Predictors of ventricular tachyarrhythmia occurring late after intracardiac repair of tetralogy of Fallot: combination of QRS duration change rate and tricuspid regurgitation pressure gradient.

Background: To determine potential predictors of ventricular tachyarrhythmia and sudden cardiac death (SCD) occurring late after repair of tetralogy of Fallot (TOF).

Methods: Since 1964, 415 patients had undergone total repair for TOF at Niigata University Hospital. Of these, 89 patients who were followed for more than 10 years at our institute were retrospectively reviewed.

Results: The mean follow-up period was 24.3 years. During the study period, one patient died of cerebral bleeding, and two patients had SCD. The overall survival rates at 20, 30, and 40 years were 100%, 94.6%, and 94.6%, respectively. Eight (9.0%) patients required re-intervention during the late period associated with right ventricular outflow (n=4), tricuspid valve (n=3), aortic valve (n=2), and others (n=2). Ten (11.2%) patients had a history of ventricular tachycardia (VT) or ventricular fibrillation (VF), and six underwent implantation of an implantable cardiac defibrillator. Multivariate analysis selected the change rate of QRS duration [ms/year; odds ratio (OR), 2.44; 95% confidence interval (CI): 1.28-4.65; P=0.007] and the pressure gradient at tricuspid valve regurgitation on echocardiography (OR, 1.12; 95% CI: 1.02-1.22; P=0.017) as risk factors for VT/VF or SCD. Trans-annular patch (TAP) repair was not an independent risk factor for ventricular arrhythmia.

Conclusions: The combination of rapid change rate of QRS duration and higher-pressure gradient at tricuspid regurgitation were risk factors for ventricular tachyarrhythmia late after TOF repair. Adequate surgical or catheter intervention for pressure and volume load in the right ventricle might decrease the prevalence of VT/VF and SCD.