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

Introduction

Maintenance of sinus rhythm is one of the major clinical and electrophysiological problem in patients with atrial fibrillation (AF). Spontaneous conversion to sinus rhythm is observed in almost 50% of patients with paroxysmal or recent onset AF and is largely dependent upon the duration of the arrhythmic episode¹.

In patients with chronic or persistent AF, different pharmacological and non pharmacological interventions have been used to restore sinus rhythm in order to reduce symptoms, improve hemodynamics and reduce the embolic risk.

The use of anti-arrhythmic drugs either given intravenously in patients admitted to hospital or orally in outpatients is generally effective, however recurrence of AF is known to occur in about 30-50% of the cases within 6 months after cardioversion^1,2. When AF persists for more than 48 hour, the efficacy of pharmacological cardioversion decreases whereas the embolic risk increases. In these patients electrical cardioversion is the most effective treatment and the concomitant pre-treatment with anticoagulant and anti-arrhythmic drugs produce two major beneficial effects: the reduction of the embolic risk at time of electrical cardioversion as well as an increase in its efficacy.

Nevertheless, also in patients in whom restoration of sinus rhythm is accomplished by DC cardioversion, recurrence of AF remains a critical problem with an incidence ranging from 40 to 70% within one year^1,2.

Recurrence ratio appears to be partially affected by anti-arrhythmic therapy and related to the presence of those factors such as presence or absence of underlying heart disease, left atrial enlargement, duration of arrhythmia and extent of left ventricular dysfunction which are known to favour AF relapse^1,2.