Spatiotemporal heterogeneity in the induction of ventricular fibrillation by rapid pacing importance of cardiac restitution properties
Spatiotemporal heterogeneity in the induction of ventricular fibrillation by rapid pacing importance of cardiac restitution properties
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DOI：
10.1161/01.res.84.11.1318
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发表时间：
1999-06-11
影响因子：
20.1
通讯作者：
Chen, PS
中科院分区：
文献类型：
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作者：
Cao, JM;Qu, ZL;Chen, PS
快速起搏引起室颤（VF）的机制尚不清楚。我们在10只狗中进行了计算机心外膜标测研究，使用19次起搏序列。第一串起搏间期（PI）为300 ms，然后逐渐缩短，直至诱发VF。对于每个PI，我们构建了有效不应期（ERP）的恢复曲线。当PI较长时，激活周期长度（CL）在整个标测区域是恒定的。然而，随着PI缩短，CL变化的时空复杂性增加，ERP恢复曲线的斜率增加。在5只狗中，我们记录了在长短CL变化的部位由波断引起的VF。计算机模拟研究使用Luo-Rudy I心室动作电位模型在模拟的二维组织再现了正常ERP和传导速度（CV）的恢复性能完好时的实验结果。通过改变CV和ERP恢复在这个模型中，我们发现，CV恢复创建空间CL的变化，而ERP恢复的基础上的时间，心跳到心跳的变化，在快速起搏的不应期。总之，CV和ERP恢复的相互作用在心脏激活中产生时空振荡，其随着PI降低而增加振幅，最终在内在异质性位点处引起波破裂。这种初始的波破碎然后导致螺旋波和VF的形成。这些发现支持CV和ERP恢复在快速起搏引发VF中的关键作用。
The mechanism by which rapid pacing induces ventricular fibrillation (VF) is unclear. We performed computerized epicardial mapping studies in 10 dogs, using 19-beat pacing trains. The pacing interval (PI) of the first train was 300 ms and then was progressively shortened until VF was induced. For each PI, we constructed restitution curves for the effective refractory period (ERP). When the PI was long, the activation cycle length (CL) was constant throughout the mapped region. However, as the PI shortened, there was an increase in the spatiotemporal complexity of the CL variations and an increase in the slope of the ERP restitution curve. In 5 dogs, we documented the initiation of VF by wavebreak at the site of long-short CL variations. Computer simulation studies using the Luo-Rudy I ventricular action potential model in simulated 2-dimensional tissue reproduced the experimental results when normal ERP and conduction velocity (CV) restitution properties were intact. By altering CV and ERP restitutions in this model, we found that CV restitution creates spatial CL variations, whereas ERP restitution underlies temporal, beat-to-beat variations in refractoriness during rapid pacing. Together, the interaction of CV and ERP restitutions produces spatiotemporal oscillations in cardiac activation that increase in amplitude as the PI decreases, ultimately causing wavebreak at the site of intrinsic heterogeneity. This initial wavebreak then leads to the formation of spiral waves and VF. These findings support a key role for both CV and ERP restitutions in the initiation of VF by rapid pacing.