Very high-power and short-duration radiofrequency ablation for atrial fibrillation in a Latin American low-volume private center.

BACKGROUND: Center volume and operator experience/training are important factors impacting outcomes in AFib CA. Setting for RF delivery (power, duration, and contact force) associated with better outcomes remains to be determined. METHODS: This is an observational, longitudinal, and retrospective study. All consecutive procedures performed between December 12, 2013, and March 9, 2023, in a low-volume private center in Latin America were analyzed. Procedure characteristics and outcomes were compared between STD and vHPSD. RESULTS: Two hundred ten procedures were performed on 194 patients. Median annual number of procedures was 19 (7-29). Median age was 62 (52-68), and majority were male (71%). Median procedure duration was 155 (125-195) min, mean fluoroscopy time 32.8 ± 15 min and mean fluoroscopy dose 373.5 ± 208.9 mGray. Median follow-up was 27 months, significantly longer in STD compared with vHPSD group (43 [31-68] vs. 13 [8-19], respectively; P ≤ 0.001). The recurrence rate was 33.2% and major complications 8.6%. Compared with STD, vHPSD resulted in a significantly shorter procedure duration (125 vs. 180 min, P ≤ 0.001), shorter fluoroscopy time (22.7 ± 9.5 vs. 39.2 ± 14.3 min, P ≤ 0.001), and lower fluoroscopy dose (283.8 ± 161.1 vs. 438.3 ± 216.1 mGray, P ≤ 0.001). No long-term recurrence difference was observed when the follow-up periods were comparable. No difference in complication rate was observed (8.5% vs. 8.6%, P = 0.988). CONCLUSIONS: Outcomes in AFib CA in a Latin American low-volume private center can be considered acceptable, with efficacy and safety similar to those reported in the literature. Compared with STD ablation, vHPSD showed higher efficiency with similar efficacy and safety.

Catheter ablation of frequent monomorphic ventricular arrhythmias in Andersen-Tawil syndrome: case report and focused literature review.

BACKGROUND/PURPOSE: Andersen-Tawil syndrome type 1 is a rare autosomal dominant disease caused by a KCNJ2 gene mutation and clinically characterized by dysmorphic features, periodic muscular paralysis, and frequent ventricular arrhythmias (VAs). Although polymorphic and bidirectional ventricular tachycardias are prevalent, PVCs are the most frequent VAs. In addition, a "dominant" morphology with RBBB pattern associated with either superior or inferior axis is seen in most of the patients. Due to the limited efficacy of most antiarrhythmic drugs, catheter ablation (CA) is an alternative in patients with monomorphic VAs. Based on our experience, we aimed to review the arrhythmogenic mechanisms and substrates for VAs, and we analyzed the potential reasons for CA failure in this group of patients. METHODS: Case report and focused literature review. RESULTS: Catheter ablation has been reported to be unsuccessful in all of the few cases published so far. Most of the information suggests that VAs are mainly originated from the left ventricle and probably in the Purkinje network. Although identifying well-established and accepted mapping criteria for successful ablation of a monomorphic ventricular arrhythmia, papillary muscles seem not to be the right target. CONCLUSIONS: More research is needed to understand better the precise mechanism and site of origin of VAs in Andersen-Tawil syndrome patients with this particular "dominant" monomorphic ventricular pattern to establish the potential role of CA.