St Paul Heart Clinic, 225 N. Smith Ave. #400, St Paul, MN 55102, USA.
Eur J Heart Fail. 2010 Dec;12(12):1317-24. doi: 10.1093/eurjhf/hfq162. Epub 2010 Sep 23.
Right ventricular (RV) pacing is an iatrogenic cause of heart failure (HF) that has not been well studied. We assessed whether HF patients paced from the right ventricle (RVp) adversely remodel and respond to cardiac resynchronization therapy (CRT) in a similar way to HF patients without right ventricular pacing (nRVp).
Echocardiograms were performed before and ∼5 months after CRT in 31 RVp and 49 nRVp HF patients. Longitudinal intraventricular dyssynchrony using tissue Doppler imaging (TDI) was calculated as the standard deviation of time to peak systolic displacement by tissue tracking (SD-TT) of 12 segments. Longitudinal dyssynchrony within a wall (intramural dyssynchrony) was assessed by two methods: quantifying the number of segments with initial abnormal apical displacement (IMD score) and using a cross-correlation synchrony index (CCSI). Despite similar ejection fractions (EFs) of 28% prior to CRT, left ventricular end-diastolic volume was significantly smaller (143±54 vs. 183±62, P=0.004) in RVp. The standard deviation of time to peak systolic displacement by tissue tracking (83.4±34.9 vs. 67.9±26.6, P=0.03) and IMD score (3.1±1.8 vs. 1.3±1.7, P<0.001) were greater in RVp. Cardiac resynchronization therapy significantly improved EF and volumes in both groups. Ejection fraction increased more in RVp (12.8±9.2% vs. 7.4±7.6%, P=0.007). Intraventricular dyssynchrony and both measures of intramural septal dyssynchrony improved to a greater extent post-CRT in RVp.
Right ventricular pacing patients differ from nRVp HF patients in that they have smaller ventricles and greater intraventricular and intramural septal dyssynchrony. Right ventricular pacing HF patients respond better to CRT with greater improvements in EF, and intraventricular and intramural septal dyssynchrony.
右心室（RV）起搏是心力衰竭（HF）的一种医源性原因，但尚未得到充分研究。我们评估了接受 RV 起搏（RVp）的 HF 患者与未接受 RV 起搏（nRVp）的 HF 患者在心室重构和对心脏再同步治疗（CRT）的反应方面是否相似。
31 例 RVp 和 49 例 nRVp HF 患者在 CRT 前和 CRT 后约 5 个月进行了超声心动图检查。使用组织多普勒成像（TDI）计算 12 节段的组织追踪收缩期位移达峰时间的标准差（SD-TT）作为纵向室内不同步的指标。通过两种方法评估壁内纵向不同步（壁内不同步）：量化初始异常心尖位移的节段数（IMD 评分）和使用互相关同步指数（CCSI）。尽管 CRT 前的左心室射血分数（EF）相似（28%），但 RVp 的左心室舒张末期容积明显较小（143±54 比 183±62，P=0.004）。RVp 的组织追踪收缩期位移达峰时间标准差（83.4±34.9 比 67.9±26.6，P=0.03）和 IMD 评分（3.1±1.8 比 1.3±1.7，P<0.001）更大。两组 CRT 均显著改善 EF 和容量。RVp 的 EF 增加更多（12.8±9.2%比 7.4±7.6%，P=0.007）。RVp 的室内不同步和两种壁内室间隔不同步的指标在 CRT 后改善更明显。
与 nRVp HF 患者相比，RVp 患者的心室较小，室内和壁内室间隔不同步程度更大。RVp HF 患者对 CRT 的反应更好，EF 以及室内和壁内室间隔不同步的改善更大。
