Miga D E, Case C L, Gillette P C
South Carolina Children's Heart Center, Medical University of South Carolina, Charleston 29425, USA.
Clin Cardiol. 1996 Sep;19(9):726-8. doi: 10.1002/clc.4960190910.
Premature ventricular contractions (PVCs) may occur in 0.3 to 2.2% of routine resting electrocardiograms (ECGs) in children with structurally normal hearts.
This study tests the hypothesis that repolarization abnormalities are present more frequently on the surface ECG in pediatric patients with benign ventricular ectopy.
A retrospective study was performed examining 32 children with benign ventricular ectopy and structurally normal hearts. The surface ECG was carefully reviewed, concentrating on repolarization abnormalities as evidenced by a prolonged QTc, a prolonged JTc, and/or an abnormal T-wave vector. QTc was calculated using Bazett's formula and considered prolonged if > 440 ms, and the JTc was calculated using a formula analogous to Bazett's formula and considered prolonged if > 340 ms. The T-wave vector was considered normal if between 0 to +90 degrees, concordant with the frontal QRS axis and within 60 degrees of the QRS axis. There were 13 females (41%) and 19 males (59%) with an average age of 9.1 years (range 1-16.1 years). These patients were then compared with age- and gender-matched controls. Fourteen of 32 study patients (44%) and 2 of 32 controls (6%) had evidence of repolarization abnormalities.
Using chi 2 analysis, there was a significant difference between groups (p = 0.0005). No patient had an abnormal T-wave vector and there were no other significant ECG abnormalities. There was no significant relationship between repolarization abnormalities and patient gender or age.
A significant percentage (44%; P = 0.0005) of children with benign ventricular ectopy have associated repolarization abnormalities as evidenced by a prolonged QTc and/or JTc. This finding suggests that children with "benign PVCs" may have repolarization changes indicative of underlying substrate abnormalities.
在心脏结构正常的儿童中，室性早搏（PVCs）在常规静息心电图（ECG）中的发生率为0.3%至2.2%。
本研究检验的假设是，在患有良性室性异位心律的儿科患者中，复极异常在体表心电图上出现的频率更高。
进行了一项回顾性研究，对32例患有良性室性异位心律且心脏结构正常的儿童进行检查。仔细复查体表心电图，重点关注复极异常，表现为QTc延长、JTc延长和/或T波向量异常。QTc使用Bazett公式计算，若>440毫秒则认为延长，JTc使用类似于Bazett公式的公式计算，若>340毫秒则认为延长。若T波向量在0至+90度之间、与额面QRS轴一致且在QRS轴60度范围内，则认为正常。有13名女性（41%）和19名男性（59%），平均年龄为9.1岁（范围1至16.1岁）。然后将这些患者与年龄和性别匹配的对照组进行比较。32例研究患者中有14例（44%）和32例对照组中有2例（6%）有复极异常的证据。
使用卡方分析，两组之间存在显著差异（p = 0.0005）。没有患者T波向量异常，也没有其他显著的心电图异常。复极异常与患者性别或年龄之间没有显著关系。
相当比例（44%；P = 0.0005）的患有良性室性异位心律的儿童存在相关的复极异常，表现为QTc和/或JTc延长。这一发现表明，患有“良性PVCs”的儿童可能有复极变化，提示潜在的基质异常。
