Trigonum Lesion–Based Bachmann Bundle Isolation Strategy for Persistent Atrial Fibrillation

Background: Persistent atrial fibrillation (AF) particularly after pulmonary vein isolation (PVI) is frequently driven by non–pulmonary vein arrhythmia substrates. The left atrial (LA) insertion of the Bachmann bundle (BB), located along the anterior LA wall, may play a critical role in arrhythmia maintenance. We evaluated the safety and efficacy of a Trigonum-lesion ablation strategy targeting BB conduction in patients with persistent AF.

Objective: To compare the acute procedural and long-term arrhythmia outcomes of adjunctive Trigonum lesion-based BB isolation versus conventional linear lesion-based substrate modification after PVI.

Methods: This retrospective study included consecutive patients with LA anterior wall substrate who underwent ablation for persistent AF between 2023 and 2025. Patients were stratified according to ablation strategy: PVI + Trigonum lesion (Trigonum group) or PVI + linear lesion (non-Trigonum group) (Figure 1). The primary endpoint was freedom from any atrial tachyarrhythmia at 12 months. Secondary endpoints included acute AF termination, procedural characteristics, and periprocedural complications.

Results: A total of 179 patients were analyzed (Trigonum group n=79; non-Trigonum group n=100). Acute AF termination to sinus rhythm, atrial tachycardia, or typical atrial flutter was achieved more frequently in patients treated with additional Trigonum lesion (n=61; 77% vs n=23; 23%, P<0.001). At 12 months, atrial tachyarrhythmia recurrence was significantly lower in the Trigonum group (8% vs 28%, P<0.001). Procedural parameter and procedure related complications were not substantially different between groups.