Thibault Bernard, Roy Denis, Guerra Peter G, Macle Laurent, Dubuc Marc, Gagné Pierre, Greiss Isabelle, Novak Paul, Furlani Aldo, Talajic Mario
Department of Medicine, Montreal Heart Institute, Montreal, Quebec, Canada.
Pacing Clin Electrophysiol. 2005 Jul;28(7):613-9. doi: 10.1111/j.1540-8159.2005.00158.x.
Cardiac resynchronization therapy (CRT) has been shown to improve symptoms of patients with moderate to severe heart failure. Optimal CRT involves biventricular or left ventricular (LV) stimulation alone, atrio-ventricular (AV) delay optimization, and possibly interventricular timing adjustment. Recently, anodal capture of the right ventricle (RV) has been described for patients with CRT-pacemakers. It is unknown whether the same phenomenon exists in CRT systems associated with defibrillators (CRT-ICD). The RV leads used in these systems are different from pacemaker leads: they have a larger diameter and shocking coils, which may affect the occurrence of anodal capture.
We looked for anodal RV capture during LV stimulation in 11 consecutive patients who received a CRT-ICD system with RV leads with a true bipolar design. Fifteen patients who had RV leads with an integrated design were used as controls. Anodal RV and LV thresholds were determined at pulse width (pw) durations of 0.2, 0.5, and 1.0 ms.
RV anodal capture during LV pacing was found in 11/11 patients at some output with true bipolar RV leads versus 0/15 patients with RV leads with an integrated bipolar design. Anodal RV capture threshold was more affected by changes in pw duration than LV capture threshold. In CRT-ICD systems, RV leads with a true bipolar design with the proximal ring also used as the anode for LV pacing are associated with a high incidence of anodal RV capture during LV pacing. This may affect the clinical response to alternative resynchronization methods using single LV stimulation or interventricular delay programming.
心脏再同步治疗（CRT）已被证明可改善中重度心力衰竭患者的症状。最佳CRT包括单独的双心室或左心室（LV）刺激、房室（AV）延迟优化以及可能的心室间时间调整。最近，已描述了CRT起搏器患者右心室（RV）的阳极夺获现象。尚不清楚在与除颤器相关的CRT系统（CRT-ICD）中是否存在相同现象。这些系统中使用的RV导线与起搏器导线不同：它们直径更大且有电击线圈，这可能会影响阳极夺获的发生。
我们在11例接受具有真正双极设计RV导线的CRT-ICD系统的连续患者中，寻找LV刺激期间的RV阳极夺获。将15例具有一体化设计RV导线的患者作为对照。在脉冲宽度（pw）为0.2、0.5和1.0 ms时测定RV和LV的阳极阈值。
在一些输出水平下，11例使用真正双极RV导线的患者中有11例在LV起搏期间出现RV阳极夺获，而15例使用一体化双极设计RV导线的患者中无一例出现。与LV夺获阈值相比，RV阳极夺获阈值受pw持续时间变化的影响更大。在CRT-ICD系统中，近端环也用作LV起搏阳极的真正双极设计的RV导线与LV起搏期间RV阳极夺获的高发生率相关。这可能会影响使用单一LV刺激或心室间延迟程控的替代再同步方法的临床反应。
