Superior vena cava isolation using a pentaspline pulsed-field ablation catheter: feasibility and safety in patients undergoing atrial fibrillation catheter ablation.

AIMS: Superior vena cava (SVC) isolation during atrial fibrillation catheter ablation is limited by the risk of collateral damage to the sinus node and/or the phrenic nerve. Due to its tissue-specificity, we hypothesized the feasibility and safety of pulsed-field ablation (PFA)-based SVC isolation. METHODS AND RESULTS: One hundred and five consecutive patients undergoing PFA-based AF catheter ablation were prospectively included. After pulmonary vein isolation (±posterior wall isolation and electrical cardioversion), SVC isolation was performed using a standardized workflow. Acute SVC isolation was achieved in 105/105 (100%) patients after 6 ± 1 applications. Transient phrenic nerve stunning occurred in 67/105 (64%) patients but without phrenic nerve palsy at the end of the procedure and at hospital discharge. Transient high-degree sinus node dysfunction occurred in 5/105 (4.7%) patients, with no recurrence at the end of the procedure and until discharge. At the 3-month follow-up visit, no complication occurred. CONCLUSION: SVC isolation using a pentaspline PFA catheter is feasible and safe.

Recurrent acute myocarditis: An under-recognized clinical entity associated with the later diagnosis of a genetic arrhythmogenic cardiomyopathy.

Background: Myocardial inflammation has been consistently associated with genetic arrhythmogenic cardiomyopathy (ACM) and it has been hypothesized that episodes mimicking acute myocarditis (AM) could represent early inflammatory phases of the disease. Objective: We evaluated the temporal association between recurrent acute myocarditis (RAM) episodes and the later diagnosis of a genetic ACM. Materials and methods: Between January 2012 and December 2021, patients with RAM and no previous cardiomyopathy were included (Recurrent Acute Myocarditis Registry, NCT04589156). A follow-up visit including clinical evaluation, resting and stress electrocardiogram, cardiac magnetic resonance imaging, and genetic testing was carried out. Endpoints of the study was the incidence of both ACM diagnosis criteria and ACM genetic mutation at the end of follow-up. Results: Twenty-one patients with RAM were included and follow-up was completed in 19/21 patients (90%). At the end of follow-up, 3.3 ± 2.9 years after the last AM episode, 14/21 (67%) patients with an ACM phenotype (biventricular: 10/14, 71%; left ventricular: 4/14, 29%) underwent genetic testing. A pathogenic or likely pathogenic mutation was found in 8/14 patients (57%), 5/8 in the Desmoplakin gene, 2/8 in the Plakophillin-2 gene, and 1/8 in the Titin gene. Family history of cardiomyopathy or early sudden cardiac death had a positive predictive value of 88% for the presence of an underlying genetic mutation in patients with RAM. Conclusion: RAM is a rare entity associated with the latter diagnosis of an ACM genetic mutation in more than a third of the cases. In those patients, RAM episodes represent early inflammatory phases of the disease. Including RAM episodes in ACM diagnosis criteria might allow early diagnosis and potential therapeutic interventions.