Zeppenfeld Katja, Schalij Martin J, Bartelings Margot M, Tedrow Usha B, Koplan Bruce A, Soejima Kyoko, Stevenson William G
Department of Cardiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
Circulation. 2007 Nov 13;116(20):2241-52. doi: 10.1161/CIRCULATIONAHA.107.723551. Epub 2007 Oct 29.
Catheter ablation of ventricular tachycardia (VT) after repair of congenital heart disease can be difficult because of nonmappable VTs and complex anatomy. Insights into the relation between anatomic isthmuses identified by delineating unexcitable tissue using substrate mapping techniques and critical reentry circuit isthmuses might facilitate ablation.
Sinus rhythm voltage mapping of the right ventricle was performed in 11 patients with sustained VT after repair of congenital heart disease. Unexcitable tissue from patch material, valve annulus, or dense fibrosis, identified from bipolar voltage (<0.5 mV) and pacing threshold (>10 mA), was defined as an anatomic isthmus boundary bordering 4 isthmuses between (1) the tricuspid annulus and scar/patch in the anterior right ventricular outflow, (2) the pulmonary annulus and right ventricular free wall scar/patch, (3) the pulmonary annulus and septal scar/patch, and (4) the septal scar/patch and tricuspid annulus. The reentry circuit isthmuses of all induced 15 VTs (mean cycle length, 276+/-78 ms; 73% poorly tolerated), identified by activation, entrainment, and/or pace mapping, were located in an anatomic isthmus (11 of 15 VTs in anatomic isthmus 1). Transecting the anatomic isthmuses by ablation lesions abolished all VTs. During 30.4+/-29.3 months of follow-up, 91% of patients remained free of VT.
Reentry circuit isthmuses in VT late after repair of congenital heart disease are located within anatomically defined isthmuses bordered by unexcitable tissue. The boundaries can be identified with 3-dimensional substrate mapping and connected by ablation lines during sinus rhythm. These findings should facilitate catheter and surgical ablation of stable and unstable VTs.
先天性心脏病修复术后的室性心动过速（VT）导管消融可能会很困难，原因在于无法标测的室性心动过速和复杂的解剖结构。通过使用基质标测技术描绘不可兴奋组织来确定解剖峡部与关键折返环路峡部之间的关系，可能会有助于消融。
对11例先天性心脏病修复术后发生持续性室性心动过速的患者进行了右心室窦性心律电压标测。根据双极电压（<0.5 mV）和起搏阈值（>10 mA）确定的补片材料、瓣膜环或致密纤维化形成的不可兴奋组织被定义为解剖峡部边界，其界定了4个峡部，分别位于（1）三尖瓣环与右心室流出道前部的瘢痕/补片之间，（2）肺动脉环与右心室游离壁瘢痕/补片之间，（3）肺动脉环与间隔瘢痕/补片之间，以及（4）间隔瘢痕/补片与三尖瓣环之间。通过激动标测、拖带标测和/或起搏标测确定的所有诱发的15次室性心动过速（平均周长，276±78 ms；73%耐受性差）的折返环路峡部均位于解剖峡部内（15次室性心动过速中有11次位于解剖峡部1）。通过消融线横断解剖峡部可消除所有室性心动过速。在30.4±29.3个月的随访期间，91%的患者未再发生室性心动过速。
先天性心脏病修复术后晚期室性心动过速的折返环路峡部位于由不可兴奋组织界定的解剖峡部内。这些边界可通过三维基质标测来识别，并在窦性心律期间通过消融线连接起来。这些发现应有助于稳定和不稳定室性心动过速的导管消融和手术消融。
