Mechanical circulatory assistance by intra-aortic balloon pumping for the treatment of cardiogenic shock.

Although the shock state due to acute myocardial infarction may be reversed by IABP in 80 per cent of patients, 55 to 65 per cent remain balloon-dependent. Therefore some attempt to correct the underlying anatomic abnormalities (reversible ischaemic areas and/or mechanical defects) appears necessary if these patients are to survive. With IABP catheterization studies performed in these critically-ill patients are well tolerated. Myocardial depression after cardiopulmonary by-pass is often related to subendocardial ischaemia. The combination of IABP and surgery has resulted in survival of approximately 50 per cent of patients in cardiogenic shock secondary either to a mechanical defect complicating myocardial infarction or to open-heart surgery.