Abstract: OBJECTIVE: To investigate the effect of acupuncture at Neiguan(PC 6) on cardiac function using echocardiography in rat models of myocardial ischemia(MI) induced by isoproterenol(ISO).METHODS: Twenty-seven Sprague-Dawley rats were randomly assigned to normal, model, and acupuncture groups. The model and acupuncture groups were given injections of ISO(85 mg/kg) to establish the MI model. After model establishment,the acupuncture group was treated with acupuncture at Neiguan(PC 6) for 30 min. Echocardiography was used to monitor diastolic and systolic function for 30 min starting from the time after the acupuncture needles were removed. Changes in the length of left ventricular internal diameter at end-diastole(LVIDd), length of left ventricular internal diameter at end-systole(LVIDs), the ratio of mitral peak velocity at early diastole and atrial contraction(E/A), ejection fraction(EF), fractional shortening(FS), and stroke volume(SV) were measured.RESULTS: Compared with the model group at 0and 15 min after needles were removed, the means of LVIDd and LVIDs were significantly lower(P < 0.01) in the acupuncture group. In the acupuncture group, the means of LVIDd and LVIDs15 min after the needles were removed were significantly higher(P < 0.01) than those at 0 min. The means of E/A, EF, FS, and SV significantly decreased(P < 0.01) from 0 to 15 min in the acupuncture group.CONCLUSION: These findings indicate that acupuncture at Neiguan(PC 6) can affect cardiac function by increasing left ventricular diastolic and systolic function in MI rat models, but the effect only lasts for 15 min.

Key words: Acupuncture, Point PC 6(Neiguan), Myocardial ischemia, Heart function tests, Echocardiography, Isoproterenol