Question 1

Which of the following drugs significantly increases the levels of cyclic guanosine monophosphate?&#10;A) Milrinone&#10;B) Nesiritide&#10;C) Dobutamine&#10;D) Inamrinone&#10;E) Digoxin

Accepted Answer

Nesiritide is recombinant human B-type natriuretic peptide whose action is counter to that of the renin-angiotensin and sympathetic systems on the peripheral vascular caliber. The other drugs listed do not significantly affect cyclic GMP levels.

Question 2

Systolic failure secondary to ischemic cardiomyopathy leads to all of the following except:&#10;A) Down regulation of the sympathetic nervous system&#10;B) Peripheral vasoconstriction leading to an increased afterload&#10;C) Activation of the renin-angiotensin system&#10;D) Fluid retention&#10;E) Remodeling of the functional proteins within the myocardium

Accepted Answer

The sympathetic nervous system is up regulated in the condition of a failing heart. Increased sympathetic tone leads to peripheral vasoconstriction and an increased afterload, further worsening the condition.

Question 3

ACE inhibitors are a common treatment for heart failure; this is because:&#10;A) Afterload is reduced&#10;B) Peripheral resistance is increased&#10;C) Long-term mortality is reduced&#10;D) Preload is reduced&#10;E) A, C, and D

Accepted Answer

ACE inhibitors are a mainstay in the treatment of CHF. They should be used even if diuretics and other antihypertensive medications are being used. They reduce aldosterone-mediated fluid retention and reduce peripheral vascular resistance via less circulating angiotensin II.

Question 4

The use of sympathomimetics such as norepinephrine should be used with caution in patients on beta adrenergic blockers due to:&#10;A) Creation of acute malignant hypertension&#10;B) Adverse effect of pulmonary hypertension&#10;C) Acute hypertension due to unopposed alpha-1 receptor blockade&#10;D) Reduced renal blood flow&#10;E) Ventilation-perfusion mismatch

Accepted Answer

With beta blockers, alpha receptors remain unopposed and can create peripheral vasoconstriction and hypertension.

Question 5

The effects of digitalis glycosides are best described as:&#10;A) Intracellular calcium increases leading to higher contractility&#10;B) Increased myocardial automaticity&#10;C) Increased parasympathetic discharge and decreased heart rate&#10;D) Refractory period remains the same even though heart rate is decreased&#10;E) Both A and C

Accepted Answer

Cardiac automaticity is decreased and the refractory period is lengthened with the use of cardiac glycosides. There is also a decreased heart rate partially due to increased parasympathetic tone. This decreases myocardial oxygen demands and increases time for ventricular filling during diastole.

Deck 23: Drugs to Treat Heart Failure