a. Angiotensin-converting enzyme inhibitors (ACE inhibitors) belong to a unique class of vasodilators. ACE inhibitors block a specific enzyme (angiotensin converting enzyme) that converts angiotensin I to angiotensin II. Angiotensin II is one of the most potent vasodilators in the body. The mechanism of action of ACE inhibitors in the treatment of congestive heart failure relies on the ability to cause both arterial and venous vasodilation through this inhibition, thereby decreasing the workload on the heart. Hemodynamic effects associated with long term use include increased cardiac function and decreased blood pressure and heart rate. Significant improvements are seen in exercise tolerance and left ventricular size. ACE inhibitors are well tolerated and have been shown to decrease hospitalizations and deaths. For these reasons, agents in this class are first line pharmacologic treatment for congestive heart failure.
b. ACE Inhibitors are often initiated immediately after a heart attack or when a patient still has mild symptoms of heart failure. The starting dose is low and titrated (gradually increased) up to the maximum tolerated dose (based on heart rate and blood pressure). The most bothersome side effect is a dry cough which develops in some patients. Other side effects include angioedema (facial swelling) and elevated potassium levels.
c. Agents included in this class include captopril (Capoten®), enalapril (Vasotec®), lisinopril (Prinivil®, Zestril®), and ramipril (Altace®)
Was this article helpful?