Grubb B P, Durzinsky D, Temesy-Armos P, Hahn H, Elliott L
Division of Cardiology, Medical College of Ohio, Toledo 43699.
Pacing Clin Electrophysiol. 1992 Jun;15(6):845-8. doi: 10.1111/j.1540-8159.1992.tb03072.x.
A 17-year-old white male was found to have nonobstructive hypertrophic cardiomyopathy after suffering three severe syncopal episodes. He experienced an episode of sustained polymorphic ventricular tachycardia during exercise tolerance testing that required cardioversion. Electrophysiological studies were able to reproduce sustained polymorphic ventricular tachycardia that was unresponsive to standard pharmacotherapy. An automatic implantable defibrillator was placed. However, during implantation with the rate sensing electrodes on the left ventricle, it was found that the extremely polymorphic nature of the tachycardia caused such rapid fluctuations in the sensed R wave signal that the device could not properly detect the tachycardia. This was felt to be due to the automatic gain control circuit of the Ventak 1550. The problem was solved by moving the rate sensing electrodes to the lateral right ventricle. This case suggests that the unique arrhythmic substrate of hypertrophic cardiomyopathy may present sensing difficulties during automatic implantable defibrillator insertion.
一名17岁白人男性在经历三次严重晕厥发作后被诊断为非梗阻性肥厚型心肌病。他在运动耐量测试期间发生了一次持续性多形性室性心动过速，需要进行心脏复律。电生理研究能够诱发对标准药物治疗无反应的持续性多形性室性心动过速。于是植入了自动植入式除颤器。然而，在将心率感知电极置于左心室进行植入时，发现心动过速的极端多形性导致感知到的R波信号快速波动，以至于该设备无法正确检测到心动过速。这被认为是由于Ventak 1550的自动增益控制电路所致。通过将心率感知电极移至右心室侧壁，问题得以解决。该病例表明，肥厚型心肌病独特的心律失常基质可能在自动植入式除颤器植入过程中带来感知困难。
