Mechanical Intraaortic Cardiac Assistance in Cardiogenic Shock

CARDIOGENIC shock as a complication of acute myocardial infarction accounts for a significant proportion of cardiac deaths in this country. The mortality continues to range from 85 to 95% in various series.1,2Vasopressors do not appear to contribute significantly to reduction of this mortality.3,4 Seeking a new approach to the treatment of cardiogenic shock, we investigated intraaortic phase-shift balloon pumping, a mechanical method for temporary circulatory support proposed and used experimentally by Moulopoulos et al.5The results of our animal studies utilizing balloon pumping, reported previously,6indicated that the assistance procedure effectively supports the circulation of animals in induced shock or left ventricular failure. In addition, it was evident that prolonged pumping had no adverse effects on either the subject or the equipment. On this basis, we began a limited clinical trial in June 1967. In this effort, our aims were to demonstrate that phase-shift pumping