Right ventricular performance was studied relative to right coronary artery flow in the chloralose-anesthetized, open chest dog. The right coronary artery was cannulated for measurement and control of flow and pressure. Under control conditions, right coronary artery occlusion caused no change in cardiac output, or right and left ventricular pressures, although right ventricular contractile force fell markedly. With right coronary artery flow intact, incremental pulmonary artery obstruction caused a corresponding decline in cardiac output and elevation of right ventricular end-diastolic pressure with eventual total right ventricular failure and systemic shock. With right coronary artery occlusion, identical degrees of pulmonary artery obstruction resulted in more pronounced changes in cardiac output and right ventricular end-diastolic pressure with right ventricular failure occurring at a much lower level of right ventricular stress.
Harold Brooks, Edward S. Kirk, Pantel S. Vokonas, Charles W. Urschel, Edmund H. Sonnenblick