RADIOFREQUENCY CATHETER ABLATION OF SEPTAL ACCESSORY ATRIOVENTRICULARPATHWAYS

Objective-Septal accessory atrioventricular pathways are recognised as being more difficult to ablate than pathways in other locations. This paper describes an experience of 48 consecutive patients with septal accessory pathways who had catheter ablation with radiofrequency curre nt. Patients and methods-There were 28 male and 20 female patients, me an (SD) age 35 (17). 43 patients had a single accessory pathway and 5 patients had multiple accessory pathways. Preexcitation was present in 37 patients, and 11 patients had concealed accessory pathways. 21 pat ients had had a previous electrophysiological study. Catheter ablation was undertaken with radiofrequency current delivered by a standard un ipolar technique or by delivery of current across the septum (the bipo lar technique). Results-The median total procedure time was 167 (83) m inutes including a 30-40 minute observation period after the abolition of conduction by the accessory pathway. The median total fluoroscopic time was 56 (30) minutes. 42 (88%) out of 48 patients had successful ablation of the pathway during the first session. In the six patients in whom the procedure failed, five had a midseptal pathway and one had a right anteroseptal pathway. A second attempt at ablation was made i n two patients and succeeded in both. In total, 49 accessory pathways were successfully ablated in 44 (92%) out of 48 patients. The bipolar technique was used in 11 patients and succeeded in 10 patients. Standa rd unipolar current delivery had previously failed in Seven of the 11 patients. Complications developed in two patients with a mid septal pa thway (one with complete atrioventricular block and the other with a s mall pericardial effusion). Conclusion-Radiofrequency catheter ablatio n of septal accessory pathways is efficacious and safe. The procedure time can be shortened and success rate can be increased after improvem ent of the technique-that is, consideration of a bipolar approach for energy delivery in difficult cases.