Reversible protective effect of propafenone or flecainide during atrial fibrillation in patients with an accessory atrioventricular connection.
In 34 patients with a symptomatic accessory atrioventricular connection the reversible protective effect of orally administered flecainide (300 mg/day) and of propafenone (900 mg/day) in control of ventricular response during atrial fibrillation by exercise was assessed. The study consisted of three sections of 1 week each: an initial treatment phase during which propafenone or flecainide was administered, a drug-free phase, and a period of crossover to treatment with the other drug. At the end of each phase, transesophageal stimulation was performed during physical exercise to induce atrial fibrillation episodes: the goal was to control the persistence of drug effectiveness. At rest, the mean and shortest R-R interval during the period of induced atrial fibrillation in patients who were treated with flecainide or propafenone increased significantly as compared with the drug-free period. On the other hand, at maximum exercise levels no difference in both shortest and mean R-R intervals during atrial fibrillation was observed between patients who were treated with flecainide and those who were treated with propafenone, as well as between flecainide treatment and the drug-free period, whereas a slightly significant difference persisted with propafenone treatment (p less than 0.05). In addition, at maximum exercise levels no significant difference in the number of preexcited QRS complexes among the three treatments was noted. The data from this study suggests that a reversible protective effect against rapid ventricular rate as the result of an episode of atrial fibrillation exists during exercise in patients with a symptomatic accessory atrioventricular connection who are treated with flecainide or propafenone.
Auricchio
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Department of Cardiac Surgery, University of Rome, Tor Vergata, European Hospital, Italy.
D000328:Adult; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology; D001283:Atrioventricular Node / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005424:Flecainide / Q000627:therapeutic use*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D011405:Propafenone / Q000627:therapeutic use*; D011446:Prospective Studies; D014927:Wolff-Parkinson-White Syndrome / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology
D011405:Propafenone; D005424:Flecainide