Radiofrequency energy modification of the atrioventricular junction in patients with atrial fibrillation: Modes of ventricular response under autonomic blockade and long-term effect

The short- and long-term effect of radiofrequency (RF) modification of the AV junction on ventricular rate and left ventricular function and the diffe rent types of ventricular response during energy application under autonomi c nervous blockade were assessed in 28 patients with medically refractory a trial fibrillation. During the successful RF application, ventricular rate slowed progressively (type I response, ten patients) or accelerated at firs t and then slowed (type II response, 11 patients). Type 11 response was ass ociated with a more anterior ablation site compared to Type I response. A p rimary successful outcome was achieved in 21 patients. Inadvertent complete AV block developed in three patients, while in four patients AV nodal abla tion was performed after an unsuccessful modification attempt. During 6-mon th follow-up, the ventricular rate was adequately controlled in only four p atients. Among the 16 patients with a recurrence of uncontrolled AF were al l 10 patients with type I response and 6 of 11 patients with type 11 respon se. One patient died suddenly 10 weeks after the procedure.