Division of Cardiology, Heart Institute, Children's Hospital Colorado, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colorado.
Division of Cardiology, Heart Institute, Children's Hospital Colorado, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colorado.
J Heart Lung Transplant. 2018 Jul;37(7):870-878. doi: 10.1016/j.healun.2018.01.1308. Epub 2018 Feb 6.
Electrical and right ventricular (RV) mechanical dyssynchrony has been previously described in pediatric pulmonary arterial hypertension (PAH), but less is known about the relationship between electrical dyssynchrony and biventricular function. In this study we applied cardiac magnetic resonance (CMR) imaging to evaluate biventricular size and function with a focus on left ventricular (LV) strain mechanics in pediatric PAH patients with and without electrical dyssynchrony.
Fifty-six children with PAH and comprehensive CMR evaluation were stratified based on QRS duration z-score, with electrical dyssynchrony defined as z-score ≥2. Comprehensive biventricular volumetric, dyssynchrony, and strain analysis was performed.
Nineteen PAH patients had or developed electrical dyssynchrony. Patients with electrical dyssynchrony had significantly reduced RV ejection fraction (35% vs 50%, p = 0.003) and greater end-diastolic (168 vs 112 ml/m, p = 0.041) and end-systolic (119 vs 57, ml/m, p = 0.026) volumes. Patients with electrical dyssynchrony had reduced RV longitudinal strain (-14% vs -19%, p = 0.007), LV circumferential strain measured at the free wall (-19% vs -22%, p = 0.047), and the LV longitudinal strain in the septal region (-10% vs -15%, p = 0.0268). LV mechanical intraventricular dyssynchrony was reduced in patients with electrical dyssynchrony at the LV free wall (43 vs 19 ms, p = 0.019).
The electrical dyssynchrony is associated with the reduced LV strain, enlarged RV volumes, and reduced biventricular function in children with PAH. CMR assessment of biventricular mechanical function with respect to QRS duration may help to detect pathophysiologic processes associated with progressed PAH.
电和右心室（RV）机械不同步已在儿科肺动脉高压（PAH）中得到描述，但对于电不同步与双心室功能之间的关系了解较少。在这项研究中，我们应用心脏磁共振（CMR）成像评估了有和无电不同步的儿科 PAH 患者的双心室大小和功能，重点是左心室（LV）应变力学。
根据 QRS 持续时间 z 评分，对 56 名接受 PAH 综合 CMR 评估的儿童进行分层，电不同步定义为 z 评分≥2。进行全面的双心室容量、不同步和应变分析。
19 名 PAH 患者存在或出现电不同步。电不同步患者的 RV 射血分数明显降低（35%比 50%，p=0.003），舒张末期（168 比 112 ml/m，p=0.041）和收缩末期容积（119 比 57，ml/m，p=0.026）较大。电不同步患者的 RV 纵向应变降低（-14%比-19%，p=0.007），LV 游离壁圆周应变降低（-19%比-22%，p=0.047），LV 间隔区纵向应变降低（-10%比-15%，p=0.0268）。电不同步患者 LV 游离壁的 LV 机械室内不同步减少（43 比 19 ms，p=0.019）。
电不同步与 PAH 患儿 LV 应变降低、RV 容积增大和双心室功能降低有关。CMR 评估 QRS 持续时间与双心室机械功能的关系有助于检测与进展性 PAH 相关的病理生理过程。
