OBJECTIVETo observe effects of acupuncture at Neiguan (PC 6) on function of sinoatrial node, so as to provide experimental basis for clinical application of Neiguan (PC 6) to treatment of heart diseases.

METHODSFifty cases of heart diseases were randomly divided into 2 groups, a no-blocking group (n = 35) and a blocking group (n = 15). In the no-blocking group, sinoatrial node recovery time (SNRT), sinoatrial conduction time (SACT), sinoatrial node effective refractory period (SNERP) and heart rate (HR) were determined by using esophagus-left cardiac atrium regulating pulsation technique before and after acupuncture at Neiguan (PC 6); and in the blocking group, the vegetative nerve was blocked by intravenous injection of Propanolol and Atropine, and then SNRT, SACT, SNERP and intrinsic heart rate (IHR) were detected before and after acupuncture.

RESULTSIn the no-blocking group there were significant differences in SACT, SNERP and HR (all P < 0.05) and no significant difference in SNRT (P > 0.05) before and after treatment. In the blocking group, there were no significant differences in SNRT, SACT and SNERP and a significant difference in IHR before and after acupuncture (P < 0.05).

CONCLUSIONAcupuncture at Neiguan (PC 6) has a significant effect on function of sinoatrial node, and the mechanism is possibly related with the bidirectional regulative action of acupuncture at Neiguan (PC 6) on the autonomic nerve in the sinoatrial node.