Natale A, Sra J, Axtell K, Akhtar M, Newby K, Kent V, Geiger M J, Brandon M J, Kearney M M, Pacifico A
VA Medical Center, Duke University, Durham, NC 27705, USA.
Circulation. 1996 Jan 1;93(1):91-8. doi: 10.1161/01.cir.93.1.91.
The purpose of this study was to prospectively analyze redetection problems after unsuccessful shock with different lead systems and devices.
We prospectively analyzed detection and redetection characteristics among transvenous implantable cardioverter-defibrillators (ICDs) using standard bipolar and integrated bipolar sensing. Monophasic and biphasic ICDs were included. Subthreshold shocks were intentionally delivered, and redetection of ventricular fibrillation (VF) was assessed before discharge and at 1, 3, 6, and 12 months later. Sensing of VF resulting from antitachycardia pacing and low-energy cardioversion ( < or = 2 J) also was analyzed. Before inclusion in the study, each patient underwent subthreshold shock testing at three different time intervals. Among the 160 ICDs with standard bipolar sensing, 530 VF inductions were analyzed. After the failed shocks, undersensing was more frequent (3% versus 20%, P<.01) but did not remarkably prolong redetection (3.1 +/- 0.8 versus 3.3 +/- 1.1 seconds). Among the 201 ICDs with integrated bipolar sensing, 80 were connected to a CPI device (60 Ventak 1600-Endotak 60 series and 20 PRx II 1715-Endotak 70 series) and 121 to the Ventritex defibrillator (91 Endotak 60 series, 14 TVL systems, and 16 Endotak 70 series). After 252 failed shocks, redetection was prolonged with the CPI system (3.1 +/- 1.4 versus 4.6 +/- 3.6 seconds, P<.05) but did not change after 396 failed shocks with the Ventritex ICD (5.4 +/- 1.9 versus 4.9 +/- 2.2 seconds). This may reflect different nominal settings for detection and redetection. In 9 of 121 patients with Ventritex and 1 of 80 with the CPI ICDs, the devices failed to redetect VF. However, redetection malfunction was never observed in patients with integrated bipolar systems with >6-mm electrode separation. After antitachycardia pacing in 1 patient and a 2-J shock in 1 patient, ventricular tachycardia turned into VF, which was undetected. Both patients used the Endotak 60 series-Cadence combination. None of the patients showing VF undersensing had sudden death at follow-up. Only 3 of the 12 patients with sensing malfunction were on antiarrhythmia drugs at the time of testing. Analysis of endocardial electrograms showed that failure to redetect VF is not associated with a uniform reduction but with a rapid and repetitive change of electrogram amplitude.
Standard bipolar sensing redetects VF more effectively than integrated bipolar sensing. Endocardial electrogram analysis provides insights into the understanding of the mechanism of undersensing, and certain lead-device combinations result in a higher occurrence of VF undersensing. The clinical relevance of this phenomenon remains unknown.
本研究的目的是前瞻性分析不同导联系统和设备电击失败后的重新检测问题。
我们前瞻性分析了使用标准双极和集成双极感知的经静脉植入式心律转复除颤器（ICD）的检测和重新检测特征。纳入了单相和双相ICD。故意进行亚阈值电击，并在放电前以及1、3、6和12个月后评估心室颤动（VF）的重新检测情况。还分析了抗心动过速起搏和低能量心脏转复（≤2 J）导致的VF感知情况。在纳入研究前，每位患者在三个不同时间间隔进行亚阈值电击测试。在160个具有标准双极感知的ICD中，分析了530次VF诱发情况。电击失败后，感知不足更常见（3%对20%，P<0.01），但并未显著延长重新检测时间（3.1±0.8秒对3.3±1.1秒）。在201个具有集成双极感知的ICD中，80个连接到CPI设备（60个Ventak 1600 - Endotak 60系列和20个PRx II 1715 - Endotak 70系列），121个连接到Ventritex除颤器（91个Endotak 60系列，14个TVL系统和16个Endotak 70系列）。在252次电击失败后，CPI系统的重新检测时间延长（3.1±1.4秒对4.6±3.6秒，P<0.05），但Ventritex ICD在396次电击失败后重新检测时间未改变（5.4±1.9秒对4.9±2.2秒）。这可能反映了检测和重新检测的不同标称设置。在121例使用Ventritex的患者中有9例以及80例使用CPI ICD的患者中有1例，设备未能重新检测到VF。然而，在电极间距>6 mm的集成双极系统患者中从未观察到重新检测故障。在1例患者进行抗心动过速起搏和1例患者进行2 J电击后，室性心动过速转变为VF，但未被检测到。两名患者均使用Endotak 60系列 - Cadence组合。在随访中，所有显示VF感知不足的患者均未发生猝死。在测试时，12例感知故障患者中只有3例正在服用抗心律失常药物。心内膜电图分析表明，未能重新检测到VF并非与电图幅度的均匀降低相关，而是与电图幅度的快速重复变化相关。
标准双极感知比集成双极感知更有效地重新检测VF。心内膜电图分析有助于深入理解感知不足的机制，并且某些导联 - 设备组合导致VF感知不足的发生率更高。这种现象的临床相关性仍然未知。
