Current status of counterpulsation in cardiac assistance: a summary of experimental experience in the dog.

Synchronized counterpulsation was applied to two groups of nine dogs using a new fluid-coupled pulse generator. Pump performance and synchronization were superior to earlier pneumatic systems. Improvement in cardiac function was evidenced by reduction in left ventricular pressure, work and oxygen consumption. Peripheral hemodynamics were adversely affected as evidenced by reduction in blood pressure, cardiac output, renal and carotid blood flows and decrease in central venous oxygen saturation. Evaluation of counterpulsation in acute left ventricular failure produced in 15 dogs by serial coronary ligations revealed that the elevated left atrial pressure was reduced, but neither cardiac output nor arterial pressure was improved by counterpulsation.