Acceleration of functional reentry by rapid pacing in anisotropic cardiac monolayers: Formation of multi-wave functional reentries
Acceleration of functional reentry by rapid pacing in anisotropic cardiac monolayers: Formation of multi-wave functional reentries
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DOI：
10.1016/j.cardiores.2005.09.014
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发表时间：
2006-02-01
影响因子：
10.8
通讯作者：
Tung, L
中科院分区：
文献类型：
--
作者：
Bursac, N;Tung, L
目的：通过快速穴位起搏转复心动过速有时会导致一过性或稳定期的心率加快(加速)、心电图形态改变和/或纤颤。本研究旨在探讨快速起搏对单层培养心肌细胞功能折返动力学的影响。方法：采用微量研磨法制备完全融合、各向异性的新生大鼠心肌细胞单层。结果：点起搏易诱发单环各向异性功能折返，呈单形性光学伪心电信号，平均旋转周期为193+/-52ms(n=71个单层)。以比折返率快10%-50%的速度快速起搏来尝试通过快速起搏来折返的尝试在57/71单层成功。在14/71个单层中，旋转波数稳定地增加1~4个，使pCG速度加快10-70%，并转变为不同的单态或多态pCG。由此产生的多波功能性折返根据其旋转波的数量和方向进行了分类。多波再入的波数越多，单层细胞的放电速度越快。重要的是，只有在传导速度恢复关系相对较深和较宽的单层中才能诱导稳定的加速度。再次应用点起搏进一步加速、减速或最终终止折返活动。结论：旋转波的稳定倍增和深而宽的传导速度恢复关系是快速起搏稳定加速功能性折返的可能机制。(C)2005年欧洲心脏病学会。爱思唯尔出版，版权所有。
Objective: Attempts to cardiovert tachycardia by rapid point pacing can sometimes result in transient or stable increase of the heart rate (acceleration), changed ECG morphology, and/or fibrillation. The goal of this study was to investigate the effect of rapid pacing on the dynamics of functional reentry in monolayer cultures of cardiac cells.Methods: Fully confluent, uniformly anisotropic monolayers of neonatal rat ventricular myocytes were prepared using methods of microabrasion. Cells were paced by a point electrode at rest and during functional reentry, and membrane voltages were optically mapped.Results: Point pacing readily induced single loop anisotropic functional reentry with monomorphic optical pseudo-ECG (PECG) and average rotation period of 193 +/- 52 ms (n = 71 monolayers). Attempts to cardiovert reentry by rapid pacing at rates 10-50% faster than the reentry rate were successful in 57/71 monolayers. In 14/71 monolayers, the number of rotating waves was stably increased by 1 to 4, yielding a 10-70% acceleration of pECG rate and change to a different monomorphic or polymorphic pECG. The resulting multi-wave functional reentries were classified based on the number and direction of their rotating waves. The higher the number of waves in the multi-wave reentry, the more accelerated was the rate of cell firing in the monolayer. Importantly, stable acceleration was only inducible in monolayers with relatively deep and broad conduction velocity restitution relationships. Reapplication of point pacing further accelerated, decelerated, or eventually terminated the reentrant activity.Conclusions: These results suggest that stable multiplication of rotating waves in conjunction with a deep and broad conduction velocity restitution relationship is a possible mechanism for stable acceleration of functional reentry by rapid pacing. (C) 2005 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.