Prevalence of atrial arrhythmias in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Background Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited cardiomyopathy, characterized by right ventricular dysfunction and ventricular arrhythmias. Limited information is available concerning atrial arrhythmias in ARVD/C. Objective The purpose of this study was to characterize spontaneous atrial arrhythmias in a large registry population of ARVD/C patients. Methods Patients (n = 248) from the Johns Hopkins ARVD/C registry who met the diagnostic criteria and had undertaken genotype analysis were included. Medical records of each were reviewed to ascertain incidence and characteristics of atrial arrhythmia episodes. Detailed demographic, phenotypic, and structural information was obtained from registry data. Results Thirty-five patients with ARVD/C (14%) experienced one or more types of atrial arrhythmia during median follow-up of 5.78 (interquartile range 8.52) years. Atrial fibrillation was the most common atrial arrhythmia, occurring in 80% of ARVD/C patients with atrial arrhythmias. Patients developed atrial arrhythmias at a mean age of 43.0 ± 14.0 years. Atrial arrhythmia patients obtained a total of 22 inappropriate implantable cardioverter-defibrillator shocks during follow-up. Older age at last follow-up (P <.001) and male gender (P =.044) were associated with atrial arrhythmia development. Patients with atrial arrhythmias had a higher occurrence of death (P =.028), heart failure (P <.001), and left atrial enlargement on echocardiography (P =.004). Conclusion Atrial arrhythmias are common in ARVD/C and present at a younger age than in the general population. They are associated with male gender, increasing age, and left atrial enlargement. Atrial arrhythmias are clinically important as they are associated with inappropriate implantable cardioverter-defibrillator shocks and increased risk of both death and heart failure.