Cooklin M, Olsovsky M R, Brockman R G, Shorofsky S R, Gold M R
Department of Medicine, University of Maryland Medical System, Baltimore 21201, USA.
J Am Coll Cardiol. 1999 Aug;34(2):358-62. doi: 10.1016/s0735-1097(99)00214-4.
The purpose of this study was to compare transvenous atrial defibrillation thresholds with lead configurations consisting of an active left pectoral electrode and either single or dual transvenous coils.
Low atrial defibrillation thresholds are achieved using complex lead systems including coils in the coronary sinus. However, the efficacy of more simple ventricular defibrillation leads with active pectoral pulse generators to defibrillate atrial fibrillation (AF) is unknown.
This study was a prospective, randomized assessment of shock configuration on atrial defibrillation thresholds in 32 patients. The lead system was a dual coil Endotak DSP lead with a left pectoral pulse generator emulator. Shocks were delivered either between the right ventricular coil and an active can in common with the proximal atrial coil (triad) or between the atrial coil and active can (transatrial).
Delivered energy at defibrillation threshold was 7.1 +/- 6.0 J in the transatrial configuration and 4.0 +/- 4.2 J in the triad configuration (p < 0.005). Moreover, a low threshold (< or = 3 J) was observed in 69% of subjects in the triad configuration but only 47% in the transatrial configuration. Peak voltage and shock impedance were also lowered significantly in the triad configuration. Left atrial size was the only clinical predictor of the defibrillation threshold (r = 0.57, p < 0.002).
These results indicate that low atrial defibrillation thresholds can be achieved using a single-pass transvenous ventricular defibrillation lead with a conventional ventricular defibrillation pathway. These data support the development of the combined atrial and ventricular defibrillator system.
本研究旨在比较经静脉心房除颤阈值，其采用由一个主动式左胸电极与单根或双根经静脉线圈组成的导联配置。
使用包括冠状窦线圈在内的复杂导联系统可实现较低的心房除颤阈值。然而，带有主动胸壁脉冲发生器的更简单的心室除颤导联对房颤（AF）进行除颤的疗效尚不清楚。
本研究是一项对32例患者心房除颤阈值的电击配置进行前瞻性、随机评估的研究。导联系统是带有左胸脉冲发生器模拟器的双线圈Endotak DSP导联。电击在右心室线圈与与近端心房线圈共用的主动电极罐之间（三联组）或在心房线圈与主动电极罐之间（经心房）进行。
经心房配置下除颤阈值时的释放能量为7.1±6.0 J，三联组配置下为4.0±4.2 J（p<0.005）。此外，三联组配置中69%的受试者观察到低阈值（≤3 J），而经心房配置中仅为47%。三联组配置中的峰值电压和电击阻抗也显著降低。左心房大小是除颤阈值的唯一临床预测指标（r = 0.57，p<0.002）。
这些结果表明，使用具有传统心室除颤路径的单通道经静脉心室除颤导联可实现较低的心房除颤阈值。这些数据支持心房和心室联合除颤器系统的开发。
