Pharmacology Antihypertensives #14

Question

The nurse is caring for a patient with heart failure who is receiving a prescribed angiotensin-converting enzyme inhibitor (ACE inhibitor). The patient is asking how the drug works for heart failure. What will the nurse include in teaching the patient about this medication? Select all that apply.

Answers

  1. The ACE inhibitor reduces fluid volume
    • Rationale:

      This answer is not correct because ACE inhibitors do not cause diuresis. They relax blood vessels as vasodilation occurs, which decreases blood pressure, which subsequently decreases the workload of the heart.

  2. The ACE inhibitor relaxes blood vessels and lowers blood pressure
    • Rationale:

      This answer is correct because blood vessels are relaxed during vasodilation that occurs with action of ACE inhibitor with the inhibition of production of angiotensin II. Angiotensin II is a potent vasoconstrictor so decreasing this will cause relation of the blood vessels and decreased blood pressure.

  3. The ACE inhibitor reduces workload on the heart
    • Rationale:

      This answer is correct because once ACE inhibitors are activated in the body, angiotensin II (a powerful vasoconstrictor) is inhibited, producing vasodilation or relaxation of the blood vessels, decreased blood vessels. These actions naturally decrease the workload of the heart since the heart does not have to work harder to overcome the narrowed, vasoconstricted vessels.

  4. The ACE inhibitor decreases pulmonary venous pressure.
    • Rationale:

      This answer is not correct because ACE inhibitors do not decrease pulmonary venous pressure but they relax blood vessels as vasodilation occurs, which decreases blood pressure, which subsequently decreases the workload of the heart. These actions are very helpful in treatment of heart failure. Diuretics reduce fluid volume and decrease pulmonary venous pressure. There are some combination medications which have ACE inhibitors and diuretics, which could be used to treat heart failure.

  5. The ACE inhibitor prevents vasoconstriction and secretion of aldosterone.
    • Rationale:

      This answer is incorrect because although ACE inhibitors prevent vasoconstriction, they do not prevent the secretion of aldosterone. This is the function of Angiotension II receptor blockers (ARBs).

Overview

Angiotensin-converting enzyme inhibitors (ACE inhibitors) treat heart failure by relaxing blood vessels, lowering blood pressure, and reducing workload on the heart.

Explanation

ACEIs are considered the first-choice drug over angiotensin receptor blockers (ARBs). ACEIs block the action of an enzyme that causes narrowing of the heart vessels, and as a result, the vessels relax and widen. As a result, ACEIs have a vasodilation effect, which lowers blood pressure and reduces workload on the heart. They also offer additional benefit by preventing remodeling, which is an effect that leads to progressive cardiac deterioration. ACEIs do not reduce fluid volume or decrease pulmonary venous pressure; however, diuretics reduce fluid volume and decrease pulmonary venous pressure. Some ACEIs are combined with diuretic therapy. The question is specific for just ACEIs and not ACEIs/Diuretic combinations.

Learning Outcomes

Angiotensin-converting enzyme inhibitors (ACE inhibitors) are medications that inhibit the enzyme needed to convert angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor in the body so inhibiting this conversion allows ACE inhibitors to produce a vasodilation action. The blood vessels are relaxed during vasodilation. ACE inhibitors also lower the blood pressure as vasodilation occurs, which helps reduce the workload of the heart. Heart failure patients benefit from the actions of ACE inhibitors because the heart lacks the ability to pump as effectively, placing it at risk for further failure if increased workload from extra fluids and vasoconstriction is present.

Test Taking Tip

Angiotensin-converting enzyme inhibitors (ACE inhibitors) generally have a suffix ending of “-pril”.

Video Rationale