Left ventricular and unidirectional intra-aortic balloon pumping: Effects on hemodynamics in canine cardiogenic shock

Abstract

Intra-aortic balloon pumping (IABP) is currently the supportive treatment of choice for the management of refractory left ventricular power failure. However, in the extremely low output state, IABP may be hemodynamically ineffective, and a more direct left ventricular assist is desirable. Left ventricular balloon pumping (LVBP) is an effective cardiac assist device in the experimental low output state. LVBP both alone and in combination with IABP was evaluated in an experimental canine cardiogenic shock preparation. With LVBP alone, significant improvement was seen in the following: mean aortic flow (AoF), +46.2 per cent; aortic pressure (AoP), +15.1 per cent; left ventricular stroke work (LVSW), +147.0 per cent; left ventricular dp/dt (LVdp/dt), +52.9 per cent; coronary sinus flow (CSF), +24.6 per cent; and myocardial oxygen consumption +25.2 per cent. There was a concomitant decrease in left ventricular end-diastolic pressure (LVEDP) -71.6 per cent and left atrial pressure (LAP) -62.7 per cent. The combination of LVBP and IABP showed further improvement in CSF (+6.1 per cent) and further decreases in LVdp/dt (-8.7 per cent), LVEDP (-48.0 per cent), LAP (-28.9 per cent) and myocardial oxygen consumption (-33.3 per cent). The results indicate that LVBP may be a promising circulatory assist and that, in the extremely low output state, the addition of IABP decreased myocardial oxygen consumption and offered a transition in mechanical cardiac support which was initiated with LVBP.