A patient is taking a beta₁-adrenergic drug to improve the stroke volume of the heart. The nurse caring for this patient knows that this drug acts by increasing: A) cardiac afterload. B) cardiac preload. C) myocardial contractility. D) venous return.

Question

Quizplus · Accepted Answer

Beta₁-adrenergic agents help increase the heart's stroke volume by increasing myocardial contractility. Cardiac afterload is determined primarily by the degree of peripheral resistance caused by constriction of arterioles; increasing afterload would decrease stroke volume. Beta₁-adrenergic agents do not affect afterload. Cardiac preload is the amount of stretch applied to the cardiac muscle before contraction and is determined by the amount of venous return. Beta₁-adrenergic agents do not affect cardiac preload. Venous return is determined by the systemic filling pressure and auxiliary muscle pumps and is not affected by beta₁-adrenergic agents.

A Patient Is Taking a Beta1-Adrenergic Drug to Improve the Stroke

A Patient Is Taking a Beta₁-Adrenergic Drug to Improve the Stroke