Arrhythmogenic right ventricular cardiomy- opathy is characterized by progressive ven- tricular myocyte loss with replacement by fatty or fibrous tissue, and is associated with progressive ventricular dysfunction that may involve both ventricles. VA, syncope, and SCD may occur at a relatively young age, particularly in the second and third decades of life and often occurring during physical Sustained VT is an important predictor of SCA and SCD or appropri- ate ICD shocks in patients with arrhythmogenic right ventricular cardiomyopathy.S7.3-10,S7.3-13 In patients receiving an ICD for primary prevention, appropriate ICD shocks are reported in 24% to As sustained VT in arrhythmogenic right ventricular cardiomy- opathy patients is monomorphic in 55% to 90% of episodes based on ICD interrogation or elec- antitachycardia pacing algorithms are used to terminate VT. 4. Frequent PVCs, >760 to 1000 per 24 hours dur- ing ambulatory rhythm monitoring, correlate with The presence of NSVT or sustained VT is an important predictor of adverse The increased arrhythmia risk conferred by intense exercise is consistent with beta-adrenergic modu- lation of disease expression.S7.3-17,S7.3-20,S7.3-21 An observational registry reported that treatment with atenolol or amiodarone was associated with less clinically relevant VA, while sotalol was associ- ated with no effect or increased arrhythmia.S7.3-15 Ambulatory monitoring to assess VA burden and adequacy of beta-blocker therapy is usually 5. 