Intraaortic Balloon Pump

Abstract

The intra‐aortic balloon pump (IABP) is an implanted cardiac assist device that utilises the principle of counterpulsation to provide temporary assistance to the failing heart. The balloon inflates during diastole (relaxation) and deflates before systole (contraction). This has two primary effects. First, it causes a decrease in the peak aortic blood pressure during systole, called systolic unloading. Second, it causes an increase in the mean aortic blood pressure during diastole, called diastolic augmentation. Systolic unloading decreases the oxygen demand of the heart and is enhanced by earlier balloon deflation. Diastolic augmentation increases the oxygen supply to the heart and is enhanced by later balloon deflation. The IABP therefore improves the myocardial oxygen balance and this can help the failing heart to recover. Furthermore, fine adjustment of the balloon deflation time can maximize this improvement. This article introduces the medical theory and need for intra‐aortic balloon pumping. A brief historical background is then presented. The techniques and principles of counterpulsation are then described. The article concludes with an examination of current developments and problems in this arena.