Left-sided slow pathway ablation for atrioventricular nodal reentrant tachycardia: a single center experience

In some cases of atrioventricular nodal reentrant tachycardia (AVNRT), ablation of the slow pathway (SP) at the inferoseptal right-atrium may be ineffective. Some alternative sites for ablation can present distinct challenges and potential complications (e.g. risk of atrioventricular [AV] block with ablation closer to the AV node, ineffective energy delivery due to high impedance and risk for vessel damage with ablation in the coronary sinus [CS]).

Methods: We conducted a retrospective analysis of AVNRT ablation cases performed at our center between January 2010 and September 2024. Of 997 patients (619 [62%] female, mean age: 55±15years) who underwent ablation for AVNRT, 107 (10.7%) presented with atypical AVNRT. Following ineffective ablation at the conventional right-sided SP site (R-SP group) in 18 patients (1.8%; 10 female), left-sided SP ablation (L-SP group) via transseptal access was performed in the inferoseptal region of the left atrium. Of these 18 patients, 13 had typical AVNRT, 5 atypical AVNRT.

Patients in the L-SP group were older (64±14 vs. 55±15 years; p = 0.01). Procedural times and ablation duration were significantly longer for the L-SP group (186±48 vs. 98±32 minutes; p < 0.001 and 617±129 vs. 181±177 seconds; p < 0.001). For all these patients, the left-sided approach was successful.

Left-sided SP ablation of AVNRT via transseptal access is a feasible and effective alternative when conventional right-sided ablation at the typical SP site is unsuccessful.