4-heterotricyclic substituted 1,4-dihydropyridines with a potent selective bradycardic effect

A series of 4-heterotricyclic substituted 1,4-dihydropyridines were prepared. The compounds were evaluated for inotropic, chronotropic and calcium antagonist properties. The tested compounds are fairly good as calcium antagonists, but exert potent selective bradycardic effects.