[Effective dose of flecainide for arrhythmia in children].

Nine children with arrhythmia (1 automatic atrial tachycardia, 1 premature ventricular construction, and 7 ventricular tachycardia) who started oral treatment using flecainide were studied. All but 2 cases (1 post operative ventricular septal defect, 1 post operative tetralogy of Fallot) had ostensibly normal heart on physical examination, chest X ray and echocardiogram. To raise serum level above 200ng/ml, flecainide dose over 80mg/m2 or 3mg/kg was needed. There was negative correlation between dose (y: mg/kg) and age (x: year) (y = 5.2-0.16x, r = 0.88) in this group. No serious side effect indicating the need to discontinue further medication was detected. In electrocardiogram, PR, QRS and QT interval was not changed before or after the medication. Premature ventricular contraction disappeared in 2 of 8 cases (25%), decreased in number in 3 (38%), did not change in 1 (13%) and increased in number in 2 (25%). However ventricular tachycardia rate decreased or disappeared in all of the 5 cases whose ventricular tachycardia was detected in Holter electrocardiogram. Flecainide seems more effective for sustained ventricular tachycardia than for nonsustained ventricular tachycardia.