Background: Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation following MVS is limited.) CA can be challenging given perivalvular substrate in the setting of mitral annuloplasty or prosthetic valves. Objective: To investigate the characteristics, safety, and outcomes of radiofrequency catheter ablation (CA) in patients with prior mitral valve surgery (MVS) and ventricular arrhythmias (VA). Methods: We identified consecutive patients with prior MVS who underwent CA for VT or PVC between January 2013- December 2018. We investigated the mechanism of arrhythmia, ablation approach, peri-operative complications, and outcomes. Results: In our cohort of 31 patients (77% men, mean age 62.3±10.8 years, left ventricular ejection fraction 39.2±13.9%) with prior MVS underwent CA (16 VT; 15 PVC). Access to the left ventricle was via transseptal approach in 17 patients, and a retrograde aortic approach was used in 13 patients. A combined transseptal and retrograde aortic approach was used in one patient, and a percutaneous epicardial approach was combined with trans-septal approach in 1patient. Heterogenous scar regions were present in 94% of VT patients and scar-related reentry was the dominant mechanism of VT. Clinical VA substrates involved the peri-mitral area in 6 patients with VT and 5 patients with PVC ablation. No procedure-related complications were reported. The overall recurrence-free rate at 1-year was 72.2%; 67% in the VT group and 78% in the PVC group. No arrhythmia-related death was documented on long-term follow-up. Conclusion: CA of VAs can be performed safely and effectively in patients with MVS

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic arrhythmia syndrome characterized by adrenergically-triggered ventricular arrhythmias, syncope, and sudden cardiac death. Several small studies suggest that atrial arrhythmias (AAs) are common in patients with CPVT. Objective: To determine the incidence and type of AAs observed within a large, single-center cohort of CPVT cases as well as the efficacy and durability of AA-directed management. Methods: In this retrospective study, the electronic medical record of 129 patients (52% female; average age at diagnosis 20.8  15.3 years) with CPVT (95% with a putative CPVT1-causative RYR2 variant) between 01/2000 and 09/2019 were reviewed for electrocardiographic evidence of AAs. Clinical features and efficacy of pharmacologic and ablation therapy were assessed. Results: Overall, 10/129 (7.8%) CPVT patients, all RYR2 variant-positive, had evidence of an AA (atrial fibrillation/flutter in 6, atrial tachycardia in 3, and supraventricular tachycardia in 1). The median age at AA diagnosis was 23 (14.2-35.5) years. 8/10 of patients experienced symptoms attributed to their AA, including inappropriate shocks. All patients were trialed on anti-arrhythmics, including -blockers, and/or flecainide. Owing to drug failure (1/10), drug intolerance (1/10), or patient preference (2/10); 4/10 patients received an ablation. Over a median follow-up of 23.5 (4.5-63) months, no AA recurrences were observed. Conclusion: Compared to prior studies, the incidence of AAs in this large, single-center referral cohort of CPVT patients was substantially lower (7.8% vs. 26%-35%). Although larger multi-center studies are needed to confirm, this study suggests that ablation is efficacious and durable in CPVT-associated AAs.