they were randomly assigned to three treatment groups : ( 1 ) individualized antiarrhythmic therapy based on efficacy in multiple 24-h ecgs and drug level determinations ( starting with mexiletine or quinidine ; n = 79 ) , ( 2 ) treatment with low-dose amiodarone ( 200-400 mg/day after a loading phase ; n = 73 ) , and ( 3 ) no antiarrhythmic therapy ( n = 86 ) .
C0034414
quinidine
C0003195
antiarrhythmic