Pharmacological and Parenteral Therapies Q 18

---

In evaluating the effect of nitroglycerin, Nurse Arthur should know that it reduces preload and relieves angina by:

  

     A. Increasing contractility and slowing heart rate

     B. Increasing AV conduction and heart rate

     C. Decreasing contractility and oxygen consumption

     D. Decreasing venous return through vasodilation

    

    

Correct Answer: D. Decreasing venous return through vasodilation.

---

The significant effect of nitroglycerin is vasodilation and decreased venous return, so the heart does not have to work hard.

---

Option A: Nitroglycerin does not increase contractility. Cardiac work is decreased by venodilation, reducing anginal symptoms secondary to demand ischemia.

Option B: AV conduction is not increased through nitroglycerin, and an increased heart may increase the blood pressure, which is contrary to the desired effects of nitroglycerin,

Option C: Contractility is not significantly affected by nitroglycerin. The desired vasodilatory effect increases perfusion and does not directly reduce oxygen consumption.

---