Background:The long-term predicted value of microvolt T-wave altans (MTWA) for ventricular tachyarrhythmia in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains unclear.Our study explored the characteristics of MTWA and its prognostic value when combined with an electrophysiologic study (EPS) in patients with ARVC.Methods:All patients underwent non-invasive MTWA examination with modified moving average (MMA) analysis and an EPS.A positive event was defined as the first occurrence of sudden cardiac death,documented sustained ventricular tachycardia (VT),ventricular fibrillation,or the administration of appropriate implantable cardioverter defibrillator therapy including shock or antitachycardia pacing.Results:Thirty-five patients with ARVC (age 38.6 ± 11.0 years;28 males) with preserved left ventricular (LV) function were recruited.The maximal TWA value (MaxValt) was 17.0 (11.0-27.0) μV.Sustained VT was induced in 22 patients by the EPS.During a median follow-up of 99.9 ± 7.7 months,15 patients had positive clinical events.When inducible VT was combined with the MaxValt,the area under the curve improved from 0.739 to 0.797.The receiver operating characteristic curve showed that a MaxValt of 23.5 μV was the optimal cutoff value to identify positive events.The multivariate Cox regression model for survival showed that MTWA (MaxValt,hazard ratio [HR],1.06;95％ confidence interval [CI],1.01-1.11;P =0.01) and inducible VT (HR,5.98;95％ CI,1.33-26.8;P =0.01) independently predicted positive events in patients with ARVC.Conclusions:MTWA assessment with MMA analysis complemented by an EPS might provide improved prognostic ability in patients with ARVC with preserved LV function during long-term follow-up.