The Effect of Pure Right Ventricular Ischemia on Right and Left Ventricular Performance in the Anesthetized Dog

Abstract

This study was planned to investigate the effect of ischemic dysfunction of the free wall of the right ventricle on right and left ventricular performance in the presence of a normally contracting interventricular septum. The experiments were performed in 6 anesthetized dogs in which echocardiogram, electrocardiogram, aortic blood pressure and left and right ventricular pressure were recorded. In the dog, the contractility of the septum is not affected by the occlusion of the right coronary artery which does not perfuse this part of the myocardium. Complete occlusion of the major individual ventricular branches and partial occlusion of the main right coronary artery did not impair right ventricular performance. Only complete occlusion of the main artery affected right and left ventricular function as revealed by echocardiogram. Reduced output by the ischemic right ventricle caused a reduction in left ventricular diastolic and systolic dimensions and in left ventricular developed pressure without any effect on left ventricular end-diastolic pressure.

Right coronary autoregulation in conscious, chronically instrumented dogs

“…Because the right ventricle differs markedly from the left ventricle in work performed, oxygen extraction and consumption, and transmural pressure, differences in the RC flow-RV function relation might be expected. The canine RC artery does not supply the interventricular septum or at least one-fourth of the RV margin adjacent to posterior longitudinal groove, so it is not surprising that complete occlusion of the RC has been reported to have little effect on RV systolic pressure (13). Clearly, evaluation of the RC flow-RV function relation requires direct assessment of function in the perfusion territory of the RC as was accomplished in the present study.…”