[Study of minimal cardiac transit times in normal persons during beta-sympathicolysis (author's transl)].

The effects of single equipotent doses of Propranolol and Carazolol on cardiac haemodynamics of normal persons were investigated in a placebo-controlled double-blind study by radiocardiographic measurements of minimal cardiac transit times (MTTs). 90 min after oral application of 40 mg Propranolol a significant (p less than 0.005) prolongation of MTTs between the right auricle and the aortic root by 25% could be observed. A corresponding effect after treatment with 5 mg Carazolol was not recognizable (p greater than 0.05). Both substances strongly reduced the heart rate. The negative chronotropic effects of both beta-blockers were indistinguishable (p greater than 0.05).