S. Cullen et al., PROGNOSTIC-SIGNIFICANCE OF VENTRICULAR ARRHYTHMIA AFTER REPAIR OF TETRALOGY OF FALLOT - A 12-YEAR PROSPECTIVE-STUDY, Journal of the American College of Cardiology, 23(5), 1994, pp. 1151-1155
Objectives. The aim of this study was to examine the prognostic signif
icance of ventricular arrhythmia on the ambulatory electrocardiogram (
ECG) after repair of tetralogy of Fallot. Background. Ventricular arrh
ythmia is common after repair of tetralogy of Fallot and has been prop
osed as the basis for late sudden death. The prognostic significance o
f ventricular arrhythmia on ambulatory ECG and the indications for the
rapy are uncertain. Methods. We performed a 48-h ambulatory ECG in 86
patients (3 to 45 years old [mean age 14 years]) after repair of tetra
logy of Fallot. These patients were then followed up prospectively for
12 years. Results. At initial assessment in 1980, 47 patients (55%) h
ad infrequent uniform ventricular extrasystoles (16 patients) or norma
l cardiac rhythm (31 patients) (Group 1), and 39 patients (45%) had fr
equent uniform ventricular extrasystoles (>30/h, 2 patients), complex
extrasystole (30 patients) or nonsustained ventricular tachycardia (7
patients) (Group 2), There were no significant clinical or hemodynamic
differences between the groups. In addition, nine patients had suprav
entricular tachyarrhythmia. Antiarrhythmic therapy was prescribed only
for the 10 patients who had symptoms attributable to arrhythmia. Ther
e were two sudden deaths in Group 1 (4%) and one nonsudden death in Gr
oup 2 (2.5%). The absolute difference in mortality between groups was
therefore 1.5% (95% confidence limits -6% to + 9%), excluding a clinic
ally significant difference in outcome. All but 1 of the 39 patients w
ith complex ventricular arrhythmia are alive and well, including those
with elevated (greater than or equal to 60 mm Hg) right ventricular p
ressure. Conclusions. Nonsustained ventricular arrhythmia on ambulator
y ECG does not identify patients at high risk for sudden death after r
epair of tetralogy of Fallot. There does not appear to be any advantag
e in potentially dangerous long-term antiarrhythmic therapy for asympt
omatic postoperative patients.