we examined the steady-state action potential duration ( apd ) within a wide range of cycle lengths ( cl ) in cardiac dog purkinje ( p ) and ventricular ( v ) muscle fibers in the presence of : lidocaine ( l ) 4 and 8 micrograms/ml , mexiletine ( m ) 4 and 8 micrograms/ml , flecainide ( f ) 1 and 4 micrograms/ml , disopyramide ( d ) 3.1 and 10 micrograms/ml , quinidine ( q ) 2.5 , 5 , and 10 micrograms/ml , bretylium tosylate ( b ) 5 and 10 micrograms/ml , and sotalol ( s ) 5 micrograms/ml .
C0018787
cardiac
C0018827
ventricular