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108 II DRUGS AFFECTING THE AUTONOMIC NERVOUS SYSTEM
Case Study Help for the Heart
. L. is a highly successful scientist who spends ANSWER: Dobutamine injection would provide
Tlong hours in the laboratory and is constantly in particular benefit in meeting the therapeutic needs
demand as a speaker and reviewer for scientific of this patient. Dobutamine augments ventricular
papers and grants. He has a family history of contractility and thus enhances cardiac output,
cardiovascular disease, having lost both his father especially stroke volume, in patients with depressed
and grandfather before either reached age 60. He cardiac function. It does this by stimulating
has recently noticed decreased energy, especially -adrenoceptors in the heart while producing
during exercise, and had symptoms (difficulty in relatively little increase in chronotropic activity or
breathing, chest pain) that took him to the any significant elevation in systemic blood pressure
emergency department. The examining physician since it lacks -adrenoceptor stimulating effects.
thought the best treatment would be short-term Thus, in contrast to a nonselective -adrenoceptor
therapy with a directly acting inotropic agent, stimulant such as isoproterenol, which increases
especially one that would not markedly increase an cardiac output primarily by increasing heart rate,
already elevated heart rate. Based on a knowledge dobutamine s actions increase cardiac output
of the distribution of cardiovascular autonomic without being accompanied by either a marked
receptors, which of the following agents increase in heart rate or a significant increase in
epinephrine, norepinephrine, amphetamine, or systemic vascular resistance.
dobutamine would be a logical choice to use in
this initial short-term treatment? [ Pobierz całość w formacie PDF ]