Utility of Substrate Mapping Using Extrasystole to Localise Comprehensive Ventricular Tachycardia Circuits: Results From Intra-operative Mapping Studies. - Mumtaz M; Downar E; Kawada S; Zammit-Burg M; Anderson R; Massé S; Nair MKK; Nanthakumar J; Ghauri FM; Sánchez AP; Bhaskaran A (The Canadian journal of cardiology, 2023)