Ventricular tachyarrhythmias are an important mode of sudden death in patients with cardiomyopathy. Animal studies suggest that abnormal ventricular repolarization can lead to ventricular arrhythmias. In humans, the relevance of cardiac repolarization as a substrate for arrhythmogenesis is not well understood. Our laboratory is characterizing the spatiotemporal distribution of ventricular repolarization in patients with cardiomyopathy and defining the dynamic range of repolarization in response to physiologic stress that can trigger ventricular arrhythmias. The experiments involve body surface and intracardiac recordings of repolarization under varying physiological conditions. Using linear and nonlinear dynamics, several aspects of cardiac repolarization are quantified including spatiotemporal heterogeneity, restitution, memory and alternans. The knowledge gained from our experiments will provide better understanding of the pathogenesis of lethal ventricular arrhythmias in cardiomyopathic patients which may lead to the development of novel antiarrhythmic therapies.
J Interv Card Electrophysiol. 2018 Oct 08;:
J Electrocardiol. 2018 Jul - Aug;51(4):720-722
Reduced T wave alternans in heart failure responders to cardiac resynchronization therapy: Evidence of electrical remodeling.
PLoS One. 2018;13(6):e0199637
Complex interactions in a novel SCN5A compound mutation associated with long QT and Brugada syndrome: Implications for Na+ channel blocking pharmacotherapy for de novo conduction disease.
PLoS One. 2018;13(5):e0197273
Spatial Relationships of Complex Fractionated Atrial Electrograms and Continuous Electrical Activity to Focal Electrical Sources: Implications for Substrate Ablation in Human Atrial Fibrillation.
JACC Clin Electrophysiol. 2017 Nov;3(11):1220-1228
T-Wave Morphology Analysis in Congenital Long QT Syndrome Discriminates Patients From Healthy Individuals.
JACC Clin Electrophysiol. 2017 Apr;3(4):374-381
Circ Arrhythm Electrophysiol. 2017 Sep;10(9):
Curr Cardiol Rep. 2017 Aug 16;19(9):88
Automated Quantification of Low-Amplitude Abnormal QRS Peaks From High-Resolution ECG Recordings Predicts Arrhythmic Events in Patients With Cardiomyopathy.
Circ Arrhythm Electrophysiol. 2017 Jul;10(7):
HeartRhythm Case Rep. 2017 Jan;3(1):22-26
Scientist, Toronto General Hospital Research Institute (TGHRI)
Associate Professor, Department of Physiology, University of Toronto