Phase-shift balloon pumping in cardiogenic shock

Twenty-one patients with intractable shock (in 20, secondary to myocardial infarction; in one, probably due to aneurysm-induced left ventricular pump failure) were treated with mechanical circulatory assistance utilizing an intraaortic balloon. In 16 patients circulatory failure developed within 36 hours of the onset of myocardial infarction. Shock was permanently reversed in 13 of these patients, and 5 were well 7 to 18 months after mechanical assistance; 2 long-term survivors died, one 19 months, and the other 7 months, after balloon pumping. In 5 patients in whom the onset of circulatory failure was delayed to 36 hours or more after myocardial infarction, shock was reversed during active mechanical assistance. The limiting factor in 4 of these patients was the natural evolution of the infarct to necrosis and myocardial rupture. In contrast, 18 patients, in whom mechanically assisted circulation was indicated but for various reasons could not be performed, died from shock. On the basis of this limited experience, we believe that mechanical circulatory assistance has a real therapeutic role in the treatment of intractable circulatory failure developing relatively early in the course of acute myocardial infarction. Its efficacy in so-called delayed circulatory failure requires further clarification.