Department of Cardiology, Isala klinieken, Zwolle, The Netherlands.
J Cardiovasc Electrophysiol. 2011 Jun;22(6):677-83. doi: 10.1111/j.1540-8167.2010.01968.x. Epub 2010 Dec 6.
cardiac resynchronization therapy (CRT) may improve prognosis in patients with chronic right ventricular (RV) pacing, and optimal lead position can decrease nonresponders. We evaluated the clinical and echocardiographic response to CRT in patients with previous chronic RV pacing, using pressure-volume loop analyses to determine the optimal left ventricular (LV) lead position during implantation.
In this single-blinded, randomized, controlled crossover study, 40 patients with chronic RV apical pacing and symptoms of heart failure, decreased LV ejection fraction (LVEF) or dyssynchrony were included. During implantation, stroke work (SW), LVEF, cardiac output, and LV dP/dt(max) were assessed by a conductance catheter. Clinical and echocardiographic response was studied during a 3-month period of RV pacing (RV period, LV lead inactive) and a 3-month period of biventricular pacing (CRT period). At the optimal LV lead position, SW (37 ± 41%), LVEF (16 ± 13%), cardiac output (29 ± 16%), and LV dP/dt(max) increased (11 ± 11%) significantly during biventricular pacing compared to baseline. Additional benefit could be achieved by pressure-volume loop guided selection of the best left-sided pacing location. RV outflow tract pacing did not improve hemodynamics. During follow-up, symptoms improved during CRT, VO(2,max) increased 10% and significant improvements in LVEF, LV volumes, and mitral regurgitation were observed as compared to the RV period.
CRT in patients with chronic RV pacing causes significant improvement of both LV function as measured by pressure-volume loops during implantation and clinical and echocardiographic improvement during follow-up. Pressure-volume loops during implantation may facilitate selection of the most optimal pacing site.
心脏再同步治疗（CRT）可能改善慢性右心室（RV）起搏患者的预后，而最佳的导联位置可以减少无反应者。我们使用压力-容积环分析评估了既往慢性 RV 起搏患者接受 CRT 的临床和超声心动图反应，以确定植入过程中最佳的左心室（LV）导联位置。
在这项单盲、随机、对照交叉研究中，纳入了 40 例慢性 RV 心尖起搏且有心力衰竭症状、LV 射血分数（LVEF）降低或不同步的患者。在植入过程中，通过传导导管评估了每搏功（SW）、LVEF、心输出量和 LV dP/dt(max)。在 3 个月的 RV 起搏期（RV 期，LV 导联不活动）和 3 个月的双心室起搏期（CRT 期）中研究了临床和超声心动图的反应。在最佳 LV 导联位置，与基线相比，双心室起搏时 SW（37 ± 41%）、LVEF（16 ± 13%）、心输出量（29 ± 16%）和 LV dP/dt(max)（11 ± 11%）显著增加。通过压力-容积环引导选择最佳的左侧起搏位置可以获得额外的益处。RV 流出道起搏不能改善血液动力学。在随访期间，与 RV 期相比，CRT 期间症状改善，VO(2,max)增加 10%，LVEF、LV 容积和二尖瓣反流均有显著改善。
在慢性 RV 起搏患者中进行 CRT 可显著改善植入过程中压力-容积环测量的 LV 功能，以及随访期间的临床和超声心动图改善。植入过程中的压力-容积环分析可能有助于选择最佳的起搏部位。
