Effects of Propafenone Plus Digoxin on Ventricular Rate During Atrial Fibrillation: A Randomized Study

Abstract

Aim olthe study was to evaluate the effect of digoxin (D) in combination with propafenone (P) on the ventricular rate during stable atrial fibrillation (AF). We evaluated 15 patients (pts.) (age 57 ± 9 years. NYHA ≤ 2) with stable AF during effort by cycloergometer in a randomized study with four phases: 1) no treatment, for control (C). 2) in steady state treatment with oral digoxin (D) at at 0 125–0.375 mg/die according to serum digoxin levels (0.8–1.8 ng/ml). 3) three hours after oral loading with propafenone (P) at 600 mg. and 4) three hours after oral loading with propafenone while assuming oral digoxin (D + Pl. The sequence of C. D, P and D + P phases was randomised and the exercise tests were performed every 7-10 days at the same. C D P D+P Basal HR (bpm) 104 ± 23 97 ± 20 98 ± 16 93 ± 27 Max HR (bpm) 185 ± 25 172 ± 34 * 165 ± 35 * 152 ± 33 ** Ex. Time (sec) 485 ± 150 512 ± 165 509 ± 199 493 ± 145 * p < 0.05 vs C ** p < 0.01 vs C,D,P Either after P or D + P heart rate resulted lower than control not only at peak exercise but also at the second and fourth minute of effort (p < 0.03 and p < 0.01, respectively) resulting in a more gradual HR increase during the first phases of effort. No major side effect occurred. In conclusion in pts. with stable AF propafenone is able to achieve a significant control of HR increase during effort, probably by virtue of its slight beta-blocking effect. Moreover the combination of D + P results in an additive effect with a better control of HR during effort.