Effects of a left ventricular assist device on the myocardium in ischemia-reperfusion injury.

Abstract

OBJECTIVE: It is suggested that apoptosis plays a role in heart diseases. The effect of left ventricular assist device (LVAD) on apoptosis at ischemia-reperfusion myocardial injury is unclear. We investigated the effect by assisting the ischemia-reperfusion myocardial injury models with LVAD. METHODS: Twelve swines were divided into two groups: the control group and LVAD group. The diagonal branch of the left coronary artery was occluded and released after 35 min. Reperfusion was performed, and observed for 3 hrs. The LVAD group was assisted by LVAD from 5 min before reperfusion to 3 hrs after it. Cardiac function, coronary flow, and cardiac tissue blood flow were measured. Pathologic assay was performed with terminal deoxynucleotidyl transferase-mediated dUTP in situ nick end labeling (TUNEL) and hematoxylin and eosin (HE) staining. mRNA of Bcl-xL and Bak were measured. RESULTS: Ejection fraction, cardiac output, and Emax in the LVAD group were improved (p<0.05 vs. the control group). There were less necrotic cells in the LVAD group than in the control group. There were more TUNEL positive cells in the LVAD group than in the control group. mRNA of Bcl-xL and Bak in LVAD group were high. CONCLUSION: The aggravation of cardiac dysfunction was limited to a minimum in the LVAD group.