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

OBJECTIVE: 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. METHOD: 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. RESULTS: 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. CONCLUSION: Our findings suggest that TEA may reduce myocardial apoptosis and decrease extent of structural damage and abnormalities in the myocardium.