the fast sodium channel inhibitors quinidine , carticaine and benzylamino-5,6-dihydro-8,9-dimethoxy-imidazo-5,1-a-isoquinoline hydrochloride ( he-36 ) increase threshold of ac-arrhythmia in left atria and papillary muscles , whereas the slow channel inhibitor verapamil is ineffective in concentrations up to 6 mumol/l .
C0034414
quinidine
C0003811
arrhythmia