911-38 Effect of Single Loading Oral Propafenone or Digoxin in Recent Onset Atrial Fibrillation: Conversion to Sinus Rhythm and Modulation of Ventricular Rate. A Randomized, Placebo Controlled Study

Abstract

A population of 105 patients (pts) with recent onset (< 72 hours) atrial fibrillation (AF) without clinical signs of heart failure were randomly treated with a single loading oral dose of propafenone (PFN) (600 mg) or digoxin (DIG) (1 mg) or with placebo (PLA). A 24-hour holter monitoring was performed and conversion to sinus rhythm (SR) after 2, 4 and 24 hours was considered as criterion of efficacy. We also evaluated the effect on mean ventricular rate (MVR) in those pts with still lasting AF four hours after drug administration. The 3 groups were comparable as to gender, age, etiology, duration of AF, mean ventricular rate at baseline and left atrial dimension. Conversion to SR PFN (n = 36) DIG (n = 34) PLA (n = 35) p value after 2 hours 16 (44%) 5 (15%) 7 (20%) 0.011 after 4 hours 25 (69%) 11 (32%) 12 (34%) 0.002 after 24 hours 30 (83%) 24 (71%) 25 (71%) ns Mean conversion time within 4 hours was 139 ± 117’ for PFN, 123 ± 66’ for DIG and 116 ± 78’ for PLA (p = ns). Reduction MVR PFN (n = 11) DIG (n = 23) PLA (n = 23) p value baseline (bpm) 134 ± 20 133 ± 29 136 ± 28 † ; ‡ < 0.001 after 2 hours 106 ± 22 † 113 ± 32 ‡ 124 ± 29 vs baseline (-21%) ** (1-15%) (-9%) ** * = 0.002 after 4 hours 92 ± 15 † 104 ± 29 ‡ 121 ± 27 °° < 0.01 (-31%) °/* (-22%) °/°° (-11%) */°° °; ** < 0.05 No serious adverse effects were noted in either group. Phases of regular tachycardia were observed in 3 pts of each group, but only in 2 cases, both receiving placebo, 1: 1 AV conduction ensued. 1) Oral loading dose of PFN is safely and promptly efficacious in converting recent onset AF to SR. 2) The efficacy of oral PFN is significantly superior in comparison to oral DIG while oral loading dose of DIG is no better than placebo. 3) PFN and DIG are both effective in reducing MVR in pts with recentonset AF who did not revert to SR or who reverted late after drug administration.