Termination of equine atrial fibrillation by quinidine: an optical mapping study.
Termination of equine atrial fibrillation by quinidine: an optical mapping study.
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DOI：
10.1016/j.jvc.2008.10.002
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发表时间：
2008-12-01
期刊：
影响因子：
--
通讯作者：
Kornreich, Bruce G
中科院分区：
文献类型：
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作者：
Fenton, Flavio H;Cherry, Elizabeth M;Kornreich, Bruce G
目的：首次对马心房进行光学标测研究，以评估心房颤动(房颤)的时空动力学以及奎尼丁终止房颤的作用。模拟：4匹心血管检查正常的马的完整、灌流的心房标本。材料和方法：用快速起搏方案诱发房颤，并用光学标测方法确定空间优势频率分布、电活动图和单像素光信号。在诱发房颤后，灌流葡萄糖酸奎尼丁，并在奎尼丁终止房颤的过程中监测这些参数。结果：马房颤发生在动作电位时程和舒张期的空间梯度背景下，在不同区域以快起搏频率产生交替、传导阻滞和文克巴赫传导。奎尼丁通过降低最大频率和增加频率均匀度来终止房颤，并阻止随后的再诱导。结论：动作电位的异质性和DI的异质性在马的心房以快起搏的频率促进交替和传导阻滞，有利于房颤的发生。奎尼丁通过降低最大频率和增加频率均匀度来终止房颤。我们的结果与奎尼丁延长有效不应期从而减少频率的假设是一致的。
OBJECTIVE: To perform the first optical mapping studies of equine atrium to assess the spatiotemporal dynamics of atrial fibrillation (AF) and of its termination by quinidine.ANIMALS: Intact, perfused atrial preparations obtained from four horses with normal cardiovascular examinations.MATERIALS AND METHODS: AF was induced by a rapid pacing protocol with or without acetylcholine perfusion, and optical mapping was used to determine spatial dominant frequency distributions, electrical activity maps, and single-pixel optical signals. Following induction of AF, quinidine gluconate was perfused into the preparation and these parameters were monitored during quinidine-induced termination of AF.RESULTS: Equine AF develops in the context of spatial gradients in action potential duration (APD) and diastolic interval (DI) that produce alternans, conduction block, and Wenckebach conduction in different regions at fast pacing rates. Quinidine terminates AF and prevents subsequent reinduction by reducing the maximal frequency and increasing frequency homogeneity.CONCLUSIONS: Heterogeneity of APD and DI promote alternans and conduction block at fast pacing rates in the equine atrium, predisposing to the development of AF. Quinidine terminates AF by reducing maximum frequency and increasing frequency homogeneity. Our results are consistent with the hypothesis that quinidine increases effective refractory period, thereby decreasing frequency.