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.
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
Pacing Clin Electrophysiol. 2017 Feb 03;:
Circ Arrhythm Electrophysiol. 2016 Nov;9(11):
Usefulness of 14-Day Holter for Detection of Nonsustained Ventricular Tachycardia in Patients With Hypertrophic Cardiomyopathy.
Am J Cardiol. 2016 Jul 29;
Comput Biol Med. 2016 Jul 8;77:1-8
Response to Letter Regarding Article, "Outcome of Apparently Unexplained Cardiac Arrest: Results From Investigation and Follow-Up of the Prospective Cardiac Arrest Survivors With Preserved Ejection Fraction Registry".
Circ Arrhythm Electrophysiol. 2016 Apr;9(4)
A mutation in the atrial-specific myosin light chain gene (MYL4) causes familial atrial fibrillation.
Nat Commun. 2016;7:11303
Rapid Device-Detected Non-Sustained Ventricular Tachycardia in the Risk Stratification of Hypertrophic Cardiomyopathy.
Pacing Clin Electrophysiol. 2016 Mar 30;
Indian Pacing Electrophysiol J. 2015 May-Jun;15(3):168-71
Scientist, Toronto General Hospital Research Institute (TGHRI)
Associate Professor, Department of Physiology, University of Toronto