CHARACTERIZATION OF THE EXCITABLE GAP IN A FUNCTIONALLY DETERMINED REENTRANT CIRCUIT - STUDIES IN THE STERILE PERICARDITIS MODEL OF ATRIAL-FLUTTER
CHARACTERIZATION OF THE EXCITABLE GAP IN A FUNCTIONALLY DETERMINED REENTRANT CIRCUIT - STUDIES IN THE STERILE PERICARDITIS MODEL OF ATRIAL-FLUTTER
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DOI：
10.1161/01.cir.90.4.1997
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发表时间：
1994-10-01
期刊：
影响因子：
37.8
通讯作者：
WALDO, AL
中科院分区：
文献类型：
--
作者：
NIWANO, S;ORTIZ, J;WALDO, AL
背景 在犬无菌性心包炎模型中，在稳定心房扑动期间，在折返回路中引入单次早搏，以检验以下假设：（1）尽管折返回路在功能上是确定的，但存在完全可兴奋间隙； (2)折返电路中的可激励间隙不均匀； (3) 折返回路中传导的不均匀性解释了早搏的影响。 方法和结果 使用多路复用系统记录 9 只狗 18 次心房扑动期间来自右心房游离壁的 190 个单极电图。在所有 18 次发作中，过早刺激捕获了心房扑动折返回路。在最长的耦合间隔下，最靠近起搏部位的返回周期没有延长。随着过早刺激的耦合间隔减少，返回周期逐渐增加，这与折返电路中不均匀的传导变化有关。结果是与早搏的引入相关的耦合间隔也不是恒定的。在慢传导区域，总（即完全加部分）可兴奋间隙的平均持续时间为 12+/-4 ms，并且总是短于其他区域的总可兴奋间隙（22+/-6 ms，P
Background Single premature beats were introduced in the reentrant circuit during stable atrial flutter in the canine sterile pericarditis model to test the hypotheses that (1) despite the fact that the reentrant circuit is functionally determined, there is a fully excitable gap; (2) the excitable gap in the reentrant circuit is not uniform; and (3) inhomogeneities of conduction in the reentrant circuit explain the effects of premature beats.Methods and Results A multiplexing system was used to record 190 unipolar electrograms from the right atrial free wall during 18 atrial flutter episodes in 9 dogs. In all 18 episodes, premature stimuli captured the atrial flutter reentrant circuit. At the longest coupling intervals, the return cycle at the site closest to the pacing site did not prolong. As the coupling interval of the premature stimulus decreased, the return cycle then progressively increased, associated with changes in conduction in the reentrant circuit that were not uniform. The result was that coupling intervals associated with introduction of the premature beat also were not constant. The mean duration of the total (ie, fully plus partially) excitable gap was 12+/-4 ms in areas of slow conduction, and it was always shorter than the total excitable gap in other areas (22+/-6 ms, P