14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-139

A novel microcatheter approach to the ablation of atrial fibrillation: safety and feasibility in 43 patients

Michelle Adam, Zoltan Csanadi, Claudio Tondo, Paolo Della Bella, Roberto De Ponti, Jorge A. Salerno, George Theodorakis, Ernst G. Vester, Annibale Sandro Montenero, for the REVELATION™.
European Atrial Fibrillation Group

Reasons to map and cure atrial fibrillation

Advances in understanding of the electrophysiological mechanism responsible for the maintenance of atrial fibrillation have brought with them the recognition that this arrhythmia may cause a tachycardia-induced atrial cardiomyopathy that results in electrophysiological and anatomic remodeling of the atria.

The term “electrical remodeling”, now frequently used, has been introduced by Wijffels⁸ to indicate long-term changes in refractory period that resulted in loss of rate adaptation and caused an increase in the rate, inducibility, and stability of the atrial fibrillation.

These electrophysiological changes lead to short term (seconds or minutes) and then to mild (hours or day) or very long-term (months or years) metabolic changes that result to irreversible structural damage (fibrosis, fatty degeneration). Thus the “electrical remodeling” may lead to an “anatomical remodeling”. Moreover recently Elvan9 confirmed the findings of Wijffels and found that rapid pacing-induced atrial fibrillation in dogs prolonged intra-atrial conduction time and also depressed sinus node function. This latter observation raises the possibility that the tachycardia-induced atrial myopathy also causes sinus node remodeling and may contribute to clinical presentation such as the bradycardia-tachycardia syndrome.

Thus attempts to restore sinus rhythm are warranted under the premise that sinus rhythm begets sinus rhythm.

As Maze operation was attempted with success in patients undergoing heart surgery for atrial fibrillation associated with valvular disease, the idea of creating linear lesions with RF catheter was subsequently taken into consideration by electrophysiologists. The apparition of a new type of catheter whose characteristics would permit to create linear lesions in the atrium allowed to attempt a “Maze type” intervention with RF ablation catheters. As a consequence, this type of procedure, less invasive and with a lesser morbidity, allows to treat also patients with a “normal” heart that would not benefit from the surgical procedure.