Our proposal is designed to characterize the electrical heterogeneity intrinsic to the atrial and ventricular myocardium, to which our group has contributed significantly over the past many years.
Our specific aims are to: 1) probe differences in sodium channel and action potential characteristics of atrial vs. ventricular cells isolated from the canine heart and assess how these distinctions contribute to atrial-selective sodium channel inhibition and suppression of atrial fibrillation by INa blockers;2) determine to what extent the electrical and pharmacologic heterogeneities uncovered in the canine right atrium exist in the left atrium;3) determine to what extent electrical and pharmacologic heterogeneities uncovered in canine right and left atria of normal dogs differ from those of respective tissues and cells isolated from heart failure dogs (HF); 4) assess the propensity for the development of atrial fibrillation in atria isolated from heart failure dogs and define the substrate and triggers that underlie arrhythmogenesis. 5) assess the effectiveness of different classes of sodium channel blockers in terminating and suppressing re-induction of AF, determine to what extent these agents are atrial-selective, and the mechanisms involved;6) probe the basis for atrial-selective sodium channel block responsible for the anti-AF effects of sodium channel blockers in HF dogs;and 7) assess the influence of parasympathetic agonists on the development of AF in atria isolated from normal and heart failure dogs. The principal goals of our proposal are to probe the extent to which electrical heterogeneities exist between the right and left atrium and ventricles of the canine heart and examine how amplification of these heterogeneities contributes to the development of atrial and ventricular arrhythmias in the normal heart as well as in structurally compromised hearts isolated from dogs with pacing-induced dilated cardiomyopathy. The proposed project is a clinically relevant research inquiry designed to advance our understanding of atrial arrhythmia development and approach to therapy. The central focus involving a test of the hypothesis that atrial-selective modulation of the sodium channel can prevent AF without significantly altering ventricular electrophysiology is innovative and exciting and has the potential to produce a paradigm shift in the pharmacologic approach to therapy of AF, one of the greatest unmet medical needs facing our society. Successful completion of the project will also identify the ionic and cellular mechanisms that contribute to atrial selectivity, thus creating a unique platform for the development of novel therapies that could potentially find their way to the bedside.
Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in the clinic, affecting an estimated 2.5 million Americans. Its prevalence is age-related and is increasing sharply with aging of the population, to the point where the term epidemic has been applied. AF is a major complication associated with congestive heart failure (CHF), which affects an estimated 5 million patients in the United States and is a major cause of hospitalization and mortality. Currently available therapeutic options all have intrinsic limitations and new approaches to the pharmacologic management of atrial fibrillation are critically needed. Safe and effective pharmacologic treatment for AF is one of the greatest unmet medical needs facing our society. Successful completion of the studies proposed in this competing renewal will significantly advance this goal and lead to the development of innovative and effective pharmacologic treatments for AF.
|Burashnikov, Alexander; Antzelevitch, Charles (2018) Is extensive atrial fibrosis in the setting of heart failure associated with a reduced atrial fibrillation burden? Pacing Clin Electrophysiol 41:1289-1297|
|Hasdemir, Can; Juang, Jimmy Jyh-Ming; Kose, Sedat et al. (2018) Coexistence of atrioventricular accessory pathways and drug-induced type 1 Brugada pattern. Pacing Clin Electrophysiol 41:1078-1092|
|Savio-Galimberti, Eleonora; Argenziano, Mariana; Antzelevitch, Charles (2018) Cardiac Arrhythmias Related to Sodium Channel Dysfunction. Handb Exp Pharmacol 246:331-354|
|Di Diego, José M; Antzelevitch, Charles (2018) J wave syndromes as a cause of malignant cardiac arrhythmias. Pacing Clin Electrophysiol :|
|Krych, Michalina; Biernacka, El?bieta Katarzyna; Poni?ska, Joanna et al. (2017) Andersen-Tawil syndrome: Clinical presentation and predictors of symptomatic arrhythmias - Possible role of polymorphisms K897T in KCNH2 and H558R in SCN5A gene. J Cardiol 70:504-510|
|Patocskai, Bence; Yoon, Namsik; Antzelevitch, Charles (2017) Mechanisms Underlying Epicardial Radiofrequency Ablation to Suppress Arrhythmogenesis in Experimental Models of Brugada Syndrome. JACC Clin Electrophysiol 3:353-363|
|Antzelevitch, Charles; Patocskai, Bence (2017) Ajmaline-Induced Slowing of Conduction in the Right Ventricular Outflow Tract Cannot Account for ST Elevation in Patients With Type I Brugada ECG. Circ Arrhythm Electrophysiol 10:|
|Mizusawa, Yuka; Morita, Hiroshi; Adler, Arnon et al. (2016) Prognostic significance of fever-induced Brugada syndrome. Heart Rhythm 13:1515-20|
|Patocskai, Bence; Barajas-Martinez, Hector; Hu, Dan et al. (2016) Cellular and ionic mechanisms underlying the effects of cilostazol, milrinone, and isoproterenol to suppress arrhythmogenesis in an experimental model of early repolarization syndrome. Heart Rhythm 13:1326-34|
|Antzelevitch, Charles; Patocskai, Bence (2016) Brugada Syndrome: Clinical, Genetic, Molecular, Cellular, and Ionic Aspects. Curr Probl Cardiol 41:7-57|
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