Objective: To observe the effect of electroacupuncture (EA) of "Shenmen" (HT 7) and "Zhizheng" (SI 7) on cardiac function and electrical activities of the cardiac sympathetic nerve in acute myocardial schemia rabbits.
Methods: Forty livid-blue rabbits were randomly divided into normal control, model, "Shenmen" (HT 7) and "Zhizheng" (517) groups with 10 cases in each group. Acute myocardial ischemia (AMI) model was established by intravenous injection of pituitrin (3 U/kg). Changes of heart rate (HR), maximum rising rate (+dp/dt max) and maximum descending rate (-dp/dt max) of the left ventricular systolic pressure (LVSP), and discharges of cardiac sympathetic nerve (superior cardiac branch) were recorded. EA (2 Hz, 5 V) was applied to bilateral "Shenmen" (HT 7) and "Zhizheng" (SI 7) for 30 mm.
Results: After AMI, HR, LVSP, +dp/dt max and firing frequency of cardiac sympathetic nerve decreased significantly (P < 0.01), and -dp/dt max increased obviously in model group (P < 0.01). Compared with model group, HR, +dp/dt max and cardiac sympathetic discharge of HT7 and S17 groups increased significantly 10 mm and 20 mm after EA (P < 0.05, 0.01), and -dp/dt max of the later 2 groups reduced evidently 20 mm after EA (P < 0.05, 0.01). No significant differences were found between HT7 and control groups in HR, LVSP and the firing frequency of cardiac nerve 20 mm and 30 mm after EA, and between S17 and control groups in the firing frequency of cardiac nerve 30 mm after EA (P > 0.05). The effects of group HT7 were significantly better than those of S17 (P < 0.05).
Conclusion: EA of both HT7 and S17 can obviously improve cardiac function and electrical activity of cardiac sympathetic nerve in AMI, and the effects of HT7 are markedly better than those of S17.