Experimental study of right ventricular assists for severe right ventricular failure

Abstract

The efficacy of two right ventricular assist systems for severe right ventricular failure caused by multiple ligation of the right coronary artery and right ventricular free wall with ventricular septal infarction was studied in 20 adult dogs in order to determine a better assist system in terms of hemodynamics and ventricular function. Two types of assist systems, a right ventricular bypass (RVAS) and an RVAS with intraaortic balloon pumping (IABP) were applied. The assist flow changed the preoperative aortic blood flow by 20%, 40%, 60% and 80%, respectively. The RVAS decreased the preload of RV and resulted in an effective RV assist. But RVAS did not effectively improve the aortic pressure (AP), left atrial pressure (LAP), aortic flow (AF), coronary sinus flow (CSF), left ventricular end diastolic pressure (LVEDP), LV stroke work (LVSW), or the endocardial viability ratio (EVR). On the other hand, RVAS with IABP significantly improves AP, LAP, AF, CSF, LVEDP, LVSW, and EVR as compared with the data of RVAS only. The optimal assist flow during RVAS with IABP might be 40-60% of the preoperative aortic blood flow.