Echocardiographic and signal averaged ECG indices associated with non-sustained ventricular tachycardia after repair of tetralogy of Fallot

Abstract

Objective-To identify any possible association between diVerent readily available non-invasive indices and potential malignant ventricular arrhythmias in patients with repaired tetralogy of Fallot. Design-27 consecutive patients, mean (SD) age 27.3 (11.7) years, were studied 15.7 (6.7) years after corrective surgery for tetralogy of Fallot, using 12 lead ECG, 24 hour Holter recordings, signal averaged ECG, and echocardiography. The following variables were measured: standard QRS duration, filtered QRS duration (fltQRS), low amplitude signal duration, and root mean square voltage of the last 40 ms of the fltQRS (RMS-40), as well as right ventricular systolic pressure, right ventricular ejection fraction, and the ratio of the maximum short axis diameters of the right and left ventricles (RD:LD). Results-All patients had right bundle branch block, with a mean QRS duration of 137.1 (14.9) ms. There were no patients with sustained arrhythmia. Five patients had runs of non-sustained ventricular tachycardia (group A) and the other 22 patients did not (group B). Univariate analysis showed that fltQRS and RD:LD ratio were significantly associated with nonsustained ventricular tachycardia. In addition, a fltQRS > 148 ms, low amplitude signal > 32.5 ms, RMS-40 < 23 µV, and RD:LD ratio > 1.05 were cut oV points with a high sensitivity for detecting patients with non-sustained ventricular tachycardia. Conclusions-Abnormal signal averaged ECG and echocardiographic variables are associated with potentially malignant ventricular arrhythmias on the Holter recordings in asymptomatic patients with repaired tetralogy of Fallot. (Heart 2001;85:57-60)

Patients Operated for Tetralogy of Fallot and with Non-Sustained Ventricular Tachycardia Have Reduced Heart Rate Variability

“…Non-invasive indices of electrical instability have been studied in patients with ToF repair [1,4,9,10]. Gatzoulis et al [10] reported that a QRS duration of 180 ms or more had a 100% sensitivity and 95% specificity as a risk factor for malignant ventricular arrhythmias.…”

Signal‐averaged electrocardiography: Past, present, and future

“…Abnormal SAECG parameters are frequently detected in this setting, as shown in a series of 27 patients with Fallot tetralogy and complete right bundle branch block; in this report, abnormal SAECG was associated with nonsustained monomorphic VT on Holter recordings. 39 In another clinical study, 40 LPs correlated with the inducibility of VT during programmed ventricular stimulation and the occurrence of VT during follow-up, suggesting a role in risk stratification of asymptomatic patients with surgically repaired tetralogy of Fallot.…”

Implantable defibrillators: from the adult cardiac to the grown up congenital heart disease patient

“…Late potentials on signal averaged electrocardiogram are not infrequently found in postoperative ToF patients and are associated with the presence of non-sustained VT even with less pronounced degrees of QRS prolongation (Fig. 3) [39]. The analysis of signal averaged electrocardiogram on the time domain requires the application of modified criteria, as the postoperative TOF patient has a widened QRS complex on the unfiltered 12 lead ECG due to the underlying right bundle branch block [40].…”