Some theoretical results on the observability of repolarization heterogeneity on surface ECG

Assessing repolarization heterogeneity (RH) from surface ECG recording is an open issue in modern electrocardiography, despite the fact that several indexes measured on the T-wave have been proposed and tested. To understand how RH occurring at myocite level is reflected on T-wave shapes, in this paper we propose a mathematical framework that combines a simple statistical model of cardiac repolarization times with the dominant T-wave formalism. Within this framework we compare different T-wave features such as T-wave amplitude, T-wave amplitude variability or QT intervals and we describe mathematically how they are linked to the spatial and temporal components of repolarization heterogeneity.