Sarubbi B, Pacileo G, Ducceschi V, Pisacane C, Russo M G, Santangelo L, Iacono A, Calabrò R
Servizio di Cardiologia Pediatrica, Ospedale V Monaldi, Napoli.
Cardiologia. 1998 Apr;43(4):407-15.
Malignant ventricular arrhythmias have been reported in patients with repaired tetralogy of Fallot. The aim of this study was to examine ventricular repolarization time indexes, in terms of both absolute measures and dispersion across the myocardium, in young patients operated on for tetralogy of Fallot (32 patients; 19 males and 13 females, mean age 11.1 +/- 3.4 years); these electrocardiographic parameters have been shown to be effective in the identification of electrical myocardial instability and hence of risk for ventricular arrhythmias too. The electrocardiographic data of the study group were compared with those of 22 age-matched asymptomatic control subjects (14 males and 8 females, mean age 12 +/- 1.5 years). Furthermore it has also been investigated the possible influence on ventricular repolarization of known negative prognostic factors relative to the surgical approach, age at intervention, and presence of pulmonary obstruction and/or regurgitation. No patients in the study group revealed at the Holter recordings and/or at the exercise test severe ventricular arrhythmias. From the analysis of ventricular depolarization, expressed by QRS duration, emerged that it resulted significantly longer in total Fallot group (p < 0.0001), and in each subgroup (p < 0.05) compared to the control group. Particularly, patients operated through a right ventricular approach showed higher values of QRS interval (p < 0.05) than those operated through combined transatrial-transpulmonary approach. All patients operated on for tetralogy of Fallot showed, compared to control subjects, a non homogeneous prolongation of ventricular repolarization across the myocardium, as confirmed by the significant increase in the absolute indexes of ventricular repolarization, JTc (p < 0.001), QT (p < 0.0001) and QTc (p < 0.0001) with a concomitant prolongation of the indexes of dispersion of ventricular recovery time, QTc dispersion (p < 0.0001), JTc dispersion (p < 0.0001), "adjusted" QTc dispersion (p < 0.05) and T peak-T end interval (p < 0.0001). The non homogeneous ventricular repolarization across the myocardium, preceding the development of arrhythmic events, could be the effect of the right ventricular morphological and functional changes of tetralogy of Fallot predisposing to the development of ventricular reentry tachyarrhythmias.
法洛四联症修复术后的患者中曾有恶性室性心律失常的报道。本研究旨在检测法洛四联症手术治疗的年轻患者（32例，男19例，女13例，平均年龄11.1±3.4岁）的心室复极时间指标，包括绝对值指标以及心肌复极离散度；这些心电图参数已被证明在识别心肌电不稳定进而识别室性心律失常风险方面有效。将研究组的心电图数据与22例年龄匹配的无症状对照者（男14例，女8例，平均年龄12±1.5岁）的数据进行比较。此外，还研究了与手术方式、干预时年龄、肺动脉梗阻和/或反流的存在相关的已知不良预后因素对心室复极的可能影响。研究组中无患者在动态心电图记录和/或运动试验中显示严重室性心律失常。通过对以QRS时限表示的心室去极化分析发现，与对照组相比，法洛四联症总体组（p<0.0001）以及每个亚组（p<0.05）的QRS时限均显著更长。特别是，经右心室途径手术的患者的QRS间期值（p<0.05）高于经心房-肺动脉联合途径手术的患者。与对照者相比，所有接受法洛四联症手术的患者均显示心肌复极在整个心肌中呈非均一性延长，这一点通过心室复极绝对值指标JTc（p<0.001）、QT（p<0.0001）和QTc（p<0.0001）的显著增加以及心室复极时间离散度指标QTc离散度（p<0.0001）、JTc离散度（p<0.0001）、“校正”QTc离散度（p<0.05）和T峰-T末间期（p<0.0001）的同时延长得到证实。心律失常事件发生之前心肌复极的非均一性可能是法洛四联症右心室形态和功能改变导致室性折返性快速心律失常发生的结果。
