Differing Electrophysiological Effects of Various Antiarrhythmic Drugs on the Cardiac Chamber in Atrial Fibrillation / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: Long-term antiarrhythmic drug therapy remains the principal approach for suppressing atrial fibrillation (AF) and maintaining sinus rhythm. In this study, we examined the differing electrophysiological effects of various antiarrhythmic drugs on the cardiac chamber and atrial selectivity in patients with AF. METHODS: We analyzed 134 patients (60.4 +/- 12.5 years, MF = 1.141) who were administered a single antiarrhythmic agent for AF over 6 months amiodarone (group A), flecainide (group F), or propafenone (group P). The P wave, QRS complex duration and dispersion, and QT interval and its dispersion were evaluated using a standard 12-lead electrocardiogram. RESULTS: There was no significant difference in age, gender ratio, or associated diseases among the three groups. In group A, Pmax, Pmin, P dispersion, QRSmax, QRSmin, and QRS dispersion were shorter than in groups F and P, whereas Pmax/QRSmax was the highest in group A (A = 1.2, F = 0.9, P = 1.0; p < 0.01). QTcmax and QTcmin were longer in group A, whereas QTc dispersion and the QT peak to end (A = 13.3 +/- 11.2, F = 30.7 +/- 24.9, P = 31.8 +/- 21.6; p < 0.01) were shorter in group A than in the other groups. CONCLUSIONS: Amiodarone had a weaker, but more selective, inhibitory effect on intra-atrial conduction, and inhibited ventricular repolarization more effectively and homogenously than flecainide or propafenone. These differing electrophysiological effects may contribute to the superior effectiveness and safety of amiodarone over flecainide or propafenone.