降发性室上性心动过速可由折返运动,自动性异常及触发活动等三种机制之一引起,其中折返运动最常见,其激动波在一闭合的环形区内发生连续地扩散而导致持续的折返性心律失常;其次是在心房或房室交界区发生频率比窦房结更快的自发性除极:再其次是触发活动,它是由其前的动作电位所引起的滞后除极的一种动作电位。 阵发性室上性心动过速的解剖基础及类型 Down-induced supraventricular tachycardia can be caused by the reentry movement, abnormalities and triggering activity triggered by one of three mechanisms, of which the most common reentry movement, the excitement wave in a closed loop continuously diffuse and lead to sustained Of reentrant arrhythmias; followed by spontaneous depolarization in the atrial or atrioventricular junction more frequently than in the sinus node: followed by triggering activity, which is caused by the preceding action potential lagged depolarization An action potential. Anatomical basis and type of paroxysmal supraventricular tachycardia