This invention relates to benzazepine derivatives of formula I ##STR1## wherein A is --CH.sub.2 CH.sub.2 -- or --CH.dbd.CH--;R.sub.1 is hydrogen, chlorine, bromine, C.sub.1 -C.sub.3 alkyl, amino, C.sub.1 -C.sub.3 alkylamino, C.sub.1 -C.sub.3 dialkylamino, acylamino, hydroxy, C.sub.1 -C.sub.3 alkoxy or phenyl C.sub.1 -C.sub.3 alkoxy;R.sub.2 is hydrogen, chlorine, bromine, hydroxy, C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 alkoxy or phenyl C.sub.1 -C.sub.3 alkoxy or, together with R.sub.1, can be C.sub.1 -C.sub.3 alkylenedioxy;R.sub.3 is hydrogen, chlorine, bromine or C.sub.1 -C.sub.3 alkoxy;R.sub.4 is hydrogen, benzyl, C.sub.1 -C.sub.3 alkyl or C.sub.3 -C.sub.5 alkenyl;R.sub.5 is hydrogen, halogen, C.sub.1 -C.sub.3 alkyl or C.sub.1 -C.sub.3 alkoxy;R.sub.6 is hydrogen, C.sub.1 -C.sub.3 alkyl or C.sub.1 -C.sub.3 alkoxy or, together with R.sub.5, can be a C.sub.1 -C.sub.2 alkylenedioxy;X is an imino, optionally substituted by a benzyl or C.sub.1 -C.sub.3 alkyl, or is oxygen, sulphur, sulphinyl or sulphonyl;Y is an imino, optionally substituted by a benzyl or C.sub.1 -C.sub.3 alkyl, or is methylene or carbonyl;m and n are each independently 2, 3 or 4; and nontoxic, pharmaceutically acceptable addition salts thereof. These compounds have valuable pharmacological properties, particularly the effect of lowering heart rate and reducing the O.sub.2 requirement of the heart.