Yim D, Mertens L, Morgan C T, Friedberg M K, Grosse-Wortmann L, Dragulescu A
The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
Int J Cardiovasc Imaging. 2017 May;33(5):711-720. doi: 10.1007/s10554-016-1046-2. Epub 2016 Dec 22.
Impaired ventricular myocardial mechanics are observed in patients with repaired tetralogy of Fallot (rTOF). Effects of pulmonary valve replacement (PVR) on ventricular remodeling are controversial. The objective was to assess the impact of surgical PVR on ventricular mechanics in pediatric patients after rTOF. Speckle-tracking analysis was performed in 50 rTOF children, aged 12.6 ± 3.3 years, pre-operatively and 14.5 ± 2.2 months post-PVR. Early post-operative studies 2.2 ± 0.6 months post-PVR were performed in 28 patients. Cardiac magnetic resonance (CMR) pre- and post-PVR was collected. Mid-term post-PVR right ventricular (RV) longitudinal strain increased above pre-operative strain (-19.2 ± 2.7 to -22.0 ± 3.0%, p < 0.001) with increases observed in individual RV segments. Left ventricular (LV) strain did not differ at medium-term follow-up. LV and RV longitudinal strain was reduced early post-operatively, followed by recovery of biventricular systolic strain by mid-term follow-up. CMR RV end-diastolic indexed volumes correlated with RV strain pre-operatively (r = 0.432, p = 0.005) and at mid-term follow-up (r = 0.532, p = 0.001). Volume-loaded RVs had reduced early RV basal longitudinal strain compared to pressure-loading conditions. Reversed basal counterclockwise rotation was associated with lower mid-term global LV and basal RV strain compared to patients with normal rotation. An increase in mid-term global and regional RV strain beyond pre-operative values suggests positive RV remodeling and adaptation occurs in children post-PVR. Patients with larger pre-operative RV volumes had lower RV strain post-operatively. The impact of LV rotation on RV mechanics highlights the presence of ventriculo-ventricular interactions. These findings have important clinical implications in pediatric rTOF patients towards identifying pre-operative factors that predict RV post-operative remodeling.
在法洛四联症修复术（rTOF）患者中观察到心室心肌力学受损。肺动脉瓣置换术（PVR）对心室重塑的影响存在争议。目的是评估手术PVR对rTOF患儿心室力学的影响。对50名年龄为12.6±3.3岁的rTOF儿童在术前及PVR术后14.5±2.2个月进行斑点追踪分析。对28例患者在PVR术后2.2±0.6个月进行早期术后研究。收集PVR术前和术后的心脏磁共振（CMR）数据。PVR术后中期右心室（RV）纵向应变高于术前应变（从-19.2±2.7%增至-22.0±3.0%，p<0.001），且各个RV节段均有增加。左心室（LV）应变在中期随访时无差异。LV和RV纵向应变在术后早期降低，随后在中期随访时双心室收缩应变恢复。CMR RV舒张末期指数容积在术前（r=0.432，p=0.005）和中期随访时（r=0.532，p=0.001）与RV应变相关。与压力负荷情况相比，容量负荷的RV早期RV基底纵向应变降低。与正常旋转的患者相比，基底逆时针旋转反向与中期整体LV和基底RV应变较低相关。中期整体和局部RV应变超过术前值表明PVR术后儿童出现了积极的RV重塑和适应。术前RV容积较大的患者术后RV应变较低。LV旋转对RV力学的影响突出了心室-心室相互作用的存在。这些发现对小儿rTOF患者识别预测RV术后重塑的术前因素具有重要临床意义。
