Applied Signal Processing Group, Swiss Federal Institute of Technology, EPFL-STI-SCI-JMV, Bâtiment ELD, Station 11, 1015 Lausanne, Switzerland.
Med Biol Eng Comput. 2012 Feb;50(2):155-63. doi: 10.1007/s11517-011-0859-3. Epub 2012 Jan 21.
Due to their transient nature, spontaneous terminations of atrial fibrillation (AF) are difficult to investigate. Apparently, confounding experimental findings about the time scale of this phenomenon have been reported, with values ranging from 1 s to 1 min. We propose a biophysical modeling approach to study the mechanisms of spontaneous termination in two models of AF with different levels of dynamical complexity. 8 s preceding spontaneous terminations were studied and the evolution of cycle length and wavefront propagation were documented to assess the time scale and anatomical location of the phenomenon. Results suggest that termination mechanisms are dependent on the underlying complexity of AF. During simulated AF of low complexity, the total process of spontaneous termination lasted 3,200 ms and was triggered in the left atrium 800 ms earlier than in the right atrium. The last fibrillatory activity was observed more often in the right atrium. These asymmetric termination mechanisms in both time and space were not observed during spontaneous terminations of complex AF simulations, which showed less predictable termination patterns lasting only 1,600 ms. This study contributes to the interpretation of previous clinical observations, and illustrates how computer modeling provides a complementary approach to study the mechanisms of cardiac arrhythmias.
由于心房颤动 (AF) 的瞬时性质，自发性终止很难进行研究。显然，关于这种现象的时间尺度的混杂实验结果已经有报道，其值范围从 1 秒到 1 分钟。我们提出了一种生物物理建模方法来研究两种具有不同动力学复杂性水平的 AF 模型中的自发性终止机制。研究了自发性终止前 8 秒，记录了心动周期长度和波前传播的演变，以评估现象的时间尺度和解剖位置。结果表明，终止机制取决于 AF 的潜在复杂性。在低复杂性的模拟 AF 中，自发性终止的总过程持续了 3200 毫秒，并且在左心房比右心房早 800 毫秒被触发。最后一次纤维性活动更常在右心房观察到。在复杂 AF 模拟的自发性终止期间，没有观察到这种在时间和空间上不对称的终止机制，复杂 AF 模拟的终止模式更不可预测，仅持续 1600 毫秒。本研究有助于对以前的临床观察结果的解释，并说明了计算机建模如何提供一种补充方法来研究心脏心律失常的机制。
