From the Arrhythmia and Electrophysiology Unit (F.Z., E.B., G.P.), Division of Cardiology (C.F., L.R., S.A.), and Department of Internal Medicine (A.M.), Santa Maria Della Misericordia Hospital, Rovigo, Italy; Department of Molecular Medicine, of Padua, Padua, Italy (F.N.); and Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands (F.P.).
Circ Arrhythm Electrophysiol. 2014 Jun;7(3):377-83. doi: 10.1161/CIRCEP.113.000850. Epub 2014 Mar 25.
One of the reasons for patient nonresponse to cardiac resynchronization therapy is a suboptimal left ventricular (LV) pacing site. LV electric delay (Q-LV interval) has been indicated as a prognostic parameter of cardiac resynchronization therapy response. This study evaluates the LV delay for the optimization of the LV pacing site.
Thirty-two consecutive patients (23 men; mean age, 71±11 years; LV ejection fraction, 30±6%; 18 with ischemic cardiomyopathy; QRS, 181±25 ms; all mean±SD) underwent cardiac resynchronization therapy device implantation. All available tributary veins of the coronary sinus were tested, and the Q-LV interval was measured at each pacing site. The hemodynamic effects of pacing at different sites were evaluated by invasive measurement of LV dP/dtmax at baseline and during pacing. Overall, 2.9±0.8 different veins and 6.4±2.3 pacing sites were tested. In 31 of 32 (96.8%) patients, the highest LV dP/dtmax coincided with the maximum Q-LV interval. Q-LV interval correlated with the increase in LV dP/dtmax in all patients at each site (AR1 ρ=0.98; P<0.001). A Q-LV value >95 ms corresponded to a >10% in LV dP/dtmax. An inverse correlation between paced QRS duration and improvement in LV dP/dtmax was seen in 24 patients (75%).
Pacing the LV at the latest activated site is highly predictive of the maximum increase in contractility, expressed as LV dP/dtmax. A positive correlation between Q-LV interval and hemodynamic improvement was found in all patients at every pacing site, a value of 95 ms corresponding to an increase in LV dP/dtmax of ≥10%.
患者对心脏再同步治疗无反应的原因之一是左心室（LV）起搏部位不理想。LV 电延迟（Q-LV 间期）已被作为心脏再同步治疗反应的预后参数。本研究评估 LV 延迟以优化 LV 起搏部位。
连续 32 例患者（23 例男性；平均年龄 71±11 岁；左心室射血分数 30±6%；18 例缺血性心肌病；QRS 181±25 ms；均为平均值±标准差）接受心脏再同步治疗装置植入。所有可用的冠状窦支流均进行了测试，并在每个起搏部位测量 Q-LV 间期。通过在基线和起搏时侵入性测量 LV dP/dtmax 评估不同部位起搏的血液动力学效应。总体而言，测试了 2.9±0.8 条不同的静脉和 6.4±2.3 个起搏部位。在 32 例患者中的 31 例（96.8%）中，LV dP/dtmax 的最大值与 Q-LV 间期的最大值一致。在所有患者中，每个部位的 Q-LV 间期均与 LV dP/dtmax 的增加相关（AR1 ρ=0.98；P<0.001）。Q-LV 值>95 ms 对应于 LV dP/dtmax 的增加>10%。在 24 例患者（75%）中观察到起搏 QRS 持续时间与 LV dP/dtmax 改善之间呈负相关。
在最晚激活的部位起搏 LV 对收缩力的最大增加具有高度预测性，表现为 LV dP/dtmax。在所有患者的每个起搏部位都发现 Q-LV 间期与血液动力学改善呈正相关，95 ms 的值对应于 LV dP/dtmax 的增加≥10%。
