[Comparative study of a slow-release quinidine preparation and flecainide administered in 2 daily doses for the treatment of extrasystole].

The new anti-arrhythmic agent flecainide was compared in a single-blind cross-over study to arabogalactane quinidine sulfate in the treatment of stable chronic extrasystole, using a fixed twice-daily dose protocol. Results were assessed by the Holter method. 12 patients (7 men and 5 women) with an average age of 56.5 were selected on the basis of stable and essentially ventricular extrasystole (VES) in 11 cases, and essentially atrial extrasystole (AES) in the remaining case. All patients however had some VES and 6 had some AES, and 5 patients had bursts of VES. The protocol provided for four sequences lasting one week each: one fixed, for selection, and the other three random, flecainide (375 mg), quinidine (660 mg), or placebo (2 doses). Data on each were recorded for Holter analysis. Statistical comparison of results was performed by studying variances on an equilibrated block. Comparison between the selection and placebo sequences showed the stability of the arrhythmia whatever its type. Against ectopic complexes as a whole, only flecainide had significant activity (p less than 0.01). Against AES, both compounds were active (p less than 0.05), quinidine more than flecainide (-73%/63%: a non-significant difference). Only flecainide was active against VES (-88.5%). Quinidine did not significantly reduce VES (-56%).(ABSTRACT TRUNCATED AT 250 WORDS)