Berul C I, Callans D J, Schwartzman D S, Preminger M W, Gottlieb C D, Marchlinski F E
Clinical Electrophysiology Laboratory, Presbyterian Medical Center, Philadelphia, Pennsylvania 19104.
J Am Coll Cardiol. 1995 Feb;25(2):431-6. doi: 10.1016/0735-1097(94)00418-p.
The purpose of this study was to prospectively evaluate postshock redetection of ventricular fibrillation by a system that coupled an implantable cardioverter-defibrillator with an automatic gain control sense amplifier and a transvenous lead system.
Redetection of ventricular fibrillation after an unsuccessful first shock has not been systematically evaluated. Previous studies have suggested that sensing performance of some lead systems may be adversely affected by the delivery of subthreshold shocks.
The time required for both initial detection and redetection of ventricular fibrillation was compared in 22 patients. These times were estimated by subtracting the capacitor charge time from the total event time.
A total of 113 successful and 57 unsuccessful initial shocks were delivered during induced ventricular fibrillation. The mean +/- SD initial time to detection of ventricular fibrillation was 5.5 +/- 1.7 s (range 2.4 to 10.8); the time to redetection ranged from 1.5 to 18.5 s (mean 4.5 +/- 2.8, p = NS vs. detection time). Abnormal redetection episodes, defined as a redetection time > 10.2 s (i.e., > 2 SD above the mean redetection time), were observed in 4 (18%) of 22 patients.
Redetection of ventricular fibrillation after a subthreshold first shock may be delayed. Device testing with intentional delivery of subthreshold shocks to verify successful postshock redetection of ventricular fibrillation should be performed routinely in all patients.
本研究的目的是前瞻性评估一种将植入式心脏复律除颤器与自动增益控制传感放大器及经静脉导联系统相结合的系统对室颤电击后再检测的情况。
首次电击未成功后室颤的再检测尚未得到系统评估。先前的研究表明，某些导联系统的传感性能可能会受到阈下电击的不利影响。
比较了22例患者室颤初始检测和再检测所需的时间。这些时间通过从总事件时间中减去电容器充电时间来估算。
在诱发室颤期间共进行了113次成功的初始电击和57次未成功的初始电击。室颤初始检测的平均±标准差时间为5.5±1.7秒（范围2.4至10.8秒）；再检测时间为1.5至18.5秒（平均4.5±2.8秒，与检测时间相比p=无显著性差异）。在22例患者中有4例（18%）观察到异常再检测事件，定义为再检测时间>10.2秒（即高于平均再检测时间2个标准差以上）。
阈下首次电击后室颤的再检测可能会延迟。应常规对所有患者进行有意施加阈下电击以验证电击后室颤成功再检测的设备测试。
