Electrophysiology Section, Cardiovascular Division, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pa., USA.
Circ Arrhythm Electrophysiol. 2010 Feb;3(1):63-71. doi: 10.1161/CIRCEP.109.859942. Epub 2009 Dec 11.
ECG criteria identifying epicardial (EPI) origin for ventricular tachycardia (VT) in nonischemic cardiomyopathy have not been determined. Endocardial (ENDO) and EPI basal left ventricle fibrosis characterizes the VT substrate.
We assessed the QRS from 102 basal-superior/lateral EPI and 67 comparable ENDO pace maps in 14 patients with nonischemic cardiomyopathy. Pace mapping focused on low bipolar voltage areas. Published morphology criteria: q wave in lead I (QWLI) and no q waves in inferior leads and interval criteria: pseudo-delta wave > or =34 ms, intrinsicoid deflection time > or =85 ms, shortest RS complex > or =121 ms, and maximum deflection index > or =0.55 were assessed for ability to identify EPI origin. Sixteen EPI and 8 ENDO of the 34 mapped VTs (71%) in the study population and 14 EPI and 7 ENDO VTs from an 11-patient validation cohort were localized to basal-superior/lateral left ventricle and corroborated pacing data. A QWL1 was seen in EPI but not ENDO pace maps (91% versus 4%; P<0.001), identified 14 of 16 EPI VTs (sensitivity, 88%), and was seen in 1 of 8 ENDO VTs (specificity, 88%). None of the remaining criteria achieved similar sensitivity without specificity <50%. We identified 4 criteria (q waves in inferior leads, pseudo-delta wave > or =75 ms, maximum deflection index > or =0.59, and QWL1) having > or =95% specificity and > or =20% sensitivity in identifying EPI/ENDO origin for pace maps. This 4-step algorithm identified the origin in 109 of 115 pace maps (95%), 21 of 24 VTs (88%) in the study population, and 19 of 21 VTs (90%) in validation cohort.
Morphological ECG features that describe the initial QRS vector can help identify basal-superior/lateral EPI VTs in nonischemic cardiomyopathy.
非缺血性心肌病中心律失常性室性心动过速（VT）的心电图标准仍未确定。心内膜（ENDO）和心外膜（EPI）基底左心室纤维化是 VT 基质的特征。
我们评估了 14 例非缺血性心肌病患者的 102 个基底-上/外侧 EPI 和 67 个可比的 ENDO 起搏图的 QRS。起搏图侧重于低双极电压区域。发表的形态学标准：I 导联 Q 波（QWLI）和下壁导联无 Q 波以及间期标准：伪 delta 波>或=34ms，固有偏转时间>或=85ms，最短 RS 复合体>或=121ms，最大偏转指数>或=0.55 用于确定 EPI 起源的能力。研究人群中 34 例 mappedVT 中有 16 例 EPI 和 8 例 ENDO（71%），11 例验证队列中有 14 例 EPI 和 7 例 ENDOVT，这些 VT 均定位于基底-上/外侧左心室，并证实了起搏数据。EPI 起搏图中可见 QWL1，但在 ENDO 起搏图中不可见（91%对 4%；P<0.001），识别出 16 例 EPI VT 中的 14 例（敏感性，88%），在 8 例 ENDO VT 中仅见 1 例（特异性，88%）。其余标准的敏感性均未达到 88%，而特异性<50%。我们确定了 4 项标准（下壁导联 Q 波、伪 delta 波>或=75ms、最大偏转指数>或=0.59 和 QWL1），其特异性>或=95%，敏感性>或=20%，用于识别起搏图的 EPI/ENDO 起源。该 4 步算法在研究人群中 115 个起搏图中的 109 个（95%）、24 个 VT 中的 21 个（88%）和验证队列中的 21 个 VT 中的 19 个（90%）中确定了起源。
描述初始 QRS 向量的心电图特征有助于识别非缺血性心肌病中的基底-上/外侧 EPIVT。
