Schoonderwoerd Bas A, Van Gelder Isabelle C, Tieleman Robert G, Bel Klaas J, Crijns Harry J G M
Department of Cardiology, Thoraxcenter, University Hospital Groningen, The Netherlands.
Pacing Clin Electrophysiol. 2002 Mar;25(3):287-90. doi: 10.1046/j.1460-9592.2002.00287.x.
It is well known that atrial tachycardia causes atrial electrical remodeling, characterized by shortening of atrial effective refractory periods (AERPs) and loss of physiological adaptation of AERP to rate. However, the nature and time course of changes in ventricular effective refractory periods (VERP) caused by rapid rates are to be established. After being instrumented with epicardial electrodes on both atria and both ventricles nine goats were subjected to 1 week of rapid AV pacing with a rate of 240 beats/min and an AV delay of 100 ms. Pacing was only interrupted for measurement of left and right AERPs and VERPs at three basic cycle lengths (BCL) of 400 ms, 300 ms, and 200 ms during sinus rhythm in the conscious animal. Left and right AERPs decreased at all BCLs, reaching minimum values after 3 days (right AERP at BCL of 400 ms, 96 +/- 16 ms after 3 days vs 144 +/- 16 ms at baseline, P < 0.05). In contrast, both left and right VERPs did not change at any BCL. This study demonstrates a difference between the atria and ventricles with respect to tachycardia induced changes in refractoriness.
众所周知，房性心动过速会导致心房电重构，其特征是心房有效不应期（AERP）缩短以及AERP对心率的生理适应性丧失。然而，快速心率引起的心室有效不应期（VERP）变化的性质和时间进程尚待确定。在9只山羊的心房和心室均植入心外膜电极后，使其以240次/分钟的速率和100毫秒的房室延迟进行1周的快速房室起搏。在清醒动物的窦性心律期间，仅在400毫秒、300毫秒和200毫秒这三个基本周期长度（BCL）下中断起搏以测量左、右AERP和VERP。在所有BCL下，左、右AERP均降低，3天后达到最小值（BCL为400毫秒时，右AERP在3天后为96±16毫秒，而基线时为144±16毫秒，P<0.05）。相比之下，在任何BCL下，左、右VERP均未改变。这项研究表明，在心动过速引起的不应期变化方面，心房和心室之间存在差异。
