Premature ventricular contraction variability in arrhythmogenic right ventricular dysplasia/cardiomyopathy

INTRODUCTION: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited cardiomyopathy, characterized by right ventricular dysfunction and ventricular arrhythmias. Premature ventricular contractions (PVCs) are an important measure in determining disease severity and constitute a minor criterion in the 2010 Task Force Criteria for the diagnosis of ARVD/C. Little information is available regarding the variability in PVCs.

METHODS AND RESULTS: Patients (n = 40) from the Johns Hopkins ARVD/C registry, meeting diagnostic criteria were included. Single lead continuous 12-lead electrocardiogram (ECG) monitors (Zio® Patches) were applied to monitor PVC counts. Detailed demographic, phenotypic, and structural information were obtained from registry data. ECG monitors were worn for a mean period of 159.3 hours (±39.3). Average 24-hour PVC count in this population was 1,090.5 (interquartile range = 1,711). One-way analysis of variance demonstrated statistically significant interday variance in mean hourly PVC counts in 76% of ARVD/C-positive subjects (28/37, 3 cases excluded due to insufficient data). Eleven individuals (27.5%) had maximum 24-hour PVC counts of >500 with a corresponding minimum 24-hour PVC count of <500. The average 24-hour PVC count for each patient was derived for each day recorded. The 24-hour PVC count placed 89.6% of counts (223/249) on the correct side of the 500-PVC count.

CONCLUSION: Statistically significant variation between 24-hour PVC counts is present in the ARVD/C population. However, 24-hour ECG monitoring was sufficient to identify 89.6% of 24-hour periods to the correct grouping based on 2010 Task Force Criteria.