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

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

RT-88

Impairment (remodeling?) of cardiac autonomic response after cardioversion of chronic atrial fibrillation

Antonio Michelucci, Chiara Lazzeri, Luigi Padeletti, Giuseppe Bagliani*, Andrea Colella, Alessandra Sabini, Renato Zipoli, Alessandro Costoli, Paolo Pieragnoli, Gianfranco Gensini, Franco Franchi.
Department of Internal Medicine and Cardiology, University of Florence, *Ospedale di Foligno, Italy

The effects of pacing-induced atrial fibrillation on sinus node function have been recently evaluated in a closed-chest canine model¹. These data showed that pacing-induced chronic atrial fibrillation causes sinus node dysfunction, prolonged intra-atrial conduction time, shortened atrial refractoriness and perpetuated atrial fibrillation. These Authors observed that these changes reversed gradually after termination of atrial fibrillation, postulating a reversible electrical remodeling of the sinus node as well as of the atrial myocardium.

In order to assess the effect(s) of chronic atrial fibrillation on sinus node modulation, we evaluated heart rate variability in 24-hour ECG-recordings in thirty patients after electrical cardioversion in comparison with data from a group of age and sex-matched healthy subjects.