Introduction: Radiofrequency catheter ablation of anteroseptal accessory pathways (APs) carries high risk of heart block due to its close proximity to the atrioventricular (AV) node and the His bundle. We describe the electrocardiographic and electrophysiological characteristics of a successful ablation location in these patients.
Methods: Between January 2005 and December 2011, 780 consecutive patients were referred to Tehran Heart Center for electrophysiological study and catheter ablation of APs. Thirty-one patients with anteroseptal APs (23 males, mean age=36.5 ±15.3 years) were recruited in the study and 28 of them with successful ablation were evaluated further.
Results: In the 28 patients with successful ablation, the ECG had 89% sensitivity in detecting manifest APs. In endocardial electrophysiological mapping, the atrial side of AV groove was the optimal ablation site (A:V?1:3) ,and in case of H presence in the ablation catheter, a small H and a large A:H amplitude ratio ? 3:1 was the positive predictor and junctional rhythm presence was a negative predictor of a successful ablation location.
Conclusions: Proper use of low-power energy for catheter ablation and precise determination of electrophysiological characteristics can help accomplish successful ablation of anteroseptal and para-Hisian APs with the lowest complication rate possible