High-Resolution Mapping of Postinfarction Reentrant Ventricular Tachycardia: Electrophysiological Characterization of the Circuit.
High-Resolution Mapping of Postinfarction Reentrant Ventricular Tachycardia: Electrophysiological Characterization of the Circuit.
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DOI：
10.1161/circulationaha.116.021955
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发表时间：
2016-07-26
期刊：
影响因子：
37.8
通讯作者：
Josephson ME
中科院分区：
文献类型：
--
作者：
Anter E;Tschabrunn CM;Buxton AE;Josephson ME
室性心动过速（VT）回路的体内描述受到时空分辨率不足的限制。我们利用一种新的高分辨率标测技术来表征梗死后折返性VT回路的电生理特性。15只猪，用球囊闭塞左前降支诱发心肌梗死（MI）。动物在MI后6-8周进行研究。使用Rhythmia™标测系统进行VT的激动标测。激动时间基于双极和单极电描记图的组合。检查了回路不同区域对重复起搏的反应。共诱导了56例单形性VT（每只动物3.8±2.1例）。其中，21例（37.5%）血流动力学稳定，允许标测回路。峡部长16.4±7.2mm，宽7.4±2.8mm。传导速度在峡部“入口”的向内弯曲处最慢（0.28±0.2m/sec），在向外弯曲“出口”处稍快（0.40±0.3m/sec），在中央峡部接近正常（0.62±0.2m/sec）。在3只动物中，绘制了具有共享同一峡部的相反轴的2个VT形态。共享峡部内的传导速度依赖于激活向量，在近端曲率处始终较慢。通过激动标测确定的峡部部位超速起搏与峡部夹带标准一致。然而，通过夹带定义的峡部尺寸超过通过激活标测测量的峡部尺寸32%± 18%。在梗死后折返性室性心动过速中，传导速度在近端和远端弯曲处最慢。夹带映射高估了峡部的真实大小。VT的高分辨率激动标测可以更好地指导消融治疗。
In-vivo description of ventricular tachycardia (VT) circuits is limited by insufficient spatiotemporal resolution. We utilized a novel high-resolution mapping technology to characterize the electrophysiological properties of the post-infarction reentrant VT circuit. In 15 swine, myocardial infarction (MI) was induced by left anterior descending artery balloon occlusion. Animals were studies 6–8 weeks after MI. Activation mapping of VTs was performed using the Rhythmia™ mapping system. Activation time was based on a combination of bipolar and unipolar electrograms. The response to overdrive pacing from different zones of the circuit was examined. A total of 56 monomorphic VTs were induced (3.8±2.1 per animal). Among these, 21 (37.5%) were hemodynamically stable and allowed mapping of the circuit. Isthmuses were 16.4±7.2mm long and 7.4±2.8mm wide. Conduction velocities were slowest at the inward curvature into the isthmus “entrance” (0.28±0.2m/sec), slightly faster at the outward curvature “exit” (0.40±0.3m/sec) and nearly normal at the central isthmus (0.62±0.2m/sec). In 3 animals 2 VT morphologies with opposite axis sharing the same isthmus were mapped. Conduction velocities within the shared isthmus were dependent on the activation vector, consistently slower at the proximal curvature. Overdrive pacing from isthmus sites determined by activation mapping was consistent with entrainment criteria for isthmus. However, dimensions of the isthmus defined by entrainment exceeded dimensions of the isthmus measured by activation mapping by 32%±18%. In post-infarction reentrant VT, conduction velocities are slowest at the proximal and distal curvatures. Entrainment mapping overestimates the true size of the isthmus. High-resolution activation mapping of VT may better guide ablation therapy.