Haemodynamic observations with KO. 1366 (bunitrolol), a new beta-adrenergic blocking agent.

The haemodynamic effects of a new beta-adrenergic blocking agent KO.1366 (bunitrolol) were assessed in 10 males admitted to hospital for investigation of chest pain. Measurements were made at rest, during atrial pacing at 100 beats/min, and during hand grip exercise, before and afterintravenous administration of KO.1366 at a dosage of 0.05 mg/kg body weight. There was a 12% (p less than 0.01) slowing in resting heart rate and alpha 4% (p less than 0.05) slowing in exercise heart rate after drug administration. Resting left ventricular end diastolic pressure rose by 2.2 mm Hg (p less than 0.01) following the drug, but there was no significant change during pacing or exercise. Left ventricular systolic pressure and its first derivative did not change significantly. Cardiac output rose slightly, and stroke volume at rest and during exercise showed a considerable increase. In the dosage used, KO.1366 has an important chronotropic effect on the heart without causing significant myocardial depression.