Chorro F J, Sanchis J, Lopez-Merino V, Such L, Avellana J A, Valentin V
Department of Medicine, University Medical School, Valencia, Spain.
Pacing Clin Electrophysiol. 1991 May;14(5 Pt 1):842-53. doi: 10.1111/j.1540-8159.1991.tb04115.x.
The influence of the timing of a nontransmitted or transmitted atrial impulse on the atrioventricular (AV) conduction time of the subsequent impulse was studied in nine isolated rabbit hearts. AV conduction curves were determined by applying the atrial extrastimulus test. The extrastimulus was delivered preceded or not by an interposed atrial impulse whose coupling interval with respect to the last atrial beat of a basic train was kept constant at 100, 120, 140, 160, 175, 200, 225, 250, and 300 msec. In all experiments, there was a "concealment interval," i.e., the AV effective refractory period was longer than the atrial functional refractory period, and in seven experiments was comprised between 100 and 160 msec. For any given extrastimulus coupling interval in the presence of an interposed nontransmitted atrial impulse, AV conduction time was significantly greater than in its absence; the increase was greater than the longer the nontransmitted atrial impulse coupling interval, i.e., the shorter the subsequent transmitted impulse coupling interval with respect to the previous interposed nontransmitted impulse. The AV conduction curves relating the extrastimulus AV conduction time to its coupling interval with respect to the last atrial impulse of the basic train fitted to a hyperbolic model both in the absence of the interposed atrial impulse and in its presence (mean square residual 31 +/- 23 msec2), and the interposed atrial impulse modified the constants of the functions; the slope of the linear transformations was progressively more negative as the interposed atrial impulse was delayed. Furthermore, the effects of the interposed atrial impulse--transmitted or not--on AV conduction time of the subsequent impulse were qualitatively similar, their magnitude depending on the time elapsed were qualitatively similar, their magnitude depending on the time elapsed between the two.
在九个离体兔心脏中研究了未下传或下传的心房冲动的发生时间对随后冲动的房室（AV）传导时间的影响。通过应用心房期外刺激试验来确定AV传导曲线。在插入的心房冲动之前或之后给予期外刺激，该插入的心房冲动与基础刺激串的最后一个心房搏动的耦合间期保持恒定，分别为100、120、140、160、175、200、225、250和300毫秒。在所有实验中，均存在一个“隐匿间期”，即AV有效不应期长于心房功能不应期，在七个实验中其范围在100至160毫秒之间。对于在存在插入的未下传心房冲动的情况下的任何给定期外刺激耦合间期，AV传导时间显著长于不存在该冲动时；未下传心房冲动的耦合间期越长，增加幅度越大，即相对于先前插入的未下传冲动，随后下传冲动的耦合间期越短。在不存在插入心房冲动和存在插入心房冲动的情况下，将期外刺激AV传导时间与其相对于基础刺激串最后一个心房冲动的耦合间期相关联的AV传导曲线均符合双曲线模型（均方残差为31±23毫秒²），并且插入的心房冲动改变了函数的常数；随着插入的心房冲动延迟，线性变换的斜率逐渐变得更负。此外，插入的心房冲动（无论是否下传）对随后冲动的AV传导时间的影响在性质上相似，其幅度取决于两者之间经过的时间。
