Department of Cardiology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan.
Department of Heart Rhythm management, Yokohama Rosai Hospital, Yokohama, Japan.
Europace. 2022 Apr 5;24(4):587-597. doi: 10.1093/europace/euab245.
A high-density pace-mapping can depict an abrupt transition in paced QRS morphology from a poor to excellent match, unmasking the critical component of ventricular tachycardia (VT) isthmus from the entrance to exit. We sought to assess pace-mapping at multiple sites within the endo- and epicardial scars to identify the VT isthmus in patients with ischaemic (ICM) and non-ischaemic cardiomyopathy (NICM).
Colour-coded maps correlating to the percentage matches between 12-lead electrocardiograms during VT and pace-mapping [referred to as correlation score maps (CSMs)] were analysed. We studied 115 CSMs (80 endo- and 35 epicardial CSMs) in 37 patients (17 ICM, 20 NICM). The CSM with an abrupt change (AC) in pacemap score (AC-type) on the endocardium was more frequently observed in ICM than in NICM [11/39 (28%) vs. 1/41 (2%); P = 0.001]. Among 35 CSMs that were analysed by the combined endo- and epicardial mapping, 10 (29%) CSMs exhibited non-AC-type on the endocardium; however, AC-type was present on the opposite epicardium. Although 24 (69%) CSMs did not show AC-type on both the endocardium and epicardium, 16 of them had either an excellent (>90%) or poor (<0%) correlation score on either side, associated with isthmus exit or entrance, respectively. However, the remaining eight CSMs had neither excellent nor poor scores.
The CSM may provide electrophysiological information to localize the endo- and epicardial VT isthmus. The absence of AC-type CSM on the endocardium, which is frequently observed in NICM, appears to indicate the sub-epicardial or intramural course of the critical isthmus.
高密度标测能够描绘起搏 QRS 形态从较差匹配到极好匹配的急剧转变，揭示出从入口到出口的室性心动过速（VT）峡部的关键部位。我们试图评估心内膜和心外膜瘢痕内多个部位的起搏标测，以确定缺血性（ICM）和非缺血性心肌病（NICM）患者的 VT 峡部。
分析了与 VT 期间 12 导联心电图之间的匹配百分比相关的彩色编码图（称为相关得分图（CSM））。我们研究了 37 名患者（17 名 ICM，20 名 NICM）的 115 个 CSM（80 个心内膜和 35 个心外膜 CSM）。心内膜上起搏图得分急剧变化（AC）的 CSM 在 ICM 中比在 NICM 中更常见[11/39（28%）比 1/41（2%）；P=0.001]。在通过心内膜和心外膜联合标测分析的 35 个 CSM 中，10 个（29%）CSM 在心内膜上表现为非 AC 型；然而，在对侧心外膜上存在 AC 型。尽管 24 个（69%）CSM 在心内膜和心外膜上均未显示 AC 型，但其中 16 个在任一侧均具有极好（>90%）或较差（<0%）的相关得分，分别与峡部出口或入口相关。然而，其余 8 个 CSM 既没有极好的分数，也没有较差的分数。
CSM 可提供电生理信息以定位心内膜和心外膜 VT 峡部。在 NICM 中经常观察到的心内膜上缺乏 AC 型 CSM 似乎表明关键峡部的亚心外膜或心内下走行。
