Risk of atrial arrhythmias in patients with ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy

BACKGROUND In arrhythmogenic right ventricular cardiomyopathy (ARVC), risk of atrial arrhythmias (AAs) persists after ventricular tachycardia (VT) ablation. OBJECTIVE The purpose of this study was to determine the type, prevalence, outcome, and risk correlates of AA in ARVC in patients undergoing VT ablation. METHODS Prospectively collected procedural and clinical data on ARVC patients undergoing VT ablation were analyzed. Risk score for typical atrial flutter was determined from univariate logistic regression analysis. RESULTS Of 119 consecutive patients with ARVC and VT ablation, 40 (34%) had AA: atrial fibrillation (AF) in 31, typical isthmusdependent atrial flutter (AFL) in 27, and atrial tachycardia/atypical flutter (AT) in 10. Seventeen patients (43%) with AA experienced inappropriate defibrillator therapy, with 15 patients experiencing shocks. Ablation was performed for typical AFL in 21 (53%), AT in 5 (13%), and pulmonary vein isolation for AF in 4 (10%) patients and prevented AA in 78% and all AFL during additional mean follow-up of 65 months. Risk score for typical flutter included age >40 years (1 point), >moderate right ventricular dysfunction (2 points), >moderate tricuspid regurgitation (2 points), >moderate right atrial dilation (2 points), and right ventricular volume >250 cc (3points), with score >4 identifying 50% prevalence of typical flutter. CONCLUSION AAs are common in patients with ARVC and VT, can result in inappropriate implantable cardioverter-defibrillator shocks, and typically are controlled with atrial ablation. A risk score can be used to identify patients at high risk for typical AFL who may be considered for isthmus ablation at the time of VT ablation.