Introduction: Feasibility of radiofrequency (RF) ablation using a two-catheter technique without coronary sinus catheterization was studied in 100 consecutive patients with a single concealed left free-wall accessory pathway.
Methods and results: Tachycardia was induced by electrical stimulation in the right atrium/right ventricle, and the presence of a concealed left free-wall accessory pathway was suggested electrocardiographically (negative P wave in leads I and/or aVL during orthodromic tachycardia) or by earlier atrial activation in the pulmonary artery compared to the high right atrium. Mapping of the mitral annulus was performed during right ventricular pacing or orthodromic tachycardia, and RF energy was applied at the site with the earliest retrograde atrial activation. Ablation was considered effective if tachycardia could not be induced, and if VA dissociation or exclusive retrograde nodal conduction was observed. Ablation was initially successful in 98 of 100 patients. Mean number of radiofrequency pulses were 3.2 +/- 2. Mean fluoroscopy time and total procedure time was 14 +/- 9 and 107 +/- 32 minutes, respectively. There were no complications related to the procedure. At a mean follow-up of 22 +/- 13 months, two patients experienced tachycardia recurrence and required a second procedure, which was successful.
Conclusions: Our results suggest that RF catheter ablation of concealed left free-wall accessory pathways can be safely, effectively, and rapidly performed using a simplified two-catheter technique with no need for coronary sinus catheterization.