Effect of a new beta-adrenergic blocking agent, ICI 66082, on exercise haemodynamics and airway resistance in angina pectoris

Abstract

A new cardioselective beta-adrenergic blocking agent, ICI 66082, was studied in io patients with severe effort-limiting angina pectoris, of whom all but one later went to bypass operation. The effect on maximal working capacity and airways resistance was compared before and after a single intravenous dose of 5 mg ICI 66082 andpropranolol. The haemodynamic effects of ICI 66082 were also studied during cardiac catheterization in the same patients during supine exercise provoking chest pain. Propranolol and ICI 66082 were equipotential in their blocking effect on exercise heart rate. In contrast to propranolol, ICI 66082 did not block the beta-receptors of the lung. Maximal working capacity was higher after ICI 66082 than after propranolol (+9%/0) and compared to the control period (+ I9%). This could be explained by a decrease found, after ICI 66082 administration, in both cardiac ouput (stroke volume unchanged) and aortic pressure during exercise with no change in the peripheral vascular resistance.