Provocation of atrial fibrillation triggers during ablation: does the use of general anesthesia affect inducibility?

Introduction: The autonomic nervous system exerts important effects upon atrial fibrillation (AF) initiation. The strategy of anesthesia used during AF ablation may impact the provocation of AF triggers. We hypothesized that the use of general anesthesia (GA) would reduce the incidence of provokable AF triggers in patients undergoing AF ablation compared to patients studied while receiving only conscious sedation (CS).

Methods And Results: We performed a prospective, case control study comparing the incidence of provokable AF triggers in a consecutive series of patients undergoing AF ablation under GA using a standard trigger induction protocol. We compared the frequency and distribution of AF triggers to a second cohort of historical controls (matched for age, gender, left atrial dimension, and AF phenotype) who underwent ablation while receiving CS. We calculated that 44 total subjects (22 patients in each group) were required to detect a 50% reduction in the incidence of AF triggers in the GA cohort. There was no difference between the 2 groups in the rate of AF trigger inducibility (77% vs. 68%, P = 0.26) or the number of triggers provoked per patient (1.2 ± 0.8 vs. 1.3 ± 0.8, P = 0.38). Patients ablated under GA required higher doses of phenylephrine during the trigger induction protocol (408.3 mg [52-600] vs. 158.3 mg [0-75]; P = 0.003), and tended to require higher doses of isoproterenol to initiate triggers (92.8 mg [20-111] vs. 63.6 mg [6-103]; P = 0.25).

Conclusion: AF trigger induction during GA is both safe and efficacious.