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

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

RT-26

Sympathetic activation and recurrence of atrial fibrillation after electrical cardioversion

Federico Lombardi, Andrea Colombo, Diego Tarricone, Barbara Basilico, Massimo Garbin, Romana Ravaglia, Cesare Fiorentini.
Cardiologia, Dipartimento di Medicina, Chirurgia e Odontoiatria, Ospedale S. Paolo, University of Milan, Italy

Abstract

Recurrence of atrial fibrillation (AF) is a major clinical problem. Several factors such as type of underlying heart disease, left atrial dimension, duration of arrhythmia are known to influence the efficacy of pharmacological or electrical cardioversion and the maintenance of sinus rhythm. Autonomic mechanisms may be involved not only in the onset of AF but also in its maintenance and termination. We used spectral analysis of short term heart rate variability to evaluate autonomic modulation of sinus node in two different subsets of patients: 27 subjects with episodes of paroxysmal AF during a 24 hour Holter recording and 73 patients with persistent AF.

Signs of sympathetic activation and reduced vagal tone were more evident before than after paroxysmal AF episodes. In patients with persistent AF in whom sinus rhythm was restored by means of electrical cardioversion AF, a spectral profile characterised by signs of sympathetic activation identified a subgroup of subjects with a relative risk of 3.78 of early AF recurrence.

Thus, evaluation of autonomic control mechanisms seems capable of providing important information not only in the understanding of factors likely to favour AF occurrence but also to identify patients with a greater risk of recurrence after cardioversion.

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