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. Patients with arrhythmogenic right ventricular cardiomyopathy have a significantly increased risk of SCD during exertion.S7.3-16,S7.3-17,S7.3-20,S7.3-21 Vigorous exercise in patients with arrhythmogenic right ventricular cardiomyopathy has been shown to impair myocardial function by echocardiogra- phy and cardiac MRI.S7.3-19 Participation in high intensity/duration or endurance physical activity accelerates the penetrance/disease progression and arrhythmic risk for arrhythmogenic right ventricular cardiomyopathy patients and muta- tion positive individuals, as well as mutation positive family members.S7.3-17,S7.3-19 S7.3-21 Patients with arrhythmogenic right ventricular cardiomy- opathy who participate in competitive sports are at increased risk for VT or SCD, compared with those who participate in recreational sports or Exercise influences disease progression in a linear manner; family members who limited activity to less than the AHA recommended minimum for activity guide- lines (<650 metabolic equivalent hours per year [MET-Hr/year]) were less likely to develop VA or In a study of arrhyth- mogenic right ventricular cardiomyopathy pro- bands and exercise, athletes (defined as subjects with 4h vigorous exercise/week) were found to have reduced biventricular function compared with nonathletes in arrhythmogenic right ven- tricular cardiomyopathy patients and in muta- tion-positive family members.S7.3-19 Many advise limiting exercise intensity and duration to <650 6. 