NURSING 6005 CHAPTER 43: REVIEW OF HEMODYNAMICS TEXT BANK

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. ANS: C 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. DIF: Cognitive Level: Analysis REF: Regulation of Cardiac Output | Determinants of Cardiac Output | Stroke Volume TOP: Nursing Process: Evaluation MSC: NCLEX Client Needs Category: Physiologic Integrity: Physiologic Adaptation