[Changes in the ischemic myocardium in experimental paired stimulation of the heart]

In dog experiments the dynamics of electrophysiological and morphological indices of the ischemic myocardium in sinus tachycardia was compared with that in deceleration of cardiac contraction under the effect of paired stimulation. Intensification of the damaging effect of a 40-minute occlusion of the coronary artery complicated by destructive changes of the cardiomyocytes was revealed after deceleration of the rhythm; in reperfusion of the ischemic area the effect of electrogram restoration was diminished, which was attended with deeper focal damage to the heart muscle.