Objective To observe the effect and mechanism of electro-acupuncture at Ximen （PC4） on the heart rate of the ventricular tachycardia model rats.Methods Forty SD rats were randomized into 4 groups with 10 in each:normal group

model group

electro-acupuncture Chize （LU5） group and electro-acupuncture Ximen （PC4） group.The normal group was not treated.The other 3 groups were made ventricular tachycardia （VT） models with cesium chloride （CsCl） injected into femoral vein.The electrocardiogram （ECG） and heart rate of the models were observed and recorded.After modeling

the electro-acupuncture Chize （LU5） group and electro-acupuncture Ximen （PC4） group were treated with electro-acupuncture at Chize （LU5） and Ximen （PC4） respectively for 5 minutes.The colorimetry was adopted to detect the content of and plasma nitric oxide （NO） of all 4 groups.Results After CsCl injection

the heart rate of the model group

electro-acupuncture Chize （LU5） group

and electro-acupuncture Ximen （PC4） group was significantly quickened （P<0.01）.The heart rate of the model group and electro-acupuncture Chize （LU5） group was not recovered in the whole observing period.The heart rate of the electro-acupuncture Ximen （PC4） group was significantly reduced 5 minutes after treatment

compared with the model group and electro-acupuncture Chize （LU5） group

the difference was significant （P<0.01）.In comparison of the 4 groups

the content of NO of the model group was significantly decreased than that of the normal group （P<0.01）

NO of the electro-acupuncture Ximen （PC4） group was significantly increased than that of model group and electro-acupuncture Chize （LU5） group （P<0.01 or P<0.05）

and it was not significantly different from that of the normal group.Conclusion The electro-acupuncture at Ximen （PC4） can regulate the heart rate for anti-arrhythmia through inhibiting the heart sympathetic nerve and exciting the vagus nerve to increase the NO release.