RADIOFREQUENCY CATHETER ABLATION AND MODULATION OF ATRIOVENTRICULAR-CONDUCTION IN PATIENTS WITH ATRIAL-FIBRILLATION

We attempted radiofrequency ablation of the AV junction with a sequential right- and left-sided approach in 78 patients affected by severely symptomatic, drug refractory atrial fibrillation. Stable third-degree AV block was obtained in 99% of cases and, after 3 months, persisted in 92% of cases. single session, stepwise, radiofrequency modulation of the AV node was attempted in 13 patients with paroxysmal atrial fibrillation. During sinus rhythm, ablation of the slow; and fast AV node pathways was performed in order to increase the nodal refractory period or to slow conduction. Clinically successful modulation of Av conduction was achieved in 15% of cases and persisted during a 3-month follow-up. In conclusion, AV junction ablation is a well-established means of treating atrial fibrillation, but implies the implant of a permanent pacemaker. AV node modulation avoids the pacemaker implant, but is efficacious only in a minority of patients. Thus, in patients affected by paroxysmal atrial fibrillation, AV modulation should be attempted first; if this is ineffective, AV ablation can be performed during the same session.