Department of Cardiology Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, the Netherlands.
Department of Cardiology Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, the Netherlands.
J Card Fail. 2016 Feb;22(2):133-42. doi: 10.1016/j.cardfail.2015.10.020. Epub 2015 Nov 10.
Patients with left ventricular (LV) dyssynchrony have a marked misbalance in LV myocardial work distribution, with wasted work in the septum and increased work in the lateral wall. We hypothesized that a low septum-to-lateral wall (SL) myocardial work ratio at baseline predicts acute LV pump function improvement during cardiac resynchronization therapy (CRT).
Twenty patients (age 65 ± 10 y, 15 men) underwent cardiac magnetic resonance (CMR) tagging for regional LV circumferential strain assessment and invasive pressure-volume loop assessment at baseline and during biventricular pacing. Segmental work at baseline was calculated from regional strain rate and LV pressure. Subsequently, the SL work ratio was calculated and related to acute pump function (stroke work [SW]) improvement during CRT. During biventricular pacing, SW increased by 33% (P <.001). SL work ratio at baseline was found to be significantly related to SW improvement by means of CRT (R = -0.54; P = .015). Moreover, it proved to be the only marker that was significantly related to acute response to CRT, whereas QRS duration and other measures of dyssynchrony or dyscoordination were not.
The contribution of the septum to LV work varies widely in CRT candidates with left bundle branch block. The lower the septal contribution to myocardial work at baseline, the higher the acute pump function improvement that can be achieved during CRT.
左心室（LV）不同步的患者 LV 心肌做功分布存在明显失衡，室间隔做功浪费，侧壁做功增加。我们假设基线时室间隔与侧壁（SL）心肌做功比低可预测心脏再同步治疗（CRT）期间 LV 泵功能的急性改善。
20 例患者（年龄 65±10 岁，男性 15 例）在基线和双心室起搏时进行心脏磁共振（CMR）标记以评估局部 LV 圆周应变和侵入性压力-容积环评估。基线时的节段性做功通过局部应变率和 LV 压力计算。随后计算 SL 工作比，并与 CRT 期间的急性泵功能（每搏功 [SW]）改善相关。在双心室起搏时，SW 增加了 33%（P<.001）。基线时的 SL 工作比与 CRT 时的 SW 改善显著相关（R=-0.54；P=.015）。此外，它是唯一与 CRT 急性反应显著相关的标志物，而 QRS 持续时间和其他不同步或不协调的指标则不然。
在左束支传导阻滞的 CRT 候选者中，室间隔对 LV 做功的贡献差异很大。基线时室间隔对心肌做功的贡献越低，CRT 期间可实现的急性泵功能改善就越高。
