THE EFFECT OF PURE RIGHT-VENTRICULAR ISCHEMIA ON RIGHT AND LEFT-VENTRICULAR PERFORMANCE IN THE ANESTHETIZED DOG

This study was planned to investigate the effect of ischemic dysfuncti on of the free wall of the right ventricle on right and left ventricul ar performance in the presence of a normally contracting interventricu lar septum. The experiments were performed in 6 anesthetized dogs in w hich echocardiogram, electrocardiogram, aortic blood pressure and left and right ventricular pressure were recorded. In the dog, the contrac tility of the septum is not affected by the occlusion of the right cor onary artery which does not perfuse this part of the myocardium. Compl ete occlusion of the major individual ventricular branches and partial occlusion of the main right coronary artery did not impair right vent ricular performance. Only complete occlusion of the main artery affect ed right and left ventricular function as revealed by echocardiogram. Reduced output by the ischemic right ventricle caused a reduction in l eft ventricular diastolic and systolic dimensions and in left ventricu lar developed pressure without any effect on left ventricular end-dias tolic pressure.