Experimental study on significance of QRS area map--comparison with VAT map

The QRS area map, which is obtained by time integration of the QRS potential, is assumed to correlate with the ventricular activation time (VAT) map. Using 16 mongrel dogs, the QRS area map and VAT map from cardiac and body surface were compared during sinus rhythm and left and right ventricular endocardial pacing. The cardiac surface QRS area map resembled the cardiac surface VAT map, and it was considered useful to estimate the excitation sequence. The body surface QRS area map localized the stimulus site more easily during pacing than the body surface VAT map. Therefore, it was considered useful to determine the site at which a ventricular extrasystole occurs. The QRS area map proved to be more reproducible than the VAT map.