Cellular basis for trigger and maintenance of ventricular fibrillation in the Brugada syndrome model - High-resolution optical mapping study
Cellular basis for trigger and maintenance of ventricular fibrillation in the Brugada syndrome model - High-resolution optical mapping study
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DOI：
10.1016/j.jacc.2005.12.064
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发表时间：
2006-05-16
影响因子：
24
通讯作者：
Sunagawa, Kenji
中科院分区：
文献类型：
--
作者：
Aiba, Takeshi;Shimizu, Wataru;Sunagawa, Kenji
目的：在Brugada综合征模型中，我们研究了复极化和去极化异常如何促进室性心动过速和随后的心室颤动（VF）的发展。再极化和去极化异常被认为是Brugada综合征中cod型st段抬高（br -ugada-心电图[ECG]）和VF发生的机制。方法采用高分辨率（256 × 256）光学成像技术，对基线和经特非那定（5 μ mol/l）、pinacidil （2 μ mol/l）和匹西奈德（5 μ mol/l）处理后的Brugada-ECG （n = 20）动脉灌注犬右心室楔形进行研究。我们记录了Brugada-ECG条件下自发性2期再入性(P2R)-超收缩期和随后的自终止型多态性室性心动过速（PVT）或VF发作，并分析了每种情况下心外膜传导速度和动作电位持续时间（APD）恢复。结果10种药物中有9种在Brugada-ECG上成功定位了41次自发性p2r -早搏，其中33次起源于心外膜最大复极梯度（GR(max): 176 +/- 54 ms/mm）区域，导致PVT （n = 12）或VF （n = 5）。心外膜GR（max）在PVT和VF之间无显著差异。在所有的VF病例中，第一次p2r -早搏时的破波产生了多个小波，而在PVT病例中，没有发生破波或破波后的波碰撞和终止。此外，与PVT相比，VF病例的传导速度恢复移位更低，APD恢复的变化更大。结论Brugada-ECG患者心外膜复极梯度陡，心内膜未出现p2r -心动过速，进一步的去极化和复极化异常可能导致p2r -心动过速退化。[J]中华医学会心内科杂志，2006;47:2074-85](c) 2006
OBJECTIVES We examined how repolarization and depolarization abnormalities contribute to the development of extrasystoles and subsequent ventricular fibrillation (VF) in a model of the Brugada syndrome.BACKGROUND Repolarization and depolarization abnormalities have been considered to be mechanisms of the coved-type ST-segment elevation (Br-ugada-electrocardiogram [ECG]) and development of VF in the Brugada syndrome.METHODS We used high-resolution (256 x 256) optical mapping techniques to study arterially perfused canine right ventricular wedges (n = 20) in baseline and in the Brugada-ECG produced by administration of terfenadine (5 mu mol/l), pinacidil (2 mu mol/l), and pilsicainide (5 mu mol/l). We recorded spontaneous episodes of phase 2 re-entrant (P2R)-extrasystoles and subsequent self-terminating polymorphic ventricular tachycardia (PVT) or VF under the Brugada-ECG condition and analyzed the epicardial conduction velocity and action potential duration (APD) restitutions in each condition.RESULTS Forty-one episodes of spontaneous P2R-extrasystoles in the Brugada-ECG were successfully mapped in 9 of 10 preparations, and 33 of them were originated from the maximum gradient of repolarization (GR(max): 176 +/- 54 ms/mm) area in the epicardium, leading to PVT (n = 12) or VF (n = 5). The epicardial GR(max) was not different between PVT and VF. Wave-break during the first P2R-extrasystole produced multiple wavelets in all VF cases, whereas no wave-break or wave-break followed by wave collision and termination occurred in PVT cases. Moreover, conduction velocity restitution was shifted lower and APD restitution was more variable in VF cases than in PVT cases.CONCLUSIONS Steep repolarization gradient in the epicardium but not endocardium develops P2R-extrasystoles in the Brugada-ECG condition, which might degenerate into VF by further depolarization and repolarization abnormalities. (J Am Coll Cardiol 2006;47:2074-85) (c) 2006 by the American College of Cardiology Foundation.