Russo Giulia, Folino Antonio Franco, Mazzotti Elisa, Rebellato Luca, Daliento Luciano
Department of Cardiology, University of Padua, Padua, Italy.
J Cardiovasc Electrophysiol. 2005 Mar;16(3):288-92. doi: 10.1046/j.1540-8167.2005.40312.x.
Surgical repair of tetralogy of Fallot is complicated by the occurrence of ventricular tachycardia (VT). Among different indexes proposed to assess prognosis of these patients, the study of QRS and repolarization provided useful information. Controversial results come from the analysis of signal-averaging ECG (SAECG). The aim of our study was to identify patients operated for tetralogy of Fallot at higher risk of sudden death by means of SAECG.
Sixty-six consecutive patients, mean age 26 +/- 10 years, were studied 17.7 +/- 5.8 years after total correction for tetralogy of Fallot using standard ECG, 24-hour Holter recordings, SAECG, and echocardiography. The following variables were measured: standard QRS duration, filtered QRS duration (fQRS), high-frequency and low-amplitude signal duration (HFLA), root mean square of the mean voltage in the terminal portion of filtered QRS (RMS), left and right end-diastolic volumes, and ejection fractions. During a mean follow-up period of 7.3 +/- 3.1 years, 12 patients had episodes of sustained VT and two of them suddenly died. All patients had complete right bundle branch block. Patients with VT were characterized by a significantly longer fQRS duration at all filter settings. On the contrary, there was no difference in standard QRS duration in patients with or without VT. At a multivariate analysis, left ventricular ejection fraction and fQRS were independent predictors for VT.
A longer fQRS duration is associated with an increased risk in developing malignant ventricular arrhythmias in asymptomatic patients after total correction of tetralogy of Fallot.
法洛四联症的外科修复手术因室性心动过速（VT）的发生而变得复杂。在为评估这些患者预后而提出的不同指标中，对QRS波群和复极化的研究提供了有用信息。信号平均心电图（SAECG）分析得出的结果存在争议。我们研究的目的是通过SAECG识别接受法洛四联症手术的猝死高风险患者。
连续纳入66例患者，平均年龄26±10岁，在法洛四联症完全矫正术后17.7±5.8年，采用标准心电图、24小时动态心电图记录、SAECG和超声心动图进行研究。测量以下变量：标准QRS波群时限、滤波后QRS波群时限（fQRS）、高频低振幅信号时限（HFLA）、滤波后QRS波群终末部平均电压的均方根（RMS）、左、右舒张末期容积和射血分数。在平均7.3±3.1年的随访期内，12例患者发生持续性室性心动过速，其中2例猝死。所有患者均有完全性右束支传导阻滞。发生室性心动过速的患者在所有滤波设置下fQRS波群时限均显著延长。相反，有或无室性心动过速的患者标准QRS波群时限无差异。多因素分析显示，左心室射血分数和fQRS是室性心动过速的独立预测因素。
在法洛四联症完全矫正术后的无症状患者中，fQRS波群时限延长与发生恶性室性心律失常的风险增加相关。
