Winter J, Zimmermann N, Lidolt H, Dees H, Perings C, Vester E G, Poll L, Schipke J D, Contzen K, Gams E
Department of Thoracic and Cardiovascular Surgery, Heinrich-Heine-University, Duesseldorf, Germany.
Am J Cardiol. 2000 Nov 2;86(9A):71K-75K. doi: 10.1016/s0002-9149(00)01294-7.
Reduction of the defibrillation energy requirement offers the opportunity to decrease implantable cardioverter defibrillator (ICD) size and to increase device longevity. Therefore, the purpose of this prospective study was to obtain confirmed defibrillation thresholds (DFTs) of < or = 15 J in each patient with an endocardial dual-coil lead system incorporating an active pectoral pulse generator (TRIAD lead system: RV- --> SVC+ + CAN+). According to our previous clinical and experimental studies, we tried to lower DFTs that were > 15 J by repositioning the distal coil of the endocardial lead system in the right ventricle. A total of 190 consecutive patients requiring ICDs for ventricular fibrillation and/or recurrent ventricular tachycardia were investigated at the time of ICD implantation (42 women, 148 men; mean age 61.9 +/- 12.0 years; mean left ventricular ejection fraction 42.7 +/- 16.6%). Coronary artery disease was present in 139 patients; nonischemic dilated cardiomyopathy in 34 patients; and other etiologies in 17 patients; 47 patients had undergone previous cardiac surgery. Regardless of optimal pacing and sensing parameters, for patients having DFTs > 15, we repositioned the distal coil of the endocardial lead system toward the intraventricular septum to include this part of both ventricles within the electrical defibrillating field. In 177 of 190 patients, induced ventricular fibrillation was successfully terminated with < or = 15 J (group I) using the initial lead position. Repositioning of the endocardial lead was necessary in 13 patients whose DFT(plus) (DFT(plus) = second additional success at lowest energy level) were > 15 J (group II). In all patients, repositioning was successful within a 15 J energy level (100% success). The mean DFT(plus) was 7.3 +/- 3.5 J (group I) and 11.0 +/- 4.5 J (group II; p<0.005). The mean DFT(plus) of all patients enrolled in the study was 7.6 +/- 3.7 J (range: 2 to 15 J). In 87% of all patients, DFT(plus) of < or = 10 J was achieved. Repositioning of the endocardial lead in the right ventricle is a simple and effective method to reduce intraoperative high DFTs. As a result of this procedure, ICDs with a 20 J output should be sufficient for the vast majority (87%) of our patients. Furthermore, we were able to avoid additional subcutaneous or epicardial electrodes in all patients.
降低除颤能量需求为减小植入式心律转复除颤器（ICD）尺寸并延长设备使用寿命提供了契机。因此，本前瞻性研究的目的是在每例使用带有主动胸壁脉冲发生器的心内膜双线圈导联系统（TRIAD导联系统：右心室→上腔静脉 + + 外壳 +）的患者中获得确认的除颤阈值（DFT）≤15 J。根据我们之前的临床和实验研究，我们试图通过重新定位心内膜导联系统在右心室的远端线圈来降低>15 J的DFT。在ICD植入时对总共190例因心室颤动和/或复发性室性心动过速需要植入ICD的连续患者进行了研究（42例女性，148例男性；平均年龄61.9±12.0岁；平均左心室射血分数42.7±16.6%）。139例患者患有冠状动脉疾病；34例患者患有非缺血性扩张型心肌病；17例患者有其他病因；47例患者曾接受过心脏手术。无论起搏和感知参数是否最佳，对于DFT>15的患者，我们将心内膜导联系统的远端线圈重新定位至室间隔，以使两个心室的这一部分都包含在电除颤区域内。在190例患者中的177例中，使用初始导联位置以≤15 J成功终止了诱发的心室颤动（I组）。13例DFT（加）（DFT（加）=最低能量水平下的第二次额外成功）>15 J的患者需要重新定位心内膜导联（II组）。在所有患者中，重新定位在15 J能量水平内成功（成功率100%）。I组的平均DFT（加）为7.3±3.5 J，II组为11.0±4.5 J（p<0.005）。纳入研究的所有患者的平均DFT（加）为7.6±3.7 J（范围：2至15 J）。在所有患者的87%中，实现了DFT（加）≤10 J。在右心室重新定位心内膜导联是一种简单有效的降低术中高DFT的方法。由于这一操作，输出为20 J的ICD应该足以满足我们绝大多数（87%）患者的需求。此外，我们能够在所有患者中避免额外的皮下或心外膜电极。
