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Pulmonary vein isolation (PVI) is the cornerstone in atrial fibrillation (AF) ablation; yet, the role of arrhythmogenic superior vena cava (SVC) is increasingly recognized and different ablation strategies have been employed in this context. SVC can act as a trigger or perpetuator of AF, and its significance might be more pronounced in patients undergoing repeated ablation. Several cohorts have examined efficacy, safety and feasibility of SVC isolation (SVCI) among AF patients. The majority of these studies explored as-needed SVCI during index PVI, and only a minority of them included repeated ablation subjects and non-radiofrequency energy sources. Studies of heterogeneous design and intent have explored both empiric and as-needed SVCI on top of PVI and reported inconclusive results. These studies have largely failed to demonstrate any clinical benefit in terms of arrhythmia recurrence, although safety and feasibility are undisputable. Mixed population demographics, small number of enrollees and short follow-up are the main limitations. Procedural and safety data are comparable between empiric SVCI and as-needed SVCI, and some studies suggested that empiric SVCI might be associated with reduced AF recurrences in paroxysmal AF patients. Currently, no study has compared different ablation energy sources in the setting of SVCI, and no randomized study has addressed as-needed SVCI on top of PVI. Furthermore, data regarding cryoablation are still in their infancy, and regarding SVCI in patients with cardiac devices more safety and feasibility data are needed. PVI non-responders, patients undergoing repeated ablation and patients with long SVC sleeves could be potential candidates for SVCI, especially via an empiric approach. Although many technical aspects remain unsettled, the major question to answer is which clinical phenotype of AF patients might benefit from SVCI?

Despite advances in ablative therapies, outcomes remain less favorable for persistent atrial fibrillation often due to presence of non-pulmonary vein triggers and abnormal atrial substrates. This review highlights advances in ablation technologies and notable scientific literature on clinical outcomes associated with pursuing adjunctive ablation targets and substrate modification during persistent atrial fibrillation ablation, while also highlighting notable future directions.

Pulmonary vein isolation (PVI) is the cornerstone in atrial fibrillation (AF) ablation; yet, the role of arrhythmogenic superior vena cava (SVC) is increasingly recognized and different ablation strategies have been employed in this context. SVC can act as a trigger or perpetuator of AF, and its significance might be more pronounced in patients undergoing repeated ablation. Several cohorts have examined efficacy, safety and feasibility of SVC isolation (SVCI) among AF patients. The majority of these studies explored as-needed SVCI during index PVI, and only a minority of them included repeated ablation subjects and non-radiofrequency energy sources. Studies of heterogeneous design and intent have explored both empiric and as-needed SVCI on top of PVI and reported inconclusive results. These studies have largely failed to demonstrate any clinical benefit in terms of arrhythmia recurrence, although safety and feasibility are undisputable. Mixed population demographics, small number of enrollees and short follow-up are the main limitations. Procedural and safety data are comparable between empiric SVCI and as-needed SVCI, and some studies suggested that empiric SVCI might be associated with reduced AF recurrences in paroxysmal AF patients. Currently, no study has compared different ablation energy sources in the setting of SVCI, and no randomized study has addressed as-needed SVCI on top of PVI. Furthermore, data regarding cryoablation are still in their infancy, and regarding SVCI in patients with cardiac devices more safety and feasibility data are needed. PVI non-responders, patients undergoing repeated ablation and patients with long SVC sleeves could be potential candidates for SVCI, especially via an empiric approach. Although many technical aspects remain unsettled, the major question to answer is which clinical phenotype of AF patients might benefit from SVCI?

Objective: The purpose of this study was to evaluate the difference in effectiveness and safety of high-power, short-duration (HPSD) radiofrequency catheter ablation (RFA) guided by relatively low ablation index (AI) values and conventional RFA in paroxysmal atrial fibrillation (PAF) patients., Methods: The HPSD RFA strategy (40-50 W, AI 350-400 for anterior, 320-350 for posterior wall; n = 547) was compared with the conventional RFA strategy (25-40 W, without AI; n = 396) in PAF patients who underwent their first ablation. Propensity-score matching analyses were used to compare the outcomes of the two groups while controlling for confounders., Results: After using propensity-score matching analysis, the HPSD group showed a higher early recurrence rate (22.727% vs. 13.636%, p = 0.003), similar late recurrence rate, and comparable safety ( p = 0.604) compared with the conventional group. For late recurrent atrial arrhythmia types, the rate of regular atrial tachycardia was significantly higher in the HPSD group ( p = 0.013). Additionally, the rate of chronic pulmonary vein reconnection and non-pulmonary vein triggers during repeat procedures was similar in both groups., Conclusions: For PAF patients, compared with the conventional RFA strategy, the HPSD RFA strategy at relatively low AI settings had a higher early recurrence rate, similar long-term success rate, and comparable safety.