adrenergic receptor agonists isoproterenol 【pharmacological Actions】 Heart:stimulation cardiac output is increased because of positive inotropic and chronotropic effects.This may lead to palpitation,sinus tachycardia,and more serious arrhythmias. Blood vessel:vasodi lation Blood pressure:decreased because IS0 lowers peripheral vascular resistance,primarily in skeletal muscle.β adrenergic receptor agonists — isoproterenol 【pharmacological Actions】 Heart: stimulation cardiac output is increased because of positive inotropic and chronotropic effects. This may lead to palpitation, sinus tachycardia, and more serious arrhythmias. Blood vessel: vasodilation Blood pressure: decreased because ISO lowers peripheral vascular resistance, primarily in skeletal muscle. Bronchial muscle: dilation