Objective To study the effect of
bupivacaine on cardiac function and energy metabolism. Methods 24 SD rats were randomly
divided into 3 groups: control group, 6 μmol/L
bupivacaine group (B 1) and 12 μmol/L bupivacaine group (B 2)(n=8 each). The isolated Langendroff perfused model was used. All hearts were perfused with K-H buffer at constant pressure for 30 min, then 6 μmol/L and 12 μmol/L bupivacaine were added to the perfusate in groups B 1 and B 2 respectively. Heart rate (HR), left ventricular developmental pressure (LVDP), developmental pressure(DP), +dp/dt and -dp/dt were recorded at 5, 10, 15, 25 min of perfusion with bupivacaine. The ATP level of myocardium was measured at 25 min. Results HR was
significantly decreased in B 1 and B 2 after drug treatment, while HR in B 2 was much lower than in B 1. DP,+dp/dt and -dp/dt in B 1 and B 2 were significantly decreased,compared with those in control group. The ATP level of myocardium in B 2 was significantly lower than in B 1 and control groups. Conclusion Bupivacaine lowers heart rate and inhibits contractility of myocardium in isolated perfused heart. The decrement of contractility may be related to the alteration of energy metabolism.