18. Atrial Fibrillation: Electrical Cardioversion and Drug Prophylaxis

The effects of Omega-3 fatty acids (n-3) on cardiac membrane stabilization are well known. Reduction of ventricular arrhythmias and sudden death has been reported; fewer data exist regarding the effects of n-3 on atrial arrhythmias. Objective of this preliminary report is to evaluate the reduction of atrial arrhythmias after treatment with n-3 in pts with DDD pace-makers (PM). Methods we examined 40 pts with paroxismal atrial fibrillation (PAF) recorded at the periodic (every four months) PM controls. The PMs were implanted more than 1 year earlier for AV block (14 pts), synus bradicardia (8 pts), bradi-tachy syndrome (16 pts) and CHF (biventricular, 2 pts); the underlying cardiac pathologies were hypertensive disease in 24 pts, mitral regurgitation in 28, stable CAD in 16. All pts had bipolar atrial and ventricular leads with proper sensing function; the PMs were programmed in DDD or DDDr mode with minimum rate of 70 to 85 bpm. At the study entry, all pts were treated with n-3 (1 gr/d); no changes in PM programming and in the previous pharmacological therapy were allowed. The PM memories were interrogated after 4 months of treatment to evaluate the number and burden of PAF episodes; the percentage reduction of PAF burden (D burden) was calculated. At this point, the treatment was discontinued and the pts were evaluated 4 months later. Statistical analyses were performed with the T-Student test. Results 2 pts early discontinued the treatment complaining adverse drug effects (abdominal pain and diarrhoea). They were included in the intention-to-treat analysis. The patient population showed a dramatic reduction in episodes and burden of PAF during the treatment period. The episodes of PAF in the pre-treatment period resulted 450 ± 1190, and the PAF burden 3,92% of time; in the treatment period resulted respectively 147±346 (p = 0,07) and 1,01% (p = 0,042), with a mean PAF burden reduction of 69%. After the withdrawal of drug, the PAF episodes raised to 488±1687 (p = 0,100) and the PAF burden to 2,8% (p = 0,005). Even after the exclusion from analysis of the 9 pts with non sustained-PAF (<30 sec), the treatment reduced the PAF episodes (559 vs 172, p=0,079) and burden (5,17% vs 1,39%, p=0,042). Conclusions our data suggest a powerful effect of n-3 in reduction of PAF in these pts, without significant adverse effects. Although we expected a beneficial effect, we were extremely surprised of the magnitude of these results, so that we started a multicentric, double blinded trial on the atrial anti-arrhythmic effects of n-3.