Effects of right ventricular ischemia on left ventricular geometry and the end-diastolic pressure-volume relationship in the dog.

Abstract

We studied the effects of right ventricular ischemia on left ventricular three-dimensional geometry Received Dec. 31, 1984; revision accepted July 5, 1985. Presented in part at the 56th Scientific Sessions of The American Heart Association, Anaheim, CA, 1983. evaluated left ventricular geometry nor measured left ventricular volume.The goal of the present study was to elucidate the effects of right ventricular ischemia on left ventricular geometry and the end-diastolic pressure-volume relationship in dogs, and to consider the importance of the intact pericardium. To this end, we measured septallateral, anterior-posterior, and apical-basal dimensions of the left ventricle with three pairs of ultrasonic dimension gauges, during right coronary artery (RCA) occlusions with the pericardium intact and open. MethodsAnimal preparation and instrumentation. Sixteen mongrel dogs weighing 13 to 24 kg (average 16.9) were anesthetized with ketamine hydrochloride (5 to 7 mg/kg im) followed by intravenous a-chloralose (50 mg/kg) and urethane (500 mg/kg). After endotracheal intubation, ventilation was maintained, by a volume respirator, with room air. A bilateral thoracotomy was performed in each dog in the fifth intercostal space with transection of the sternum. The electrocardiogram was continuously monitored in a limb lead (lead II). Arterial blood was repeatedly sampled for measurements of pH, Po2, and Pco2 with a blood gas analyzer (Acid-Base Laboratory, ABL2d), and supplemen-

Significance of the Right Ventricular Free Wall in Dogs with and without Pulmonary Constriction.

“…In dog, since the right coronary artery distributes to the right ventricular free wall, not to the left ventricle or the interventricular septum (Goldstein et al 1982; Goto et al 1985), the reduction in coronary artery flow causes a depressed state of the right ventricular free wall movement without disturbance of the left ventricle. Therefore, the right coronary artery flow reduction employed in the present experiment is useful for evaluating the significance of the right ventricular free wall in cardiac function.…”

“…In addition, it has been postulated that this diastolic interaction between the two ventricles would be enhanced by the pericardium (Janicki and Weber 1978; Spadaro et al 1979Spadaro et al , 1981Shirato et al 1982). It was also reported that when the right ventricle is loaded, the interventricular septum shifts toward the left ventricle (Bemis et al 1974;Santamore et al 1976;Glantz et al 1978;Goto et al 1985). Thus, in the present experiment, the increase in right ventricular volume at ischemia might also modify the left ventricular diastolic pressure-volume relationship, that is, decrease in end-diastolic length with no change in enddiastolic pressure, and disturb blood filling to the left ventricle.…”

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

“…Goto et al [ 13] compared the reductions in aortic flow and LVSP obtained in the dog after partial occlusion of the inferior vena cava with those observed in the same animal after complete occlusion of the right coronary artery. While partial occlusion of the inferior vena cava was characterized by a decrease in LVEDP, no change in LVEDP was observed after complete occlusion of the main right cor onary artery.…”

Behavior of right and left ventricles during episodes of variant angina in relation to the site of coronary vasospasm.

“…This condition may be even more severe during inferior infarction in patients with multivessel disease, which could limit the compensatory response from areas not involved in the necrosis; moreover, a low RV output may further affect perfusion of the left coronary artery system and precipitate cardiogenic shock. 34,35 Inferior Variant Angina and Stable Angina…”