窦房结内起搏点游走的电生理学研究

Electrophysiologic Study on Siuns Pacemaker shifts. Zhang Delt &

同步记录了43例体表ECG,右房内电图(IEG)和窦房结电图(SNE),旨在探讨窦房结内起搏点的游走现象及其临床意义。43例的自发游走率为11.6％,心房快速起搏(AP)所诱发的游走率为32.6％。游走时窦性周期(SCL)和直接窦房传导时间(TAC Td)均较游走前显著延长。窦房结功能正常组(正常组,35例)及病态窦房结综合征组(SSS组,8例)的自发游走率分别是11.4％和12.5％(P>0.05),AP诱发的游走率分别是25.7％和62.5％(P<0.05)。

Spontaneous sinus Pacemaker shifts (SPS) and shifts after overdrive atrial pacing were assessed 43 cases in whom stable sinus node electrograms were obtained were selected forstudy, eight of the 43 cases having sick sinus syndrome (SSS group), the other 35 devoid of sinus node dysfunction (normal group). SPS occur red spontaneously in 11.4％ of the normal group and 12.5％ of the SSS group respectively (P>0.05); and were induced after overdrive atrial pacing in 25.7％ of the normal group and 62.5％ of the SSS group respectively (P<0.05). The SPS were characterized by loss or inversion of the primary negativity, with or without morphological changes of P wave on ECG, in association with significant prolongation of direct sinoatrial conduction time and sinus cycle length. It is concluded that, 1. the human sinus node has dominant and subsidiary foci; 2. after overdrive atrial pacing, SPS occurs more frequently in patients with SSS than those in patients without SSS, which may be useful in evaluation of sinus node function.