Bogun Frank, Li Yi-Gang, Groenefeld Gerian, Hohnloser Stefan H, Schuger Claudio, Oral Hakan, Pelosi Frank, Knight Bradley, Strickberger S Adam, Morady Fred
Division of Cardiology, Henry Ford Hospital, Detroit, Michigan 48202-9888, USA.
J Cardiovasc Electrophysiol. 2002 Mar;13(3):237-41. doi: 10.1046/j.1540-8167.2002.00237.x.
Multiple forms of ventricular tachycardia (VT) after myocardial infarction may result from multiple reentrant circuits that share an isthmus or from separate reentrant circuits. The prevalence of a shared isthmus in patients with multiple hemodynamically tolerated VTs has not been determined.
Criteria for a shared isthmus consisted of (1) concealed entrainment of >1 VT at a single pacing site; (2) concealed entrainment during VT and a perfect pace map of another VT at the same pacing site; or (3) concealed entrainment of VT of a given morphology that had at least two cycle lengths that varied by at least 100 msec. In a series of 19 patients (16 men and 3 women; age 65+/-14 years, ejection fraction 0.25+/-0.09) with 54 VTs (mean cycle length 494+/-98 msec), there was evidence of a shared isthmus in 23 VTs (43%) at 11 sites in 9 patients. Concealed entrainment of two different VTs was observed at 4 of 11 sites. At 5 of 11 sites there was concealed entrainment of one VT and a perfect pace map of another VT. At the remaining 2 of 11 sites, there was concealed entrainment of a VT that had two different cycle lengths. Nineteen of the 23 VTs were ablated successfully with radiofrequency energy applications at 11 sites.
In postinfarction patients with pleiomorphic, hemodynamically stable VT, a shared isthmus may be present in approximately 40% of VTs.
心肌梗死后多种形式的室性心动过速（VT）可能源于共享一个峡部的多个折返环路或源于独立的折返环路。血流动力学耐受的多种室性心动过速患者中共享峡部的发生率尚未确定。
共享峡部的标准包括：（1）在单个起搏部位隐匿性拖带>1种室性心动过速；（2）室性心动过速期间隐匿性拖带且在同一起搏部位对另一种室性心动过速有完美的起搏标测；或（3）隐匿性拖带给定形态的室性心动过速，其至少有两个周期长度相差至少100毫秒。在一系列19例患者（16例男性和3例女性；年龄65±14岁，射血分数0.25±0.09）中发生了54次室性心动过速（平均周期长度494±98毫秒），9例患者的11个部位有23次室性心动过速（43%）有共享峡部的证据。在11个部位中的4个部位观察到两种不同室性心动过速的隐匿性拖带。在11个部位中的5个部位，有一种室性心动过速的隐匿性拖带和另一种室性心动过速的完美起搏标测。在11个部位中的其余2个部位，有一种室性心动过速的隐匿性拖带，其有两个不同的周期长度。23次室性心动过速中的19次通过在11个部位应用射频能量成功消融。
在心肌梗死后多形性、血流动力学稳定的室性心动过速患者中，约40%的室性心动过速可能存在共享峡部。
