Drug Therapy of CHF

Question 1

First Line Therapy

Answer 1

ACE-I
AT receptor blockers
Diuretics
Cardiac Glycosides
Beta-blockers (mild-mod disease)

Question 2

Dopamine

Answer 2

At low concentrations, acts at B1 receptors and improves myocardial contractility (positive inotropism)

Produces less of an increase in HR compared to isoproterenol (Isuprel) and dilates renal arteries, promoting better kidney perfusion

May produce tachycardia which may increase left ventricular work

Question 3

Dopamine-induced vasodilation is mediated by:

Answer 3

direct stimulation of pre-synaptic and post-synaptic dopamine receptors.

Vasodilation of renal vasculature is noteworthy and may benefit patients with marginal GFR due to poor renal perfusion

Question 4

Dobutamine

Answer 4

Through complex actions mediated by alpha and Beta receptors enhances contractility without substantially increasing either HR or peripheral resistance.

Does not activate dopamine receptors and therefore does NOT increase renal blood flow

Because of its vasodilator properties, Dobutamine’s positive inotropism is accompanied by a decrease in afterload. For this reason, Dobutamine is favored over Dopamine for most advanced HF patients who have not improved with digoxin, diuretics, and vasodilator therapy