Abstract

BACKGROUND: The ventricular ectopic QRS interval (VEQSI) has been shown to identify structural heart disease and predict mortality. In arrhythmogenic right ventricular cardiomyopathy (ARVC) early diagnosis is difficult with current methods and life-threatening arrhythmias are common and difficult to predict. OBJECTIVES: To assess the utility of ventricular ectopic indices including VEQSI in ARVC diagnosis. METHODS: We studied 70 patients with ARVC; 30 with definite disease (47±12 years; 60% male); 40 with incomplete disease expression (44±18 years; 44% male); 116 healthy controls (40±15 years; 56% male); and 26 patients with normal heart right ventricular outflow tract (RVOT) ectopy (46±17 years; 27% male). The duration of the broadest ventricular ectopic beat during 12-lead Holter monitoring was recorded as VEQSI max. RESULTS: VEQSI max was associated with age and gender, not conducted QRS duration. Adjusted VEQSI max was greater in ARVC patients than control groups. In healthy males (44.5 years) estimated VEQSI max was 163ms (95%CI 159ms-167ms); in definite ARVC 212ms (95%CI 206ms-217ms); in incompletely expressed ARVC 204ms (95%CI 199ms-210ms); and in normal heart RVOT ectopy 171ms (95%CI 165ms-178ms). VEQSI max >180ms had 98% sensitivity and specificity for the diagnosis of ARVC (AUC 0.99; 95%CI 0.980-0.998). In our incompletely expressed ARVC patients, VEQSI max >180ms identified 88% as affected. CONCLUSION: VEQSI max distinguishes ARVC patients, including those with incomplete disease expression, from healthy controls and patients with normal heart RVOT ectopy.