the subjects were randomly assigned to three subgroups and each group received placebo ( control ) and two of the following regimens ( doses three times a day ) in a randomized sequence for 2 wk each : verapamil ( 80 mg ) and nifedipine ( 10 mg ) , verapamil ( 120 mg ) and gallopamil ( 50 mg ) , or propafenone ( 150 mg ) and quinidine ( 250 mg ) .
C0033429
propafenone
C0034414
quinidine