Observational studies

Several observational studies have reported favorable outcomes when combining PVI with targeted ablation of LVAs; a summary is provided in Table 1. Rolf et al., performed voltage-guided ablation (VGA) in 178 patients with either paroxysmal or persistent AF (18). Left atrial (LA) voltage mapping was performed in sinus rhythm (SR) using a multipolar catheter, with LVAs defined as areas with peak-to-peak voltage <0.5mV. Twelve-month freedom from AF was comparable between patients with no LVAs and those with LVAs who underwent PVI plus ablation of LVAs, and significantly higher in patients with LVAs who did not undergo such substrate modification. Ziv and colleagues performed LVA assessment on the posterior wall of the LA through point-by-point (PBP) mapping in patients with PsAF (19). Patients undergoing VGA of the posterior wall fared better than those with standard therapy, and this superiority was maintained over long-term follow-up of 5 years (20). This could highlight the role of the posterior wall as a trigger for AF, given the shared embryology with the pulmonary veins.
In keeping with these studies, Jadidi et al. also employed a peak-to-peak voltage threshold of 0.5mV, however voltage mapping was performed using a multipolar catheter with subjects in AF rather than SR (21). Only those’ LVAs, or regions bordering these, harboring distinct electrogram characteristics suggestive of arrhythmogenesis, such as fractionation spanning 70% of the AF cycle length, were targeted for ablation. They observed high rates of AF termination during LVA ablation, and combining PVI with selective VGA improved freedom from AF in PsAF compared to a standalone PVI strategy. Arruda and colleagues also evaluated LA voltage in AF utilizing a threshold of 0.5mV to delineate LVAs, however voltage mapping was performed manually in a PBP fashion (22). Single procedure success rates at 12 months were comparable in patients with LVAs who underwent PVI + VGA ablation and those without LVAs treated with PVI alone, adding credence to a prognostic role of LVAs and potential therapeutic benefit in targeting these with ablation.
Yang et al. employed VGA ablation in 86 consecutive patients with a history of non-paroxysmal AF (23). LVAs were defined as areas with peak-to-peak voltage between 0.1 – 0.4mV while transitional zones had a bipolar voltage range 0.4 – 1.3mV. Within LVAs, ablation was performed to eliminate all identified electrograms, aiming to achieve an absolute bipolar voltage of <0.1mV. Further ablation was performed in transitional zones, targeting abnormal electrograms. When compared with a historical cohort that underwent stepwise ablation, maintenance of SR and rates of post-ablation atrial tachycardia were significantly improved in the study population.