employing subsequent modified feature extraction for Arrhythmia detection based on Neuro-Fuzzy technique. This improvement is based on suitable choice of features in evaluating and predicting life threatening Ventricular Arrhythmia . Analyzing electrocardiographic signals (ECG) includes not only inspection of P, QRS and T waves, but also the causal relations they have and the temporal sequences they build within long observation periods. Wavelet-transform is used for effective feature extraction and Adaptive Neuro-Fuzzy Inference System (ANFIS) is considered for the classifier model. In a first step, QRS complexes are detected. Then, each QRS is delineated by detecting and identifying the peaks of the individual waves, as well as the complex onset and end. Finally, the determination of P and T wave peaks, onsets and ends is performed. We evaluated the algorithm on several manually annotated databases, such as MIT-BIH Arrhythmia and CSE databases, developed for validation purposes. Features based on the ECG waveform shape and heart beat intervals are used as inputs to the classifiers. The performance of the ANFIS model is evaluated in terms of training performance and classification accuracies and the results confirmed that the proposed ANFIS model has potential in classifying the ECG signals. Cross validation is used to measure the classifier performance. A testing classification accuracy of 95.13% is achieved which is a significant improvement.

  13. Assessment of Cardiac Rate and Rhythm in Fetuses with Arrhythmia via Maternal Abdominal Fetal Electrocardiography. (United States)

    Narayan, Hari K; Vignola, Emilia F; Fifer, William P; Williams, Ismee A


    Objective This study aims to report our experience using the Monica AN24 (Monica Healthcare Ltd., Nottingham, United Kingdom), a maternal transabdominal fetal electrocardiographic monitor, in a case series of fetuses with arrhythmias. Study Design We recorded fetal electrocardiograms (fECGs) on subjects with fetal arrhythmias diagnosed by fetal echocardiogram. Fetal heart rate and rhythm were determined via manual fECG analysis. Results Overall, 20 fECGs were recorded from a pool of 13 subjects. Fetal heart rate acquisition was determined to be high, medium, and poor quality in 10, 3, and 7 tracings, respectively. High-quality tracings were obtained in 9 of 11 subjects with gestational age  34 weeks. P waves were detectable in five tracings. Conclusion In subjects  34 weeks' gestational age, there was reasonable success in fetal heart rate acquisition. Further study is warranted to determine the potential role of this device in the monitoring of subjects with fetal arrhythmias.

  14. A novel algorithm for ventricular arrhythmia classification using a fuzzy logic approach. (United States)

    Weixin, Nong


    In the present study, it has been shown that an unnecessary implantable cardioverter-defibrillator (ICD) shock is often delivered to patients with an ambiguous ECG rhythm in the overlap zone between ventricular tachycardia (VT) and ventricular fibrillation (VF); these shocks significantly increase mortality. Therefore, accurate classification of the arrhythmia into VT, organized VF (OVF) or disorganized VF (DVF) is crucial to assist ICDs to deliver appropriate therapy. A classification algorithm using a fuzzy logic classifier was developed for accurately classifying the arrhythmias into VT, OVF or DVF. Compared with other studies, our method aims to combine ten ECG detectors that are calculated in the time domain and the frequency domain in addition to different levels of complexity for detecting subtle structure differences between VT, OVF and DVF. The classification in the overlap zone between VT and VF is refined by this study to avoid ambiguous identification. The present method was trained and tested using public ECG signal databases. A two-level classification was performed to first detect VT with an accuracy of 92.6 %, and then the discrimination between OVF and DVF was detected with an accuracy of 84.5 %. The validation results indicate that the proposed method has superior performance in identifying the organization level between the three types of arrhythmias (VT, OVF and DVF) and is promising for improving the appropriate therapy choice and decreasing the possibility of sudden cardiac death.

  15. Risk Prediction of One-Year Mortality in Patients with Cardiac Arrhythmias Using Random Survival Forest. (United States)

    Miao, Fen; Cai, Yun-Peng; Zhang, Yu-Xiao; Li, Ye; Zhang, Yuan-Ting


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

  16. Small-conductance Ca2+ -activated K+ channels and cardiac arrhythmias. (United States)

    Zhang, Xiao-Dong; Lieu, Deborah K; Chiamvimonvat, Nipavan


    Small-conductance Ca2+ -activated K+ (SK, KCa2) channels are unique in that they are gated solely by changes in intracellular Ca2+ and, hence, function to integrate intracellular Ca2+ and membrane potentials on a beat-to-beat basis. Recent studies have provided evidence for the existence and functional significance of SK channels in the heart. Indeed, our knowledge of cardiac SK channels has been greatly expanded over the past decade. Interests in cardiac SK channels are further driven by recent studies suggesting the critical roles of SK channels in human atrial fibrillation, the SK channel as a possible novel therapeutic target in atrial arrhythmias, and upregulation of SK channels in heart failure in animal models and in human heart failure. However, there remain critical gaps in our knowledge. Specifically, blockade of SK channels in cardiac arrhythmias has been shown to be both antiarrhythmic and proarrhythmic. This contemporary review provides an overview of the literature on the role of cardiac SK channels in cardiac arrhythmias and serves as a discussion platform for the current clinical perspectives. At the translational level, development of SK channel blockers as a new therapeutic strategy in the treatment of atrial fibrillation and the possible proarrhythmic effects merit further considerations and investigations.

  17. Benchmarking ventricular arrhythmias in the mouse--revisiting the 'Lambeth Conventions' 20 years on. (United States)

    Huggins, Catherine E; Bell, James R; Pepe, Salvatore; Delbridge, Lea M D


    The isolated Langendorff-mode perfused heart has become a valuable experimental model, used extensively to examine cardiac function, pathophysiology and pharmacology. For the clinical cardiologist an ECG is often a simple practicality, however in experimental circumstances, particularly with ex vivo murine hearts it is not always possible to obtain an ECG due to experimental recording constraints. However, the mechanical record of ventricular contractile function can be highly informative in relation to electrical state. It is difficult though to achieve consistency in these evaluations of arrhythmia as a validated common reference framework is lacking. In 1988, a group of investigators developed the 'Lambeth Conventions'--a standardised reference for the definition and classification of arrhythmias in animal experimental models of ischaemia, infarction and reperfusion in vivo. Now, two decades later it is timely to revisit the Lambeth Conventions, and to update the guidelines in the context of the marked increase in murine heart study in experimental cardiac pathophysiology. Here we describe an adjunct to the Lambeth Conventions for the reporting of ventricular arrhythmias post-ischaemia in ex vivo mouse hearts when ECG recordings are not employed. Of seven discrete and identifiable patterns of mechanical dysrhythmia observed in reperfusion, five could be classified using conventional ECG terminology: ventricular premature beat, bigeminy, trigeminy, ventricular tachycardia and ventricular fibrillation. Two additional rhythm variations detected from the pressure record are described (potentiated contraction and alternans).

  18. A Real-Time Cardiac Arrhythmia Classification System with Wearable Sensor Networks (United States)

    Hu, Sheng; Wei, Hongxing; Chen, Youdong; Tan, Jindong


    Long term continuous monitoring of electrocardiogram (ECG) in a free living environment provides valuable information for prevention on the heart attack and other high risk diseases. This paper presents the design of a real-time wearable ECG monitoring system with associated cardiac arrhythmia classification algorithms. One of the striking advantages is that ECG analog front-end and on-node digital processing are designed to remove most of the noise and bias. In addition, the wearable sensor node is able to monitor the patient's ECG and motion signal in an unobstructive way. To realize the real-time medical analysis, the ECG is digitalized and transmitted to a smart phone via Bluetooth. On the smart phone, the ECG waveform is visualized and a novel layered hidden Markov model is seamlessly integrated to classify multiple cardiac arrhythmias in real time. Experimental results demonstrate that the clean and reliable ECG waveform can be captured in multiple stressed conditions and the real-time classification on cardiac arrhythmia is competent to other workbenches. PMID:23112746

  19. A Real-Time Cardiac Arrhythmia Classification System with Wearable Sensor Networks

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    Jindong Tan


    Full Text Available Long term continuous monitoring of electrocardiogram (ECG in a free living environment provides valuable information for prevention on the heart attack and other high risk diseases. This paper presents the design of a real-time wearable ECG monitoring system with associated cardiac arrhythmia classification algorithms. One of the striking advantages is that ECG analog front-end and on-node digital processing are designed to remove most of the noise and bias. In addition, the wearable sensor node is able to monitor the patient’s ECG and motion signal in an unobstructive way. To realize the real-time medical analysis, the ECG is digitalized and transmitted to a smart phone via Bluetooth. On the smart phone, the ECG waveform is visualized and a novel layered hidden Markov model is seamlessly integrated to classify multiple cardiac arrhythmias in real time. Experimental results demonstrate that the clean and reliable ECG waveform can be captured in multiple stressed conditions and the real-time classification on cardiac arrhythmia is competent to other workbenches.

  20. Arrhythmias following Revascularization Procedures in the Course of Acute Myocardial Infarction: Are They Indicators of Reperfusion or Ongoing Ischemia?

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    Ersan Tatli


    Full Text Available Objective. The most important step in the treatment of ST elevation myocardial infarction is to sustain myocardial blood supply as soon as possible. The two main treatment methods used today to provide myocardial reperfusion are thrombolytic therapy and percutaneous coronary intervention. In our study, reperfusion arrhythmias were investigated as if they are indicators of coronary artery patency or ongoing ischemia after revascularization. Methods. 151 patients with a diagnosis of acute ST elevation myocardial infarction were investigated. 54 patients underwent primary percutaneous coronary intervention and 97 patients were treated with thrombolytic therapy. The frequency of reperfusion arrythmias following revascularization procedures in the first 48 hours after admission was examined. The relation between reperfusion arrhythmias, ST segment regression, coronary artery patency, and infarct related artery documented by angiography were analyzed. Results. There was no statistically significant difference between the two groups in the frequency of reperfusion arrhythmias (P=0.355. Although angiographic vessel patency was higher in patients undergoing percutaneous coronary intervention, there was no significant difference between the patency rates of each group with and without reperfusion arrythmias. Conclusion. Our study suggests that recorded arrhythmias following different revascularization procedures in acute ST elevation myocardial infarction may not always indicate vessel patency and reperfusion. Ongoing vascular occlusion and ischemia may lead to various arrhythmias which may not be distinguished from reperfusion arrhythmias.

  1. The effect of cannabidiol on ischemia/reperfusion-induced ventricular arrhythmias: the role of adenosine A1 receptors. (United States)

    Gonca, Ersöz; Darıcı, Faruk


    Cannabidiol (CBD) is a nonpsychoactive phytocannabinoid with anti-inflammatory activity mediated by enhancing adenosine signaling. As the adenosine A1 receptor activation confers protection against ischemia/reperfusion (I/R)-induced ventricular arrhythmias, we hypothesized that CBD may have antiarrhythmic effect through the activation of adenosine A1 receptor. Cannabidiol has recently been shown to suppress ischemia-induced ventricular arrhythmias. We aimed to research the effect of CBD on the incidence and the duration of I/R-induced ventricular arrhythmias and to investigate the role of adenosine A1 receptor activation in the possible antiarrhythmic effect of CBD. Myocardial ischemia and reperfusion was induced in anesthetized male rats by ligating the left anterior descending coronary artery for 6 minutes and by loosening the bond at the coronary artery, respectively. Cannabidiol alone was given in a dose of 50 µg/kg, 10 minutes prior to coronary artery occlusion and coadministrated with adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) in a dose of 100 µg/kg, 15 minutes prior to coronary artery occlusion to investigate whether the antiarrhythmic effect of CBD is modified by the activation of adenosine A1 receptors. The experimental groups were as follows: (1) vehicle control (n = 10), (2) CBD (n = 9), (3) DPCPX (n = 7), and (4) CBD + DPCPX group (n = 7). Cannabidiol treatment significantly decreased the incidence and the duration of ventricular tachycardia, total length of arrhythmias, and the arrhythmia scores compared to control during the reperfusion period. The DPCPX treatment alone did not affect the incidence and the duration of any type of arrhythmias. However, DPCPX aborted the antiarrhythmic effect of CBD when it was combined with it. The present results demonstrated that CBD has an antiarrhythmic effect against I/R-induced arrhythmias, and the antiarrhythmic effect of CBD may be mediated through the activation of adenosine

  2. RIESGO DE ARRITMIAS E HIPERTENSIÓN ARTERIAL / Risk of Arrhythmias and hypertension

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    Raimundo Carmona Puerta


    the development of arrhythmias in hypertensive patients. The presence of ventricular arrhythmias, from premature ventricular complexes to ventricular tachycardia, has been shown in a 10 to 27% of affected patients, a percentage that decreases with the severity of the arrhythmia. Noninvasive risk markers for ventricular arrhythmias have been summarized as follows: dispersion and variability of the QT interval, presence of late potentials, heart rate variability, abnormal morphology and T-wave alternans. All of these are related to anatomic-structural changes of the ventricular wall, which affect the action potential. The importance of knowing the epidemiology, pathophysiology, and noninvasive risk markers for arrhythmias in hypertensive patients, offers a way for the application of the proper therapeutic in the control of blood pressure and regression of hypertrophy, as has been shown by inhibitor drugs of the renin-angiotensin-aldosterone system, which decrease the risk of arrhythmias.

  3. Functional reentry and circus movement arrhythmias in the small intestine of normal and diabetic rats. (United States)

    Lammers, Wim J E P; Stephen, B; Karam, S M


    In a few recent studies, the presence of arrhythmias based on reentry and circus movement of the slow wave have been shown to occur in normal and diseased stomachs. To date, however, reentry has not been demonstrated before in any other part of the gastrointestinal system. No animals had to be killed for this study. Use was made of materials obtained during the course of another study in which 11 rats were treated with streptozotocin and housed with age-matched controls. After 3 and 7 mo, segments of duodenum, jejunum, and ileum were isolated and positioned in a tissue bath. Slow wave propagation was recorded with 121 extracellular electrodes. After the experiment, the propagation of the slow waves was reconstructed. In 10 of a total of 66 intestinal segments (15%), a circus movement of the slow wave was detected. These reentries were seen in control (n = 2) as well as in 3-mo (n = 2) and 7-mo (n = 6) diabetic rats. Local conduction velocities and beat-to-beat intervals during the reentries were measured (0.42 ± 0.15 and 3.03 ± 0.67 cm/s, respectively) leading to a wavelength of 1.3 ± 0.5 cm and a circuit diameter of 4.1 ± 1.5 mm. This is the first demonstration of a reentrant arrhythmia in the small intestine of control and diabetic rats. Calculations of the size of the circuits indicate that they are small enough to fit inside the intestinal wall. Extrapolation based on measured velocities and rates indicate that reentrant arrhythmias are also possible in the distal small intestine of larger animals including humans.

  4. Induced pluripotent stem cell derived cardiomyocytes as models for cardiac arrhythmias. (United States)

    Hoekstra, Maaike; Mummery, Christine L; Wilde, Arthur A M; Bezzina, Connie R; Verkerk, Arie O


    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 (CM) 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 have 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 CMs 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 (CPVT). 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 disorders.

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

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    Krzysztof Safranow


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

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

    Directory of Open Access Journals (Sweden)

    Maaike eHoekstra


    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. Bile acid-induced arrhythmia is mediated by muscarinic M2 receptors in neonatal rat cardiomyocytes.

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    Siti H Sheikh Abdul Kadir

    Full Text Available BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP is a common disease affecting up to 5% of pregnancies and which can cause fetal arrhythmia and sudden intrauterine death. We previously demonstrated that bile acid taurocholate (TC, which is raised in the bloodstream of ICP, can acutely alter the rate and rhythm of contraction and induce abnormal calcium destabilization in cultured neonatal rat cardiomyocytes (NRCM. Apart from their hepatic functions bile acids are ubiquitous signalling molecules with diverse systemic effects mediated by either the nuclear receptor FXR or by a recently discovered G-protein coupled receptor TGR5. We aim to investigate the mechanism of bile-acid induced arrhythmogenic effects in an in-vitro model of the fetal heart. METHODS AND RESULTS: Levels of bile acid transporters and nuclear receptor FXR were studied by quantitative real time PCR, western blot and immunostaining, which showed low levels of expression. We did not observe functional involvement of the canonical receptors FXR and TGR5. Instead, we found that TC binds to the muscarinic M(2 receptor in NRCM and serves as a partial agonist of this receptor in terms of inhibitory effect on intracellular cAMP and negative chronotropic response. Pharmacological inhibition and siRNA-knockdown of the M(2 receptor completely abolished the negative effect of TC on contraction, calcium transient amplitude and synchronisation in NRCM clusters. CONCLUSION: We conclude that in NRCM the TC-induced arrhythmia is mediated by the partial agonism at the M(2 receptor. This mechanism might serve as a promising new therapeutic target for fetal arrhythmia.

  8. 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


    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.

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

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    Zhenying Zhao


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

  10. Salade malade: malignant ventricular arrhythmias due to an accidental intoxication with Aconitum napellus. (United States)

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


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

  11. Effectiveness of morphological and spectral heartbeat characterization on arrhythmia clustering for Holter recordings (United States)

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


    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.

  12. QT dispersion and ventricular arrhythmias in children with primary mitral valve prolapse (United States)

    İmamoğlu, Ebru Yalın; Eroğlu, Ayşe Güler


    Aim: To investigate ventricular arrhythmias in children with primary mitral valve prolapse and to evaluate its relation with QT length, QT dispersion, autonomic function tests and heart rate variability measurements. Material and Methods: Fourty two children with mitral valve prolapse and 32 healthy children were enrolled into the study. Twelve-lead electrocardiograms, autonomic function tests, echocardiography and 24-hour rhythm Holter tests were performed. Electrocardiograms were magnified digitally. The QT length was corrected according to heart rate. The patients were grouped according to the number of premature ventricular contractions and presence of complex ventricular arhythmia in the 24-hour rhythm Holter monitor test. Heart rate variability measurements were calculated automatically from the 24-hour rhythm Holter monitor test. Orthostatic hypotension and resting heart rate were used as autonomic function tests. Results: The mean age was 13.9±3.3 years in the patient group and 14.6±3.1 years in the control group (p>0.05). Thirty four of the patients (81%) were female and eight (19%) were male. Twenty five of the control subjects (78%) were female and seven (22%) were male. The QT dispersion and heart rate corrected QT interval were found to be significantly increased in the children with primary mitral valve prolapse when compared with the control group (56±16 ms vs. 43±11 ms, p=0.001; 426±25 ms vs. 407±26 ms, p=0.002, respectively). In 24-hour rhythm Holter monitor tests, ventricular arrhythmias were found in 21 out of 42 patients (50%) and 6 out of 32 control subjects (18.8%) (p=0.006). QT dispersion was found to be significantly increased in patients with premature ventricular contractions ≥ 10/day and/or complex ventricular arrhythmias compared to the control group without ventricular premature beats (p=0.002). There was no significant difference in autonomic function tests and heart rate variability measurements between the patient and control

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

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    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: [Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL (United States)


    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


    Directory of Open Access Journals (Sweden)



    Full Text Available Myopathies are disorders with structural changes or functional impairment of muscle. Voluntary muscle is subject to a range of hereditary and acquired disorders affecting either its structure, or the biochemical processes which convert the chemical energy derived from cell metabolism into mechanical energy in a controlled manner. These disorders present in a limited number of ways, most commonly a symmetrical weakness of the large, power-generating proximal muscles. Drug induced myopathy comes under acquired causes of myopathy. Here we shall be presenting a case of Amiodarone induced myopathy in a 40 years old male patient of ventricular arrhythmia. We shall also discuss the further management of this presentation.

  15. Role of Genetic Testing in Patients with Ventricular Arrhythmias in Apparently Normal Hearts. (United States)

    Hofman, Nynke; Wilde, Arthur A M


    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.

  16. Use of the Surface Electrocardiogram to Define the Nature of Challenging Arrhythmias. (United States)

    Singh, David K; Peter, C Thomas


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

  17. Home monitoring system improves the detection of ventricular arrhythmia and inappropriate shock

    Institute of Scientific and Technical Information of China (English)

    WANG Huan; HUA Wei; DING Li-gang; WANG Jing; CHEN Ke-ping; ZHANG Shu


    Background The impact of home monitoring system in the early detection of ventricular arrhythmia and inappropriate shock in daily work is not clear.The aim of this study was to investigate the impact of home monitoring system on the early detection of ventricular arrhythmia and inappropriate shock in daily clinical practice.Methods Cases of implantable cardioverter defibrillator (ICD) implantation with or without the home monitoring system from June 2010 to October 2011 at our center were reviewed.Follow-up was scheduled after implantation.Data relating to the home monitoring ICD were retrieved using a remote transmitter system.Data relating to the other devices were obtained during scheduled follow-up or unscheduled visits.Results Our study involved 69 patients (mean age (68.4±17.6) years,64.3% males,26 in the home monitoring group vs.43 in the non-home monitoring group).In all,561 ventricular arrhythmia episodes were detected in 17 patients (39.5%) in the non-home monitoring group:495 episodes were ventricular tachycardia and 66 episodes were ventricular fibrillation; among these,476 episodes of ventricular tachycardia and 45 episodes of ventricular fibrillation were appropriately diagnosed (96.1% and 68.2%,respectively).In the home monitoring group,389 ventricular arrhythmia episodes were transmitted by the home monitoring system in nine patients (34.6%):348 ventricular tachycardia episodes and 41 ventricular fibrillation episodes.Device detection was appropriate in 348 ventricular tachycardia episodes (100.0%) and 36 ventricular fibrillation episodes (87.8%).The home monitoring group showed a higher appropriate detection rate of ventricular tachycardia (P <0.01) and ventricular fibrillation (P=0.02).The proportion of inappropriate shock was comparable in the two groups (6/11 in the non-home monitoring group vs.1/7 in the home monitoring group; P=O.08).Conclusions The home monitoring ICD was able to provide information relating to inappropriate

  18. Role for the Unfolded Protein Response in Heart Disease and Cardiac Arrhythmias. (United States)

    Liu, Man; Dudley, Samuel C


    The unfolded protein response (UPR) has been extensively investigated in neurological diseases and diabetes, while its function in heart disease is less well understood. Activated UPR participates in multiple cardiac conditions and can either protect or impair heart function. Recently, the UPR has been found to play a role in arrhythmogenesis during human heart failure by affecting cardiac ion channels expression, and blocking UPR has an antiarrhythmic effect. This review will discuss the rationale for and challenges to targeting UPR in heart disease for treatment of arrhythmias.

  19. Fibroblast growth factor homologous factors in the heart: a potential locus for cardiac arrhythmias. (United States)

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


    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.

  20. Classification of Arrhythmias with LDA and ANN using Orthogonal Rotations for Feature Reduction

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    Manpreet Kaur


    Full Text Available This paper presents a new approach for feature reduction by using orthogonal rotations. Wavelet coefficients for beat segments are taken as features which are reduced by factor analysis method using orthogonal rotations. LDA (Linear Discriminant Analysis and ANN (Artificial Neural Network classifiers are used for classification. The signals are taken from MIT-BIH arrhythmia database to classify into Normal, PVC, Paced, LBBB and RBBB. The performance of classification output has been compared by the performance parameters. Both the classifiers have given best overall accuracy for equimax rotation. 96% accuracy is achieved with LDA classifier,99.2% accuracy is achieved using ANN.

  1. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)


    2010315 Effects on electrical restitution of given esanolol during cardiopulmonary resuscitation in a swine ventricular fibrillation model. WEI Jie(魏捷),et al. Dept Emerg Med,Renmin Hosp,Wuhan Univ,Wuhan 430060.Chin J Emerg Med 2010;19(3):257-263. Objective To

  2. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)


    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

  3. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)


    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。

  4. Stellar Arrhythmias

    CERN Document Server

    Buchler, J R


    The light curves of the two large amplitude variable stars, R Scuti and AC Herculis, display irregular pulsation cycles with 'periods' of 75 and 35 days, respectively. We review the evidence that the observed time-series are generated by low dimensional chaotic dynamics. In particular, a global flow reconstruction technique indicates that the minimum embedding dimensions are 4 and 3 for R Sct and AC Her, respectively, whereas the fractal dimensions are inferred to be approximately 3.1 and 2.05 - 2.45, respectively. It thus appears that the dimensions of the dynamics themselves are also 4 and 3.

  5. Candiac arrhythmias

    Institute of Scientific and Technical Information of China (English)


    930062 Pathological changes of catheter abla-tion of atrioventricular junction.LI Yue(李越),et al.Dept Cardiol,43rd Hosp,Kunming.Chin Cir J 1992;7(4):350-351.Pathological examinations were carried out in34 mongrel dogs following catheter ablation ofthe AV junction,gross pathological examination

  6. Cardio-eigenoscopy: significance of this new method in prognosis of risks of fatal arrhythmia progression in AMI patients

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    Dmitry V. Issakevich


    Full Text Available The aim of the study was to evaluate the significance of cardioeigenoscopy method for the prognosis of risks of fatal arrhythmia (the primary and secondary VF progression in AMI individuals.The study was performed with the use of the PC-assisted hemodynamic analyzer Cardiocode. The cardio-eigenoscopy was developed as a methodology that is capable of presenting all ECG changes in the basis of eigenvectors of a covariance matrix of ECG amplitudes and providing an analysis of a spectrum of eigenvalues. The ECG analysis software is implemented as a real-time monitoring of a set of parameters that makes possible to evaluate the therapy effectiveness. The cardio-eigenoscopy method is capable of assessing the risk of progression of fatal arrhythmia events in MI patients. The major markers of the possible progression of fatal arrhythmia were identified. The cardioeigenoscopy provided the maximum expressibility of an ECG curve at any specified EVE values.

  7. Low dialysate potassium concentration: an overrated risk factor for cardiac arrhythmia? (United States)

    Abuelo, J Gary


    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. Arrhythmia and cardiac defects are a feature of spinal muscular atrophy model mice. (United States)

    Heier, Christopher R; Satta, Rosalba; Lutz, Cathleen; DiDonato, Christine J


    Proximal spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. Traditionally, SMA has been described as a motor neuron disease; however, there is a growing body of evidence that arrhythmia and/or cardiomyopathy may present in SMA patients at an increased frequency. Here, we ask whether SMA model mice possess such phenotypes. We find SMA mice suffer from severe bradyarrhythmia characterized by progressive heart block and impaired ventricular depolarization. Echocardiography further confirms functional cardiac deficits in SMA mice. Additional investigations show evidence of both sympathetic innervation defects and dilated cardiomyopathy at late stages of disease. Based upon these data, we propose a model in which decreased sympathetic innervation causes autonomic imbalance. Such imbalance would be characterized by a relative increase in the level of vagal tone controlling heart rate, which is consistent with bradyarrhythmia and progressive heart block. Finally, treatment with the histone deacetylase inhibitor trichostatin A, a drug known to benefit phenotypes of SMA model mice, produces prolonged maturation of the SMA heartbeat and an increase in cardiac size. Treated mice maintain measures of motor function throughout extended survival though they ultimately reach death endpoints in association with a progression of bradyarrhythmia. These data represent the novel identification of cardiac arrhythmia as an early and progressive feature of murine SMA while providing several new, quantitative indices of mouse health. Together with clinical cases that report similar symptoms, this reveals a new area of investigation that will be important to address as we move SMA therapeutics towards clinical success.

  9. Effects of Potassium Aspartate and Magnesium on Ventricular Arrhythmia in Ischemia-reperfusion Rabbit Heart

    Institute of Scientific and Technical Information of China (English)

    Jun PU; Ben HE; Cuntai ZHANG; Xiaoqing QUAN; Guoan ZHAO; Jiagao LV; Bo LI; Rong BAI; Nian LIU; Yanfei RUAN


    Summary: The aim of this study was to determine if the potassium aspartate and magnesium (PAM) prevent reperfusion-induced ventricular arrhythmias (RIVA) in ischcmia-reperfusion (IR) rabbit heart. Thirty rabbits were randomly divided into control, ischemia and PAM groups. Arterially-perfused rabbit left ventricular preparations were made, and transmural ECG as well as action potentials from both endocardium and epicardium were simultaneously recorded in the whole process of all experiments. In control group rabbit ventricular wedge preparations were continuously perfused with Tyrode's solution, and in ischemia group and PAM groups the perfusion of Tyrode's solution was stopped for 30 min. Then the ischemia group was reperfused with Tyrode's solution and the PAM group with Tyrode's solution containing 2.42 mg/L PAM, respectively. ECG, QT interval, transmural repolarization dispersion (TDR) and action potentials from epicardium and endocardium were simultaneously recorded, and the RIVA of the wedge preparation was observed. Compared with control group, TDR and incidence of RIVA were significantly increased in ischemia group (P<0.05). The incidence of RIVA in control, ischemia and PAM group was 0/10, 9/10 and 1/10, respectively. Compared with ischemia group, TDR and incidence of RIVA were significantly reduced in PAM group (P<0.05). Potassium aspartate and magnesium significantly reduce TDR and prevent ventricular arrhythmia in ischemic rabbit heart.

  10. Severe arrhythmia induced by orally disintegrating aripiprazole tablets (Bosiqing®: a case report

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    Shao Q


    Full Text Available Qing Shao,1,2,* Wei Quan,1,2,* Xiaoni Jia,1 Jianbo Chen,1 Shanbo Ma,3 Xiaohong Zhang11Xi’an Mental Health Center, Institute of Mental Health, Xi’an Medical University, Xi’an, Shaanxi, People’s Republic of China; 2Institute of Materia Medica, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China; 3Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China*These authors contributed equally to this workAbstract: Psychotropic medications have been known to cause cardiac conduction disturbances. Not much is known about the cardiovascular side effects of newer atypical antipsychotics such as aripiprazole. A case of a 13-year-old girl with schizophrenia is presented. An analysis of the presented patient’s clinical history indicates the need for a detailed analysis of the severe arrhythmia induced by aripiprazole. This presented case report contains valuable guidelines that can be of assistance in the treatment of patients with aripiprazole.Keywords: schizophrenia, aripiprazole, arrhythmia, antipsychotics


    Institute of Scientific and Technical Information of China (English)

    袁秉祥; 刘书勤; 李萍; 李新华


    Objective To study the arrhythmia induced by stimulation of nicotine-sensitive neurons in cardiac ganglial plexuses. Methods When nicotine (100μg) was injected into canine right atrial ganglial plexus (RAGP) and ganglial plexus between aorta and pulmonary artery (A-PGP) in 33 anesthetized open-chest dog, electrocardiogram, atrial force and ventricular intramyocardial pressures (IMP) were recorded. The responses were also recorded following administration of atropine or propranolol and after heart acute decentralization. Results Ventricular arrhythmia (VA) was induced by injections of nicotine into A-PGP, but not by injections of nicotine into RAGP in 13 dogs. Atrioventricilar (A-V) block was induced by nicotine activating RAGP in 10 dogs, but not by nicotine activating A-PGP. Propranolol could reduce the frequency of VA elicited by stimulating A-PGP, atropine could reduce the frequency of A-V block elicited by stimulating RAGP. After acute decentralization, VA was still induced by activation of A-PGP in 9 dogs, but A-V block elicited by stimulating RAGP was decreased. Conclusion VA is induced by stimulating N receptor in cardiac nicotine-sensitive efferent sympathetic neurons of ventricular ganglial plexus (A-PGP), and then modifying β receptor of ventricles. A-V block is elicited by stimulating N receptor in atrial ganglial plexus (RAGP), then modifying M receptor of A-V node not only via efferent parasympathetic neurons, but also via afferent pathway.

  12. Reducing mortality with device therapy in heart failure patients without ventricular arrhythmias. (United States)

    Chapa, Deborah W; Lee, Hyeon-Joo; Kao, Chi-Wen; Friedmann, Erika; Thomas, Sue A; Anderson, Jill; Bardy, Gust H


    Use of device therapy to prevent sudden cardiac death in patients with heart failure is expanding on the basis of evidence from recent clinical trials. Three multicenter prospective clinical trials-Sudden Cardiac Death in Heart Failure (SCD-HeFT); Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION); and Cardiac Resynchronization-Heart Failure (CARE-HF)-were conducted to determine the effectiveness of devices in reducing mortality in patients with heart failure who did not have a history of ventricular arrhythmias. The 3 trials varied in the devices used, the population of patients included, and the study designs. In SCD-HeFT, implantable cardioverter defibrillators were more effective than pharmacological therapy in preventing mortality among patients with mild to moderate heart failure. In COMPANION, cardiac resynchronization therapy alone and cardiac resynchronization therapy plus an implantable cardioverter defibrillator were more effective than optimal drug treatment in reducing morbidity and all-cause mortality in patients with moderate to severe heart failure. In CARE-HF, cardiac resynchronization therapy alone was more effective than optimal drug treatment in reducing all-cause mortality in patients with moderate to severe heart failure. No direct comparison of the devices used has been done. These 3 clinical trials provide clear evidence that device therapy is beneficial for some patients with heart failure, even patients who do not have a history of ventricular arrhythmia.

  13. Potassium currents in the heart: functional roles in repolarization, arrhythmia and therapeutics. (United States)

    Chiamvimonvat, Nipavan; Chen-Izu, Ye; Clancy, Colleen E; Deschenes, Isabelle; Dobrev, Dobromir; Heijman, Jordi; Izu, Leighton; Qu, Zhilin; Ripplinger, Crystal M; Vandenberg, Jamie I; Weiss, James N; Koren, Gideon; Banyasz, Tamas; Grandi, Eleonora; Sanguinetti, Michael C; Bers, Donald M; Nerbonne, Jeanne M


    This is the second of the two White Papers from the fourth UC Davis Cardiovascular Symposium Systems Approach to Understanding Cardiac Excitation-Contraction Coupling and Arrhythmias (3-4 March 2016), a biennial event that brings together leading experts in different fields of cardiovascular research. The theme of the 2016 symposium was 'K(+) channels and regulation', and the objectives of the conference were severalfold: (1) to identify current knowledge gaps; (2) to understand what may go wrong in the diseased heart and why; (3) to identify possible novel therapeutic targets; and (4) to further the development of systems biology approaches to decipher the molecular mechanisms and treatment of cardiac arrhythmias. The sessions of the Symposium focusing on the functional roles of the cardiac K(+) channel in health and disease, as well as K(+) channels as therapeutic targets, were contributed by Ye Chen-Izu, Gideon Koren, James Weiss, David Paterson, David Christini, Dobromir Dobrev, Jordi Heijman, Thomas O'Hara, Crystal Ripplinger, Zhilin Qu, Jamie Vandenberg, Colleen Clancy, Isabelle Deschenes, Leighton Izu, Tamas Banyasz, Andras Varro, Heike Wulff, Eleonora Grandi, Michael Sanguinetti, Donald Bers, Jeanne Nerbonne and Nipavan Chiamvimonvat as speakers and panel discussants. This article summarizes state-of-the-art knowledge and controversies on the functional roles of cardiac K(+) channels in normal and diseased heart. We endeavour to integrate current knowledge at multiple scales, from the single cell to the whole organ levels, and from both experimental and computational studies.

  14. Downregulation of connexin43 by microRNA-130a in cardiomyocytes results in cardiac arrhythmias. (United States)

    Osbourne, Appledene; Calway, Tyler; Broman, Michael; McSharry, Saoirse; Earley, Judy; Kim, Gene H


    MicroRNAs (miRNAs) are now recognized as critical regulators of diverse physiological and pathological processes; however, studies of miRNAs and arrhythmogenesis remain sparse. Connexin43 (Cx43), a major cardiac gap junction protein, has elicited great interest in its role in arrhythmias. Additionally, Cx43 was a potential target for miR-130a as predicted by several computational algorithms. This study investigates the effect of miR-130a overexpression in the adult heart and its effect on cardiac rhythm. Using a cardiac-specific inducible system, transgenic mice demonstrated both atrial and ventricular arrhythmias. We performed ventricular-programmed electrical stimulation and found that the αMHC-miR130a mice developed sustained ventricular tachycardia beginning 6weeks after overexpression. Western blot analysis demonstrated a steady decline in Cx43 after 2weeks of overexpression with over a 90% reduction in Cx43 levels by 10weeks. Immunofluorescent staining confirmed a near complete loss of Cx43 throughout the heart. To validate Cx43 as a direct target of miR-130a, we performed in vitro target assays in 3T3 fibroblasts and HL-1 cardiomyocytes, both known to endogenously express miR-130a. Using a luciferase reporter fused to the 3'UTR of Cx43, we found a 52.9% reduction in luciferase activity in 3T3 cells (parrhythmias.

  15. Sudden infant death syndrome caused by cardiac arrhythmias: only a matter of genes encoding ion channels? (United States)

    Sarquella-Brugada, Georgia; Campuzano, Oscar; Cesar, Sergi; Iglesias, Anna; Fernandez, Anna; Brugada, Josep; Brugada, Ramon


    Sudden infant death syndrome is the unexpected demise of a child younger than 1 year of age which remains unexplained after a complete autopsy investigation. Usually, it occurs during sleep, in males, and during the first 12 weeks of life. The pathophysiological mechanism underlying the death is unknown, and the lethal episode is considered multifactorial. However, in cases without a conclusive post-mortem diagnosis, suspicious of cardiac arrhythmias may also be considered as a cause of death, especially in families suffering from any cardiac disease associated with sudden cardiac death. Here, we review current understanding of sudden infant death, focusing on genetic causes leading to lethal cardiac arrhythmias, considering both genes encoding ion channels as well as structural proteins due to recent association of channelopathies and desmosomal genes. We support a comprehensive analysis of all genes associated with sudden cardiac death in families suffering of infant death. It allows the identification of the most plausible cause of death but also of family members at risk, providing cardiologists with essential data to adopt therapeutic preventive measures in families affected with this lethal entity.

  16. 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


    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...

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

    DEFF Research Database (Denmark)

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


    AIMS: Drug-induced QTc-prolongation, resulting from inhibition of HERG potassium channels may lead to serious ventricular arrhythmias and sudden death. We studied the quantitative anti-HERG activity of pro-arrhythmic drugs as a risk factor for this outcome in day-to-day practice. METHODS AND RESU......AIMS: Drug-induced QTc-prolongation, resulting from inhibition of HERG potassium channels may lead to serious ventricular arrhythmias and sudden death. We studied the quantitative anti-HERG activity of pro-arrhythmic drugs as a risk factor for this outcome in day-to-day practice. METHODS...... AND RESULTS: All 284,426 case reports of suspected adverse drug reactions of drugs with known anti-HERG activity received by the International Drug Monitoring Program of the World Health Organization (WHO-UMC) up to the first quarter of 2003, were used to calculate reporting odds ratios (RORs). Cases were...... defined as reports of cardiac arrest, sudden death, torsade de pointes, ventricular fibrillation, and ventricular tachycardia (n = 5591), and compared with non-cases regarding the anti-HERG activity, defined as the effective therapeutic plasma concentration (ETCPunbound) divided by the HERG IC50 value...

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

    Institute of Scientific and Technical Information of China (English)

    Yong-Fu Xiao


    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.

  19. Mechanisms and Clinical Management of Ventricular Arrhythmias following Blunt Chest Trauma

    Directory of Open Access Journals (Sweden)

    Daniel H. Wolbrom


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

  20. Repetitive nonreentrant ventriculoatrial synchrony: An underrecognized cause of pacemaker-related arrhythmia. (United States)

    Sharma, Parikshit S; Kaszala, Karoly; Tan, Alex Y; Koneru, Jayanthi N; Shepard, Richard; Ellenbogen, Kenneth A; Huizar, Jose F


    Similar to endless loop tachycardia (ELT), repetitive nonreentrant ventriculoatrial synchrony (RNRVAS) is a ventriculoatrial (VA) synchrony pacemaker-mediated arrhythmia. RNRVAS was first described in 1990 and can only occur in the presence of retrograde VA conduction and dual-chamber or cardiac resynchronization devices with tracking (P-synchronous ventricular pacing such as DDD, DDDR) or nontracking pacing modes that allow AV-sequential pacing (DDI, DDIR). RNRVAS is promoted by (1) high lower rate limit or any feature that allows rapid pacing, (2) long AV intervals, or (3) long postventricular atrial refractory period (PVARP). In contrast to ELT, RNRVAS is a less well-recognized form of pacemaker-mediated arrhythmia; thus, unlike ELT, there are no specific device algorithms to prevent, recognize, and terminate RNRVAS. However, RNRVAS has been recently shown to occur frequently. We present a series of cases, some of which were found fortuitously. Owing to its clinical implications, we propose that algorithms should be developed to prevent, identify, and terminate RNRVAS.

  1. FPGA-core defibrillator using wavelet-fuzzy ECG arrhythmia classification. (United States)

    Nambakhsh, Mohammad; Tavakoli, Vahid; Sahba, Nima


    An electrocardiogram (ECG) feature extraction and classification system has been developed and evaluated using Quartus II 7.1 belong to Altera Ltd. In wavelet domain QRS complexes were detected and each complex was used to locate the peaks of the individual waves. Then, fuzzy classifier block used these features to classify ECG beats. Three types of arrhythmias and abnormalities were detected using the procedure. The completed algorithm was embedded into Field Programmable Gate Array (FPGA). The completed prototype was tested through software-generated signals, in which test scenarios covering several kinds of ECG signals on MIT-BIH Database. For the purpose of feeding signals into the FPGA, a software was designed to read signal files and import them to the LPT port of computer that was connected to FPGA. From the results, it was achieved that the proposed prototype could do real time monitoring of ECG signal for arrhythmia detection. We also implemented algorithm in a sequential structure device like AVR microcontroller with 16 MHZ clock for the same purpose. External clock of FPGA is 50 MHZ and by utilizing of Phase Lock Loop (PLL) component inside device, it was possible to increase the clock up to 1.2 GHZ in internal blocks. Final results compare speed and cost of resource usage in both devices. It shows that in cost of more resource usage, FPGA provides higher speed of computation; because FPGA makes the algorithm able to compute most parts in parallel manner.

  2. Ivabradine protects against ventricular arrhythmias in acute myocardial infarction in the rat. (United States)

    Mackiewicz, Urszula; Gerges, Joseph Y; Chu, Sandy; Duda, Monika; Dobrzynski, Halina; Lewartowski, Bohdan; Mączewski, Michał


    Ventricular arrhythmias are an important cause of mortality in the acute myocardial infarction (MI). To elucidate effect of ivabradine, pure heart rate (HR) reducing drug, on ventricular arrhythmias within 24 h after non-reperfused MI in the rat. ECG was recorded for 24 h after MI in untreated and ivabradine treated rats and episodes of ventricular tachycardia/fibrillation (VT/VF) were identified. Forty-five minutes and twenty-four hours after MI epicardial monophasic action potentials (MAPs) were recorded, cardiomyocyte Ca(2+) handling was assessed and expression and function of ion channels were studied. Ivabradine reduced average HR by 17%. Combined VT/VF incidence and arrhythmic mortality were higher in MI versus MI + Ivabradine rats. MI resulted in (1) increase of Ca(2+) sensitivity of ryanodine receptors 24 h after MI; (2) increase of HCN4 expression in the left ventricle (LV) and funny current (IF) in LV cardiomyocytes 24 h after MI, and (3) dispersion of MAP duration both 45 min and 24 h after MI. Ivabradine partially prevented all these three potential proarrhythmic effects of MI. Ivabradine is antiarrhythmic in the acute MI in the rat. Potential mechanisms include prevention of: diastolic Ca(2+)-leak from sarcoplasmic reticulum, upregulation of IF current in LV and dispersion of cardiac repolarization. Ivabradine could be an attractive antiarrhythmic agent in the setting of acute MI.

  3. Prevalence of unknown and untreated arrhythmias in an older outpatient population screened by wireless long-term recording ECG

    Directory of Open Access Journals (Sweden)

    Lindberg T


    Full Text Available Terese Lindberg,1,2 Doris M Bohman,1 Sölve Elmståhl,2 Claes Jogréus,1 Johan Sanmartin Berglund1 1Department of Health, Blekinge Institute of Technology, Karlskrona, 2Department of Health Sciences, Lund University, Lund, Sweden Purpose: With longer life expectancies, the prevalence of arrhythmias is increasing; thus, there is a need for new methods to screen the older outpatient population. This population-based study describes the prevalence of arrhythmias in 200 outpatients aged ≥66 years. We also investigated the feasibility of wireless long-term recording (LTR using the ECG-BodyKom®.Methods: Two hundred elderly persons aged 66–93 years were recruited from the Swedish National Study on Aging and Care in 2010–2013, and data were collected via wireless LTR ECG-BodyKom.Results: Screening with the LTR ECG revealed that persistent atrial fibrillation (AF occurred in 10% of the outpatient population aged ≥66 years. Paroxysmal AF occurred in 5.5% of the population, with no difference between younger (60–80 years and older (>80 years elderly participants. Furthermore, all patients with paroxysmal AF had a CHA2DS2VASc score of ≥2 and were therefore potential candidates for follow-up and medical examination. LTR ECG-BodyKom can be considered a feasible method to screen for arrhythmias in older outpatient populations. This simple method requires little of the user, and there was high satisfaction with the equipment and a good overall experience wearing it.Conclusion: The increasing occurrence of arrhythmias in the older population, as well as the high number of untreated cases of arrhythmias such as persistent AF and paroxysmal AF, poses a challenge for health care. Therefore, it is essential to develop effective strategies for their prevention and treatment. Keywords: arrhythmia, older people, prevalence, wireless long-term ECG

  4. Cardiac arrhythmias as the initial manifestation of adult primary Sjögren's syndrome: a case report and literature review. (United States)

    Liang, Minrui; Bao, Liwen; Xiong, Nanqing; Jin, Bo; Ni, Huanchun; Zhang, Jinjin; Zou, Hejian; Luo, Xinping; Li, Jian


    Two middle-aged female patients presenting with heart palpitation and electrocardiogram revealed complex cardiac arrhythmias. A review of systems was positive for dry mouth and transient arthralgia, while laboratory and instrumental tests enabled us to make the diagnosis of primary Sjögren's syndrome (pSS). Cardiac electrophysiology revealed atrioventricular node dysfunction and impaired intraventricular conduction. Prednisone therapy induced a significant improvement in symptoms and electrocardiographic readings. The diagnosis of pSS should be considered in a patient presenting with complex cardiac arrhythmias.

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

    DEFF Research Database (Denmark)

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


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

  6. Manual treating of 2 cases with cervicogenous arrhythmia%手法治疗颈源性心律失常2例

    Institute of Scientific and Technical Information of China (English)

    林绵辉; 陈镇荣


    @@ MATERIALS AND METHODS Materials 2 cases were diagnosed as arrhythmia without clear reasons by ECG and were confirmed that they didn't suffered organic diseases.All the cases received anti- arrhythmia and heart muscle nutrition drugs and didn't gain good effects.

  7. 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.


    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.

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

    Directory of Open Access Journals (Sweden)

    Bockeria L. A.


    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

  9. Use of sympathomimetic drugs leads to increased risk of hospitalization for arrhythmias in patients with congestive heart failure

    DEFF Research Database (Denmark)

    Bouvy, M L; Heerdink, E R; De Bruin, M L;


    BACKGROUND: Sympathomimetic agents have a direct positive chronotropic effect on heart rate and may cause hypokalemia, even when administered by inhalation. In selected patients (e.g., patients with congestive heart failure [CHF]) this can lead to arrhythmias. Despite the potential adverse effects...

  10. Atrial-based pacing has no benefit over ventricular pacing in preventing atrial arrhythmias in adults with congenital heart disease

    NARCIS (Netherlands)

    Opic, P.; Yap, S.C.; Kranenburg, M. van; Dijk, A.P.J. van; Budts, W.; Vliegen, H.W.; Erven, L. van; Can, A.; Sahin, G.; Groot, N.M. de; Witsenburg, M.; Roos-Hesselink, J.W.


    AIMS: To determine whether atrial-based pacing prevents atrial arrhythmias in adults with congenital heart disease (CHD) compared with ventricular pacing. METHODS AND RESULTS: All adult CHD patients from four participating centres with a permanent pacemaker were identified. Patients with permanent a

  11. TRPA1 and Sympathetic Activation contribute to increased risk of triggered cardiac arrhythmias in hypertensive rats exposed to diesel exhaust (United States)

    Background -Diesel exhaust (DE), which is emitted from on-and off-road sources, is a complex mixture of toxic gaseous and particulate components that results in adverse cardiovascular effects. Arrhythmias, which are often triggered in the hours and days following exposure, are on...

  12. Development of the cardiac conduction system and cardiac anatomy in relation to genesis and treatment of arrhythmias

    NARCIS (Netherlands)

    Jongbloed, Monica Reina Maria


    Clinical mapping studies demonstrate that cardiac arrhythmias are often encountered at specific anatomical sites. The anatomical development of the heart and the cardiac conduction system are narrowly related. The thesis starts with a Chapter 1 that provides a general overview of the basics of cardi

  13. Treatment of cardiac arrhythmias in a mouse model of Rett syndrome with Na+-channel-blocking antiepileptic drugs. (United States)

    Herrera, José A; Ward, Christopher S; Pitcher, Meagan R; Percy, Alan K; Skinner, Steven; Kaufmann, Walter E; Glaze, Daniel G; Wehrens, Xander H T; Neul, Jeffrey L


    One quarter of deaths associated with Rett syndrome (RTT), an X-linked neurodevelopmental disorder, are sudden and unexpected. RTT is associated with prolonged QTc interval (LQT), and LQT-associated cardiac arrhythmias are a potential cause of unexpected death. The standard of care for LQT in RTT is treatment with β-adrenergic antagonists; however, recent work indicates that acute treatment of mice with RTT with a β-antagonist, propranolol, does not prevent lethal arrhythmias. In contrast, acute treatment with the Na(+) channel blocker phenytoin prevented arrhythmias. Chronic dosing of propranolol may be required for efficacy; therefore, we tested the efficacy of chronic treatment with either propranolol or phenytoin on RTT mice. Phenytoin completely abolished arrhythmias, whereas propranolol showed no benefit. Surprisingly, phenytoin also normalized weight and activity, but worsened breathing patterns. To explore the role of Na(+) channel blockers on QT in people with RTT, we performed a retrospective analysis of QT status before and after Na(+) channel blocker antiepileptic therapies. Individuals with RTT and LQT significantly improved their QT interval status after being started on Na(+) channel blocker antiepileptic therapies. Thus, Na(+) channel blockers should be considered for the clinical management of LQT in individuals with RTT.

  14. 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


    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)

  15. Beneficial effects of l-leucine and l-valine on arrhythmias, hemodynamics and myocardial morphology in rats. (United States)

    Mitręga, Katarzyna; Zorniak, Michał; Varghese, Benoy; Lange, Dariusz; Nożynski, Jerzy; Porc, Maurycy; Białka, Szymon; Krzemiński, Tadeusz F


    Branched chain amino acids (BCAA) have been shown to have a general protective effect on the heart in different animal models as well as in humans. However, so far no attempt has been made to specifically elucidate their influence on arrhythmias. Our study was performed to evaluate whether an infusion of either l-leucine or l-valine in a dose of 1mgkg(-1)h(-1) 10min before a 7-min period of left anterior descending artery occlusion followed by 15min of reperfusion, had an effect on arrhythmias measured during the reperfusion phase in the ischemia- and reperfusion-induced arrhythmias model in rats in vivo. The effect of the infusion of these substances on mean arterial blood pressure was monitored throughout the experiment. Both of the tested amino acids exhibited significant antiarrhythmic properties. l-Leucine reduced the duration of ventricular fibrillation (Pvaline decreased the duration of ventricular fibrillation (PValine lowered blood pressure in all phases of the experiment (Pvaline in the dose that was used attenuates arrhythmias and are hypotensive in their influence. Our findings lend support to the many ongoing investigations into the benefit of the application of l-leucine and l-valine in cardiology like their addition to cardioplegic solutions.

  16. The mechanism of KV4.3 voltage-gated potassium channel in arrhythmia induced by sleep deprivation in rat

    Directory of Open Access Journals (Sweden)

    Ya-jing ZHANG


    Full Text Available Objective To investigate the effect of sleep deprivation(SD on the changes in electrocardiogram and mRNA and protein expression of KV4.3 voltage-gated potassium channel in rats,and explore the related mechanisms of arrhythmia induced by SD.Methods A total of 48 adult male SD rats were randomly divided into 6 groups(8 each: normal control(CC group,tank control(TC group,1-,3-,5-and 7-day SD group.Animal model of SD was established by modified multiple platform method,and electrocardiogram was recorded on 1st,3rd,5th,and 7th of experiment.Protein and mRNA expressions of KV4.3 voltage-gated potassium channel were measured by real-time PCR and Western blotting analysis.Results The main changes on electrocardiogram following SD were arrhythmia.Compared with the CC group,rats in TC group showed sinus tachycardia in electrocardiogram: frequent atrial premature beats were observed one day after SD;ventricular arrhythmias,such as frequent polymorphic ventricular premature beats and paroxysmal ventricular tachycardia were observed three days after SD;incomplete right bundle branch block wave occurred five days after SD;the electrocardiogram showed third-degree atrioventricular(AV block wave seven days after SD,which indicated atrial arrhythmia and ventricular arrhythmia respectively.Ventricular escape beat,sinus arrest as well as the fusion of obviously elevated ST segment and T-wave were also observed.The expression levels of KV4.3 voltage-gated potassium channel decreased with prolongation of SD time.The expression of mRNA and protein of KV4.3 potassium channel in 7-day SD rats were only the one ninth and one fourth of levels in CC group.Conclusion Sleep deprivation can cause arrhythmia,and decreased expression of KV4.3 voltage-gated potassium channel may possibly be one of the reasons of arrhythmia induced by SD.

  17. Prognostic value of tissue Doppler imaging for predicting ventricular arrhythmias and cardiovascular mortality in ischaemic cardiomyopathy

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Olsen, Flemming Javier; Storm, Katrine;


    AIMS: Only 30% of patients receiving an implantable cardioverter defibrillator (ICD) for primary prevention receive appropriately therapy. We sought to investigate the value of tissue Doppler imaging (TDI) to predict ventricular tachycardia (VT), ventricular fibrillation (VF), and cardiovascular...... mortality (CVD) in patients with primary prevention ICD. METHODS AND RESULTS: In total, 151 ICD patients meeting primary prevention criteria and with no history of ventricular arrhythmias were included. All participants were examined by conventional 2D echocardiography and TDI echocardiography. Longitudinal...... systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured using TDI at six mitral annular sites and averaged to provide global estimates. Forty patients experienced the combined endpoint of VT, VF, or CVD during a median follow-up of 2.3 years. Left ventricular...

  18. Acute toxic herbal intake in a suicide attempt and fatal refractory ventricular arrhythmia. (United States)

    Strzelecki, Antoine; Pichon, Nicolas; Gaulier, Jean M; Amiel, Jean B; Champy, Pauline; Clavel, Marc


    This report involves a 54-year-old man who died following refractory ventricular fibrillation after ingestion of a plant in a suicide attempt. Repeated direct-current cardioversions were unsuccessful and no single anti-arrhythmic agent was effective for arrhythmia control. The routine blood toxicological screening was negative. Aconitine, the main toxin of Aconitum napellus was identified using a specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The whole blood concentration (24 microg/l) was higher than those reported in other aconitine-related deaths. The patient had found information about the life-threatening nature of such a toxic herb intake on a free medical encyclopedia online.

  19. Cardiovascular exercise and burden of arrhythmia in patients with atrial fibrillation - A randomized controlled trial

    DEFF Research Database (Denmark)

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


    BACKGROUND: Physical activity at moderate-high intensity is recommended to prevent lifestyle diseases. Patients with atrial fibrillation are at risk of a sedentary lifestyle due to fear of exercise-induced episodes of atrial fibrillation. The burden of arrhythmia can be reduced by physical exercise....... The effect of exercise intensity on burden of atrial fibrillation needs to be studied further. METHODS AND RESULTS: In a 12-week randomized controlled trial, 76 patients with paroxysmal/persistent atrial fibrillation were allocated to perform exercise at either low intensity or high intensity (50% and 80......% of maximal perceived exertion, respectively). Primary outcome was burden of AF measured by daily electrocardiography-reporting during 12 weeks. Secondarily, change in maximal oxygen uptake (peak VO2) and 1-year hospitalization was compared between low and high intensity exercise. Sixty-three patients...

  20. Interactive effects of social adversity and respiratory sinus arrhythmia activity on reactive and proactive aggression. (United States)

    Zhang, Wei; Gao, Yu


    Abnormal parasympathetic nervous system (PNS)-related cardiac activity has been linked to aggression. However, little is known about how it interacts with psychosocial adversity in predisposing to reactive-proactive aggression. In the current study, 84 male and female college students self-reported reactive and proactive aggression, and were assessed for respiratory sinus arrhythmia (RSA), a measure of PNS-related cardiac activity, during rest and when they contemplated an emotion-evoking decision-making task. Regression analyses showed that (a) resting RSA was positively linked to reactive aggression in conditions of high social adversity, and (b) RSA reactivity was positively associated with reactive but negatively associated with proactive aggression, in conditions of low social adversity. Main effects were not found for psychophysiological functioning or psychosocial adversity, suggesting the importance of their interaction. Findings support a biosocial basis for aggression and add additional support for the distinctions between reactive and proactive aggression.

  1. 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: [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)


    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.

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

    CERN Document Server

    Fallavollita, Pascal


    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. Buffering blood pressure fluctuations by respiratory sinus arrhythmia may in fact enhance them: a theoretical analysis

    CERN Document Server

    Buchner, Teodor; Gielerak, Grzegorz


    Using a three-compartment model of blood pressure dynamics, we analyze theoretically the short term cardiovascular variability: how the respiratory-related blood pressure fluctuations are buffered by appropriate heart rate changes: i.e. the respiratory sinus arrhythmia. The buffering is shown to be crucially dependent on the time delay between the stimulus (such as e.g. the inspiration onset) and the application of the control (the moment in time when the efferent response is delivered to the heart). This theoretical analysis shows that the buffering mechanism is effective only in the upright position of the body. It explains a paradoxical effect of enhancement of the blood pressure fluctuations by an ineffective control. Such a phenomenon was observed experimentally. Using the basis of the model, we discuss the blood pressure variability and heart rate variability under such clinical conditions as the states of expressed adrenergic drive and the tilt-test during the parasympathetic blockade or fixed rate atr...

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

    Directory of Open Access Journals (Sweden)



    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.

  5. 3D/2D Registration of Mapping Catheter Images for Arrhythmia Interventional Assistance

    Directory of Open Access Journals (Sweden)

    Pascal Fallavollita


    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.

  6. POPDC1S201F causes muscular dystrophy and arrhythmia by affecting protein trafficking (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


    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

  7. POPDC1(S201F) causes muscular dystrophy and arrhythmia by affecting protein trafficking. (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


    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, POPDC1(S201F) displayed a 50% reduction in cAMP affinity, and in skeletal muscle from patients, both POPDC1(S201F) and WT POPDC2 displayed impaired membrane trafficking. Forced expression of POPDC1(S201F) 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 (popdc1(S191F)) 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.

  8. Tedisamil and lidocaine enhance each other's antiarrhythmic activity against ischaemia-induced arrhythmias in rats. (United States)

    Sarraf, Guilda; Barrett, Terrance D; Walker, Michael J A


    1. Combinations of the action potential-widening drug tedisamil (Class III antiarrhythmic activity), and the inactivated state sodium channel blocker lidocaine (Class Ib antiarrhythmic activity) were assessed for antiarrhythmic actions in a rat model of ischaemia-induced arrhythmias and for electrophysiological actions in normal rat myocardial tissue. 2. Both tedisamil and lidocaine dose-dependently suppressed ischaemia-induced arrhythmias. The ED(50) values were 3.0+/-1.3 and 4.9+/-0.6 micro mol kg(-1) min(-1), respectively. 3. Combinations of the two drugs acted synergistically such that the ED(50) for tedisamil was reduced to 0.8+/-0.2 micro mol kg(-1) min(-1) in the presence of 2 micro mol kg(-1) min(-1) lidocaine. Similarly, the ED(50) for lidocaine was reduced to 0.7+/-0.2 micro mol kg(-1) min(-1) in the presence of 2 micro mol kg(-1) min(-1) tedisamil (both Plidocaine produced a leftward shift in the dose-response curve for tedisamil's effect on effective refractory period (Plidocaine had no effect on its own. These data indicate that the synergistic actions of combinations of tedisamil and lidocaine were mediated, at least in part, by extension of effective refractory period in normal myocardial tissue. 5. In contrast to the strategy of developing drugs that are selective for a single electrophysiological mechanism, the results of the present study suggest that effective antiarrhythmic drugs might be developed by optimising the combination of two complimentary electrophysiological mechanisms (i.e., action potential-prolonging activity and inactivated state sodium channel blockade).

  9. c-Src Kinase Inhibition Reduces Arrhythmia Inducibility and Connexin43 Dysregulation after Myocardial Infarction (United States)

    Rutledge, Cody A.; Ng, Fu Siong; Sulkin, Matthew S.; Greener, Ian D.; Sergeyenko, Artem M.; Liu, Hong; Gemel, Joanna; Beyer, Eric C.; Sovari, Ali A.; Efimov, Igor R.; Dudley, Samuel C.


    Objectives The aim of this study was to evaluate the role of c-Src inhibition on connexin43 (Cx43) regulation in a mouse model of myocardial infarction (MI). Background MI is associated with decreased expression of Cx43, the principal gap junction protein responsible for propagating current in ventricles. Activated c-Src has been linked to Cx43 dysregulation. Methods MI was induced in 12-week-old mice by coronary artery occlusion. MI mice were treated with c-Src inhibitors (PP1 or AZD0530), PP3 (an inactive analogue of PP1), or saline. Treated hearts were compared to sham mice by echocardiography, optical mapping, telemetry ECG monitoring, and inducibility studies. Tissues were collected for immunoblotting, quantitative PCR, and immunohistochemistry. Results Active c-Src was elevated in PP3-treated MI mice compared to sham at the scar border (280%, p=0.003) and distal ventricle (346%, p=0.013). PP1 treatment restored active c-Src to sham levels at the scar border (86%, p=0.95) and distal ventricle (94%, p=1.0). PP1 raised Cx43 expression by 69% in the scar border (p=0.048) and by 73% in distal ventricle (p=0.043) compared to PP3 mice. PP1-treated mice had restored conduction velocity at the scar border (PP3: 32 cm/s, PP1: 41 cm/s, p < 0.05) and lower arrhythmic inducibility (PP3: 71%, PP1: 35%, p < 0.05) than PP3 mice. PP1 did not change infarct size, ECG pattern, or cardiac function. AZD0530 treatment demonstrated restoration of Cx43 comparable to PP1. Conclusions c-Src inhibition improved Cx43 levels and conduction velocity and lowered arrhythmia inducibility after MI, suggesting a new approach for arrhythmia reduction following MI. PMID:24361364

  10. Reduction of false arrhythmia alarms using signal selection and machine learning. (United States)

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


    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.

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

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    A Garjani


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

  12. When the clock strikes: Modeling the relation between circadian rhythms and cardiac arrhythmias (United States)

    Seenivasan, Pavithraa; Menon, Shakti N.; Sridhar, S.; Sinha, Sitabhra


    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 12am-6am, with 6pm-12am 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 rhythm 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 susceptibility to cardiac arrhythmias by using a mathematical model that describes the electrical activity in ventricular tissue. We show that changes in the channel conductance that lead to extreme values for the duration of action potentials in cardiac cells can result either in abnormally high-frequency reentrant activity or spontaneous conduction block of excitation waves. Both phenomena increase the likelihood of wavebreaks that are known to initiate potentially life- threatening arrhythmias. Thus, disruptive cardiac excitation dynamics are most likely to occur in time-intervals of the day-night cycle during which the channel properties are closest to these extreme values, providing an intriguing relation between circadian rhythms and cardiac pathologies.

  13. Epileptic Patients are at Risk of Cardiac Arrhythmias: A Novel Approach using QT-nomogram, Tachogram, and Cardiac Restitution Plots (United States)

    Al-Nimer, Marwan S.; Al-Mahdawi, Sura A.; Abdullah, Namir M.; Al-Mahdawi, Akram


    Background: Sudden death is reported in patients who had a history of epilepsy and some authors believed that is due to cardiac arrhythmias. Objectives: This study aimed to predict that the epileptic patients are at risk of serious cardiac arrhythmias by QT-nomogram, tachogram (Lorenz), and cardiac restitution plots. Methods: A total number of 71 healthy subjects (Group I) and 64 newly diagnosed epileptic patients (Group II) were recruited from Al-Yarmouk and Baghdad Teaching hospitals in Baghdad from March 2015 to July 2015 and included in this study. The diagnosis of epilepsy achieved clinically, electroencephalograph record and radio-images including computerized tomography and magnetic image resonance. At the time of entry into the study, an electrocardiography (ECG) was done, and the determinants of each ECG record were calculated. The QT-nomogram, tachogram, and cardiac restitution plots were used to identify the patients at risk of cardiac arrhythmias. Results: Significant prolonged corrected QT corrected (QTc) and JT corrected intervals were observed in female compared with male at age ≥50 years while the TQ interval was significantly prolonged in males of Group II. Eight patients of Group II had a significant pathological prolonged QTc interval compared with undetectable finding in Group I. QT nomogram did not disclose significant findings while the plots of Lorenz and restitution steepness disclose that the patients of Group II were vulnerable to cardiac arrhythmias. Abnormal ECG findings were observed in the age extremities (≤18 years and ≥50 years) in Group II compared with Group I. Conclusion: Utilization of QT-nomogram, restitution steepness, and tachogram plots is useful tools for detection subclinical vulnerable epileptic patient with cardiac arrhythmias. PMID:28149075

  14. Epileptic patients are at risk of cardiac arrhythmias: A novel approach using QT-nomogram, tachogram, and cardiac restitution plots

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    Marwan S Al-Nimer


    Full Text Available Background: Sudden death is reported in patients who had a history of epilepsy and some authors believed that is due to cardiac arrhythmias. Objectives: This study aimed to predict that the epileptic patients are at risk of serious cardiac arrhythmias by QT-nomogram, tachogram (Lorenz, and cardiac restitution plots. Methods: A total number of 71 healthy subjects (Group I and 64 newly diagnosed epileptic patients (Group II were recruited from Al-Yarmouk and Baghdad Teaching hospitals in Baghdad from March 2015 to July 2015 and included in this study. The diagnosis of epilepsy achieved clinically, electroencephalograph record and radio-images including computerized tomography and magnetic image resonance. At the time of entry into the study, an electrocardiography (ECG was done, and the determinants of each ECG record were calculated. The QT-nomogram, tachogram, and cardiac restitution plots were used to identify the patients at risk of cardiac arrhythmias. Results: Significant prolonged corrected QT corrected (QTc and JT corrected intervals were observed in female compared with male at age ≥50 years while the TQ interval was significantly prolonged in males of Group II. Eight patients of Group II had a significant pathological prolonged QTc interval compared with undetectable finding in Group I. QT nomogram did not disclose significant findings while the plots of Lorenz and restitution steepness disclose that the patients of Group II were vulnerable to cardiac arrhythmias. Abnormal ECG findings were observed in the age extremities (≤18 years and ≥50 years in Group II compared with Group I. Conclusion: Utilization of QT-nomogram, restitution steepness, and tachogram plots is useful tools for detection subclinical vulnerable epileptic patient with cardiac arrhythmias.

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

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    Ayman Abunimer


    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.

  16. Usefulness of an Implantable Loop Recorder to Detect Clinically Relevant Arrhythmias in Patients With Advanced Fabry Cardiomyopathy. (United States)

    Weidemann, Frank; Maier, Sebastian K G; Störk, Stefan; Brunner, Thomas; Liu, Dan; Hu, Kai; Seydelmann, Nora; Schneider, Andreas; Becher, Jan; Canan-Kühl, Sima; Blaschke, Daniela; Bijnens, Bart; Ertl, Georg; Wanner, Christoph; Nordbeck, Peter


    Patients with genetic cardiomyopathy that involves myocardial hypertrophy often develop clinically relevant arrhythmias that increase the risk of sudden death. Consequently, guidelines for medical device therapy were established for hypertrophic cardiomyopathy, but not for conditions with only anecdotal evidence of arrhythmias, like Fabry cardiomyopathy. Patients with Fabry cardiomyopathy progressively develop myocardial fibrosis, and sudden cardiac death occurs regularly. Because 24-hour Holter electrocardiograms (ECGs) might not detect clinically important arrhythmias, we tested an implanted loop recorder for continuous heart rhythm surveillance and determined its impact on therapy. This prospective study included 16 patients (12 men) with advanced Fabry cardiomyopathy, relevant hypertrophy, and replacement fibrosis in "loco typico." No patients previously exhibited clinically relevant arrhythmias on Holter ECGs. Patients received an implantable loop recorder and were prospectively followed with telemedicine for a median of 1.2 years (range 0.3 to 2.0 years). The primary end point was a clinically meaningful event, which required a therapy change, captured with the loop recorder. Patients submitted data regularly (14 ± 11 times per month). During follow-up, 21 events were detected (including 4 asystole, i.e., ECG pauses ≥3 seconds) and 7 bradycardia events; 5 episodes of intermittent atrial fibrillation (>3 minutes) and 5 episodes of ventricular tachycardia (3 sustained and 2 nonsustained). Subsequently, as defined in the primary end point, 15 events leaded to a change of therapy. These patients required therapy with a pacemaker or cardioverter-defibrillator implantation and/or anticoagulation therapy for atrial fibrillation. In conclusion, clinically relevant arrhythmias that require further device and/or medical therapy are often missed with Holter ECGs in patients with advanced stage Fabry cardiomyopathy, but they can be detected by telemonitoring with

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

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    Xuping Song


    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.

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

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    Kuzevska-Maneva Konstandina


    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

  19. 抗心律失常药物对蟾酥致小鼠心律失常的影响%Effect of anti-arrhythmia drugs on mouse arrhythmia induced by Bufonis Venenum

    Institute of Scientific and Technical Information of China (English)

    陆文娟; 周婧; 马宏跃; 吕高红; 尤奋强; 丁安伟; 段金廒


    -adrenergic receptor antagonist), amiodarone (drugs prolonging the action potential duration) and verapamil (calcium channel blockers) on arrhythmia of mice induced by Bufonis Venenum (Chansu) and isolated mouse hearts lethal dose of Chansu. Arrhythmia of mice were induced by Chansu and then electrocardiograms (ECGs) were recorded. The changes of P-R interval, QRS complex, Q-T interval, T wave amplitude, heart rate (HR) were observed. Moreover, arrhythmia rate, survival rate and arrhythmia score were counted. Isolated mouse hearts were prefused, and the lethal dose of Chansu was recorded. Compared with control group, after pretreatment with phenytoin sodium, broadening of QRS complex and HR were inhibited, and the incidence ofventricular arrhythmia was reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with lidocaine, the prolongation of P-R interval and broadening of QRS complex were inhibited, and the incidences of ventricular arrhythmia were reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with propranolol, prolongation of P-R interval, broadening of QRS complex, prolongation of Q-T interval and HR were inhibited, and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically, while survival rate was improved. After pretreatment with amiodarone, HR was inhibited, the incidences of ventricular tachycardia were reduced dramatically. Lastly, after pretreatment with verapamil, the prolongation of P-R interval and Q-T interval were inhibited and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically; the isolated mouse hearts lethal dose of Chansu was reduced significantly. In in vivo experiments, phenytoin sodium was most effective against the mice arrhythmias induced by Chansu while cautious use of verapamil for

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

  1. Idiopathic ventricular arrhythmias detected by an implantable loop recorder in a child with exercise-induced syncope. (United States)

    Akdeniz, Celal; Ozyilmaz, Isa; Saygi, Murat; Ergul, Yakup; Tuzcu, Volkan


    Syncope is common in the general population. Despite extensive evaluation, including tilt-table testing and electrophysiologic studies, approximately 30% of cases of recurrent syncope remain unexplained. An implantable loop recorder can be used for diagnosis when recurrent syncope has an idiopathic cause. We present the case of a 9-year-old boy who had a history of recurrent, exercise-induced syncope. Results of physical examination and noninvasive diagnostic testing were inconclusive, and an electrophysiologic study revealed no inducible supraventricular or ventricular arrhythmias. Sixteen months after an implantable loop recorder was placed, the patient had a syncopal episode while swimming in a pool. Cardiopulmonary resuscitation was performed, and data from the loop recorder revealed polymorphic ventricular tachycardia and ventricular fibrillation. A cardioverter-defibrillator was subsequently implanted. Implantable loop recorders can play an important role in the diagnosis of life-threatening arrhythmias in children whose syncope is otherwise unexplained.

  2. A Statistical Index for Early Diagnosis of Ventricular Arrhythmia from the Trend Analysis of ECG Phase-portraits

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    Cappiello, Grazia; Mazomenos, Evangelos B; Maharatna, Koushik; Koulaouzidis, George; Morgan, John; Puddu, Paolo Emilio


    In this paper, we propose a novel statistical index for the early diagnosis of ventricular arrhythmia (VA) using the time delay phase-space reconstruction (PSR) technique, from the electrocardiogram (ECG) signal. Patients with two classes of fatal VA - with preceding ventricular premature beats (VPBs) and with no VPBs have been analysed using extensive simulations. Three subclasses of VA with VPBs viz. ventricular tachycardia (VT), ventricular fibrillation (VF) and VT followed by VF are analyzed using the proposed technique. Measures of descriptive statistics like mean ({\\mu}), standard deviation ({\\sigma}), coefficient of variation (CV = {\\sigma}/{\\mu}), skewness ({\\gamma}) and kurtosis (\\{beta}) in phase-space diagrams are studied for a sliding window of 10 beats of ECG signal using the box-counting technique. Subsequently, a hybrid prediction index which is composed of a weighted sum of CV and kurtosis has been proposed for predicting the impending arrhythmia before its actual occurrence. The early diagnos...


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    I. A. Kovalyov


    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

  4. Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient. (United States)

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


    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.

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

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    Mária Kovács

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

  6. 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;


    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....

  7. Pharmacological modulation of gap junction function with the novel compound rotigaptide: a promising new principle for prevention of arrhythmias. (United States)

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


    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.

  8. Effects of KR-32570, a new sodium hydrogen exchanger inhibitor, on myocardial infarction and arrhythmias induced by ischemia and reperfusion. (United States)

    Lee, Byung Ho; Yi, Kyu Yang; Lee, Sunkyung; Lee, Sunghou; Yoo, Sung-eun


    The present study was performed to evaluate the cardioprotective effects of [5-(2-methoxy-5-chloro-5-phenyl)furan-2-ylcarbonyl]guanidine (KR-32570) in rat and dog models of coronary artery occlusion and reperfusion. In addition, we sought to clarify the efficacy of KR-32570 on reperfusion-induced fatal ventricular arrhythmia. In anesthetized rats subjected to 45-min coronary occlusion and 90-min reperfusion, KR-32570 (i.v. bolus) dose-dependently reduced myocardial infarct size from 58.0% to 50.7%, 35.3%, 33.5% and 27.0% for 0.03, 0.1, 0.3 and 1.0 mg/kg, respectively (PKR-32570 (3 mg/kg, i.v. bolus) markedly decreased infarct size from 28.9% in vehicle-treated group to 8.0% (PKR-32570 dose-dependently decreased the incidence of premature ventricular contraction, ventricular tachycardia or ventricular fibrillation induced by ischemia and reperfusion in rats. Similar results were obtained in dogs with reperfusion-induced arrhythmia. In separate experiments to assess the effects of timing of treatment, KR-32570 given 10 min before or at reperfusion in rat models also significantly reduced the myocardial infarct size (40.9% and 46.1%, respectively) compared with vehicle-treated group. In all studies, KR-32570 caused no significant changes in any hemodynamic profiles. Taken together, these results indicate that KR-32570 significantly reduced the myocardial infarction and incidence of arrhythmias induced by ischemia and reperfusion in rats and dogs, without affecting hemodynamic profiles. Thus, it could be potentially useful in the prevention and treatment of myocardial injuries and lethal ventricular arrhythmias.

  9. Novel ECG-Synchronized Pulsatile ECLS System With Various Heart Rates and Cardiac Arrhythmias: An In Vitro Study. (United States)

    Wang, Shigang; Spencer, Shannon B; Kunselman, Allen R; Ündar, Akif


    The objective of this study is to evaluate electrocardiography (ECG)-synchronized pulsatile flow under varying heart rates and different atrial and ventricular arrhythmias in a simulated extracorporeal life support (ECLS) system. The ECLS circuit consisted of an i-cor diagonal pump and console, an iLA membrane ventilator, and an 18 Fr arterial cannula. The circuit was primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). An ECG simulator was used to trigger pulsatile flow and to generate selected cardiac rhythms. All trials were conducted at a flow rate of 2.5 L/min at room temperature for normal sinus rhythm at 45-180 bpm under non-pulsatile and pulsatile modes. Various atrial and ventricular arrhythmias were also tested. Real-time pressure and flow data were recorded using a custom-based data acquisition system. The energy equivalent pressure (EEP) generated by pulsatile flow was always higher than the mean pressure. No surplus hemodynamic energy (SHE) was recorded under non-pulsatile mode. Under pulsatile mode, SHE levels increased with increasing heart rates (45-120 bpm). SHE levels under a 1:2 assist ratio were higher than the 1:1 and 1:3 assist ratios with a heart rate of 180 bpm. A similar trend was recorded for total hemodynamic energy levels. There was no statistical difference between the two perfusion modes with regards to pressure drops across the ECLS circuit. The main resistance and energy loss came from the arterial cannula. The i-cor console successfully tracked electrocardiographic signals of 12 atrial and ventricular arrhythmias. Our results demonstrated that the i-cor pulsatile ECLS system can be synchronized with a normal heart rate or with various atrial/ventricular arrhythmias. Further in vivo studies are warranted to confirm our findings.

  10. Use of Intravenous Amiodarone in the Treatment of Nifekalant-Resistant Arrhythmia: A Review of 11 Consecutive Cases with Severe Heart Failure (United States)

    Nakagawa, Koji; Nakamura, Kazufumi; Kusano, Kengo Fukushima; Nagase, Satoshi; Tada, Takeshi; Murakami, Masato; Hata, Yoshiki; Morita, Hiroshi; Kohno, Kunihisa; Hina, Kazumasa; Ujihira, Tohru; Ohe, Tohru; Ito, Hiroshi


    Background: Both nifekalant hydrochloride (NIF), a selective IKr blocker, and intravenous amiodarone (AMD), a multi-channel (including IKr blocking) blocker, have been reported to be efficacious for refractory arrhythmias. However, the optimal use of those antiarrhythmic drugs for refractory arrhythmia with severe heart failure has not been established. Intravenous AMD might be effective for arrhythmias refractory to NIF in patients with severe heart failure. Here, we report that intravenous amiodarone was effective in the treatment of nifekalant-resistant in a group of arrhythmia patients with severe heart failure. Methods: Eleven severe heart failure patients who had received intravenous AMD for treatment of NIF-resistant arrhythmias were included in this study, and retrospective analysis was performed. Clinical efficacy (terminative and preventive effects on arrhythmia) of intravenous AMD was evaluated. Results: All cases were emergent cases and had depressed left ventricular ejection fraction (30 ± 13%). Clinical arrhythmias were ventricular fibrillation (VF) in four patients, ventricular tachycardia (VT) in six patients, and atrial fibrillation (AF) in one patient. NIF was administered to all patients by intravenous injection. After administration of NIF, VT/VF/AF was terminated in seven of the 10 patients, but a preventive effect was not obtained in any of the patients (NIF-resistance). Intravenous AMD (maintenance dose: 484 ± 166 mg/day) was effective both in termination (80%) and in prevention (80%) of VT/VF events in those patients. It was also effective in termination (80%) and prevention (60%) of AF events refractory to NIF. During continuous AMD administration, no significant adverse effects or proarrhythmic effects were observed in any of the patients. Five patients died within one month, but there was no arrhythmic deaths. Conclusions: Intravenous AMD was effective in NIF-resistant lethal arrhythmias and was relatively safe in emergent cases with

  11. Prevalence of and risk factors for perioperative arrhythmias in neonates and children after cardiopulmonary bypass: continuous holter monitoring before and for three days after surgery

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    Vazquez-Jimenez Jaime F


    Full Text Available Abstract Background A comprehensive evaluation of postoperative arrhythmias following surgery for congenital heart disease by continuous Holter monitoring has not been carried out. We aimed, firstly, to establish the time course of pre- and early postoperative arrhythmias by beat-to-beat analysis following cardiopulmonary bypass and, secondly, to examine which surgical procedures present risk factors for specific arrhythmias. Methods 494 consecutive patients, including 96 neonates, were studied with serial 24-hour Holter electrocardiograms before as well as uninterruptedly during the first 72 hours after surgery and prior to discharge. Results Within 24 hours of surgery 59% of the neonates and 79% of the older children developed arrhythmias. Junctional ectopic tachycardia occurred in 9% of neonates and 5% of non-neonates and ventricular tachycardia in 3% and 15%, respectively. For neonates, male sex and longer cross-clamping time independently increased the risk for arrhythmias (odds ratios 2.83 and 1.96/minute, respectively. Ventricular septal defect repair was a strong risk factor for junctional ectopic tachycardia in neonates and in older children (odds ratios 18.8 and 3.69, respectively. For infants and children, older age (odds ratio 1.01/month and closure of atrial septal defects (odds ratio 2.68 predisposed to arrhythmias of any type. Conclusions We present the largest cohort of neonates, infants and children that has been prospectively studied for the occurrence of arrhythmias after cardiac surgery. Postoperative arrhythmias are a frequent and transient phenomenon after cardiopulmonary bypass, provoked both by mechanical irritation of the conduction system and by humoral factors.

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

    DEFF Research Database (Denmark)

    Svendsen, Jesper Hastrup; Bjerrum, P J


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

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

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    Henrique Silveira Costa


    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.

  14. 胎儿心律失常的诊断和治疗%The detection and treatment of fetal arrhythmias

    Institute of Scientific and Technical Information of China (English)

    邱添; 滕银成


    胎儿心电监护及胎儿超声心动图是发现胎心律异常的主要检查手段.频发严重的胎心律异常,尤其伴心脏畸形或心脏器质性病变的胎心律异常可导致不良围产儿结局.早期诊断、及时治疗严重的胎心律异常可明显改善围产儿预后,减少围产儿不良结局的发生.%The electronic fetal monitoring and fetal echocardiogram are main methods for the detection of fetal arrhythmias. The frequency and severe fetal arrhythmias, especial associated with cardiac anomalies and structural disease could cause a bad effect on the fetus and newborn. Early diagnosis and timely treatment of fetal arrhythmias could improve the outcome of the fetus and newborn.

  15. Role of gap junction channel in the development of beat-to-beat action potential repolarization variability and arrhythmias. (United States)

    Magyar, Janos; Banyasz, Tamas; Szentandrassy, Norbert; Kistamas, Kornel; Nanasi, Peter P; Satin, Jonathan


    The short-term beat-to-beat variability of cardiac action potential duration (SBVR) occurs as a random alteration of the ventricular repolarization duration. SBVR has been suggested to be more predictive of the development of lethal arrhythmias than the action potential prolongation or QT prolongation of ECG alone. The mechanism underlying SBVR is not completely understood but it is known that SBVR depends on stochastic ion channel gating, intracellular calcium handling and intercellular coupling. Coupling of single cardiomyocytes significantly decreases the beat-to-beat changes in action potential duration (APD) due to the electrotonic current flow between neighboring cells. The magnitude of this electrotonic current depends on the intercellular gap junction resistance. Reduced gap junction resistance causes greater electrotonic current flow between cells, and reduces SBVR. Myocardial ischaemia (MI) is known to affect gap junction channel protein expression and function. MI increases gap junction resistance that leads to slow conduction, APD and refractory period dispersion, and an increase in SBVR. Ultimately, development of reentry arrhythmias and fibrillation are associated post-MI. Antiarrhythmic drugs have proarrhythmic side effects requiring alternative approaches. A novel idea is to target gap junction channels. Specifically, the use of gap junction channel enhancers and inhibitors may help to reveal the precise role of gap junctions in the development of arrhythmias. Since cell-to-cell coupling is represented in SBVR, this parameter can be used to monitor the degree of coupling of myocardium.

  16. Pet ownership, social support, and one-year survival after acute myocardial infarction in the Cardiac Arrhythmia Suppression Trial (CAST). (United States)

    Friedmann, E; Thomas, S A


    Social support and pet ownership, a nonhuman form of social support, have both been associated with increased coronary artery disease survival. The independent effects of pet ownership, social support, disease severity, and other psychosocial factors on 1-year survival after acute myocardial infarction are examined prospectively. The Cardiac Arrhythmia Suppression Trial provided physiologic data on a group of post-myocardial infarction patients with asymptomatic ventricular arrhythmias. An ancillary study provided psychosocial data, including pet ownership, social support, recent life events, future life events, anxiety, depression, coronary prone behavior, and expression of anger. Subjects (n = 424) were randomly selected from patients attending participating Cardiac Arrhythmia Suppression Trial sites and completed baseline psychosocial questionnaires. One year survival data were obtained from 369 patients (87%), of whom 112 (30.4%) owned pets and 20 (5.4%) died. Logistic regression indicates that high social support (p owning a pet (p = 0.085) tend to predict survival independent of physiologic severity and demographic and other psychosocial factors. Dog owners (n = 87, 1 died) are significantly less likely to die within 1 year than those who did not own dogs (n = 282, 19 died; p pet ownership and social support are significant predictors of survival, independent of the effects of the other psychosocial factors and physiologic status. These data confirm and extend previous findings relating pet ownership and social support to survival among patients with coronary artery disease.

  17. 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)



    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.

  18. Protective effects of Ping-Lv-Mixture (PLM), a medicinal formula on arrhythmias induced by myocardial ischemia-reperfusion. (United States)

    An, Wei; Yang, Jing


    Ping-Lv-Mixture (PLM) is a Chinese medicinal formula. The present study aimed to determine the effects of PLM on myocardial ischemia-reperfusion (MI/R) induced arrhythmias in rats. Arrhythmia model was established by occlusion of the left arterial descending coronary artery and thereafter reperfusion. A lead II electrocardiogram was monitored throughout the experiment. The results showed that pretreatment of PLM to MI/R rats significantly reduced the incidence and duration of ventricular tachycardia and ventricular fibrillation. On induction of MI/R, the activities of creatine kinase and lactate dehydrogenase were increased in vehicle group. PLM (0.04-1.00 g/kg) administration prevented the increase of these enzymes. Moreover, a significant increase of myocardium superoxide dismutase and decrease of malondialdehyde contents were observed in rats of PLM groups. On the other hand, the expressions of platelet activating factor (PAF) receptor mRNA was down-regulated in a dose-dependent manner in the PLM-treated groups by RT-PCR. Thus, it can be concluded that pretreatment with PLM inhibited lipid peroxidation in rats through suppressing the expression of PAF receptor, which may contribute to its preventive effect on myocardial ischemia-reperfusion induced arrhythmias.

  19. Respiratory sinus arrhythmia during worry forecasts stress-related increases in psychological distress. (United States)

    Gouin, Jean-Philippe; Deschênes, Sonya S; Dugas, Michel J


    Respiratory sinus arrhythmia (RSA) has been conceptualized as an index of emotion regulation abilities. Although resting RSA has been associated with both concurrent and prospective affective responses to stress, the impact of RSA reactivity on emotional responses to stress is inconsistent across studies. The type of emotional stimuli used to elicit these phasic RSA responses may influence the adaptive value of RSA reactivity. We propose that RSA reactivity to a personally relevant worry-based stressor might forecast future affective responses to stress. To evaluate whether resting RSA and RSA reactivity to worry inductions predict stress-related increases in psychological distress, an academic stress model was used to prospectively examine changes in psychological distress from the well-defined low- and high-stress periods. During the low-stress period, 76 participants completed self-report mood measures and had their RSA assessed during a resting baseline, free worry period and worry catastrophizing interview. Participants completed another mood assessment during the high-stress period. Results indicated that baseline psychological distress predicted larger decreases in RSA during the worry inductions. Lower resting RSA and greater RSA suppression to the worry inductions at baseline prospectively predicted larger increases in psychological distress from the low- to high-stress period, even after accounting for the impact of baseline distress on RSA. These results provide further evidence that RSA may represent a unique index of emotion regulation abilities in times of stress.

  20. High Accuracy Extraction of Respiratory Sinus Arrhythmia with Statistical Processing using Normal Distribution (United States)

    Numata, Takashi; Ogawa, Yutaro; Yoshida, Lui; Kotani, Kiyoshi; Jimbo, Yasuhiko

    The autonomic nervous system is important in maintaining homeostasis by mediating the opposing effects of the sympathetic and parasympathetic nervous activity on organs. Although it is known that the amplitude of RSA (Respiratory Sinus Arrhythmia) is an index of parasympathetic nervous activity, it is difficult to estimate that activity in real-time in everyday situations. It is partly caused by body motions and extrasystoles. Also, automatic recognition of the R-wave on electrocardiograms is required for real-time analysis of RSA amplitude, there is an unresolved problem of false recognition of the R-wave. In this paper, we propose a method to evaluate the amplitude of RSA accurately using statistical processing with probabilistic models. Then, we estimate parasympathetic nervous activity during body motion and isometric exercise to examine the validity of the method. As a result, using the proposed method, we demonstrate that the amplitude of RSA can be extracted with false recognition of the R-wave. In addition, an appropriate threshold for the estimate is one or five percent because waveforms of RSA amplitude do not follow the abrupt changes of the parasympathetic nervous activity evoked by isometric exercise with the threshold at ten percent. Furthermore, the method using normal distribution is found to be more appropriate than that of chi-square distribution for statistical processing. Therefore, we expect that the proposed method can evaluate parasympathetic nervous activity with high accuracy in everyday situations.

  1. Remote Magnetic Navigation: A Focus on Catheter Ablation of Ventricular Arrhythmias. (United States)

    Aagaard, Philip; Natale, Andrea; Briceno, David; Nakagawa, Hiroshi; Mohanty, Sanghamitra; Gianni, Carola; Burkhardt, J David; DI Biase, Luigi


    VT ablation is based on percutaneous catheter insertion under fluoroscopic guidance to selectively destroy (i.e., ablate) myocardial tissue regions responsible for the initiation or propagation of ventricular arrhythmias. Although the last decade has witnessed a rapid evolution of ablation equipment and techniques, the control over catheter movement during manual ablation has remained largely unchanged. Moreover, the procedures are long, and require ergonomically unfavorable positions, which can lead to operator fatigue. In an attempt to overcome these constraints, several technical advancements, including remote magnetic navigation (RMN), have been developed. RMN utilizes a magnetic field to remotely manipulate specially designed soft-tip ablation catheters anywhere in the x, y, or z plane inside the patient's chest. RMN also facilitates titration of the contact force between the catheter and the myocardial tissue, which may reduce the risk of complications while ensuring adequate lesion formation. There are several non-randomized studies showing that RMN has similar efficacy to manual ablation, while complication rates and total radiation exposure appears to be lower. Although these data are promising, larger randomized studies are needed to prove that RMN is superior to manual ablation of VT.

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

    Directory of Open Access Journals (Sweden)


    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.

  3. Cardiac Arrhythmias Classification Method Based on MUSIC, Morphological Descriptors, and Neural Network (United States)

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


    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.

  4. The role of Purkinje-myocardial coupling during ventricular arrhythmia: a modeling study.

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    Elham Behradfar

    Full Text Available The Purkinje system is the fast conduction network of the heart which couples to the myocardium at discrete sites called Purkinje-Myocyte Junctions (PMJs. However, the distribution and number of PMJs remains elusive, as does whether a particular PMJ is functional. We hypothesized that the Purkinje system plays a role during reentry and that the number of functional PMJs affect reentry dynamics. We used a computer finite element model of rabbit ventricles in which we varied the number of PMJs. Sustained, complex reentry was induced by applying an electric shock and the role of the Purkinje system in maintaining the arrhythmia was assessed by analyzing phase singularities, frequency of activation, and bidirectional propagation at PMJs. For larger junctional resistances, increasing PMJ density increased the mean firing rate in the Purkinje system, the percentage of successful retrograde conduction at PMJs, and the incidence of wave break on the epicardium. However, the mean firing of the ventricles was not affected. Furthermore, increasing PMJ density above 13/[Formula: see text] did not alter reentry dynamics. For lower junctional resistances, the trend was not as clear. We conclude that Purkinje system topology affects reentry dynamics and conditions which alter PMJ density can alter reentry dynamics.

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


    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.

  6. Sex-Based Differences in Cardiac Arrhythmias, ICD Utilisation and Cardiac Resynchronisation Therapy. (United States)

    Ghani, A; Maas, A H E M; Delnoy, P P H M; Ramdat Misier, A R; Ottervanger, J P; Elvan, A


    Many important differences in the presentation and clinical course of cardiac arrhythmias are present between men and women that should be accounted for in clinical practice. In this paper, we review published data on gender differences in cardiac excitable properties, supraventricular tachycardias, ventricular tachycardias, sudden cardiac death, and the utilisation of implantable defibrillators and cardiac resynchronisation therapy. Women have a higher heart rate at rest, and a longer QT interval than men. They further have a narrower QRS complex and lower QRS voltages on the 12-lead ECG with more often non-specific repolarisation abnormalities at rest. Supraventricular tachycardias, such as AV nodal reentrant tachycardia, are twice as frequent in women compared with men. Atrial fibrillation, however, has a 1.5-fold higher prevalence in men. The triggers for idiopathic right ventricular outflow tract tachycardia (VT) initiation are gender specific, i.e. hormonal changes play an important role in the occurrence of these VTs in women. There are clear-cut gender differences in acquired and congenital LQTS. Brugada syndrome affects men more commonly and severely than women. Sudden cardiac death is less prevalent in women at all ages and occurs 10 years later in women than in men. This may be related to the later onset of clinically manifest coronary heart disease in women. Among patients who receive ICDs and CRT devices, women appear to be under-represented, while they may benefit even more from these novel therapies.

  7. Late sodium current inhibition in acquired and inherited ventricular (dys)function and arrhythmias. (United States)

    Remme, Carol Ann; Wilde, Arthur A M


    The late sodium current has been increasingly recognized for its mechanistic role in various cardiovascular pathologies, including angina pectoris, myocardial ischemia, atrial fibrillation, heart failure and congenital long QT syndrome. Although relatively small in magnitude, the late sodium current (I(NaL)) represents a functionally relevant contributor to cardiomyocyte (electro)physiology. Many aspects of I(NaL) itself are as yet still unresolved, including its distribution and function in different cell types throughout the heart, and its regulation by sodium channel accessory proteins and intracellular signalling pathways. Its complexity is further increased by a close interrelationship with the peak sodium current and other ion currents, hindering the development of inhibitors with selective and specific properties. Thus, increased knowledge of the intricacies of the complex nature of I(NaL) during distinct cardiovascular conditions and its potential as a pharmacological target is essential. Here, we provide an overview of the functional and electrophysiological effects of late sodium current inhibition on the level of the ventricular myocyte, and its potential cardioprotective and anti-arrhythmic efficacy in the setting of acquired and inherited ventricular dysfunction and arrhythmias.

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

    Directory of Open Access Journals (Sweden)

    Chen Szi-Wen


    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.

  9. Anti-Ro/SSA antibodies and cardiac arrhythmias in the adult: facts and hypotheses. (United States)

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


    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.

  10. Treatment of arrhythmias by external charged particle beams: a Langendorff feasibility study. (United States)

    Prall, Matthias; Lehmann, H Immo; Prokesch, Hannah; Richter, Daniel; Graeff, Christian; Kaderka, Robert; Sonnenberg, Karin; Hauswald, Henrik; Weymann, Alexander; Bauer, Julia; Constantinescu, Anna; Haberer, Thomas; Debus, Jürgen; Szabó, Gábor; Korkmaz, Sevil; Durante, Marco; Packer, Douglas L; Bert, Christoph


    Hadron therapy has already proven to be successful in cancer therapy, and might be a noninvasive alternative for the ablation of cardiac arrhythmias in humans. We present a pilot experiment investigating acute effects of a 12C irradiation on the AV nodes of porcine hearts in a Langendorff setup. This setup was adapted to the requirements of charged particle therapy. Treatment plans were computed on calibrated CTs of the hearts. Irradiation was applied in units of 5 and 10 Gy over a period of about 3 h until a total dose of up to 160 Gy was reached. Repeated application of the same irradiation field helped to mitigate motion artifacts in the resulting dose distribution. After irradiation, PET scans were performed to verify accurate dose application. Acute AV blocks were identified. No other acute effects were observed. Hearts were kept in sinus rhythm for up to 6 h in the Langendorff setup. We demonstrated that 12C ions can be used to select a small target in the heart and, thereby, influence the electrical conduction system. Second, our pilot study seems to suggest that no adverse effects have to be expected immediately during heavy ion irradiation in performing subsequent experiments with doses of 30-60 Gy and intact pigs.

  11. An organized approach to the localization, mapping, and ablation of outflow tract ventricular arrhythmias. (United States)

    Hutchinson, Mathew D; Garcia, Fermin C


    The outflow tract (OT) regions of the right and left ventricles, common sites of origin for idiopathic ventricular arrhythmias (VA), have complex three-dimensional anatomical relationships. The understanding of in situ or "attitudinal" relationships not only informs the electrocardiographic interpretation of VA site of origin, but also facilitates their catheter-based mapping and ablation strategies. By viewing each patient as his or her own "control," the expected changes in ECG morphology (i.e., frontal plane QRS axis and precordial transition) between adjacent intracardiac structures (e.g., RVOT and aortic root) can be reliably predicted. Successful mapping of OT VAs involve a combination of activation and pacemapping guided by fluoroscopy, electroanatomical mapping, and intracardiac echocardiography. The purpose of this manuscript is to provide a simple, reliable strategy for catheter based mapping and ablation of OT VAs. We also discuss 2 specific challenges in OT VA mapping: (1) differentiating posterior RVOT from right coronary cusp VA origin; and (2) mapping VAs originating from the LV summit.

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

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    Bhupender Kumar Bajaj


    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.

  13. Sleep and cognitive performance: the role of income and respiratory sinus arrhythmia reactivity. (United States)

    Staton, Lori; Hinnant, J Benjamin; Buckhalt, Joseph; El-Sheikh, Mona


    A health disparities view suggests that low family income status acts as a risk factor for poor cognitive functioning. A biosystems view suggests that poor sleep and poor stress response system functioning are also risk factors. These views are rarely integrated to test multiplicative risk or protective effects from social-cultural and biological variables. We investigated interactions among familial income, children's sleep and respiratory sinus arrhythmia reactivity (RSA reactivity, indexing parasympathetic nervous system reactivity) in the prediction of cognitive performance of school-aged children. Participants were 282 children (146 boys; 35% African American and 65% European American; M age = 9.42 years, SD = .71). Mothers reported on family income. Children's sleep quality (efficiency) and duration (minutes) were assessed via a week of actigraphy. Children's RSA reactivity to an attention demanding and frustrating star tracing challenge was assessed in the lab. Children completed standardized cognitive assessments examining attention, processing speed, and crystallized cognitive functioning. Findings show that more optimal sleep efficiency and RSA reactivity interact to confer protection against poor cognitive performance, particularly for children from lower income homes. Results build on the literature and suggest that interactions between biological systems and socioeconomic variables are key for understanding children's cognitive performance.

  14. The role of late I Na in development of cardiac arrhythmias. (United States)

    Antzelevitch, Charles; Nesterenko, Vladislav; Shryock, John C; Rajamani, Sridharan; Song, Yejia; Belardinelli, Luiz


    Late I Na is an integral part of the sodium current, which persists long after the fast-inactivating component. The magnitude of the late I Na is relatively small in all species and in all types of cardiomyocytes as compared with the amplitude of the fast sodium current, but it contributes significantly to the shape and duration of the action potential. This late component had been shown to increase in several acquired or congenital conditions, including hypoxia, oxidative stress, and heart failure, or due to mutations in SCN5A, which encodes the α-subunit of the sodium channel, as well as in channel-interacting proteins, including multiple β subunits and anchoring proteins. Patients with enhanced late I Na exhibit the type-3 long QT syndrome (LQT3) characterized by high propensity for the life-threatening ventricular arrhythmias, such as Torsade de Pointes (TdP), as well as for atrial fibrillation. There are several distinct mechanisms of arrhythmogenesis due to abnormal late I Na, including abnormal automaticity, early and delayed after depolarization-induced triggered activity, and dramatic increase of ventricular dispersion of repolarization. Many local anesthetic and antiarrhythmic agents have a higher potency to block late I Na as compared with fast I Na. Several novel compounds, including ranolazine, GS-458967, and F15845, appear to be the most selective inhibitors of cardiac late I Na reported to date. Selective inhibition of late I Na is expected to be an effective strategy for correcting these acquired and congenital channelopathies.

  15. Feasibility Study on Cardiac Arrhythmia Ablation Using High-Energy Heavy Ion Beams (United States)

    Lehmann, H. Immo; Graeff, Christian; Simoniello, Palma; Constantinescu, Anna; Takami, Mitsuru; Lugenbiel, Patrick; Richter, Daniel; Eichhorn, Anna; Prall, Matthias; Kaderka, Robert; Fiedler, Fine; Helmbrecht, Stephan; Fournier, Claudia; Erbeldinger, Nadine; Rahm, Ann-Kathrin; Rivinius, Rasmus; Thomas, Dierk; Katus, Hugo A.; Johnson, Susan B.; Parker, Kay D.; Debus, Jürgen; Asirvatham, Samuel J.; Bert, Christoph; Durante, Marco; Packer, Douglas L.


    High-energy ion beams are successfully used in cancer therapy and precisely deliver high doses of ionizing radiation to small deep-seated target volumes. A similar noninvasive treatment modality for cardiac arrhythmias was tested here. This study used high-energy carbon ions for ablation of cardiac tissue in pigs. Doses of 25, 40, and 55 Gy were applied in forced-breath-hold to the atrioventricular junction, left atrial pulmonary vein junction, and freewall left ventricle of intact animals. Procedural success was tracked by (1.) in-beam positron-emission tomography (PET) imaging; (2.) intracardiac voltage mapping with visible lesion on ultrasound; (3.) lesion outcomes in pathohistolgy. High doses (40–55 Gy) caused slowing and interruption of cardiac impulse propagation. Target fibrosis was the main mediator of the ablation effect. In irradiated tissue, apoptosis was present after 3, but not 6 months. Our study shows feasibility to use high-energy ion beams for creation of cardiac lesions that chronically interrupt cardiac conduction.

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

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    Wakefield Seth E


    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.

  17. Study of atrial arrhythmias in a computer model based on magnetic resonance images of human atria (United States)

    Virag, N.; Jacquemet, V.; Henriquez, C. S.; Zozor, S.; Blanc, O.; Vesin, J.-M.; Pruvot, E.; Kappenberger, L.


    The maintenance of multiple wavelets appears to be a consistent feature of atrial fibrillation (AF). In this paper, we investigate possible mechanisms of initiation and perpetuation of multiple wavelets in a computer model of AF. We developed a simplified model of human atria that uses an ionic-based membrane model and whose geometry is derived from a segmented magnetic resonance imaging data set. The three-dimensional surface has a realistic size and includes obstacles corresponding to the location of major vessels and valves, but it does not take into account anisotropy. The main advantage of this approach is its ability to simulate long duration arrhythmias (up to 40 s). Clinically relevant initiation protocols, such as single-site burst pacing, were used. The dynamics of simulated AF were investigated in models with different action potential durations and restitution properties, controlled by the conductance of the slow inward current in a modified Luo-Rudy model. The simulation studies show that (1) single-site burst pacing protocol can be used to induce wave breaks even in tissue with uniform membrane properties, (2) the restitution-based wave breaks in an atrial model with realistic size and conduction velocities are transient, and (3) a significant reduction in action potential duration (even with apparently flat restitution) increases the duration of AF.

  18. Associations between narcissism and emotion regulation difficulties: Respiratory sinus arrhythmia reactivity as a moderator. (United States)

    Zhang, Hui; Wang, Zhenhong; You, Xuqun; Lü, Wei; Luo, Yun


    The aim of the current study was to examine the direct and interactive effects of two types of narcissism (overt and covert) and respiratory sinus arrhythmia (RSA) reactivity on emotion regulation difficulties in 227 undergraduate students. Overt and covert narcissism and emotion regulation difficulties were assessed with self-report measures (narcissistic personality inventory (NPI)-16, hypersensitive narcissism scale (HSNS), and difficulties in emotion regulation scale (DERS)), and physiological data were measured during the baseline, stress (a public-speaking task), and recovery periods in the laboratory. Results indicated that overt narcissism was negatively related to a lack of emotional awareness and emotional clarity, whereas covert narcissism was positively related to overall emotion regulation difficulties, nonacceptance of emotional responses, impulse control difficulties, limited access to emotion regulation strategies, and a lack of emotional clarity. RSA reactivity in response to a mock job interview moderated the associations between covert narcissism (as a predictor) and overall emotion regulation difficulties and impulse control difficulties (as outcomes). This finding showed that a greater stress-induced RSA decrease may serve as a protective factor and ameliorate the effect of covert narcissism on individuals' emotion regulation difficulties.

  19. Sympathetic cardiac hyperinnervation and atrial autonomic imbalance in diet-induced obesity promote cardiac arrhythmias. (United States)

    McCully, Belinda H; Hasan, Wohaib; Streiff, Cole T; Houle, Jennifer C; Woodward, William R; Giraud, George D; Brooks, Virginia L; Habecker, Beth A


    Obesity increases the risk of arrhythmias and sudden cardiac death, but the mechanisms are unknown. This study tested the hypothesis that obesity-induced cardiac sympathetic outgrowth and hyperinnervation promotes the development of arrhythmic events. Male Sprague-Dawley rats (250-275 g), fed a high-fat diet (33% kcal/fat), diverged into obesity-resistant (OR) and obesity-prone (OP) groups and were compared with rats fed normal chow (13% kcal/fat; CON). In vitro experiments showed that both OR and OP rats exhibited hyperinnervation of the heart and high sympathetic outgrowth compared with CON rats, even though OR rats are not obese. Despite the hyperinnervation and outgrowth, we showed that, in vivo, OR rats were less susceptible to arrhythmic events after an intravenous epinephrine challenge compared with OP rats. On examining total and stimulus-evoked neurotransmitter levels in an ex vivo system, we demonstrate that atrial acetylcholine content and release were attenuated in OP compared with OR and CON groups. OP rats also expressed elevated atrial norepinephrine content, while norepinephrine release was suppressed. These findings suggest that the consumption of a high-fat diet, even in the absence of overt obesity, stimulates sympathetic outgrowth and hyperinnervation of the heart. However, normalized cardiac parasympathetic nervous system control may protect the heart from arrhythmic events.

  20. Calcium Transients Closely Reflect Prolonged Action Potentials in iPSC Models of Inherited Cardiac Arrhythmia

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    C. Ian Spencer


    Full Text Available Long-QT syndrome mutations can cause syncope and sudden death by prolonging the cardiac action potential (AP. Ion channels affected by mutations are various, and the influences of cellular calcium cycling on LQTS cardiac events are unknown. To better understand LQTS arrhythmias, we performed current-clamp and intracellular calcium ([Ca2+]i measurements on cardiomyocytes differentiated from patient-derived induced pluripotent stem cells (iPS-CM. In myocytes carrying an LQT2 mutation (HERG-A422T, APs and [Ca2+]i transients were prolonged in parallel. APs were abbreviated by nifedipine exposure and further lengthened upon releasing intracellularly stored Ca2+. Validating this model, control iPS-CM treated with HERG-blocking drugs recapitulated the LQT2 phenotype. In LQT3 iPS-CM, expressing NaV1.5-N406K, APs and [Ca2+]i transients were markedly prolonged. AP prolongation was sensitive to tetrodotoxin and to inhibiting Na+-Ca2+ exchange. These results suggest that LQTS mutations act partly on cytosolic Ca2+ cycling, potentially providing a basis for functionally targeted interventions regardless of the specific mutation site.

  1. Arrhythmia detection in single- and dual-chamber implantable cardioverter defibrillators: the more leads, the better? (United States)

    Francia, Pietro; Balla, Cristina; Uccellini, Arianna; Cappato, Riccardo


    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.

  2. Gene Therapy for Ventricular Arrhythmias%室性心律失常的基因诊疗

    Institute of Scientific and Technical Information of China (English)

    王鑑萌; 梁兆光; 杨日升; 徐义喜


    Cardiac arrest is the leading cause of death in the developed countries of the world.Ventricular arrhythmias are the most prominent cause of cardiac arrest,and patients with structural heart disease are at increased risk for these abnormal heart rhythms.Drug and device therapies have important limitations that make them inadequate to meet this challenge.The cellular basis of cardiac electrical activity is the action potential.The characteristic spike and dome morphology of the action potential is caused by time-and voltage-dependent activation of various sodium,calcium and potassium channels and pumps.Arrhythmia mechanisms include reentry,abnormal automaticity and triggered activity.Reentry is a tissue-level phenomenon,requiring a critical mass of tissue for existence.Abnormal automaticity and triggered activity are cellular phenomena,capable of existing within individual cardiac myoctyes.The arrhythmia occurs when the electrical impulse is propagated from this localized source of activation to the greater myoeardium by the cell-to-cell transmission methods described above.Literature reports of gene therapy for ventricular arrhythmias show early signs of success.The researchers have proposed development of arrhythmia gene therapy as an alternative to current treatment methods.In this review,we discuss the basic mechanisms of ventricular arrhythmias and summarize the literature on the use of gene therapy for ventricular arrhythmias.%在一些发达国家,心脏骤停已成为最主要的死亡原因.快速性室性心律失常是导致心脏骤停最主要的原因,且快速性室性心律失常会增加结构性心脏病患者发病的风险.通过药物和器械治疗方法,存在较大的局限性.心脏电活动的细胞基础是动作电位.动作电位是由于时间和电压依赖性激活各种钠、钙和钾离子通道和泵产生的.心律失常机制包括折返,自律性异常和触发活动.折返是在组织水平发生的.异常的自动性和触发

  3. Cardiovascular exercise and burden of arrhythmia in patients with atrial fibrillation - A randomized controlled trial (United States)

    Bandholm, Thomas Quaade; Hakmann, Stine; Mourier, Malene; Kallemose, Thomas; Dixen, Ulrik


    Background Physical activity at moderate-high intensity is recommended to prevent lifestyle diseases. Patients with atrial fibrillation are at risk of a sedentary lifestyle due to fear of exercise-induced episodes of atrial fibrillation. The burden of arrhythmia can be reduced by physical exercise. The effect of exercise intensity on burden of atrial fibrillation needs to be studied further. Methods and results In a 12-week randomized controlled trial, 76 patients with paroxysmal/persistent atrial fibrillation were allocated to perform exercise at either low intensity or high intensity (50% and 80% of maximal perceived exertion, respectively). Primary outcome was burden of AF measured by daily electrocardiography-reporting during 12 weeks. Secondarily, change in maximal oxygen uptake (peak VO2) and 1-year hospitalization was compared between low and high intensity exercise. Sixty-three patients completed the follow-up. In the intention-to-treat analysis, we found no statistical difference in burden of atrial fibrillation between low and high intensity exercise (incidence rate ratio 0.742, 95% CI 0.29–1.91, P = 0.538). No serious adverse events were reported and there was no difference in hospitalization between the two exercise groups. Both exercise groups improved significantly in peak VO2 (low intensity: 3.62 mL O2/kg/min, SD 3.77; high intensity: 2.87 mL O2/kg/min, SD 4.98), with no statistical difference between-groups (mean difference: 0.76 mL O2/kg/min, 95% CI -3.22–1.7). Conclusions High intensity physical exercise was not superior to low intensity physical exercise in reducing burden of atrial fibrillation. HI exercise was well tolerated; no evidence of an increased risk was found for HI compared to LI exercise. Larger studies are required to further prove our findings. Trial registration NCT01817998 PMID:28231325

  4. CYP2J2 overexpression protects against arrhythmia susceptibility in cardiac hypertrophy.

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    Christina Westphal

    Full Text Available Maladaptive cardiac hypertrophy predisposes one to arrhythmia and sudden death. Cytochrome P450 (CYP-derived epoxyeicosatrienoic acids (EETs promote anti-inflammatory and antiapoptotic mechanisms, and are involved in the regulation of cardiac Ca(2+-, K(+- and Na(+-channels. To test the hypothesis that enhanced cardiac EET biosynthesis counteracts hypertrophy-induced electrical remodeling, male transgenic mice with cardiomyocyte-specific overexpression of the human epoxygenase CYP2J2 (CYP2J2-TG and wildtype littermates (WT were subjected to chronic pressure overload (transverse aortic constriction, TAC or β-adrenergic stimulation (isoproterenol infusion, ISO. TAC caused progressive mortality that was higher in WT (42% over 8 weeks after TAC, compared to CYP2J2-TG mice (6%. In vivo electrophysiological studies, 4 weeks after TAC, revealed high ventricular tachyarrhythmia inducibility in WT (47% of the stimulation protocols, but not in CYP2J2-TG mice (0%. CYP2J2 overexpression also enhanced ventricular refractoriness and protected against TAC-induced QRS prolongation and delocalization of left ventricular connexin-43. ISO for 14 days induced high vulnerability for atrial fibrillation in WT mice (54% that was reduced in CYP-TG mice (17%. CYP2J2 overexpression also protected against ISO-induced reduction of atrial refractoriness and development of atrial fibrosis. In contrast to these profound effects on electrical remodeling, CYP2J2 overexpression only moderately reduced TAC-induced cardiac hypertrophy and did not affect the hypertrophic response to β-adrenergic stimulation. These results demonstrate that enhanced cardiac EET biosynthesis protects against electrical remodeling, ventricular tachyarrhythmia, and atrial fibrillation susceptibility during maladaptive cardiac hypertrophy.

  5. Ventricular arrhythmias in competitive athletes: risk stratification with T-wave alternans

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    Rita Pizzi


    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

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


    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.

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

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    Renate Kopp

    Full Text Available Tolerance towards hypoxia is highly pronounced in zebrafish. In this study even beneficial effects of hypoxia, specifically enhanced survival of zebrafish larvae, could be demonstrated. This effect was actually more pronounced in breakdance mutants, which phenotypically show cardiac arrhythmia. Breakdance mutants (bre are characterized by chronically reduced cardiac output. Despite an about 50% heart rate reduction, they become adults, but survival rate significantly drops to 40%. Normoxic bre animals demonstrate increased hypoxia inducible factor 1 a (Hif-1α expression, which indicates an activated hypoxic signaling pathway. Consequently, cardiovascular acclimation, like cardiac hypertrophy and increased erythrocyte concentration, occurs. Thus, it was hypothesized, that under hypoxic conditions survival might be even more reduced. When bre mutants were exposed to hypoxic conditions, they surprisingly showed higher survival rates than under normoxic conditions and even reached wildtype values. In hypoxic wildtype zebrafish, survival yet exceeded normoxic control values. To specify physiological acclimation, cardiovascular and metabolic parameters were measured before hypoxia started (3 dpf, when the first differences in survival rate occurred (7 dpf and when survival rate plateaued (15 dpf. Hypoxic animals expectedly demonstrated Hif-1α accumulation and consequently enhanced convective oxygen carrying capacity. Moreover, bre animals showed a significantly enhanced heart rate under hypoxic conditions, which reached normoxic wildtype values. This improvement in convective oxygen transport ensured a sufficient oxygen and nutrient supply and was also reflected in the significantly higher mitochondrial activity. The highly optimized energy metabolism observed in hypoxic zebrafish larvae might be decisive for periods of higher energy demand due to organ development, growth and increased activity. However, hypoxia increased survival only during a

  8. Improving Managers' Psychophysical Well-Being: Effectiveness of Respiratory Sinus Arrhythmia Biofeedback. (United States)

    Munafò, Marianna; Patron, Elisabetta; Palomba, Daniela


    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.

  9. Postprocedural Outcomes and Risk Factors for Arrhythmias Following Transcatheter Closure of Congenital Perimembranous Ventricular Septal Defect: A Single-center Retrospective Study (United States)

    Zhao, Li-Jian; Han, Bo; Zhang, Jian-Jun; Yi, Ying-Chun; Jiang, Dian-Dong; Lyu, Jian-Li


    Background: Currently, transcatheter closure of perimembranous ventricular septal defect (pmVSD) is a widely accepted therapeutic modality. However, arrhythmias, especially postprocedural heart blocks, are a concern and outcomes are not very clear. This study explored the outcomes and risk factors of arrhythmias associated with transcatheter device closure of pmVSD. Methods: A total of 395 patients diagnosed with pmVSD who successfully underwent transcatheter intervention between January 2010 and December 2015 in our center were retrospectively reviewed. Electrocardiographic data before and after the procedure were collected and analyzed. We first evaluated the potential risk factors including gender, age, weight, inlet and outlet diameters of defect, subaortic rim length, occluder size, corrected occluder size into body surface area, fluoroscopy time, presence of aneurysm, and deployment position. We compared the potential risk factors between arrhythmia and nonarrhythmia groups using univariate analysis, followed by logistic analysis for independent risk factors. Results: Various arrhythmias were detected in 95 cases (24.1%) following transcatheter closure procedure. Logistic regression analysis revealed that eccentric (odds ratio [OR] 2.9, 95% confidence interval [CI]: 1.2–7.2) and large occluders (OR 2.0, 95% CI: 1.6–2.5), as well as long fluoroscopy time (OR 1.1, 95% CI: 1.1–1.2), were correlated with postprocedural arrhythmia. During 35.5 months (range: 9–80 months) of follow-up, most of the patients (74 out of 95) reverted to normal heart rhythm. Conclusions: The mid-term outcome of patients with arrhythmias after transcatheter closure of pmVSD was satisfactory as most of the patients recovered normal rhythm. Eccentric, large device and long fluoroscopy time increase the risk of arrhythmias after transcatheter closure of pmVSD. PMID:28229981

  10. 小儿心律失常71例临床分析%Clinical Analysis of 71 Cases of Pediatric Arrhythmias

    Institute of Scientific and Technical Information of China (English)



    Objective To study the clinical characteristics of pediatric cardiac arrhythmias.Methods Choose 71 patients with pediatric cardiac arrhythmias in our hospital then sorting and analyzing the data.ResultsThe pediatric arrhythmia occurrence concerned with toxic myocarditis,rheumatic fever and rheumatic heart disease. 71 cases of arrhythmia in patients with sinus arrhythmia,52 cases,15 cases of ectopic arrhythmias conduction disorders three type,4 cases by symptomatic treatment,63 cases cured,7 cases lesson,1 had no effect,the total effective rate was 98.59%.Conclusion Pediatric arrhythmia causes pure,according to the different causes for targeted treatment,the prognosis is good.%目的:探讨小儿心律失常的临床特点。方法选择我院小儿心律失常患者71例,对其资料进行整理和分析。结果小儿心律失常发生与中毒性心肌炎、风湿热、风湿性心脏病等疾病有关。71例患者的心律失常分窦性心律失常52例,异位心律失常15例,传导失常4例三个类型,经对症治疗,痊愈63例,减轻7例,无效1例,总有效率98.59%。结论小儿心律失常病因单纯,根据不同病因进行针对性治疗,预后较好。

  11. Clinical Analysis of Depressive, Anxiety Arrhythmia in Patients with Sleep and Arrhythmia%伴发抑郁、焦虑的心律失常患者睡眠与心律失常的临床分析

    Institute of Scientific and Technical Information of China (English)



    Objective The effects of sleep on arrhythmia patients with depression and anxiety disorders on arrhythmias are analyzed and discussed briefly.Methods 160 cases of arrhythmia patients and 50 healthy as the control group, depression, the self rating Anxiety Scale and Pittsburgh sleep quality index evaluation. Results The index of HRV time domain indexes anxiety group, depression group, Comorbidity groups in sleep quality factor and total score to sleep is significantly higher than the control group in the total score and the time to fal asleep,In terms of total sleep and sleep time there exists obvious difference being statisticaly significant ,P<0.05.ConclusionArrhythmia patients with depression, anxiety and comorbid anxiety and depression wil decrease obviously in HRV time domain indexes, which also shows the autonomic nervous there may be some adverse effects on the heart adjustment.%目的 对伴抑郁及焦虑情绪障碍的心律失常患者的睡眠情况对心律失常的影响进行简要的分析和探讨.方法 将160例心律失常患者和50个健康将其作为对照组,对其进行抑郁、焦虑自评量表和匹茨堡睡眠质量指数量表进行测评,同时还要对HRV指标进行详细的分析.结果 HRV时域指标方面焦虑组、抑郁组、共病组的指标都要比正常组的值要高.共病组在睡眠质量因子上和睡眠总分方面要明显比对照组高,在睡眠总分和入睡时间等方面两者存在着较为明显的统计学差异,P<0.05.结论 伴抑郁、焦虑和焦虑抑郁共病的心律失常患者在HRV时域指标会出现非常明显的下降,这也说明自主神经对心脏的调节可能存在着一些不利影响.

  12. ECG spectral and morphological parameters reviewed and updated to detect adult and paediatric life-threatening arrhythmia. (United States)

    Aramendi, E; Irusta, U; Pastor, E; Bodegas, A; Benito, F


    Since the International Liaison Committee on Resuscitation approved the use of automated external defibrillators (AEDs) in children, efforts have been made to adapt AED algorithms designed for adult patients to detect paediatric ventricular arrhythmias accurately. In this study, we assess the performance of two spectral (A(2) and VFleak) and two morphological parameters (TCI and CM) for the detection of lethal ventricular arrhythmias using an American Heart Association (AHA) compliant database that includes adult and paediatric arrhythmias. Our objective was to evaluate how those parameters can be optimally adjusted to discriminate shockable from nonshockable rhythms in adult and paediatric patients. A total of 1473 records were analysed: 751 from 387 paediatric patients ( 0.01) between the adult and paediatric patients for the shockable records; the differences for nonshockable records however were significant. Still, these parameters maintained the discrimination power when paediatric rhythms were included. A single threshold could be adjusted to obtain sensitivities and specificities above the AHA goals for the complete database. The sensitivities for ventricular fibrillation (VF) and ventricular tachycardia (VT) were 91.1% and 96.6% for VFleak, and 90.3% and 99.3% for A(2). The specificities for normal sinus rhythm (NSR) and other nonshockable rhythms were 99.5% and 96.3% for VFleak, and 99.0% and 97.7% for A(2). On the other hand, the morphological parameters showed significant differences between the adult and paediatric patients, particularly for the nonshockable records, because of the faster heart rates of the paediatric rhythms. Their performance clearly degraded with paediatric rhythms. Using a single threshold, the sensitivities and specificities were below the AHA goals, particularly VT sensitivity (60.4% for TCI and 65.8% for CM) and the specificity for other nonshockable rhythms (51.7% for TCI and 34.5% for CM). The specificities, particularly for

  13. Effects of Acetyl-L-Carnitine on Cardiac Arrhythmias and Infarct Size in Ischemic-Reperfused Isolated Rat Heart

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    Moslem Najafi


    Full Text Available This study aimed to examine whether acetyl-L-carnitine (ALC was able to reduce cardiac arrhythmias and infarct size in the ischemic-reperfused isolated rat heart.Materials and MethodsThe isolated hearts were mounted on a Langendorff apparatus then perfused by a modified Krebs-Henseleit solution during 30 min regional ischemia and 120 min reperfusion (control or by enriched Krebs solution with 0.375, 0.75, 1.5 and 3 mM of ALC (treatment groups. The ECGs were recorded and analyzed to determine cardiac arrhythmias. The infarct size was determined by using a computerized planimetry package.ResultsDuring ischemia, all used concentrations of ALC decreased number and duration of ventricular tachycardia (VT, total number of ventricular ectopic beats (VEBs (P<0.01, incidence of total ventricular fibrillation (VF and the time spent for reversible VF (P<0.05. At the reperfusion phase, duration of VT, incidence of total VF and reversible VF were significantly lowered by ALC (P<0.05. In addition, infarct size significantly was decreased in all treated groups. In the control group, the infarct size was 23±3.1%, however, ALC (0.375, 0.75 and 3 mM reduced it to 8.7±2.3, 5.3±1.4, and 8±2.9%, respectively (P<0.01. ConclusionConsidering the results, it may be concluded that ALC has protective effects against cardiac ischemia-reperfusion (I/R injuries by reduction of infarct size and arrhythmias in isolated rat heart. Among the potential cardioprotective mechanisms for ALC, increase in glucose oxidation and resulting reduced lactate production, reduction of toxic fatty acid metabolites and removing free radicals from the myocytes are more relevant.

  14. Distribution Entropy (DistEn): A complexity measure to detect arrhythmia from short length RR interval time series. (United States)

    Karmakar, Chandan; Udhayakumar, Radhagayathri K; Palaniswami, Marimuthu


    Heart rate complexity analysis is a powerful non-invasive means to diagnose several cardiac ailments. Non-linear tools of complexity measurement are indispensable in order to bring out the complete non-linear behavior of Physiological signals. The most popularly used non-linear tools to measure signal complexity are the entropy measures like Approximate entropy (ApEn) and Sample entropy (SampEn). But, these methods become unreliable and inaccurate at times, in particular, for short length data. Recently, a novel method of complexity measurement called Distribution Entropy (DistEn) was introduced, which showed reliable performance to capture complexity of both short term synthetic and short term physiologic data. This study aims to i) examine the competence of DistEn in discriminating Arrhythmia from Normal sinus rhythm (NSR) subjects, using RR interval time series data; ii) explore the level of consistency of DistEn with data length N; and iii) compare the performance of DistEn with ApEn and SampEn. Sixty six RR interval time series data belonging to two groups of cardiac conditions namely `Arrhythmia' and `NSR' have been used for the analysis. The data length N was varied from 50 to 1000 beats with embedding dimension m = 2 for all entropy measurements. Maximum ROC area obtained using ApEn, SampEn and DistEn were 0.83, 0.86 and 0.94 for data length 1000, 1000 and 500 beats respectively. The results show that DistEn undoubtedly exhibits a consistently high performance as a classification feature in comparison with ApEn and SampEn. Therefore, DistEn shows a promising behavior as bio marker for detecting Arrhythmia from short length RR interval data.

  15. 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


    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.

  16. A study of the possible relation of the cardiac arrhythmias occurrence to the polarity reversal of the solar magnetic field (United States)

    Mavromichalaki, H.; Preka-Papadema, P.; Theodoropoulou, A.; Paouris, E.; Apostolou, Th.


    The biological human system is probably affected by the solar and geomagnetic disturbances as well as the cosmic ray variations. In this work, the relation between the solar activity and cosmic ray variations and the cardiac arrhythmias over the time period 1997-2009 covering the solar cycle 23, is studied. The used medical data set refers to 4741 patients with cardiac arrhythmias and 2548 of whom were diagnosed with atrial fibrillation, obtained from the 2nd Cardiological Clinic of the General Hospital of Nicaea, Piraeus, in Greece. The smoothing method on a 365-day basis and the Pearson r-coefficient were used in order to compare these records with the number of sunspots, flares, solar proton events, coronal mass ejections and cosmic ray intensity. Applying a moving correlation function to ±1500 days, it is suggested that a change of the correlation sign between the medical data and each one of the above parameters occurs during a time interval of about 2-3 years. This interval corresponds to the time span of the polarity reversal of the solar magnetic field of this solar cycle, which always takes place around the solar cycle maximum. After then a correlation analysis was carried out corresponding to the rise (1997-2001) and the decay (2002-2009) phases of the solar cycle 23. It is noticeable that the polarity reversal of the solar magnetic field coincides with the period where the sign of the correlation between the incidence of arrhythmias and the occurrence number of the solar eruptive events and the cosmic ray intensity, changes sign. The results are comparable with those obtained from the previous solar cycle 22 based on medical data from another country.

  17. Analysis of Arrhythmia Caused by Diabetic Hypoglycemia%糖尿病低血糖诱发室性心律失常14例分析

    Institute of Scientific and Technical Information of China (English)



    目的::探讨糖尿病低血糖诱发室性心律失常作用机制及应对方法。方法:回顾性分析40例糖尿病低血糖病例在治疗前后的心律变化。结果:糖尿病低血糖有诱发室性心律失常作用。结论:糖尿病低血糖病例伴有室性心律失常时,应疑及由低血糖诱发可能性,同时糖尿病低血糖诱发的室性心律失常,只要抢救及时,大多数具有可逆性,并且预后良好。%Objective:To investigate the relationship between diabetic hypoglycemia and arrhythmia and the dealing methods.Method:Retrospectively studied 40 cases of diabetes hypoglycemia and the process before and after treatment.Result:Diabetic hypoglycemia could cause arrhythmia.Conclusion:If hypoglycemia arises with arrhythmia,it is possible that arrhythmia is caused by Hypoglycemia.Meanwhile many cases with arrhythmia caused by diabetic hypoglycemia may be reversible if saved in time.

  18. Short-term effects of fine particulate air pollution on emergency room visits for cardiac arrhythmias: a case-crossover study in Taipei. (United States)

    Chiu, Hui-Fen; Tsai, Shang-Shyue; Weng, Hsu-Huei; Yang, Chun-Yuh


    This study was undertaken to determine whether there was an association between fine particles (PM₂.₅) levels and number of emergency room (ER) visits for cardiac arrhythmias in Taipei, Taiwan. ER visits for cardiac arrhythmias and ambient air pollution data for Taipei were obtained for the period 2006-2010. The relative risk (RR) of ER visits was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single-pollutant model (without adjustment for other pollutants), increased numbers of ER cardiac arrhythmia visits were significantly associated with PM₂.₅ on both warm days (>23°C) and cool days (arrhythmias, respectively. In the two-pollutant models, PM₂.₅ levels remained significant after inclusion of sulfur dioxide (SO₂) or ozone (O₃) on both warm and cool days. This study provides evidence that higher levels of PM₂.₅ increase the risk of number of ER visits for cardiac arrhythmias.

  19. 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


    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.

  20. Discussion on treating cardiac arrhythmias from the spleen and stomach therapy%心律失常从脾胃论治刍议

    Institute of Scientific and Technical Information of China (English)

    吕国芳; 徐厚谦; 贾晓博


    通过分析心律失常的发生及与“脾胃”相关的中医理论,结合与消化系统的联系及临床实践,认为心律失常的发生机制与“脾胃”相关,指出炙甘草汤的方药特点,并联系名医经验和现代药理研究分析了心律失常从脾胃论治的机理。%Through analyzing TCM therapy and stomach related arrhythmias, combining with the digestive system, the mechanism of arrhythmias could relate to stomach. The Zhigancao decoction, clinical experience and modern pharmacological research together demonstrated the mechanism of arrhythmia treatment from spleen and stomach.

  1. 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


    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...

  2. P wave detection in ECG signals using an extended Kalman filter: an evaluation in different arrhythmia contexts. (United States)

    Rahimpour, M; Mohammadzadeh Asl, B


    Monitoring atrial activity via P waves, is an important feature of the arrhythmia detection procedure. The aim of this paper is to present an algorithm for P wave detection in normal and some abnormal records by improving existing methods in the field of signal processing. In contrast to the classical approaches, which are completely blind to signal dynamics, our proposed method uses the extended Kalman filter, EKF25, to estimate the state variables of the equations modeling the dynamic of an ECG signal. This method is a modified version of the nonlinear dynamical model previously introduced for a generation of synthetic ECG signals and fiducial point extraction in normal ones. It is capable of estimating the separate types of activity of the heart with reasonable accuracy and performs well in the presence of morphological variations in the waveforms and ectopic beats. The MIT-BIH Arrhythmia and QT databases have been used to evaluate the performance of the proposed method. The results show that this method has Se  =  98.38% and Pr  =  96.74% in the overall records (considering normal and abnormal rhythms).

  3. Marine omega-3 highly unsaturated fatty acids: From mechanisms to clinical implications in heart failure and arrhythmias. (United States)

    Glück, Tobias; Alter, Peter


    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.

  4. 静注胺碘酮治疗心律失常%Static note Amiodarone Treatment of Arrhythmia

    Institute of Scientific and Technical Information of China (English)



    胺碘酮是一种广谱抗心律失常药物,具有许多独立的药理特性,虽属III类抗心律失常药,但它对多个离子通道均有阻断作用,同时具有 I及IV类抗心律失常药性质。近年来静脉注射胺碘酮治疗难治性室上性心律失常、顽固性室性心动过速,室颤疗效甚佳。本文对本科30例心律失常患者使用静脉注射胺碘酮。现将其治疗结果记录如下。%Amiodarone is a broad-spectrum anti-arrhythmic drugs,has many pharmacological characteristics of independent,although department class III anti-arrhythmic drugs,but its effect on multiple ion channels are blocked ,at the same time is in the nature of class I and IV anti -arrhythmic drugs.In recent years the in-travenous amiodarone be well in treatment of refractory room on cardiac arrhythmia,refractory ventricular tachycardia,ventricular fibrillation in good curative effect.In this paper,the undergraduate course of 30 patients with arrhythmia intravenous amiodarone.It is presently as follows the treatment result record.

  5. 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


    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.

  6. Prophylactic Antiarrhythmic Effect of Anesthetics at Subanesthetic Concentration on Epinephrine-Induced Arrhythmias in Rats after Brain Death

    Directory of Open Access Journals (Sweden)

    Yuka Miyata


    Full Text Available The present study using brain death model of rats was designed to examine whether prophylactic administration of volatile anesthetics and propofol prevent the epinephrine-induced arrhythmias. A Fogarty catheter was placed intracranially for induction of brain death. After brain death, the rats were randomly assigned to five groups: the control group (no anesthetics, the sevoflurane group (0.8%, the isoflurane group (0.5%, the halothane group (0.3%, and the propofol group (195 μg·kg−1·min−1. These anesthetics were about 30% of ED50 of each anesthetic. The arrhythmogenic dose of epinephrine was determined in each anesthetic group. In addition, we examined left ventricular levels of connexin 43 phosphorylation 30 min after administration of each anesthetic with Western blot analysis. The arrhythmogenic dose of epinephrine in the sevoflurane group was significantly higher than that in the control group, while the arrhythmogenic dose of epinephrine in any other anesthetic group was not different. On the other hand, the ratio of phosphorylated-connexin 43/total connexin 43 was also similar among the study groups. Thus, prophylactic administration of subanesthetic dose of sevoflurane is effective in preventing epinephrine-induced arrhythmias after brain death, but phosphorylation of connexin is not involved in the antiarrhythmic property of sevoflurane.

  7. Prophylactic antiarrhythmic effect of anesthetics at subanesthetic concentration on epinephrine-induced arrhythmias in rats after brain death. (United States)

    Miyata, Yuka; Iwasaki, Mitsuo; Yamanaka, Hiroo; Sato, Masanori; Kamibayashi, Takahiko; Fujino, Yuji; Hayashi, Yukio


    The present study using brain death model of rats was designed to examine whether prophylactic administration of volatile anesthetics and propofol prevent the epinephrine-induced arrhythmias. A Fogarty catheter was placed intracranially for induction of brain death. After brain death, the rats were randomly assigned to five groups: the control group (no anesthetics), the sevoflurane group (0.8%), the isoflurane group (0.5%), the halothane group (0.3%), and the propofol group (195 μg·kg(-1) ·min(-1)). These anesthetics were about 30% of ED50 of each anesthetic. The arrhythmogenic dose of epinephrine was determined in each anesthetic group. In addition, we examined left ventricular levels of connexin 43 phosphorylation 30 min after administration of each anesthetic with Western blot analysis. The arrhythmogenic dose of epinephrine in the sevoflurane group was significantly higher than that in the control group, while the arrhythmogenic dose of epinephrine in any other anesthetic group was not different. On the other hand, the ratio of phosphorylated-connexin 43/total connexin 43 was also similar among the study groups. Thus, prophylactic administration of subanesthetic dose of sevoflurane is effective in preventing epinephrine-induced arrhythmias after brain death, but phosphorylation of connexin is not involved in the antiarrhythmic property of sevoflurane.

  8. Characterization of 2 genetic variants of Na(v) 1.5-arginine 689 found in patients with cardiac arrhythmias. (United States)

    Sottas, Valentin; Rougier, Jean-Sébastien; Jousset, Florian; Kucera, Jan P; Shestak, Anna; Makarov, Leonid M; Zaklyazminskaya, Elena V; Abriel, Hugues


    Hundreds of genetic variants in SCN5A, the gene coding for the pore-forming subunit of the cardiac sodium channel, Na(v) 1.5, have been described in patients with cardiac channelopathies as well as in individuals from control cohorts. The aim of this study was to characterize the biophysical properties of 2 naturally occurring Na(v) 1.5 variants, p.R689H and p.R689C, found in patients with cardiac arrhythmias and in control individuals. In addition, this study was motivated by the finding of the variant p.R689H in a family with sudden cardiac death (SCD) in children. When expressed in HEK293 cells, most of the sodium current (I(Na)) biophysical properties of both variants were indistinguishable from the wild-type (WT) channels. In both cases, however, an ∼2-fold increase of the tetrodotoxin-sensitive late I(Na) was observed. Action potential simulations and reconstruction of pseudo-ECGs demonstrated that such a subtle increase in the late I(Na) may prolong the QT interval in a nonlinear fashion. In conclusion, despite the fact that the causality link between p.R689H and the phenotype of the studied family cannot be demonstrated, this study supports the notion that subtle alterations of Na(v) 1.5 variants may increase the risk for cardiac arrhythmias.

  9. Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia.

    Directory of Open Access Journals (Sweden)

    Christian Eickholt

    Full Text Available OBJECTIVES: The beneficial effects of cardiac resynchronization therapy (CRT are thought to result from favorable left ventricular (LV reverse remodeling, however CRT is only successful in about 70% of patients. Whether response to CRT is associated with a decrease in ventricular arrhythmias (VA is still discussed controversially. Therefore, we investigated the incidence of VA in CRT responders in comparison with non-responders. METHODS: In this nonrandomized, two-center, observational study patients with moderate-to-severe heart failure, LV ejection fraction (LVEF ≤35%, and QRS duration >120 ms undergoing CRT were included. After 6 months patients were classified as CRT responders or non-responders. Incidence of VA was compared between both groups by Kaplan-Meier analysis and Cox regression analysis. ROC analysis was performed to determine the aptitude of LVEF cut-off values to predict VA. RESULTS: In total 126 consecutive patients (64±11 years; 67%male were included, 74 were classified as responders and 52 as non-responders. While the mean LVEF at baseline was comparable in both groups (25±7% vs. 24±8%; P = 0.4583 only the responder group showed an improvement of LVEF (36±6% vs. 24±7; p7% was found to be a predictor of a significantly lower incidence of VA (AUC = 0.606. CONCLUSIONS: Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia.

  10. Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy. (United States)

    Freyermuth, Fernande; Rau, Frédérique; Kokunai, Yosuke; Linke, Thomas; Sellier, Chantal; Nakamori, Masayuki; Kino, Yoshihiro; Arandel, Ludovic; Jollet, Arnaud; Thibault, Christelle; Philipps, Muriel; Vicaire, Serge; Jost, Bernard; Udd, Bjarne; Day, John W; Duboc, Denis; Wahbi, Karim; Matsumura, Tsuyoshi; Fujimura, Harutoshi; Mochizuki, Hideki; Deryckere, François; Kimura, Takashi; Nukina, Nobuyuki; Ishiura, Shoichi; Lacroix, Vincent; Campan-Fournier, Amandine; Navratil, Vincent; Chautard, Emilie; Auboeuf, Didier; Horie, Minoru; Imoto, Keiji; Lee, Kuang-Yung; Swanson, Maurice S; Lopez de Munain, Adolfo; Inada, Shin; Itoh, Hideki; Nakazawa, Kazuo; Ashihara, Takashi; Wang, Eric; Zimmer, Thomas; Furling, Denis; Takahashi, Masanori P; Charlet-Berguerand, Nicolas


    Myotonic dystrophy (DM) is caused by the expression of mutant RNAs containing expanded CUG repeats that sequester muscleblind-like (MBNL) proteins, leading to alternative splicing changes. Cardiac alterations, characterized by conduction delays and arrhythmia, are the second most common cause of death in DM. Using RNA sequencing, here we identify novel splicing alterations in DM heart samples, including a switch from adult exon 6B towards fetal exon 6A in the cardiac sodium channel, SCN5A. We find that MBNL1 regulates alternative splicing of SCN5A mRNA and that the splicing variant of SCN5A produced in DM presents a reduced excitability compared with the control adult isoform. Importantly, reproducing splicing alteration of Scn5a in mice is sufficient to promote heart arrhythmia and cardiac-conduction delay, two predominant features of myotonic dystrophy. In conclusion, misregulation of the alternative splicing of SCN5A may contribute to a subset of the cardiac dysfunctions observed in myotonic dystrophy.

  11. 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)



    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。

  12. Clinical Analysis of Chronic Cor Pulmonale Complicating Arrhythmia%慢性肺源性心脏病并发心律失常临床分析

    Institute of Scientific and Technical Information of China (English)

    徐桂华; 夏辉


    Objective: To analyse the clinical features of chronic cor pulmonale complicating arrhythmi-a. Method: 158 cases patients treated in our hospital with chronic cor pulmonale, including arrhythmia group of 97 patients, non - arrhythmia group of 61 patients, They were griven conventional treatment, observed the type of arrhythmia and two groups were compared the incidence of concurrent symptoms. Result: The most common type of chronic cor pulmonale complicating arrhythmia is mainly sinus tachycardia ( 42. 27% ) and atrial premature beats ( 32.99% ); Pulmonary infection, heart failure, hypoxia, electrolyte imbalance were 100% , 44. 33% , 60. 82% , 73. 20% in arrhythmia group and 85. 25% ,18. 03% , 36. 07% , 52.46% in non-arrhythmia group. There's significant difference, P<0.01. Conclusion: Chronic cor pulmonale complicating arrhythmia occurs with age , infection, hypoxia, electrolyte imbalance , heart failure and other factors, timely appropriate treatment can effectively reduce the mortality.%目的:分析慢性肺源性心脏病并发心律失常的临床特征.方法:将我院治疗的慢性肺心病患者158例,其中心律失常组97例,非心律失常组61例,给予常规治疗,观察心律失常的类型,比较两组并发症状发生情况.结果:肺源性心脏病并发心律失常最常见的类型主要为窦性心动过速(42.27%)及房性早搏(32.99%);心律失常组并发肺部感染、心力衰竭、缺氧、电解质紊乱分别为100%、44.33%、60.82%、73.20%,与非心律失常组85.25%、18.03%、36.07%、52.46%比较,有统计学差异,P<0.01.结论:肺源性心脏病并发心律失常的发生与年龄、感染、缺氧、电解质紊乱、心力衰竭等因素有关,及时给予相应的治疗能够有效地降低病死率.

  13. Efficacy of angiotensin II type 1 receptor blockade on reperfusion-induced arrhythmias and mortality early after myocardial infarction is increased in transgenic rats with cardiac angiotensin II type 1 overexpression

    NARCIS (Netherlands)

    de Boer, RA; van Geel, PP; Pinto, YM; Suurmeijer, AJH; Crijns, HJGM; van Gilst, WH; van Veldhuisen, DJ


    Angiotensin II induces ischemia/reperfusion (I/R)-induced arrhythmias and blockade of the angiotensin II type I receptor (AT1R) may therefore be beneficial in preventing arrhythmias and decreasing mortality after myocardial infarction (MI). Because the AT1R is upregulated after myocardial ischemia,

  14. Mapping epicardial fat with multi-detector computed tomography to facilitate percutaneous transepicardial arrhythmia ablation

    Energy Technology Data Exchange (ETDEWEB)

    Abbara, Suhny [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)]. E-mail:; Desai, Jay C. [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Cury, Ricardo C. [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Butler, Javed [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Nieman, Koen [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Reddy, Vivek [Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)


    A sizable portion of ventricular tachycardia circuits are epicardial, especially in patients with non-ischemic cardiomyopathy, e.g. Chagas disease. Thus there is a growing interest among the electrophysiologists in transepicardial mapping and myocardial ablation for treatment of arrhythmias. However, increased epicardial fat can be a significant hindrance in procedural success as it can mimic infarct during mapping and can also decrease the effectiveness of ablation. Quantitative knowledge of epicardial fat pre-procedure can potentially significantly facilitate the conduct and outcomes of these procedures. In this study we assessed the epicardial fat distribution and thickness in vivo in 59 patients who underwent multi-detector computed tomography (MDCT) for coronary artery assessment using a 16-slice scanner. Multiplanar reconstructions were obtained in the ventricular short axis at the basal, mid ventricular, and near the apex level, and in a four-chamber view. In the short axis slices, we measured epicardial fat diameter in nine segments, and in the four-chamber view, it was measured in five segments. In grooved segments the maximum fat thickness was recorded, while in non-grooved segments thickness at three equally spaced points were averaged. The results were as follows starting clockwise: superior inter-ventricular (IV) groove (all measurements are in mm, in basal, mid ventricular, and apical levels, respectively) (11.2, 8.6, 7.3), left ventricular (LV) superior lateral wall (1.0, 1.5, 1.7), LV inferior lateral wall (1.3, 2.2, 3.5), inferior IV groove (9.2, 6.5, 6.1), right ventricular (RV) diaphragmatic wall (1.4, 0.2, 1.0), acute margin (9.2, 7.3, 7.8), RV anterior free wall inferior (6.8, 4.0, 4.7), RV anterior free wall superior (6.5, 3.2, 3.1), RV superior wall (5.6, 2.7, 4.0), We measured the following four-chamber segments: LV apex (2.8 mm), left atrio-ventricular (AV) groove (12.7), right AV groove (14.8), RV apex (4.8), and anterior IV groove (7

  15. Stereotactic Arrhythmia Radioablation (STAR) of Ventricular Tachycardia: A Treatment Planning Study (United States)

    Fahimian, Benjamin; Soltys, Scott G; Zei, Paul; Lo, Anthony; Gardner, Edward A; Maguire, Patrick J; Loo Jr., Billy W


    Purpose The first stereotactic arrhythmia radioablation (STAR) of ventricular tachycardia (VT) was delivered at Stanford on a robotic radiosurgery system (CyberKnife® G4) in 2012. The results warranted further investigation of this treatment. Here we compare dosimetrically three possible treatment delivery platforms for STAR. Methods The anatomy and target volume of the first treated patient were used for this study. A dose of 25 Gy in one fraction was prescribed to the planning target volume (PTV). Treatment plans were created on three treatment platforms: CyberKnife® G4 system with Iris collimator (Multiplan, V. 4.6)(Plan #1), CyberKnife® M6 system with InCise 2TM multileaf collimator (Multiplan V. 5.3)(Plan #2) and Varian TrueBeamTM STx with HD 120TM MLC and 10MV flattening filter free (FFF) beam (Eclipse planning system, V.11) (Plan #3 coplanar and #4 noncoplanar VMAT plans). The four plans were compared by prescription isodose line, plan conformity index, dose gradient, as well as dose to the nearby critical structures. To assess the delivery efficiency, planned monitor units (MU) and estimated treatment time were evaluated. Results Plans #1-4 delivered 25 Gy to the PTV to the 75.0%, 83.0%, 84.3%, and 84.9% isodose lines and with conformity indices of 1.19, 1.16, 1.05, and 1.05, respectively. The dose gradients for plans #1-4 were 3.62, 3.42, 3.93, and 3.73 with the CyberKnife® MLC plan (Plan #2) the best, and the TrueBeamTM STx co-planar plan (Plan #3) the worst. The dose to nearby critical structures (lung, stomach, bowel, and esophagus) were all well within tolerance. The MUs for plans #1-4 were 27671, 16522, 6275, and 6004 for an estimated total-treatment-time/beam-delivery-time of 99/69, 65/35, 37/7, and 56/6 minutes, respectively, under the assumption of 30 minutes pretreatment setup time. For VMAT gated delivery, a 40% duty cycle, 2400MU/minute dose rate, and an extra 10 minutes per extra arc were assumed. Conclusion Clinically acceptable plans were

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

    Institute of Scientific and Technical Information of China (English)

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


    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 l-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 < 0.001).No significant difference in the left ventricular reverse remodeling and ventricular tachycardia/ventricular fibrillation (VT/VF) episodes between the TpTe immediately shortened and TpTe immediately nonshortened groups.However,patients in the TpTe at 1-year shorten had a higher rate of the left ventricular (LV) reverse remodeling (65% vs.44%,x2 =4.495,P =0.038) and less VT/VF episodes (log-rank test,x2 =10.207,P =0.001) compared with TpTe 1-year nonshortened group.TpTe immediately after CRT-D independently predicted VT/VF episodes at l-year follow-up (hazard ratio [HR],1.030;P =0.001).Conclusions:Patients with TpTe shortened at l-year after CRT had a higher rate of LV reverse remodeling and less VT/VF episodes.The acute changes of TpTe after CRT have minimal value on mechanical reverse remodeling and ventricular arrhythmia.

  17. [Electrical cardioversion in the treatment of cardiac arrhythmias during pregnancy--case report and review of literature]. (United States)

    Gałczyński, Krzysztof; Marciniak, Beata; Kudlicki, Janusz; Kimber-Trojnar, Zaneta; Leszczyńska-Gorzelak, Bozena; Oleszczukz, Jan


    The incidence of cardiac arrhythmias is estimated et 1.2 per 1000 pregnancies, usually in the third trimester and 50% of them are asymptomatic. They may appear for the first time in pregnancy or have a recurring character An important risk factor related to their appearance is the presence of structural heart disease, which complicates arrhythmias may require urgent, life-saving procedures. External electrical cardioversion is associated with the application of certain amount of energy via two electrodes placed on the thorax. It is used to treat hemodynamically unstable supraventricular tachycardias, including atrial fibrillation and atrial flutter Also in hemodynamically stable patients in whom drug therapy was ineffective elective electrical cardioversion can be use to convert cardiac arrhythmia to sinus rhythm. We present a case of a 33 years old patient with congenital heart disease surgically corrected in childhood who had first incident of atrial flutter in pregnancy. Arrhytmia occured in 26th week of gestation. The patient was hemodynamically stable and did not approve electrical cardioversion as a method of treatment therefore pharmacotherapy was started. Heart rate was controled with metoprolol and digoxin, warfarin was used to anticoagulation. Calcium and potassium were also given. Described therapy did not convert atrial flutter to sinus rhythm therefore in 33rd week of gestation after patient's approval electrical cardioversion was performed. Before cardioversion transesophageal echocardiogram was made to exclude the presence of thrombus inside atria. Energy of 50J was applied and sinus rhythm was restored. Cardiotocography during and after cardioversion did not show any significant fetal heart rate changes. Further pregnancy and puerperium were uneventful. Case report and review of the literature about cardiac arrhytmias and methods of its treatment especially in pregnant women. Analysis of medical documentation of the patient treated in the Department


    NARCIS (Netherlands)



    Objective-In the absence of an obvious cause for cardiac arrest, patients with idiopathic ventricular fibrillation are difficult to manage. A subset of patients has inducible arrhythmias. In others sympathetic excitation plays a role in the onset of the cardiac arrest. This study evaluates a prospec

  19. Reproducibility and diagnostic value of E100 event recorder for patients with complains on heart arrhythmias and no changes on multiple routine ECGs and 24-hour holter monitoring. (United States)

    Rekhviashvili, A; Baganashvili, E; Tan, K Y; Raymakers, F; Sakandelidze, Ts


    Aim of the study was to assess reproducibility and diagnostic value of E100 event recorder for patients with complains on heart arrhythmias and no abnormalities on multiple routine ECGs and/or 24-hour Holter ECG monitoring and the second one, an assessment of adherence and attitude of patients to the E100 event recorder, dependent on the results of self- assessment questionnaires. 24 patients with complains on heart arrhythmias were included in the study. All the patients were provided with the REKA E100 event monitors for 5 ± 2 days and self-assessment questionnaires to assess level of adherence and attitude of patients to the E100 event recorder. E100 event recorders revealed junctional rhythm (n=2), AV nodal reentrant tachycardia (n=2), extrasystolic arrhythmias (n=10), atrial fibrillation (n=2), WPW syndrome (n=4), ventricular tachycardia (n=1), sinus tachycardia (n=7) and complete AV block (n=1). Majority of patients consider device as easy to use, comfortable and safe. In comparison with multiple routine ECGs and 24-hour Holter ECG monitoring, E100 event recorders showed higher reproducibility and efficacy for detecting and interpreting heart arrhythmias.

  20. Effects of glucose-insulin-potassium on baroreflex sensitivity, left ventricular function and ventricular arrhythmia in the subacute phase of myocardial infarction in rats

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Guo; SHU He; SHEN Fu-Ming; MIAO Chao-Yu; SU Ding-Feng


    Objective:Glucose-insulin-potassium(GIK) is clinically used for reducing mortality in acute myocardial infarction(MI). It is known that ventricular arrhythmia, left ventricular dysfunction and impaired baroreflex sensitivity(BRS) are the three major determinants for predicting the mortality after acute MI. The present work was designed to study the effects of GIK on BRS, ventricular arrhythmia, and left ventricular function in rats with coronary artery ligature. Sprague-Dawley rats were used and the myocardial infarction was produced by ligature of the left anterior descending artery. Five weeks after coronary artery ligation, BRS was measured in conscious state with a computerized blood pressure monitoring system and left ventricular function and electrocardiogram were determined in the anaesthetized state in the subacute phase of myocardial infarction. It was found that GIK did not affect the blood pressure and heart period in both conscious and anaesthetized rats. GIK did not enhance BRS, but reduced ventricular arrhythmia and improved left ventricular function by reducing left ventricular end diastolic pressure in anaesthetized rats with MI. It is proposed that reducing ventricular arrhythmia and improving left ventricular function contribute to the effect of GIK on reducing the mortality after MI.


    NARCIS (Netherlands)



    The electropharmacologic effects and pharmacokinetics of almokalant, a new class III antiarrhythmic, were investigated in a randomized, placebo-controlled, double-blind study, and efficacy was evaluated. Ten post-myocardial infarction patients with complex ventricular arrhythmias were included and r

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

  3. 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:; Takayama, Morimasa (Dept. of Cardiology, Sakakibara Heart Inst., Tokyo (Japan)); Kitamura, Mitsunobu (Coronary Care Unit, Chiba-Hokuso Hospital of Nippon Medical School, Chiba (Japan))


    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

  4. Cardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capability and Risk for Cardiac Arrhythmias (United States)

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


    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.

  5. 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.


    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.

  6. Gap junction modifier rotigaptide decreases the susceptibility to ventricular arrhythmia by enhancing conduction velocity and suppressing discordant alternans during therapeutic hypothermia in isolated rabbit hearts

    DEFF Research Database (Denmark)

    Hsieh, Yu-Cheng; Lin, Jiunn-Cherng; Hung, Chen-Ying


    ) and 30°C (P = .042). Rotigaptide did not change connexin43 expressions and distributions during hypothermia. CONCLUSION: Rotigaptide protects the hearts against ventricular arrhythmias by increasing ventricular CV, delaying the onset of SDA, and reducing repolarization heterogeneity during TH. Enhancing...

  7. The effects of respiratory sinus arrhythmia biofeedback on heart rate variability and posttraumatic stress disorder symptoms: a pilot study. (United States)

    Zucker, Terri L; Samuelson, Kristin W; Muench, Frederick; Greenberg, Melanie A; Gevirtz, Richard N


    Recent studies have found a significant association between PTSD and low heart rate variability (HRV), a biomarker of autonomic dysregulation. Research indicates that respiratory sinus arrhythmia (RSA) biofeedback increases HRV while reducing related pathological symptoms. This controlled pilot study compared RSA biofeedback to progressive muscle relaxation (PMR) as adjunctive interventions for 38 persons with PTSD symptoms in a residential treatment facility for a substance use disorder. Both groups were assessed at pre-intervention and 4-week post-intervention. Group x time interactions revealed significantly greater reductions in depressive symptoms and increases in HRV indices for the RSA group. Both groups significantly reduced PTSD and insomnia symptoms and a statistical trend was observed for reduced substance craving for the RSA group. Increases in HRV were significantly associated with PTSD symptom reduction. Overall, these results provide preliminary support for the efficacy of RSA biofeedback in improving physiological and psychological health for individuals with PTSD.

  8. Incidence of periodontitis in Japanese patients with cardiovascular diseases: a comparison between abdominal aortic aneurysm and arrhythmia. (United States)

    Suzuki, Jun-Ichi; Aoyama, Norio; Aoki, Mieko; Tada, Yuko; Wakayama, Kouji; Akazawa, Hiroshi; Shigematsu, Kunihiro; Hoshina, Katsuyuki; Izumi, Yuichi; Komuro, Issei; Miyata, Tetsuro; Hirata, Yasunobu; Isobe, Mitsuaki


    Although there is a link between periodontitis and cardiovascular disease (CVD), the influence of periodontitis on CVD is unclear. The aim of this study was to assess the relationship between periodontal bacterial burden and CVD. We studied 142 patients with tachyarrhythmia (TA) and 25 patients with abdominal aortic aneurysm (AAA). We examined periodontitis and the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Prevotella intermedia in the patients' saliva and subgingival plaque using PCR. We also measured serum antibody titers against the pathogens using ELISA. We found that the patients with AAA had fewer remaining teeth (14.6 ± 2.0 vs. 20.9 ± 0.7, P periodontal bacterium in their saliva or subgingival plaque and serum antibody titers was comparable between the two groups. Periodontitis may have a larger affect on aneurysm progression compared to arrhythmia.

  9. Respiratory sinus arrhythmia: a marker for positive social functioning and receptive language skills in children with autism spectrum disorders. (United States)

    Patriquin, Michelle A; Scarpa, Angela; Friedman, Bruce H; Porges, Stephen W


    The current study builds on the emerging autism spectrum disorder (ASD) literature that associates autonomic nervous system activity with social function, and examines the link between respiratory sinus arrhythmia (RSA) and both social behavior and cognitive function. The RSA response pattern was assessed in 23 4- to 7-year-old children diagnosed with an ASD. Higher baseline RSA amplitudes were associated with better social behavior (i.e., more conventional gestures, more instances of joint attention) and receptive language abilities. Similar to reports of typically developing children, ASD children with higher RSA amplitude at baseline showed greater RSA and HP reactivity during an attention-demanding task. These results highlight the importance of studying RSA as a marker of positive function in children with ASD.

  10. 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;


    : 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....... from the cohort of the 'Copenhagen Holter Study' (n = 671), with no history of manifest cardiovascular (CV) disease or stroke, were studied. All had laboratory tests and 48-h ambulatory electrocardiogram (ECG) recording. The median follow-up was 6.3 years. p-Potassium was inversely associated....... Cardiovascular mortality was higher in the hypokalaemic group (hazard ratio and 95% confidence intervals: 2.62 (1.11-6.18) after relevant adjustments). Hypokalaemia in combination with excessive PVC worsened the prognosis synergistically; event rates: 83 per 1000 patient-year in subjects with both abnormalities...

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

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


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

  12. TCM in Treatment of Arrhythmia%心律失常的中医治疗分析

    Institute of Scientific and Technical Information of China (English)



    Objective To explore chinese medicine in treatment of arrhythmia. Methods 30 cases of patients with arrhythmia accepted the treatment of TCM were analyzed. Results Al the patients were cured in 13 cases,effective in 13 cases,ineffective in 4 cases,the total effective rate was 86.66%. Conclusion Clinical treatment of deficiency syndrome,nourish the heart to calm the mind,empirical. If it is caused by blood stasis should be promoting blood circulation to remove blood stasis. If caused by phlegm heat,should clear thermalization phlegm. If a long il ness,virtual reality,the complex condition of patients,should do both specimens,supplementation and attack.%目的:探讨心律失常的中医治疗方法。方法选取心律失常患者30例的中医治疗资料进行分析。结果所有患者经治疗治愈13例,有效13例,无效4例,总有效率86.66%。结论临床治疗虚证,当以养心安神为主,实证如因瘀血所致,当活血化瘀为法;若因痰热引发,又当清热化痰。若是久病,虚中有实,病情较为复杂者,则宜标本兼顾,攻补兼施。

  13. [Positive microvolt T-wave alternans as a marker of ventricular arrhythmia trigering during cardioverter-defibrillator implantation]. (United States)

    Wierzbowski, Robert; Michałkiewicz, Dariusz; Cholewa, Marian; Jacewicz, Katarzyna; Gniłka, Anna; Adamus, Jerzy


    Microvolt T-wave alternans (MTWA) is promising method for noninvasive assessment of arrhythmic risk, but its role hasn't established yet. The aim of this study was to establish the MTWA potency to predict the ventricular arrhythmia triggering during implantable cordioverter-defibrillator (ICD) implantation. Material and metods. The study group consisted of 21 patients, aged 63.0+/-8.0 years; EF was 38.0+/-12.8%. Seventeen of them had a history of myocardial infarction and 4 had non-ischemic cardiomyopathy. The reason for ICD implantation were secondary prevention due to nonfatal cardiac arrest caused by VF/VT in nineteen patients and in two patients ICD was implanted because of unexplained syncope and low EF (protocol of 50 Hz BURST and T SHOCK was applied. After ICD implantation the following tests were performed: ECG with HR, QRS and QTc evaluation, 24-hour ECG Holter monitoring with HRV assessment and MTWA evaluation during treadmill exercise test. Results. In the group with VT/VF induced by less aggressive protocol (EPS), group I (n = 10) MTWA was present in nine patients, in one the result of MTWA was indeterminate. In the group with VT/VF induced by more aggressive protocol, group II (n = 11) MTWA was present in four patients, indeterminate in four and absent in three. There was a significant (p = 0.017) difference between group I and II in the frequency of positive result of MTWA. There were no differences between the two groups according to time domain parameters of HRV such as SDNN, RMSSD and PNN50 and QTc. There was a significant difference between the two groups in time duration of QRS complexes, 118.9+/-14.7 vs. 105.6+/-11.5 accordingly (p more easily inducible by electrophysiologic study during ICD implantation. It is easier to induce ventricular arrhythmia when QRS complexes are wider, irrelevant to left ventricular dysfunction and autonomic function of the heart.

  14. 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.

  15. Influence of electromagnetic interference on implanted cardiac arrhythmia devices in and around a magnetically levitated linear motor car. (United States)

    Fukuta, Motoyuki; Mizutani, Noboru; Waseda, Katsuhisa


    This study was designed to determine the susceptibility of implanted cardiac arrhythmia devices to electromagnetic interference in and around a magnetically levitated linear motor car [High-Speed Surface Transport (HSST)]. During the study, cardiac devices were connected to a phantom model that had similar characteristics to the human body. Three pacemakers from three manufacturers and one implantable cardioverter-defibrillator (ICD) were evaluated in and around the magnetically levitated vehicle. The system is based on a normal conductive system levitated by the attractive force of magnets and propelled by a linear induction motor without wheels. The magnetic field strength at 40 cm from the vehicle in the nonlevitating state was 0.12 mT and that during levitation was 0.20 mT. The magnetic and electric field strengths on a seat close to the variable voltage/variable frequency inverter while the vehicle was moving and at rest were 0.13 mT, 2.95 V/m and 0.04 mT, 0.36 V/m, respectively. Data recorded on a seat close to the reactor while the vehicle was moving and at rest were 0.09 mT, 2.45 V/m and 0.05 mT, 1.46 V/m, respectively. Measured magnetic and electric field strengths both inside and outside the linear motor car were too low to result in device inactivation. No sensing, pacing, or arrhythmic interactions were noted with any pacemaker or ICD programmed in either bipolar and unipolar configurations. In conclusion, our data suggest that a permanent programming change or a device failure is unlikely to occur and that the linear motor car system is probably safe for patients with one of the four implanted cardiac arrhythmia devices used in this study under the conditions tested.

  16. Role of CaMKII in post acidosis arrhythmias: a simulation study using a human myocyte model. (United States)

    Lascano, Elena C; Said, Matilde; Vittone, Leticia; Mattiazzi, Alicia; Mundiña-Weilenmann, Cecilia; Negroni, Jorge A


    Postacidotic arrhythmias have been associated to increased sarcoplasmic reticulum (SR) Ca(2+) load and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) activation. However, the molecular mechanisms underlying these arrhythmias are still unclear. To better understand this process, acidosis produced by CO2 increase from 5% to 30%, resulting in intracellular pH (pHi) change from 7.15 to 6.7, was incorporated into a myocyte model of excitation-contraction coupling and contractility, including acidotic inhibition of L-type Ca(2+) channel (I(CaL)), Na(+)-Ca(2+) exchanger, Ca(2+) release through the SR ryanodine receptor (RyR2) (I(rel)), Ca(2+) reuptake by the SR Ca(2+) ATPase2a (I(up)), Na(+)-K(+) pump, K(+) efflux through the inward rectifier K(+) channel and the transient outward K(+) flow (I(to)) together with increased activity of the Na(+)-H(+) exchanger (I(NHE)). Simulated CaMKII regulation affecting I(rel), I(up), I(CaL), I(NHE) and I(to) was introduced in the model to partially compensate the acidosis outcome. Late Na(+) current increase by CaMKII was also incorporated. Using this scheme and assuming that diastolic Ca(2+) leak through the RyR2 was modulated by the resting state of this channel and the difference between SR and dyadic cleft [Ca(2+)], postacidotic delayed after depolarizations (DADs) were triggered upon returning to normal pHi after 6 min acidosis. The model showed that DADs depend on SR Ca(2+) load and on increased Ca(2+) leak through RyR2. This postacidotic arrhythmogenic pattern relies mainly on CaMKII effect on I(CaL) and I(up), since its individual elimination produced the highest DAD reduction. The model further revealed that during the return to normal pHi, DADs are fully determined by SR Ca(2+) load at the end of acidosis. Thereafter, DADs are maintained by SR Ca(2+) reloading by Ca(2+) influx through the reverse NCX mode during the time period in which [Na(+)]i is elevated.

  17. Respiratory sinus arrhythmia during anaesthesia: assessment of respiration related beat-to-beat heart rate variability analysis methods. (United States)

    Loula, P; Jäntti, V; Yli-Hankala, A


    Beat-to-beat heart rate variability analysis is a powerful tool for the diagnosis of neuropathy. Respiration-related heart rate variability (respiratory sinus arrhythmia, RSA) reflects the function of parasympathetic nervous system during spontaneous ventilation while awake. RSA is also claimed to monitor the depth of anaesthesia. Power spectrum analysis or various averaging techniques of the heart rate variability are usually applied. The current literature, however, does not usually interpret the ground rules and limitations of the method used, and this may sometimes lead to erroneous conclusions on the data. The aim of our study was to compare and analyse critically the performance of different methods of evaluating RSA during anaesthesia and positive pressure ventilation. Power spectrum analysis, the root mean square of the successive RR-interval difference (RMSSD), and two respiration related methods, RSA index and average phase RSA, were included in the comparison. To test these methods, 11 patients were anaesthetised with isoflurane and their lungs were ventilated mechanically with a frequency of 6 cycles min-1. Each patient received a bolus dose of atropine (20 micrograms kg-1) during the trial. Electrocardiogram, electroencephalogram and tracheal pressure signal from respirator were recorded and analyses were performed off-line. We demonstrated that general indices, such as RMSSD, may be strongly affected by heart rate level and other non-respiration related variations in heart rate. We also showed that the effect of unwanted fluctuations on RSA can be reduced with respiration dependent beat-to-beat methods. Furthermore we confirmed that in addition to the amplitude, also the pattern of respiratory sinus arrhythmia is of interest: the pattern is reversed in phase compared to spontaneous breathing while awake, as we have shown earlier. To analyse RSA during anaesthesia, we recommend the use of an average phase RSA method based on beat-to-beat variability

  18. Efficacy of dofetilide in the treatment of atrial fibrillation-flutter in patients with reduced left ventricular function: a Danish investigations of arrhythmia and mortality on dofetilide (diamond) substudy

    DEFF Research Database (Denmark)

    Pedersen, O D; Bagger, H; Keller, N;


    BACKGROUND: In patients with left ventricular dysfunction, atrial fibrillation and flutter (AF and AFl, respectively) are common arrhythmias associated with increased morbidity and mortality. The present study investigated the potential of dofetilide in AF-AFl patients with left ventricular...

  19. Patient-centred care of patients with ventricular arrhythmias and risk of sudden cardiac death: What do the 2015 European Society of Cardiology guidelines add? (United States)

    Norekvål, Tone M; Kirchhof, Paulus; Fitzsimons, Donna


    Nurses and allied professionals are at the forefront of care delivery in patients with arrythmogenic risk and have a responsibility to deliver care that is focused on their individual needs. The 2015 European Society of Cardiology guideline on prevention of ventricular arrhythmia and sudden cardiac death heralds a step-change in patient and family focus and interdisciplinary involvement. This development reflects a recognition within the European Society of Cardiology that chronic care of patients with cardiovascular conditions can be improved by involving all stakeholders, making use of multidisciplinary interventions, and placing the patient at the centre of the care process. In this article, taskforce contributors discuss the latest evidence and highlight some of the most pertinent issues for nurses involved in patient-centred care of patients and families with ventricular arrhythmias and/or risk of sudden death.

  20. Study on diagnosis to remote ECG monitoring for arrhythmia%远程心电监测对心律失常的诊断研究

    Institute of Scientific and Technical Information of China (English)

    韩伟华; 姚锦容; 林永霞; 黎文婷


    Objective To investigate the application value of remote ECG monitoring for arrhythmia diagnosis.Methods From April 2010 to December 2011, 80 cases of arrhythmia patients treated in our hospital were.chosen,at first,each patient had a 24-hour Holter monitoring.After the end of Holter monitoring,80 patients had the remote ECG monitoring, then we analyzed the ECG data of the two monitoring methods.Arthythmia detection rates of the two methods were calculated.The arrhythmia detection rates were compared and the types of arrhythmia were analyzed.Results The arrhythmia detection rate of 24-hour ambulatory ECG was 52.5%,3 cases were detected irregular arrhythmia; the detection rate of remote ECG monitoring was 86.3%,2 cases detected irregular arrhythmia(P < 0.05).Conclusion Remote ECG monitoring can not only bring convenience to the arrhythmia diagnosis,but also has a higher detection rate,a certain detection to irregular heart rate.It is a strong complement of hospital routine heart rate diagram check and 24-hour Holter.So remote ECG monitoring has a great significance in the clinical diagnosis of abnormal heart rhythms.%目的 探讨远程心电监测对心律失常诊断的应用价值.方法 选取2010年4月-2011年12月来我院就诊的80例心律失常患者,每位患者先进行24小时动态心电图监测,动态心电图监测结束后再进行远程心电监测.分析两种监测方法所得的心电数据,计算心律失常检出率,比较心律失常检出率并对两种方法检测出的心律失常患者进一步行心律失常类型分析.结果 24小时动态心电图中,心律失常检出率为52.5%,不规则心律失常患者检出3例;远程心电监测的心律失常检出率为86.3%,不规则心律失常患者检出2例(P<0.05).结论 远程心电监测不仅可以实行远程心电记录给心律失常诊断带来便利,检出率较高,而且对不规则心律失常也有一定检出率,是院内常规心电图检查和24小时动态

  1. Antipsychotic Drugs and the Risk of Ventricular Arrhythmia and/or Sudden Cardiac Death: A Nation‐wide Case‐Crossover Study



    Background Antipsychotics have been linked to prolongation of the QT interval. However, little is known about the risk of ventricular arrhythmia (VA) and/or sudden cardiac death (SCD) associated with individual antipsychotic drug use. This study was designed to investigate the association between specific antipsychotic drugs and the risk of VA and/or SCD. Methods and Results We conducted a case‐crossover study using a nation‐wide population‐based sample obtained from Taiwan's National Health ...

  2. 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


    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.

  3. Plakophilin-2 c.419C>T and risk of heart failure and arrhythmias in the general population

    DEFF Research Database (Denmark)

    Christensen, Alex Hørby; Kamstrup, Pia Rørbœk; Gandjbakhch, Estelle;


    in cells transfected with wild-type or mutant plakophilin-2. In conclusion, combining epidemiological data, with data on patients referred for genetic testing for ARVC or HCM/DCM, and data from in vitro studies, PKP2 c.419C>T did not associate with heart failure, arrhythmias, or premature death, with ARVC...... or HCM/DCM, or with effects in vitro, suggesting that this is not a disease-causing variant....

  4. The Effect of a Novel Highly Selective Inhibitor of the Sodium/Calcium Exchanger (NCX) on Cardiac Arrhythmias in In Vitro and In Vivo Experiments


    Kohajda, Zsófia; Farkas-Morvay, Nikolett; Jost, Norbert; Nagy, Norbert; Geramipour, Amir; Horváth, András; Varga, Richárd S.; Hornyik, Tibor; Corici, Claudia; Acsai, Károly; Horváth, Balázs; Prorok, János; Ördög, Balázs; Déri, Szilvia; Tóth, Dániel


    Background In this study the effects of a new, highly selective sodium-calcium exchanger (NCX) inhibitor, ORM-10962 were investigated on cardiac NCX current, Ca2+ transients, cell shortening and in experimental arrhythmias. The level of selectivity of the novel inhibitor on several major transmembrane ion currents (L-type Ca2+ current, major repolarizing K+ currents, late Na+ current, Na+/K+ pump current) was also determined. Methods Ion currents in single dog ventricular cells (cardiac myocy...

  5. Selective Kv1.5 blockers: development of (R)-1-(methylsulfonylamino)-3-[2-(4-methoxyphenyl)ethyl]-4-(4-methoxyphenyl)-2-imidazolidinone (KVI-020/WYE-160020) as a potential treatment for atrial arrhythmia. (United States)

    Blass, Benjamin E; Fensome, Andrew; Trybulski, Eugene; Magolda, Ronald; Gardell, Stephen J; Liu, Kun; Samuel, Manoj; Feingold, Irene; Huselton, Christine; Jackson, Chris M; Djandjighian, Laurent; Ho, Douglas; Hennan, James; Janusz, John M


    Atrial fibrillation is the most prevalent form of cardiac arrhythmia. Current treatments extend the atrial effective refractory period by nonselective blockade of cardiac ion channels. An alternative approach selectively targeting the Kv1.5 ion channel offers the opportunity for therapeutic benefit with decreased risk of adverse cardiovascular events. KVI-020 (4g) successfully demonstrated antiarrhythmic efficacy in a canine arrhythmia model, and these findings support its utility as an antiarrhythmic agent.

  6. Arrhythmia Detection in Pediatric Patients: ECG Quality and Diagnostic Yield of a Patient-Triggered Einthoven Lead-I Event Recorder (Zenicor EKG-2™). (United States)

    Usadel, Lea; Haverkämper, Guido; Herrmann, Susanne; Löber, Rebekka; Weiss, Katja; Opgen-Rhein, Bernd; Berger, Felix; Will, Joachim C


    Symptoms that may be caused by arrhythmia are common in pediatric outpatient departments, though it remains challenging to reveal paroxysmal tachycardia. This investigation evaluated prospectively the quality and diagnostic yield of a newly available handheld patient-activated event recorder (ER) in children. In 226 children (pts) aged 0-17 years with or without congenital heart defects, pacemaker/ICDs or arrhythmia, a lead-I ER ECG was created. ER ECGs were recorded by pressing the patients' thumbs on the device and were analyzed in comparison with a lead-12 ECG, as gold standard. Event recording and data transmission were possible in all cases. ECG quality of the ER showed a high accordance in measuring heart rate (ICC = 0.962), duration of QRS complexes (κ = 0.686), and PR interval (ICC = 0.750) (p < 0.001) although P wave detection remained challenging (p = 0.120). 36 % (n = 82) of the pts had heart rhythm disturbances. The ER yielded 92 % sensitivity in diagnosing supraventricular tachycardia plus 77 % sensitivity and 92 % specificity in identifying abnormal ECGs. In children, the application of the tested ER was suitable. ECGs of good quality could be performed and transmitted easily, and also complex arrhythmia analysis was possible. This ER is an excellent diagnostic device for the detection and exclusion of tachycardia in children.

  7. Use of an Implantable Loop Recorder in a Chimpanzee (Pan troglodytes) to Monitor Cardiac Arrhythmias and Assess the Effects of Acupuncture and Laser Therapy. (United States)

    Magden, Elizabeth R; Sleeper, Meg M; Buchl, Stephanie J; Jones, Rebekah A; Thiele, Erica J; Wilkerson, Gregory K


    Cardiovascular disease is a leading cause of death in captive chimpanzees and is often associated with myocardial fibrosis, which increases the risk of cardiac arrhythmias. In this case report, we present a 36-y-old male chimpanzee (Pan troglodytes) diagnosed with frequent ventricular premature complexes (VPC). We placed a subcutaneous implantable loop recorder for continual ECG monitoring to assess his arrhythmias without the confounding effects of anesthetics. During his initial treatment with the antiarrhythmia medication amiodarone, he developed thrombocytopenia, and the drug was discontinued. After reviewing other potential therapies for the treatment of cardiac arrhythmias, we elected to try acupuncture and laser therapy in view of the positive results and the lack of adverse side effects reported in humans. We used 2 well-known cardiac acupuncture sites on the wrist, PC6 (pericardium 6) and HT7 (heart 7), and evaluated the results of the therapy by using the ECG recordings from the implantable loop recorder. Although periodic increases in the animal's excitement level introduced confounding variables that caused some variation in the data, acupuncture and laser therapy appeared to decrease the mean number of VPC/min in this chimpanzee.

  8. Distinct effects of acute pretreatment with lipophilic and hydrophilic statins on myocardial stunning, arrhythmias and lethal injury in the rat heart subjected to ischemia/reperfusion. (United States)

    Čarnická, S; Adameová, A; Nemčeková, M; Matejíková, J; Pancza, D; Ravingerová, T


    Although both lipophilic and more hydrophilic statins share the same pathway of the inhibition of HMG-CoA reductase, their pleiotropic cardioprotective effects associated with the ability to cross cellular membranes, including membranes of heart cells, may differ. To test this hypothesis, isolated rat hearts were Langendorff-perfused either with simvastatin (S, 10 micromol/l) or pravastatin (P, 30 micromol/l), 15 min prior to ischemia. Control untreated hearts (C) were perfused with perfusion medium only. Postischemic contractile dysfunction, reperfusion-induced ventricular arrhythmias and infarct size were investigated after exposure of the hearts to 30-min global ischemia and 2-h reperfusion. Both lipophilic S and hydrophilic P reduced the severity of ventricular arrhythmias (arrhythmia score) from 4.3 +/- 0.2 in C to 3.0 +/- 0 and 2.7 +/- 0.2 in S and P, respectively, (both P statins indicating a different ability to cross cardiac membranes may underlie their distinct cardioprotective effects on myocardial stunning and lethal injury induced by ischemia/reperfusion.

  9. The risk of life-threatening ventricular arrhythmias in presence of high-intensity endurance exercise along with chronic administration of nandrolone decanoate. (United States)

    Abdollahi, Farzane; Joukar, Siyavash; Najafipour, Hamid; Karimi, Abdolah; Masumi, Yaser; Binayi, Fateme


    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.

  10. Comparative usefulness of beat-to-beat QT dispersion and QT interval fluctuations for identifying patients with organic heart disease at risk for ventricular arrhythmias. (United States)

    Galeano, Erdulfo J; Yoshida, Akihiro; Ohnishi, Yoshio; Okajima, Katsunori; Ishida, Akihiko; Kitamura, Hidetsuna; Kubo, Shinya; Yokoyama, Mitsuhiro


    The comparative usefulness of 10 min of beat-to-beat 12-lead QT dispersion (QTd) and QT interval variability index (QTVI) analysis for identifying patients with organic heart disease (OHD) at risk for ventricular arrhythmias was assessed in 86 subjects: 54 had OHD without a history of ventricular arrhythmias, 15 had OHD with documented ventricular tachycardia, and there were 17 controls. The following parameters were analyzed among the groups: (1) the average QTd (mean QTd), (2) the difference between the maximum and minimum QTd observed over the recording time (QTd variation), (3) the maximum difference of QTd between consecutive beats (QTd maximum), (4) the QTd standard deviation (QTd variability), and (5) QTVI, calculated in lead I or II according to an established formula: log 10 [(QTv/QTm2) / (HRv/HRm2)]. All the analyzed parameters were significantly increased in the patients with and without ventricular tachycardia when compared with the controls. QTd variation, QTd maximum and QTd variability were the only variables that remained significantly increased in the group of patients with documented ventricular tachycardia, compared with those without arrhythmia. Thus, beat-to-beat fluctuations of both the QT interval and QTd may be markers of temporal electrical instability in patients with OHD.

  11. Patient experience with a novel patch-like external loop recorder for cardiac arrhythmia detection in India. (United States)

    Shrivastav, Maneesh; Padte, Sanjay; Sinha, Nakul


    Cardiovascular disease (CVD) is reaching pandemic proportions in India. The effects of CVD are disastrous for the Indian economy as the disease strikes in the prime working ages of the labor force. The great need for therapeutic and diagnostic options combined with pressure on cost containment place emphasis on the development of low cost, credible, point of care diagnostic tools to pinpoint issues in cardiac health for the Indian consumer. A previous study of 125 patients in India examined a novel external loop recorder (ELR) for ambulatory ECG monitoring with high yield and compliance. The current study probes the patient experience, inclusive of patient comfort, ease of use, clarity of the diagnostic report, and value of the ELR. The analysis shows that 85% found this ELR comfortable to wear and deploy, 77% responded with no challenges with the use of this ELR, 60% mentioned they were inclined to seek treatment after this ELR was deployed, and 60% found good value in the device. The results indicate that this particular ELR is a high performing device with excellent patient satisfaction, indicating that the device is a suitable tool for diagnosis of cardiac arrhythmia in India.

  12. Relational victimization and proactive versus reactive relational aggression: The moderating effects of respiratory sinus arrhythmia and skin conductance. (United States)

    Wagner, Caitlin R; Abaied, Jamie L


    This research examined the moderating effect of the autonomic nervous system (ANS) on the associations between relational victimization and reactive and proactive relational aggression. Both branches of the ANS, the parasympathetic nervous system (indexed by respiratory sinus arrhythmia reactivity; RSA-Reactivity) and the sympathetic nervous system (indexed by skin conductance level reactivity; SCL-Reactivity), were examined. Emerging adults (N = 168) self-reported on relational victimization and proactive and reactive relational aggression; RSA-Reactivity and SCL-Reactivity were assessed in response to a laboratory stressor. Relational victimization predicted heightened reactive relational aggression given RSA augmentation/high SCL-Reactivity (i.e., coactivation) and RSA withdrawal/low SCL-Reactivity (i.e., coinhibition). In addition, relational victimization predicted heightened reactive relational aggression given RSA augmentation/low SCL-Reactivity (i.e., reciprocal parasympathetic activation). This study extends previous research on relational victimization and provides novel evidence that (a) exposure to relational victimization is associated with reactive relational aggression, but not proactive relational aggression, and (b) parasympathetic and sympathetic nervous system reactivity jointly moderate the link between relational victimization and reactive relational aggression.

  13. Broad implications for respiratory sinus arrhythmia development: associations with childhood symptoms of psychopathology in a community sample. (United States)

    Patriquin, Michelle A; Lorenzi, Jill; Scarpa, Angela; Calkins, Susan D; Bell, Martha Ann


    Replicating the group-based developmental trajectory methodology from our prior study (Patriquin, Lorenzi, Scarpa, & Bell. 2014. Developmental Psychobiology, 56, 317-326), the current study examines the development of baseline respiratory sinus arrhythmia (RSA) across a new, larger cohort of typically developing children at 5, 10, 24, 36, and 48 months of age and examines the trajectory relationship with symptoms of childhood psychopathology. Group-based developmental trajectory modeling replicated our prior findings of a two-group model fit: a "High RSA" and "Low RSA" group. The "Low RSA" group, which demonstrated lower baseline RSA across all time points, had significantly more childhood problems at 48 months, namely increased withdrawal, aggressive behavior, pervasive developmental problems, and oppositional defiant problems. All participants for whom there were developmental or autism spectrum concerns (n = 6; based on maternal report at 48 months) were allocated to the Low RSA trajectory group. These results suggest that consistent developmental trajectories of RSA may point to protective factors (i.e., high RSA) against developing symptoms of childhood psychopathology.

  14. 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.

  15. [Late arrhythmias in the operated interatrial communication. Analysis of sinus node function and the conduction pathways by His bundle electrocardiography]. (United States)

    Ramírez, A; Gil, M; Martínez Ríos, M A; Cárdenas, M; Pliego, J; Zamora, C; Mata, L A


    Four hundred patients with atrial septal defect treated surgically were reviewed. Thirty five (8.7%) developed arrhytmias post-surgery which persisted for over a year. Sinus bradycardia was found in 10 patients, nodal rhythm in 21, and atrial fibrilation and flutter in 4 patients. Thirty five per cent of the patients with late arrhythmias developed related symptomatology. In 14 patients the function of the sinus node was studied with electrical stimulation of the atrium and with His registry. The interatrial conduction time, AV node and His Purkinje were analized employing various stimulation frequencies. All the cases studied had normal intra-atrial conduction; the response of the atrio-ventricular node to increasing frequencies was normal, an the intraventricular conduction remained constant. In 8 patients (52%), alterations of the sinus node were found; these consisted of prolonged post-stimulation pauses, Wenckebach's type sinoatrial block and suppression of sinus automatism employing vagal procedures or through electrical stimulation. A patient with severe bradycardia detected by dynamic electrocardiography had to be treated with a permanent pacemaker. We confirm that these arrhytmias are not produced by lesions of the internodal tracts, and that an alteration of the sinus node is frequent without a concomitant lesion of the intraventricular pathway. The lesion to the nutrient artery could be due to trauma and/or surgically induced. The response to anticholinergic drugs was good. Prolonged observation of these patients could increase the morbility of these arrythmias and raise doubts of the surgical indications in cases with moderate hemodynamic repercussion.

  16. Respiratory Sinus Arrhythmia as an Index of Vagal Activity during Stress in Infants: Respiratory Influences and Their Control (United States)

    Ritz, Thomas; Bosquet Enlow, Michelle; Schulz, Stefan M.; Kitts, Robert; Staudenmayer, John; Wright, Rosalind J.


    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

  17. Respiratory sinus arrhythmia as an index of vagal activity during stress in infants: respiratory influences and their control.

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    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.

  18. Metoprolol in acute myocardial infarction reduces ventricular arrhythmias both in the early stage and after the acute event. (United States)

    Rehnqvist, N; Olsson, G; Erhardt, L; Ekman, A M


    Fifty three of the 5778 patients included in the MIAMI (Metoprolol in Acute Myocardial Infarction) trial were investigated with long-term ECG recordings in order to evaluate the effect of acute beta-blockade on premature ventricular complexes in and after acute myocardial infarction. Twenty five patients were given placebo and 28 metoprolol in a double-blind randomized fashion for 15 days. After this period the patients were put on open beta-blockade without breaking individual study codes. The mean number of premature ventricular complexes during the inclusion day (day 0) was the same in the two groups. The median numbers were also similar in the two groups: 190 and 154 in the placebo and metoprolol groups, respectively. Metoprolol significantly reduced the median number of premature ventricular complexes in the randomized period. The median numbers on days 1, 2 and 15 were 146, 101, 84 in the placebo group and 73, 59 and 10 in the metoprolol group, respectively (P less than 0.05). Also during the further follow-up, when investigated 1, 3 and 6 months after the infarction, the median number of premature ventricular complexes was lower in the metoprolol group (74, 257, 142 in the placebo group and 7, 5 and 11 in the metoprolol group, P less than 0.05). This indicates that metoprolol treatment in the acute phase of myocardial infarction reduces ventricular arrhythmias both in the early stage and also after the acute event.

  19. Child sex and respiratory sinus arrhythmia reactivity as moderators of the relation between internalizing symptoms and aggression. (United States)

    Aults, Christopher D; Cooper, Patrick J; Pauletti, Rachel E; Jones, Nancy Aaron; Perry, David G


    Previous studies have examined sex differences in physiological responding, including respiratory sinus arrhythmia (RSA) reactivity in response to changing stimulus conditions involving situation specific or gender related cues, in children and adolescents. The present study examined whether RSA reactivity moderates the relation between aggression and internalizing symptoms and whether there are sex differences in this effect. Participants were 82 adolescents (M age = 12.1 years; 44 girls) from the general middle-school population. Peer nominations assessed aggression and internalizing symptoms, and RSA reactivity (defined as change in RSA from baseline to task) was recorded while participants anticipated and responded to an 85 dB signaled white-noise burst. For girls, internalizing symptoms were associated with aggression only if girls showed low RSA reactivity from baseline to task; there was no effect for boys. This association was absent when girls showed high RSA reactivity. Thus, child sex appears to influence not only levels of physiological responding but also relations of physiological responding to comorbidity of adjustment problems.

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

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    Achá Renato Enrique Sologuren


    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.

  1. Randomized cluster crossover trials for reliable, efficient, comparative effectiveness testing: design of the Prevention of Arrhythmia Device Infection Trial (PADIT). (United States)

    Connolly, Stuart J; Philippon, Francois; Longtin, Yves; Casanova, Amparo; Birnie, David H; Exner, Derek V; Dorian, Paul; Prakash, Ratika; Alings, Marco; Krahn, Andrew D


    Randomized clinical trials are a major advance in clinical research methodology. However, there are myriad important questions about the effectiveness of treatments used in daily practice that are not informed by the results of randomized trials. This is in part because of important limitations inherent in the methodology of randomized efficacy trials which are performed with tight control of inclusion, exclusion, treatment, and follow-up. This approach enhances evaluation of clinical efficacy (performance in controlled situations) but increases complexity and is not well suited to test clinical effectiveness (performance under conditions of actual use). The cluster crossover trial is a new concept for efficient comparative effectiveness testing. Deep tissue infection occurs in 2% of patients after arrhythmia device implantation, usually requires system extraction, and increases mortality. There is variation in antibiotic prophylaxis used to reduce implanted device infections. To efficiently evaluate the comparative effectiveness of antibiotic strategies now in use, we designed a cluster crossover clinical trial, which randomized implanting centres to 1 of 2 prophylactic antibiotic strategies, which became the standard care at the centre for 6 months, followed by crossover to the other strategy, rerandomization, and second crossover. This method greatly reduces trial complexity because it aligns study procedures with usual clinical care and increases generalizability. Pilot studies have tested the feasibility and an 10,800-patient trial, funded by the Canadian Institutes of Health Research, is now under way. The cluster crossover randomized trial design is well suited to efficiently test comparative effectiveness of existing treatments where there is variability of practice, clinical equipoise, and minimal risk.

  2. Improving Detection of Arrhythmia Drug-Drug Interactions in Pharmacovigilance Data through the Implementation of Similarity-Based Modeling.

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    Santiago Vilar

    Full Text Available Identification of Drug-Drug Interactions (DDIs is a significant challenge during drug development and clinical practice. DDIs are responsible for many adverse drug effects (ADEs, decreasing patient quality of life and causing higher care expenses. DDIs are not systematically evaluated in pre-clinical or clinical trials and so the FDA U. S. Food and Drug Administration relies on post-marketing surveillance to monitor patient safety. However, existing pharmacovigilance algorithms show poor performance for detecting DDIs exhibiting prohibitively high false positive rates. Alternatively, methods based on chemical structure and pharmacological similarity have shown promise in adverse drug event detection. We hypothesize that the use of chemical biology data in a post hoc analysis of pharmacovigilance results will significantly improve the detection of dangerous interactions. Our model integrates a reference standard of DDIs known to cause arrhythmias with drug similarity data. To compare similarity between drugs we used chemical structure (both 2D and 3D molecular structure, adverse drug side effects, chemogenomic targets, drug indication classes, and known drug-drug interactions. We evaluated the method on external reference standards. Our results showed an enhancement of sensitivity, specificity and precision in different top positions with the use of similarity measures to rank the candidates extracted from pharmacovigilance data. For the top 100 DDI candidates, similarity-based modeling yielded close to twofold precision enhancement compared to the proportional reporting ratio (PRR. Moreover, the method helps in the DDI decision making through the identification of the DDI in the reference standard that generated the candidate.

  3. The role of cromakalim and a nitric oxide synthase blocker in cardiac arrhythmia in the intact baboon model. (United States)

    Hay, L; Schutte, P J; Du Plooy, W J; Kahler, C P


    The arrhythmogenic effect of adenosine triphosphate (ATP)-sensitive potassium channel openers is controversial and may be dependent on the type of animal model used. Information on the effect of these drugs in the normal primate model is limited. The purpose of this study was first to determine the arrhythmogenic properties of cromakalim in the baboon and second to determine whether N-omega-nitro-L-arginine methyl ester (L-NAME) has any effect on the induced arrhythmia. Adult (2-4 years old) baboons (Papio ursinus) were anesthetized with a continuous i.v. infusion of ketamine (100 mg/ ml), diazepam (5 mg/ml), and saline (ratio 2:2:50) at a rate of 40-60 ml/h. Sympathetic responses were inhibited by administration of propranolol (1 mg/kg) before the start of the experiments. Cromakalim (30 microg/kg) was administered before and after L-NAME (7.5 mg/kg), and the parameters were monitored for 15 min after each intervention. A Millar double-tipped microcatheter was used to record left ventricular and aortic pressures. Lead II of the ECG was monitored. During a 15-min period after administration of cromakalim, 22.3 +/- 6.0 abnormal ventricular complexes were recorded. L-NAME administration significantly reduced these abnormal complexes to 4.5 +/- 2 (paired t test, p < or = 0.05). We therefore conclude that cromakalim has arrhythmogenic properties in the baboon and that these can be attenuated by L-NAME.

  4. Effect of regional differences in cardiac cellular electrophysiology on the stability of ventricular arrhythmias: a computational study (United States)

    Clayton, Richard H.; Holden, Arun V.


    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.

  5. Drug-induced Inhibition and Trafficking Disruption of ion Channels: Pathogenesis of QT Abnormalities and Drug-induced Fatal Arrhythmias. (United States)

    Cubeddu, Luigi X


    Risk of severe and fatal ventricular arrhythmias, presenting as Torsade de Pointes (TdP), is increased in congenital and acquired forms of long QT syndromes (LQTS). Drug-induced inhibition of K+ currents, IKs, IKr, IK1, and/or Ito, delay repolarization, prolong QT, and increase the risk of TdP. Drug-induced interference with IKr is the most common cause of acquired LQTS/TdP. Multiple drugs bind to KNCH2-hERG-K+ channels affecting IKr, including antiarrythmics, antibiotics, antivirals, azole-antifungals, antimalarials, anticancer, antiemetics, prokinetics, antipsychotics, and antidepressants. Azithromycin has been recently added to this list. In addition to direct channel inhibition, some drugs interfere with the traffic of channels from the endoplasmic reticulum to the cell membrane, decreasing mature channel membrane density; e.g., pentamidine, geldalamicin, arsenic trioxide, digoxin, and probucol. Other drugs, such as ketoconazole, fluoxetine, norfluoxetine, citalopram, escitalopram, donepezil, tamoxifen, endoxifen, atazanavir, and roxitromycin, induce both direct channel inhibition and impaired channel trafficking. Although many drugs prolong the QT interval, TdP is a rare event. The following conditions increase the risk of drug-induced TdP: a) Disease states/electrolyte levels (heart failure, structural cardiac disease, bradycardia, hypokalemia); b) Pharmacogenomic variables (presence of congenital LQTS, subclinical ion-channel mutations, history of or having a relative with history of drug-induced long QT/TdP); c) Pharmacodynamic and kinetic factors (high doses, women, elderly, metabolism inhibitors, combining two or more QT prolonging drugs, drugs that prolong the QT and increase QT dispersion, and drugs with multiple actions on ion channels). Because most of these conditions are preventable, careful evaluation of risk factors and increased knowledge of drug use associated with repolarization abnormalities are strongly recommended.

  6. Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

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    Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia [University Hospital of Pisa, Cardio-Thoracic and Vascular Department, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)


    To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic {sup 99m}Tc-tetrofosmin and {sup 123}I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target

  7. Spatial memory and long-term object recognition are impaired by circadian arrhythmia and restored by the GABAAAntagonist pentylenetetrazole. (United States)

    Ruby, Norman F; Fernandez, Fabian; Garrett, Alex; Klima, Jessy; Zhang, Pei; Sapolsky, Robert; Heller, H Craig


    Performance on many memory tests varies across the day and is severely impaired by disruptions in circadian timing. We developed a noninvasive method to permanently eliminate circadian rhythms in Siberian hamsters (Phodopus sungorus) [corrected] so that we could investigate the contribution of the circadian system to learning and memory in animals that are neurologically and genetically intact. Male and female adult hamsters were rendered arrhythmic by a disruptive phase shift protocol that eliminates cycling of clock genes within the suprachiasmatic nucleus (SCN), but preserves sleep architecture. These arrhythmic animals have deficits in spatial working memory and in long-term object recognition memory. In a T-maze, rhythmic control hamsters exhibited spontaneous alternation behavior late in the day and at night, but made random arm choices early in the day. By contrast, arrhythmic animals made only random arm choices at all time points. Control animals readily discriminated novel objects from familiar ones, whereas arrhythmic hamsters could not. Since the SCN is primarily a GABAergic nucleus, we hypothesized that an arrhythmic SCN could interfere with memory by increasing inhibition in hippocampal circuits. To evaluate this possibility, we administered the GABAA antagonist pentylenetetrazole (PTZ; 0.3 or 1.0 mg/kg/day) to arrhythmic hamsters for 10 days, which is a regimen previously shown to produce long-term improvements in hippocampal physiology and behavior in Ts65Dn (Down syndrome) mice. PTZ restored long-term object recognition and spatial working memory for at least 30 days after drug treatment without restoring circadian rhythms. PTZ did not augment memory in control (entrained) animals, but did increase their activity during the memory tests. Our findings support the hypothesis that circadian arrhythmia impairs declarative memory by increasing the relative influence of GABAergic inhibition in the hippocampus.

  8. Prediction of very late arrhythmia recurrence after radiofrequency catheter ablation of atrial fibrillation: The MB-LATER clinical score (United States)

    Mujović, Nebojša; Marinković, Milan; Marković, Nebojša; Shantsila, Alena; Lip, Gregory Y. H.; Potpara, Tatjana S.


    Reliable prediction of very late recurrence of atrial fibrillation (VLRAF) occuring >12 months after catheter ablation (CA) in apparently “cured” patients could optimize long-term follow-up and modify decision-making regarding the discontinuation of oral anticoagulant therapy. In a single-centre cohort of consecutive patients post radiofrequency AFCA, we retrospectively derived a novel score for VLRAF prediction. Of 133 consecutive post AFCA patients (mean age 56.9 ± 11.8 years, 63.9% male, 69.2% with paroxysmal AF) who were arrhythmia-free at 12 months (excluding 3-month “blanking period”), 20 patients expirienced a VLRAF during a 29.1 ± 10.1-month follow-up, with a 3-year cumulative VLRAF rate of 31.1%. The MB-LATER score (Male, Bundle brunch block, Left atrium ≥47 mm, Type of AF [paroxysmal, persistent or long-standing persistent], and ER-AF = early recurrent AF), had better predictive ability for VLRAF (AUC 0.782) than the APPLE, ALARMc, BASE-AF2, CHADS2, CHA2DS2VASc or HATCH score (AUC 0.716, 0.671, 0.648, 0.552, 0.519 and 0.583, respectively), resulted in an improved net reclassification index (NRI) of 48.6–95.1% and better identified patients with subsequent VLRAF using decision-curve analysis (DCA). The MB-LATER score provides a readily available VLRAF risk assessment, and performs better than other scores. Validation of the MB-LATER score in other cohorts is underway. PMID:28106147

  9. Weather-induced ischemia and arrhythmia in patients undergoing cardiac rehabilitation: another difference between men and women (United States)

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


    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.

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

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    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.

  11. 低钾血症致心律失常的心电图特点与临床分析%Hypokalemia Induced Arrhythmia ECG Characteristics and Clinical Analysis

    Institute of Scientific and Technical Information of China (English)



    目的:探讨低钾血症致心律失常的心电图特点与临床的关系。方法分析160例低钾血症所致心律失常的低钾病因、临床表现、血钾浓度与心律失常关系及心律失常的转归。结果低钾血症所致的心律失常多见于急性失钾的青壮年,血钾降低的程度与心律失常的发生率,其差异有高度显著性P<0.01;血钾越低,心律失常发生率越高。结论除重症室性心律失常外,通常的病例经积极有效补钾后,病情好转快,预后好,不急于使用抗心律失常药物,以避免引发更严重的心律失常。%Objective To study the hypokalemia induced arrhythmia characteristics and the relationship between clinical electrocardiogram (ECG). Methods Analysis of 160 cases with arrhythmia induced by hypokalemia low potassium etiology, clinical manifestation, potassium concentration relation with arrhythmia and outcome of cardiac arrhythmias.Results The cardiac arrhythmias of hypokalemia caused by acute potassium loss of young adults, see more at the extent of the potassium lower and the incidence of arrhythmia, highly signifi cant difference (P < 0.01); Potassium is lower, the higher the incidence of arrhythmia. Conclusion In addition to the severe ventricular arrhythmia, usually cases after positive and effective complement potassium, improved fast, prognosis is good, don't rush to the use of anti-arrhythmic drugs, in order to avoid caused more serious arrhythmia.

  12. Comparison of four single-drug regimens on ventricular rate and arrhythmia-related symptoms in patients with permanent atrial fibrillation. (United States)

    Ulimoen, Sara R; Enger, Steve; Carlson, Jonas; Platonov, Pyotr G; Pripp, Are H; Abdelnoor, Michael; Arnesen, Harald; Gjesdal, Knut; Tveit, Arnljot


    Rate control of atrial fibrillation (AF) is a main treatment modality. However, data are scarce on the relative efficacy of calcium channel blockers and β blockers or between drugs within each class. The purpose of the present study was to compare the effect of 4 rate-reducing, once-daily drug regimens on the ventricular heart rate and arrhythmia-related symptoms in patients with permanent AF. We included 60 patients (mean age 71 ± 9 years, 18 women) with permanent AF in an investigator-blind cross-over study. Diltiazem 360 mg/day, verapamil 240 mg/day, metoprolol 100 mg/day, and carvedilol 25 mg/day were administered for 3 weeks in a randomized sequence. The 24-hour heart rate was measured using Holter monitoring, and arrhythmia-related symptoms were assessed using the Symptom Checklist questionnaire before randomization and on the last day of each treatment period. The 24-hour mean heart rate was 96 ± 12 beats/min at baseline (no treatment), 75 ± 10 beats/min with diltiazem, 81 ± 11 beats/min with verapamil, 82 ± 11 beats/min with metoprolol, and 84 ± 11 beats/min with carvedilol. All drugs reduced the heart rate compared to baseline (p <0.001 for all). The 24-hour heart rate was significantly lower with diltiazem than with any other drug tested (p <0.001 for all). Compared to baseline, diltiazem significantly reduced both the frequency (p <0.001) and the severity (p = 0.005) of symptoms. In contrast, verapamil reduced symptom frequency only (p = 0.012). In conclusion, diltiazem 360 mg/day was the most effective drug regimen for reducing the heart rate in patients with permanent AF. Arrhythmia-related symptoms were reduced by treatment with the calcium channel blockers diltiazem and verapamil, but not by the β blockers.

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

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    Stoičkov Viktor


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

  14. Chiropractic Treatment of Cervicogenic Arrhythmia in 34 Cases%整脊法治疗颈源性心律失常34例

    Institute of Scientific and Technical Information of China (English)



      目的:观察整脊法治疗颈源性心律失常的临床疗效.方法:将70例颈源性心律失常患者随机分为治疗组和对照组,治疗组采用定点旋转复位法治疗,对照组采用常规推拿治疗,两各疗程后观察疗效.结果:治疗组总有效率94.1%,对照组总有效率75.0%,治疗组高于对照组(P<0.05).结论:整脊法治疗颈源性心律失常操作安全,疗效显著,值得推广.%Objective: To observe the clinical effect of chiropractic therapy with cervicogenic arrhythmia. Methods: 70 cases of cervi-cogenic arrhythmia patients were randomly divided into treatment group and control group, treatment group were treated with Fixed-point rotation reduction method, while the control group adopted conventional massage therapy, and observed curative effect after two courses. Results: The total effective rate of treatment group was 94.1%, that of control group was 75%, the treatment group was better than treatment group (P<0.05). Conclusion: Chiropractic treatment of cervicogenic arrhythmia is operational safety and obvious curative effect, which is worth if promotion.

  15. 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)


    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.)

  16. Long QT, alteration of calcium-phosphate product, prevalence of ventricular arrhythmias and sudden death in peritoneal dialysis patients: a Holter study

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    Pierluigi Di Loreto


    Full Text Available Materials and methods We studied 79 patients on peritoneal dialysis. Each underwent 24-h electrocardiography (Holter monitoring and measurement of the rate-corrected QT interval (QTc. We analyzed the correlation between QTc and plasma levels of Ca++, PO4−, K+, Na+, Mg++, and parathyroid hormone (PTH. Results The mean QTc was 0.445 ± 0.04 s. In 55 patients, the QTc was prolonged (> 0.45 s. Mean laboratory values for the group were: PTH 344 ± 25 pg/mL, Ca++ 9.27 ± 0.11 mg/dL, PO4− 5.5 ± 1.5 mg/dL, Na+ 139.6 ± 3.4 mmol/L, K+ 4.04 ± 0.64 mmol/L, and Mg++ 2.52 ± 0.43 mg/dL. Holter monitoring revealed complex premature ventricular contractions in 44 patients, monomorphic premature ventricular contractions in 16, and nonsustained ventricular tachycardia (NSVT in 10. The QTc was significantly correlated with plasma levels of PO4− (r = 0.045, p < 0.05, PTH (r = 0.077, p < 0.02, and Ca++ (r = 0.076, p < 0.02. Eleven patients had Lown class 4a or 4b ventricular arrhythmias, and their mean QTc was 465 ± 0.02 ms. Ten had NSVT and their QTc was 464 ± 0.03 ms. Eleven patients died suddenly (mean QTc 465 ± 0.03 ms; all 11 had either NSTV or Lown class 4 ventricular arrhythmias. Conclusions Long QTc seems to be associated with an increased prevalence of ventricular arrhythmias that may be the cause of sudden cardiac death.

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

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    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


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    M. M. Rogova


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

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

    DEFF Research Database (Denmark)

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


    PURPOSE: We investigated whether Brugada syndrome (BrS)-associated variants identified in the general population have an effect on J-point elevation as well as whether carriers of BrS variants were more prone to experience syncope and malignant ventricular arrhythmia and had increased mortality....../620; noncarriers 9/5,524; P = 0.24), or overall mortality (hazard ratio 0.93, 95% CI 0.63-1.4). CONCLUSIONS: Our data indicate that a significant number of BrS-associated variants are not the monogenic cause of BrS.Genet Med advance online publication 06 October 2016Genetics in Medicine (2016); doi:10.1038/gim...

  20. The value of ultrasound in diagnosis of fetal arrhythmias%超声诊断胎儿心律失常的价值

    Institute of Scientific and Technical Information of China (English)

    刘旭晴; 孟繁坤; 穆凌


    目的:探讨超声诊断胎儿心律失常的价值。方法对年龄20~40岁、妊娠20~40周患有乙型肝炎孕妇、疑有心律失常的76例胎儿进行超声检查。依据检查结果作出诊断,并利用超声随访。结果30例胎儿心律失常中,10例心动过速,6例心动过缓,14例胎儿不规则心律,其中2例心脏结构重度异常放弃胎儿,其余胎儿均正常出生。结论胎儿心脏M型超声、脉冲多普勒检测心脏及脐动脉血流频谱等可以诊断胎儿心律失常。%Objective To analyze the value of ultrasound in the diagnosis of fetal arrhythmias .Methods 76 cases of pregnant women with hepatitis B ,aged at 20~40 years old ,with 20~40 weeks of pregnancy ,were subjected to ultra-sound examination because their fetuses were suspected to be suffering from arrhythmia .Then ,a diagnosis was made on the basis of test results and a follow-up was conducted by use of ultrasound .Results In this work ,there were 30 cases of fetal arrhythmias ,10 cases of heartbeat tachycardia ,6 cases of slow heartbeat ,and 14 cases of fetal irregular rhythm .As 2 patients had severe structural abnormalities of the heart ,therefore ,the fetuses were given up .The remaining fetuses were normal birth .Conclusion Fetal heart ultrasonography (type M ) ,Pulse Doppler heart ,and umbilical blood flow can diagnose fetal arrhythmias .

  1. Multistep ion channel remodeling and lethal arrhythmia precede heart failure in a mouse model of inherited dilated cardiomyopathy.

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    Takeshi Suzuki

    Full Text Available BACKGROUND: Patients with inherited dilated cardiomyopathy (DCM frequently die with severe heart failure (HF or die suddenly with arrhythmias, although these symptoms are not always observed at birth. It remains unclear how and when HF and arrhythmogenic changes develop in these DCM mutation carriers. In order to address this issue, properties of the myocardium and underlying gene expressions were studied using a knock-in mouse model of human inherited DCM caused by a deletion mutation ΔK210 in cardiac troponinT. METHODOLOGY/PRINCIPAL FINDINGS: By 1 month, DCM mice had already enlarged hearts, but showed no symptoms of HF and a much lower mortality than at 2 months or later. At around 2 months, some would die suddenly with no clear symptoms of HF, whereas at 3 months, many of the survivors showed evident symptoms of HF. In isolated left ventricular myocardium (LV from 2 month-mice, spontaneous activity frequently occurred and action potential duration (APD was prolonged. Transient outward (I(to and ultrarapid delayed rectifier K(+ (I(Kur currents were significantly reduced in DCM myocytes. Correspondingly, down-regulation of Kv4.2, Kv1.5 and KChIP2 was evident in mRNA and protein levels. In LVs at 3-months, more frequent spontaneous activity, greater prolongation of APD and further down-regulation in above K(+ channels were observed. At 1 month, in contrast, infrequent spontaneous activity and down-regulation of Kv4.2, but not Kv1.5 or KChIP2, were observed. CONCLUSIONS/SIGNIFICANCE: Our results suggest that at least three steps of electrical remodeling occur in the hearts of DCM model mice, and that the combined down-regulation of Kv4.2, Kv1.5 and KChIP2 prior to the onset of HF may play an important role in the premature sudden death in this DCM model. DCM mice at 1 month or before, on the contrary, are associated with low risk of death in spite of inborn disorder and enlarged heart.

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

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    Luqia Hou

    Full Text Available 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

  3. Impact of potentially lethal ventricular arrhythmias on long-term outcome in patients with chronic heart failure

    Institute of Scientific and Technical Information of China (English)

    LIU Ye-hong; SHEN Wei-feng; SU Jing-ying; WANG Lin-jie; LI Jin-ping; ZHOU Qing-fen; GAN Qian; CHAI Xi-chen; DAI Li-ying; ZHANG Feng-ru


    Background Potentially lethal ventricular arrhythmias (PLVAs) occur frequently in survivors after acute myocardial infarction and are increasingly recognized in other forms of structural heart diseases.This study investigated the prevalence and prognostic significance of PLVAs in patients with chronic heart failure (CHF).Methods Data concerning demographics,etiology of heart failure,NYHA functional class,biochemical variables,electrocardiographic and echocardiographic findings,and medical treatments were collected by reviewing hospital medical records from 1080 patients with NYHA Ⅱ-Ⅳ and a left ventricular (LV) ejection fraction ≤45%.PLVAs were defined as multi-focal ventricular ectopy (>30 beats/h on Holter monitoring),bursts of ventricular premature beats,and nonsustained ventricular tachycardia.All-cause mortality,sudden death,and rehospitalization due to worsening heart failure,or cardiac transplantation during 5-year follow-up after discharge were recorded.Results The occurrence rate of PLVAs in CHF was 30.2%,and increased with age; 23.4% in patients <45 years old,27.8% in those between 45-65 years old,and 33.5% in patients >65 years old (P=0.033).Patients with PLVAs had larger LV size and lower ejection fraction (both P <0.01) and higher all-cause mortality (P=0.014) during 5-year follow-up than those without PLVAs.Age (OR 1.041,95% Cl 1.004-1.079,P=0.03) and LV end-diastolic dimension (OR 1.068,95% Cl 1.013-1.126,P=0.015) independently predicted the occurrence of PLVAs.And PLVA was an independent factor for all-cause mortality (RR 1.702,95% Cl 1.017-2.848,P=0.031) and sudden death (RR 1.937,95% CI 1.068-3.516,P=0.030) in patients with CHF.Conclusion PLVAs are common and exert a negative impact on Iona-term clinical outcome in patients with CHF.

  4. Platelets and cardiac arrhythmia

    Directory of Open Access Journals (Sweden)

    Jonas S De Jong


    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.

  5. Categories of Arrhythmias (United States)

    ... Kawasaki Disease Long Q-T Syndrome Marfan Syndrome Metabolic Syndrome Mitral Valve Prolapse Myocardial Bridge Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden ...

  6. Medications for Arrhythmia (United States)

    ... child about this before the doctor visit. Medicine Management Tools For Patients Keeping Track / Developing a System ... while you're out. Some pharmacists will prepare blister packs for daily or weekly medications. Ask your ...

  7. Arrhythmias (For Parents) (United States)

    ... a small battery-operated device implanted into the body (near the collarbone) through a surgical procedure. Connected to the heart by a wire, a pacemaker can detect if the heart rate is too slow and send electrical signals to speed up the heartbeat. Defibrillators. A small ...

  8. 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. (United States)

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


    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.

  9. 老年肺心病合并心律失常29例临床分析%The clinical analysis of 29 cases cor pulmonale old patients combined with arrhythmia

    Institute of Scientific and Technical Information of China (English)



    ObjectiveTo explore the clinical characteristics of old patients with cor pulmonale and arrhythmia,in order to provide clinical experience of prevention and treatment for cor pulmonale patients with arrhythmia.Methods Retrospectively analyzed the clinical data of 61 cases elderly cor pulmonale patients from May 2009 to May 2014 in our hospital, statistics the incidence of arrhythmia and distribution of the proportion of all kinds of arrhythmia, and observed the relationship between cardiac arrhythmias and cardiac function and electrolyte disorder.Results 29 cases out of 61 cases of elderly patients who suffered from cor pulmonale merged arrhythmia, the incidence of arrhythmia was 47.54%. The type of arrhythmia mainly was atrial premature beat,10 cases, accounting for 34.48%; center function of 2 cases out of 29 patients with cor pulmonale and arrhythmia was classification into classⅠ, accounting for 6.9%; Ⅱ level were 4 cases, accounting for 13.79%; Ⅲ level were 11 cases, accounting for 37.93%; Ⅳ grade were 12 cases, accounting for 44.82%. In the 29 patients with cor pulmonale and arrhythmia , 11 cases were decompensated acidosis, accounting for 37.93%; 10 cases were hypokalemia, accounting for 34.48%; 8 cases were Hyponatremia, accounting for 27.58%.ConclusionElderly patients with cor pulmonale have greater risk of arrhythmia, cor pulmonale with arrhythmia is closely related to the hypoxemia, cardiac function and electrolyte disorders, clinical comprehensive measures should be taken for treatment.%目的:探讨老年肺心病合并心律失常临床特点,为肺心病合并心律失常的防治提供临床经验。方法回顾性分析2009年5月~2014年5月我院收治的61例老年肺心病患者临床资料,统计心律失常发生率及各种类型心律失常分布构成比,观察心律失常与心功能和电解质紊乱的关系。结果61例老年肺心病患者中合并心律失常29例,心律失常发生率为47.54%。心律失

  10. Huangzhi Oral Liquid Prevents Arrhythmias by Upregulating Caspase-3 and Apoptosis Network Proteins in Myocardial Ischemia-Reperfusion Injury in Rats

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    Xu Ran


    Full Text Available To study the effect of Huangzhi oral liquid (HZOL on I/R after 2 h and 4 h and determine its regulatory function on caspase-3 and protein networks. 70 SD male rats were randomly divided into seven groups and established myocardial I/R injury model by ligating the left anterior descending coronary artery. Myocardial infarction model was defined by TTC staining and color of the heart. The levels of CK-MB, CTnI, C-RPL, SOD, and MDA were tested at 2 h and 4 h after reperfusion. HE staining and ultramicrostructural were used to observe the pathological changes. The apoptotic index (AI of cardiomyocyte was marked by TUNEL. The expression levels of caspase-3, p53, fas, Bcl-2, and Bax were tested by immunohistochemistry and western blot. HZOL corrected arrhythmia, improved the pathologic abnormalities, decreased CK-MB, CTnI, C-RPL, MDA, AI, caspase-3, p53, fas, and Bax, and increased SOD ans Bcl-2 with different times of myocardial reperfusion; this result was similar to the ISMOC (P>0.05. HZOL could inhibit arrhythmia at 2 and 4 h after I/R and ameliorate cardiac function, which was more significant at 4 h after reperfusion. This result may be related to decreased expression of caspase-3, p53, and fas and increased Bcl-2/Bax ratio.

  11. 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. (United States)

    Scarle, Simon


    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.

  12. Almanac 2013: cardiac arrhythmias and pacing--an editorial overview of selected research that has driven recent advances in clinical cardiology. (United States)

    Liew, Reginald


    Important advances have been made in the past few years in the fields of clinical cardiac electrophysiology and pacing. Researchers and clinicians have a greater understanding of the pathophysiological mechanisms underlying atrial fibrillation (AF), which has transpired into improved methods of detection, risk stratification, and treatments. The introduction of novel oral anticoagulants has provided clinicians with alternative options in managing patients with AF at moderate to high thromboembolic risk and further data has been emerging on the use of catheter ablation for the treatment of symptomatic AF. Another area of intense research in the field of cardiac arrhythmias and pacing is in the use of cardiac resynchronisation therapy (CRT) for the treatment of patients with heart failure. Following the publication of major landmark randomised controlled trials reporting that CRT confers a survival advantage in patients with severe heart failure and improves symptoms, many subsequent studies have been performed to further refine the selection of patients for CRT and determine the clinical characteristics associated with a favourable response. The field of sudden cardiac death and implantable cardioverter defibrillators also continues to be actively researched, with important new epidemiological and clinical data emerging on improved methods for patient selection, risk stratification, and management.This review covers the major recent advances in these areas related to cardiac arrhythmias and pacing.

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


    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

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

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo


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

  15. 运动性心律失常研究现状与前景%Status Quo and Prospects of the Researches on Athletic Arrhythmia

    Institute of Scientific and Technical Information of China (English)



    arrhythmia.This often affects athletes' systematic training and the improvement of athletic performance,which is the vexation of athletes and coaches.Study on sports medicine shows that after intensive training and repeated intensive exercise,some decompensated changes occur in the morphological structures and functional metabolism of cardiac cell and subcellular fraction,which causes athletic myocardial micro-damage.Besides,right atrium,right ventricle and heart tissues beneath endomembrane are the sensitive areas of heart toward intensive training and repeated intensive exercise.These areas are called vulnerable parts.Though athletic myocardial micro-damage has been known and athletic arrhythmia is correlated to athletic myocardial micro-damage,etiology,pathology and pathogenesis are not yet clear.It is difficult to diagnose,predict and prevent athletic myocardial micro-damage and athletic cardiac accident at an early stage.Researches on the hidden heart trouble of some elite athletes prove that there is higher risk of arrhythmia for elite athletes,especially for those who have had many years of specific training.Some athletes have to quit the competitions or retire.Athletic arrhythmia has become one of the main reasons affecting athletes' physical ability,health,training and competition and restricting the improvement of some elite athletes' performance.Some retired athletes are obsessed with permanent heart arrhythmia.The article discusses the types,pathology and pathogenesis of athletic arrhythmia and look into future researches in this regard.The aim of this study is to enhance the researches on electro-production and molecular pathology of athletic arrhythmia so as to avoid the occurrence of cardiovascular accidents,protect athletes' health and stretch athletes' sports career.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  17. Excellent survival and low incidence of arrhythmias, stroke and heart failure long-term after surgical ASD closure at young age. A prospective follow-up study of 21-33 years

    NARCIS (Netherlands)

    J.W. Roos-Hesselink (Jolien); F.J. Meijboom (Folkert); S.E.C. Spitaels (Silja); E.M.W.J. Utens (Elisabeth); A.J.J.C. Bogers (Ad); M.L. Simoons (Maarten); E.H.M. van Rijen (Susan); R.T. van Domburg (Ron)


    textabstractAIMS: Although studies have suggested good long-term results, arrhythmias, pulmonary hypertension and left ventricular dysfunction are mentioned as sequelae long-term after surgical atrial septal defect closure at young age. Most studies were performed only by questionnaire and in a retr

  18. 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;


    OBJECTIVE: To evaluate heart rate, heart rate variability, and arrhythmia frequency as well as changes in cardiac biomarker values and their association with heart rate in horses before and after an endurance ride. DESIGN: Cross-sectional study. ANIMALS: 28 Arabian horses competing in a 120- or 160......-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...

  19. Influencing Factors and Prevention Strategies of Arrhythmia in Hemodialysis Patients%血液透析患者发生心律失常的影响因素及其护理对策

    Institute of Scientific and Technical Information of China (English)



    Objective To evaluate the influencing factors of arrhythmia caused by hemodialysis(HD) so as to provide basis for establishing the corresponding prevention strategies. Methods From April 2010 to January 2011,84 HD patients in the hospital were enrolled in the study. The frequency of arrhythmia during the hemodialysis was recorded. Then the HD patients were divided into arrhythmia group and non-arrhythmiagroup. Comparisons were conducted on the general situation and blood biochemical parameters between the two groups. And Logistic regression analysis was used to determine the risk factors of arrhythmia caused by hemodialysis. Results The hemoglobin and the frequency of hemodialysis in the arrhythmiagroup were significantly less than those of the non-arrhythmia group (P<0. 05),and the age and dewatering' amount in the arrhythmia group were significantly higher than those of the non-arrhythmia group (P<0. 05). However,no significant difference was detected on the course of disease,potassium and calcium concentration,albumin,and serum creatinine before and after HD(P>0. 05). Logistic regression analysis showed that individual dewatering amount, HD number and hemoglobin were the independent risk factors related to arrhythmia. Conclusion Excessive amount of dewatering amount, less frequency of hemodialysis and anemia are the risk factors of arrhythmia caused by hemodialysis. To further improve nursing quality,HD patients must be given with clinically targeted nursing education,strengthened nursing of patients at high risk arrhythmias and a perfect rescue measures.%目的 探讨血液透析( hemodialysis,HD)患者发生心律失常的影响因素,以期为制定相应的防治策略提供资料.方法 选取2010年4月至2011年1月在温岭市第一人民医院血液净化中心门诊行HD的患者为研究对象,统计其在HD过程中发生心律失常的次数.按照有无发生心律失常将患者分为心律失常组和非心律失常组,比较两组患者

  20. 慢性肺源性心脏病并发心律失常389例临床分析%A Clinical Study of Arrhythmias in Patients with Cor Pulmonale

    Institute of Scientific and Technical Information of China (English)

    张炜平; 周长钰


    目的 探讨慢性肺源性心脏病(以下简称肺心病)心律失常的临床特征及治疗原则.方法 本组患者共389例,全部于入院后48 h内通过24 h心电监护或多次常规12导联心电图检查,及时发现心律失常类型并加以分析.结果 本组肺心病患者合并心律失常率达68.89%(268例),其心律失常类型以窦性心动过速、窦性心律不齐及房性期前收缩为主,严重心律失常如室上性心动过速、室性期前收缩、房室传导阻滞、心房颤动、左右束支传导阻滞等也常出现.心律失常的出现及严重程度与心力衰竭程度、肺部感染、低氧血症、水电解质紊乱等密切相关.结论 肺心病心律失常发生率较高,且与肺心病患者病情严重程度密切相关,而心律失常治疗应通过积极的病因及并发症治疗,使用抗心律失常药物不是最佳办法.%Objective To study the clinical characteristics and therapeutic principles of arrhythmias complicated with cor pulmonale. Methods Patients with cor pulmonale ( n = 389 ) were enrolled. The patients received 24-hour ambulatory or 12-lead electrocardiography ( ECG ) monitoring within 48 hours of enrollment. Arrhythmias were identified and analyzed. Results Cor pulmonale patients were complicated with arrhythmias at a rate of 68.89% ( n = 268 ). The arrhythmias consisted mainly of sinal tachycardia, sinal arrhythmia, and atrial premature contraction. Severe arrhythmias were also identified, such as supraventricular tachycardia,ventricular premature contraction, atrioventricular blockade, atrial fibrillation, and bundle transduction blockade. The occurrence and severity of arrhythmias were closely associated with cardiac failure, pulmonary infection, hypoxia, and water/electrolyte disturbance. Conclusion Core pulmonale is frequently complicated with arrhythmias whilst the severity of arrhythmias is closely associated with the underlying disease. The treatment of arrhythmias focuses on the