Isoprenaline belongs to the positive inotropic drugs of the heart, this drug is an agonist of beta receptors, and has a strong agonistic effect on both beta1 and beta2 receptors, but has no effect on alpha receptors, the main effects on blood pressure are. It acts on β1 receptors in the heart to increase myocardial contraction, heart rate and conduction velocity, and increase the amount of blood discharged from the heart and the amount of post-oxygenation of cardiac muscle cells, thus having the effect of increasing blood pressure. It also acts on the β2 receptors of vascular smooth muscle, causing a significant diastolic effect on the blood vessels of skeletal muscle, so that there is a significant cardiovascular effect, resulting in an increase in systolic blood pressure, a decrease in diastolic blood pressure, and a larger pulse pressure difference. It can act on the β2 receptor of bronchial smooth muscle to relax the bronchial smooth muscle, therefore, it has a compound effect of lowering blood pressure.