Correlation between serum concentration and pharmacological effect on atrioventricular conduction time of the antiarrhythmic drug propafenone.

Seven patients with cardiac dysrhythmias received a single, oral, therapeutically effective dose of the antiarrhythmic drug propafenone. The serum levels correlated well with changes in atrioventricular conduction times during the postabsorptive elimination phase (r = 0.8610, p less than 0.001). The mean half-lives of the serum level and the electrocardiographic effect (PQ-time) were 3.6 +/- .2 h and 3.8 +/- 0.6 h, respectively.