Department of Cardiovascular Diseases, University Hospital Gasthuisberg, Catholic University Leuven, Herestraat 49, 3000 Leuven, Belgium.
Eur Heart J. 2014 Jan;35(1):48-55. doi: 10.1093/eurheartj/eht294. Epub 2013 Aug 4.
Contradicting reports have been published regarding the relation between a dobutamine-induced increase in either cardiac dyssynchrony or left-ventricular ejection fraction (LVEF) and the response to cardiac resynchronization therapy (CRT). Using apical rocking (ApRock) as surrogate dyssynchrony parameter, we investigated the dobutamine stress echocardiography (DSE)-induced changes in left-ventricular (LV) dyssynchrony and LVEF and their potential pathophysiological interdependence.
Fifty-eight guideline-selected CRT candidates were prospectively enrolled for low-dose DSE. Dyssynchrony was quantified by the amplitude of ApRock. An LVEF increase during stress of >5% was regarded significant. Scar burden was assessed by magnetic resonance imaging. Mean follow-up after CRT implantation was 41 ± 13 months for the occurrence of cardiac death. ApRock during DSE predicted CRT response (AUC 0.88, 95% CI 0.77-0.99, P < 0.001) and correlated inversely with changes in EF (r = -0.6, P < 0.001). Left-ventricular ejection fraction changes during DSE were not associated with CRT response (P = 0.082). Linear regression analysis revealed an inverse association of LVEF changes during DSE with both, total scar burden (B = -2.67, 95CI -3.77 to -1.56, P < 0.001) and the DSE-induced change in ApRock amplitude (B = -1.23, 95% CI -1.53 to -0.94, P < 0.001). Kaplan-Meier analysis revealed that DSE-induced increase in ApRock, but not LVEF, was associated with improved long-term survival.
During low-dose DSE in CRT candidates with baseline dyssynchrony, myocardial contractile reserve predominantly results in more dyssynchrony, but less in an increase in LVEF. Dyssynchrony at baseline and its dobutamine-induced changes are predictive of both response and long-term survival following CRT.
关于多巴酚丁胺引起的心脏不同步或左心室射血分数（LVEF）增加与心脏再同步治疗（CRT）反应之间的关系，已有相互矛盾的报道。我们使用心尖摆动（ApRock）作为心脏不同步的替代参数，研究了左心室（LV）不同步和 LVEF 的多巴酚丁胺负荷超声心动图（DSE）诱导变化及其潜在的病理生理相关性。
前瞻性纳入 58 名符合指南的 CRT 候选者进行低剂量 DSE。通过 ApRock 的幅度来量化不同步性。应激时 LVEF 增加>5%被认为是显著的。通过磁共振成像评估瘢痕负荷。CRT 植入后的平均随访时间为 41±13 个月，以发生心脏死亡。DSE 期间的 ApRock 预测 CRT 反应（AUC 0.88，95%CI 0.77-0.99，P<0.001），并与 EF 变化呈负相关（r=-0.6，P<0.001）。DSE 期间 LVEF 的变化与 CRT 反应无关（P=0.082）。线性回归分析显示，DSE 期间 LVEF 的变化与总瘢痕负荷（B=-2.67，95%CI-3.77 至-1.56，P<0.001）和 DSE 诱导的 ApRock 幅度变化（B=-1.23，95%CI-1.53 至-0.94，P<0.001）呈负相关。Kaplan-Meier 分析显示，DSE 诱导的 ApRock 增加，而不是 LVEF 增加，与长期生存改善相关。
在有基线不同步的 CRT 候选者中进行低剂量 DSE 时，心肌收缩储备主要导致更多的不同步，但导致 LVEF 增加较少。基线不同步及其多巴酚丁胺诱导的变化可预测 CRT 后的反应和长期生存。
