A summary of the work in synchronous assisted circulation undertaken at the Tufts-New England Medical Center Hospitals for the past year is presented.Counterpulsation, introduced in 1958, reduces myocardial oxygen consumption and increases coronary flow. It was applied to seven patients with terminal cardiogenic shock: one patient survived and three showed temporary improvement.The synchronous external assist makes possible control of the blood volume distribution, increases the cardiac output and decreases the pressure work of the left ventricle. The procedure does not require cannulation of the vascular system and is atraumatic.The same concept has been applied to the right ventricle using synchronous respiration.An "in-series" subcutaneously exteriorized prosthetic left ventricle, capable of long-term left ventricular assist, is under development. The device can atrialize the left ventricle. It requires no intracorporeal source of energy.This program offers hope for the development of effective temporary and long-term circulatory-assist procedures.