Stevenson W G, Wiener I, Weiss J N
Division of Cardiology, UCLA School of Medicine 90024.
Am Heart J. 1987 Dec;114(6):1396-9. doi: 10.1016/0002-8703(87)90542-4.
To determine if electrical stimulation during the basic ventricular drive train introduces local effects that influence ventricular refractoriness during endocardial stimulation in humans, 10 patients were studied. With a hexapolar catheter with 3 mm interelectrode distances positioned at the right ventricular apex, the ventricular functional and effective refractory periods were determined for unipolar cathodal stimuli of 2 and 5 times diastolic threshold. Stimulation was performed with both the scanning extrastimulus (S2) and basic ventricular drive stimuli (S1) delivered to the same site and to sites separated by 6 mm. The functional refractory period was not changed by delivering the basic drive and extrastimuli to the same as opposed to separate sites (273.5 +/- 16 vs 273.5 +/- 19 msec during stimulation at 2 times threshold and 270 +/- 16 vs 270 +/- 18 msec at 5 times threshold; p = NS). The longest S1-S2 interval at which S2 failed to capture (effective refractory period) was longer by 5.5 +/- 8.2 msec at twice threshold (0.05 less than p less than 0.10) and 5.5 +/- 3.5 msec at 5 times threshold stimulation (p less than 0.01) when the basic drive and extrastimuli were delivered to separate sites. This is consistent with later activation of the extrastimulus sites during the basic drive when the stimulation sites were separate. Thus, with this method of endocardial programmed electrical stimulation, separation of the stimulation sites for the basic drive and extrastimuli does not affect ventricular refractoriness determined by the extrastimulus technique.
为了确定在基础心室驱动序列期间进行电刺激是否会产生局部效应，从而影响人体心内膜刺激时的心室不应期，对10名患者进行了研究。将电极间距为3毫米的六极导管置于右心室心尖处，测定2倍和5倍舒张阈值的单极阴极刺激下的心室功能不应期和有效不应期。刺激通过将扫描额外刺激（S2）和基础心室驱动刺激（S1）传递至同一部位以及相隔6毫米的部位来进行。与将基础驱动刺激和额外刺激传递至不同部位相比，传递至同一部位时，功能不应期未发生改变（在2倍阈值刺激时为273.5±16毫秒与273.5±19毫秒，在5倍阈值刺激时为270±16毫秒与270±18毫秒；p = 无显著性差异）。当基础驱动刺激和额外刺激传递至不同部位时，在2倍阈值刺激下，S2未能夺获的最长S1 - S2间期（有效不应期）延长了5.5±8.2毫秒（0.05 < p < 0.10），在5倍阈值刺激时延长了5.5±3.5毫秒（p < 0.01）。这与当刺激部位分开时，在基础驱动期间额外刺激部位的较晚激动是一致的。因此，采用这种心内膜程控电刺激方法，基础驱动刺激和额外刺激的刺激部位分开并不影响通过额外刺激技术测定的心室不应期。
