Bitterman Yuval, Bulic Anica, Mueller Brigitte, Steve Fan Chun-Po, Friedberg Mark K
Labatt Family Heart Centre, Department of Paediatrics, Hospital for Sick Children (SickKids), Toronto, Ontario, Canada. Electronic address: https://twitter.com/YuvalBit.
Labatt Family Heart Centre, Department of Paediatrics, Hospital for Sick Children (SickKids), Toronto, Ontario, Canada.
Can J Cardiol. 2025 Jun;41(6):1172-1181. doi: 10.1016/j.cjca.2025.02.015. Epub 2025 Feb 11.
Patients with repaired tetralogy of Fallot (rTOF) develop electromechanical dyssynchrony (EMD), which detrimentally affects right ventricular (RV) function and exercise capacity. However, EMD evolution over childhood is unknown.
We retrospectively studied serial ECG, Holter, echocardiography, cardiac magnetic resonance, and exercise data of rTOF patients, over the first 18-years of life, who underwent repair from 2010 to 2020. Mechanical dyssynchrony parameters were evaluated at ages 8-12 and 14-18 years.
A total of 95 patients (61% male) were followed for a median 15.7 years (range 8-18 years). QRS duration (QRSd) increased steeply in the first 6 years and gradually through adolescence. Prolonged QRSd was associated with decreased VO (P = 0.001), peak workload (P = 0.008), and RV ejection fraction (RVEF). RVEF decreased by 1.3% (-0.7 to -1.9) for every 10 ms increase in QRSd (P < 0.001). Patients with QRSd z score > 2 had a declining RVEF, despite a stable pulmonary insufficiency fraction and indexed RV end-diastolic volume throughout childhood. QRS fractionation (fQRS) increased during the first 6 years and then again in adolescence, which temporally coincided with the onset of arrhythmias. fQRS was associated with decreased RVEF (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.9-1; P = 0.05) and RV longitudinal strain (OR 1.02; 95% CI 1.01-1.04; P = 0.008). 70.5% of patients had a septal flash at the first mechanical dyssynchrony assessment, which was associated with longer QRSd (median 124 ms [interquartile range (IQR) 107-136 ms] vs 100 ms [IQR 93-118 ms]; P = 0.019).
Electrical dyssynchrony is associated with progressive RV dysfunction and exercise intolerance over the course of childhood in rTOF, independently from pulmonary insufficiency. This raises the question of considering RV resynchronisation therapy in selected patients with symptomatic RV dysfunction and EMD.
法洛四联症修复术后（rTOF）患者会出现机电不同步（EMD），这对右心室（RV）功能和运动能力产生不利影响。然而，儿童期EMD的演变尚不清楚。
我们回顾性研究了2010年至2020年接受修复手术的rTOF患者在生命的前18年中的系列心电图、动态心电图、超声心动图、心脏磁共振和运动数据。在8至12岁和14至18岁时评估机械不同步参数。
共随访95例患者（61%为男性），中位随访时间为15.7年（范围8至18年）。QRS时限（QRSd）在最初6年急剧增加，并在整个青春期逐渐增加。QRSd延长与VO降低（P = 0.001）、峰值工作量（P = 0.008）和右心室射血分数（RVEF）降低相关。QRSd每增加10 ms，RVEF下降1.3%（-0.7至-1.9）（P < 0.001）。尽管整个儿童期肺功能不全分数和右心室舒张末期容积指数稳定，但QRSd z评分>2的患者RVEF仍在下降。QRS碎裂（fQRS）在最初6年增加，然后在青春期再次增加，这在时间上与心律失常的发作相吻合。fQRS与RVEF降低（优势比[OR] 0.94；95%置信区间[CI] 0.9 - 1；P = 0.05）和右心室纵向应变降低（OR 1.02；95% CI 1.01 - 1.04；P = 0.008）相关。70.5%的患者在首次机械不同步评估时有间隔闪烁，这与更长的QRSd相关（中位124 ms [四分位间距（IQR）107 - 136 ms] 对比100 ms [IQR 93 - 118 ms]；P = 0.019）。
在rTOF儿童期，电不同步与右心室功能进行性障碍和运动不耐受相关，与肺功能不全无关。这就提出了在有症状的右心室功能障碍和EMD的特定患者中考虑右心室再同步治疗的问题。
