Gaita F, Bocchiardo M, Porciani M C, Vivalda L, Colella A, Di Donna P, Caponi D, Bruzzone M, Padeletti L
Division of Cardiology, Ospedale Civile of Asti, Asti, Italy.
Am J Cardiol. 2000 Nov 2;86(9A):165K-158K. doi: 10.1016/s0002-9149(00)01229-7.
Biventricular pacing has been proposed to resynchronize ventricular contraction in patients with congestive heart failure (CHF) and interventricular conduction delay. However, the sudden death rate is still high despite the improvement in cardiac performance. Devices combining biventricular pacing with implantable cardioverter defibrillator (ICD) backup are now under clinical investigation to demonstrate whether they can decrease sudden death. From the first implant of an ICD with biventricular transvenous pacing on August 1998 to April 2000, 96 patients underwent such implants: 67 (70%) received pacemakers alone and 29 (30%), who had class I ICD indications, received combined pacemaker/ICD systems. During a mean follow-up of 283 +/- 170 days, 13 (14%) patients died: 5 of 29 (17%) in the ICD group and 8 of 67 (12%) in the pacemaker group. A total of 15 patients (52%) had ICD shocks and 6 patients (21%) had 113 episodes of ventricular tachyarrhythmias, of which 96 (85%) were converted to sinus rhythm with antitachypacing. The echocardiograms showed a narrowing of the delay between the onset of right and left ventricular outflow from 40 +/- 37 msec to 17 +/- 16 msec (p = 0.03) and a reduction of the mitral regurgitation area from 7 +/- 3.8 cm2 to 5 +/- 4 cm2 (p = 0.04) at 3 months. Functional class improved from 2.8 +/- 0.7 to 1.6 +/- 0.5 (p <0.001) 3 months after implant. Thus, ischemic patients with reduced left ventricular ejection fraction and ventricular tachyarrhythmias seem good candidates for biventricular pacing with ICD backup. The sudden death risk for those with idiopathic dilated cardiomyopathy, however, is difficult to stratify, and the choice of ICD backup has to be considered on the basis of patient safety, as well as of costs.
双心室起搏已被提议用于使充血性心力衰竭（CHF）和心室间传导延迟患者的心室收缩重新同步化。然而，尽管心脏功能有所改善，但猝死率仍然很高。目前正在对双心室起搏与植入式心脏复律除颤器（ICD）备用装置相结合的设备进行临床研究，以证明它们是否能降低猝死率。从1998年8月首次植入带有双心室经静脉起搏功能的ICD到2000年4月，96例患者接受了此类植入：67例（70%）仅接受起搏器植入，29例（30%）因有I类ICD适应症而接受了起搏器/ICD联合系统植入。在平均283±170天的随访期间，13例（14%）患者死亡：ICD组29例中有5例（17%），起搏器组67例中有8例（12%）。共有15例患者（52%）接受了ICD电击，6例患者（21%）发生了113次室性快速心律失常发作，其中96次（85%）通过抗快速起搏转为窦性心律。超声心动图显示，右心室和左心室流出起始之间的延迟从40±37毫秒缩短至17±16毫秒（p = 0.03），二尖瓣反流面积在3个月时从7±3.8平方厘米减少至5±4平方厘米（p = 0.04）。植入后3个月，心功能分级从2.8±0.7改善至1.6±0.5（p<0.001）。因此，左心室射血分数降低且伴有室性快速心律失常的缺血性患者似乎是双心室起搏联合ICD备用装置的良好候选者。然而，对于特发性扩张型心肌病患者，猝死风险难以分层，必须在考虑患者安全性以及成本的基础上决定是否选择ICD备用装置。
