Effects of thoracic epidural anesthesia on cardiac function and myocardial cell apoptosis in isoproterenol-induced chronic heart failure rats.

Abstract

This study aimed to investigate the effects of thoracic epidural anesthesia (TEA) on cardiac function and myocardial cell apoptosis in isoproterenol (ISO) induced chronic heart failure (CHF) rats. Rats were classified into 4 groups: the healthy control, ISO-induced CHF, ISO + TEA, and sham-treated groups. After 4 weeks, the animals in each group were examined by echocardiography. Invasive hemodynamic measurements were also preformed. Echocardiographic findings suggested that rats in the ISO + TEA group exhibited decreased left ventricular end-systolic (LVES) and left ventricular end-diastolic (LVED), and increased left ventricular ejection fraction (LVEF) and left ventricular shortening fraction (LVFS) compared with rats in the ISO-induced CHF group. Rats in the ISO + TEA group showed improved left ventricular systolic pressure (LVSP) and left ventricular end-diastolic pressure (LVEDP) compared with rats in the ISO-induced CHF group. Additionally, rats in the ISO + TEA group had significant decrease in LV and RV mass indexes (LVMI and RVMI) compared with rats in the ISO-induced CHF rats. Myocardial ultrastructure in the ISO + TEA group significantly improved compared with the ISO-induced CHF group. TEA significantly reduced the percent of TUNEL-positive cells in the ISO + TEA group compared with the ISO-induced CHF group. Compared with the ISO-induced CHF group, Bcl-2 expression of rats in the ISO + TEA group was significantly increased, while Bax expression was significantly attenuated. Our findings suggest that TEA may reduce myocardial apoptosis and decrease extent of structural damage and abnormalities in the myocardium.