正常心脏的搏动,首先來自竇房结的冲动。此冲动迅速下传至左、右两心房引起心房的收縮。而后,再顺次传布至房室结、房室束、房室束枝,最后抵达浦頃野氏纤维与心肌相连,引起两心室的同时收縮。在正常情况下,竇房结每分鐘产生60——80次有规则的冲动,由于其冲动的频率較心脏其他神經肌肉組織所产生的冲动頻率为快,所以竇房結能夠經常地控制 Normal heart beat, first from the impulse of the sinus node. This impulse quickly downloaded to the left and right atria caused atrial contraction. Then, then spread to the atrioventricular node, atrioventricular bundle, atrioventricular bundle branches, and finally arrived in Po is wild fibers connected with the myocardium, causing simultaneous contraction of the two ventricles. Under normal circumstances, the sinus node produce 60--80 regular impulses per minute, because its frequency of impulses is faster than the impulse frequency generated by other neuromuscular tissues in the heart, so the sinus node can be controlled frequently