Abstract
The present study was undertaken to compare hemodynamic status during ventricular pacing at different sites. Ten mongrel dogs were used. By epicardial mapping the point of an early breakthrough was determined on each of the body surface areas corresponding to the left and right ventricles place with bipolar pacing electrodes. Then measurements of hemodynamic parameters and epicardial mapping were done during left ventricular pacing, during right ventricular pacing and during biventricular pacing. The pattern of epicardial mapping varied with different pacing sites and was invariably different from that of the sinus rhythm. The time required for spread of epicardial excitation was remarkably longer during ventricular pacing than during the sinus rhythm and did not become noticeably shorter during the biventricular pacing than during the left ventricular pacing. As for hemodynamic parameters, a significantly higher max dp/dt value for the left ventricule was obtained during the left ventricular pacing than during the right ventricular pacing, with differences between the pacing sites being noticeably significantt in this respect. In terms of hemodynamics, the left ventricular pacing was found to be better than the right ventricular pacing and virtually equivalent to biventricular pacing.
