Background: Catheter ablation (CA) of atrioventricular nodal reentry tachycardia (AVNRT) by modulation or ablation of the slow pathway (SP) is an established treatment modality with excellent efficacy and safety. Data regarding gender-related differences in these patients is scarce.
Methods: Consecutive patients undergoing radiofrequency (RF) SP modulation or ablation for AVNRT in a single center over a three-year period (2011 to 2013) were retrospectively analyzed in a large hospital data base. This involved patient receiving an index CA for an AVNRT using conventional RF ablation (power settings) until SP modulation/ablation. Patients were divided into two groups according to gender {female group (F) and male group (M)}. Baseline characteristics, procedural information and complications were documented and compared between the groups.
Results: A total of 218 patients were included in this study {F: n=145/218 (66.5%) and M: n=73/218 (33.5%), p<0.0001}. Baseline characteristics revealed no significant difference in age (F: 50.5 ± 16.8, M: 54.4 ± 17.3, p=0.1) or comorbidities such as arterial hypertension {F: n=37/145 (25.5%), M: n=24/73 (32.9%), p=0.3}, diabetes mellitus {F: n=7/145 (4.8%), M: n=4/73 (5.8%), p=0.99} or heart failure (n=2/73, 2.7%). Prevalence of cardiovascular disease was significantly higher in males {F: n=3/145 (2.1%), M: n=9/73 (12.3%), p=0.003}. Presence of implantable electronic devices (n=2/73, 2.7%), channelopathies (n=2/73, 2.7%) and chronic kidney disease (n=1/73, 1.4%) were only observed in the male group. No significant difference was observed in proof of dual AV-nodal conduction {F: n=87/145 (60%), M: n=41/73 (56.2%), p=0.7}, beta-agonist-requirement {F: n=49/145 (33.8%), M: n=30/73 (41.1%), p=0.3}, atropine-requirement {F: n=13/145 (9%), M: n=5/73 (6.8%), p=0.8}, intraprocedural onset of other atrial arrhythmias {F: n=5/145 (3.4%), M: n=4/73 (5.5%), p=0.5}, AVNRT induction {F: n=118/145 (81.4%), M: n=59/73 (80.8%), p=0.99}, presence of an atypical AVNRT {F: n=4/145 (2.8%), M: n=1/73 (1.4%), p=0.7}, ablation of the SP {F: n=89/145 (61.4%), M: n=51/73 (69.9%), p=0.2}, and procedure times (F: 75 ± 23 min, M: 70 ± 8 min, p=0.07). Tachycardia cycle-length was significantly faster in the female group (F: 341 ± 59 ms, M: 368 ± 80.6 ms, p=0.05). Fluoroscopy times (F: 9.2 ± 3.8 min, M: 5.7 ± 2.6 min, p<0.0001) and dose-area product were both higher in the female group (F: 444.25 ± 266 cGycm2, M: 261 ± 90 cGycm2, p<0.0001). There was no significant difference in overall complications between groups, however, pericardial effusion was only observed in the male group {F: n=4/145 (2.8%) (n=1 groin complication, n=3 transient AV-block), M: n=4/73 (5.5%) (n=2 pericardial effusion, n=1 groin complication, n=1 transient AV-block), p=0.4}.
Conclusion: Catheter ablation of AVNRT only shows marginal gender-related differences. The significant differences observed in this study were higher disease burden at baseline with higher tendency for pericardial effusion in males and faster AVNRT cycle-length and longer fluoroscopy times in females.
