13th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 1998

January 24-31, 1998
Marilleva, Trento, Italy

RT-145

Dual chamber pacemaker in patients with
atrial fibrillation submitted for ablation of the atrio-ventricular junction

Diran Igidbashian*, Patrizio Mazzone, Mariano Rillo, Maria Luisa Loricchio, Carlo Pappone.
Department of Cardiology, S. Raffaele Hospital, Milan,
*Department of Cardiology, Civil Hospital, Legnago, Italy

Introduction

Paroxysmal atrial fibrillation is one of the most common forms of sustained arrhythmias and represents an important management problem^1-3 because of the usually alarming onset of symptoms, the disability these produce, specially in the setting of an underlying heart disease, and the sometimes unsatisfactory results, or possible deleterious effects^4,5, of drug therapy.

Radiofrequency ablation of the atrio-ventricular junction^6,7, followed by the implantation of an automatic mode switching DDD/DDDR dual chamber pacemaker^8,9, is an accepted treatment for therapy resistant paroxysmal atrial fibrillation¹⁰.

A number of studies have demonstrated that in the presence of atrial fibrillation with rapid or difficult to control ventricular response, particularly if associated with congestive heart failure, radiofrequency ablation of the atrio-ventricular junction and the implantation of a pacemaker leads to a reduction of physical limitations, to an improvement of the quality of life, of the functional class and of the left ventricular ejection fraction^10-15. While some of these studies have comparatively analysed possible contributing factors, none seem to have taken into consideration a possible role of the pacing mode (DDD or DDDR) and in particular of the influence of the rate responsive function, specially regarding atrial fibrillation prevention. It was therefore decided to conduct a randomised, crossover, pilot study to evaluate the effects of DDD versus DDDR pacing modes of an automatic mode-switching double chamber device, in a patient population referred for radiofrequency ablation of the atrio-ventricular junction and permanent dual chamber stimulation as a treatment of hemodynamically ill-tolerated, rapid ventricular response, drug-resistant, paroxysmal atrial fibrillation.