Mechanical support of the left ventricle in ischemia induced left ventricular failure: an experimental study.

ABSTRACT

OBJECTIVE: this study compares the hemodynamic effects of intra-aortic balloon pumping (IABP), left ventricular assist device (LVAD), and extracorporeal membrane oxygenation (ECMO) in left ventricular failure in pigs. METHODS: In 29 pigs weighing 12 +/- 0.7 kg left ventricular failure was induced by ligating the left anterior descending coronary artery. Eight animals served as controls. Eight pigs were treated by IABP, seven by LVAD, and six by ECMO. The study period lasted four hours. Hemodynamic and oxygen transport/uptake parameters were measured continuously or intermittently. RESULTS: Six animals of the ECMO and LVAD groups survived the 4 hour period, but only 3 and 4 animals of the IABP and control groups survived (p less than 0.05). Cardiac index decreased about 48% and 22% in the control and IABP groups (p less than 0.05), whereas there was only a slight decrease in the ECMO (9%) and LVAD (14%) groups. Oxygen delivery fell significantly in the control and IABP groups (p less than 0.05), compared with only a slight change in the LVAD and ECMO groups. CONCLUSION: ECMO is the most effective system for temporary circulatory support in severe ventricular failure. LVAD maintains cardiac output when pulmonary blood flow is provided. IABP is less efficient in supporting the failing heart, especially in the presence of severe ventricular arrhythmias.