Noninvasive ECG imaging (ECGI): Mapping the arrhythmic substrate of the human heart

This short communication accompanies my presentation at the International Congress on Sudden Cardiac Death held in Prague, March 30–April 1, 2017. It summarizes briefly studies of the cardiac electrophysiological substrate in patients with hereditary arrhythmogenic syndromes – the Long QT and Brugada syndromes – conducted noninvasively, in situ, using Electrocardiographic Imaging (ECGI). The same noninvasive approach was used to map the electrophysiological substrate of a post-infarction myocardial scar and to relate this substrate to the pattern of activation during reentrant ventricular tachycardia. My thoughts about a potential role for ECGI in cardiac research and clinical care are also expressed briefly, with examples from on-going work in my laboratory. •ECGI can map noninvasively the cardiac electrophysiologic and arrhythmic substrate.•In the long QT syndrome, epicardial action potential duration is prolonged nonuniformly, creating steep dispersion.•In Brugada syndrome, both repolarization and conduction abnormalities are observed.•ECGI can localize noninvasively the origin and circuits of ventricular tachycardia (VT).