Electrocardiographic correlates of ventricular arrhythmias in repaired congenital heart disease.

Sudden cardiac death (SCD) is a major cause of mortality in congenital heart disease (CHD). Ventricular arrhythmias (VAs) are responsible for 80% of SCD. However, the clinical characteristics of patients with CHD and VAs are not fully understood. This study was undertaken to evaluate clinical and electrocardiographic characteristics of patients with CHD based on the presence or absence of VAs. We identified 28 patients with CHD with VAs (men, n = 15; 35.9 ± 16.5 years). Two patients with channelopathies were excluded from the analysis. The most common diagnoses in patients with VAs were a transposition of the great arteries (n = 8, 30.8%), followed by tetralogy of Fallot (n = 7, 26.9%). Compared with patients without VA (n = 43), those with VAs had a longer QRS (160.6 ± 52.9 ms vs 133.4 ± 29.3 ms; P = .004), a higher prevalence of fragmented QRS (65.4% vs 37.2%; P = .022) and more epsilon wave (23.1% vs 2.3%; P = .005). Multivariable analysis showed that QRS > 180 ms (odds ratio [OR], 22.23; 95% confidence interval [CI], 2.40-206.53) and epsilon wave (OR, 14.33; 95% CI, 1.47-139.58) were significantly associated with VAs. During a median follow-up duration of 5.4 years, 5 patients (19.2%) received appropriate ICD therapy, and 3 patients (11.5%) died of heart failure. The assessment of QRS duration and the presence of fQRS and epsilon waves in patients with CHD could improve risk prediction for the development of VAs. These electrocardiogram (ECG) features could assist in clinical decision-making and might consequently reduce mortality.