AMCA Electrocardiogram (EKG) Practice Exam 2025 – The Comprehensive All-in-One Guide to Exam Success!

The correct choice pertains to ACE inhibitors, which are a class of medication that have a significant role in lowering overall resistance in vascular beds. These medications work by inhibiting the enzyme that converts angiotensin I to angiotensin II, a powerful vasoconstrictor. By blocking this conversion, ACE inhibitors cause blood vessels to dilate, which effectively reduces vascular resistance and lowers blood pressure. This mechanism is particularly beneficial in treating conditions like hypertension and heart failure.

Other classes of medications, such as beta-blockers and calcium channel blockers, also influence blood pressure but through different mechanisms. Beta-blockers primarily decrease heart rate and the force of heart contractions, which can lower blood pressure but do not directly affect vascular resistance as significantly as ACE inhibitors. Calcium channel blockers work by preventing calcium from entering heart and blood vessel cells, leading to relaxation of the vascular smooth muscle, thereby also lowering blood pressure, yet this action is not as comprehensive in reducing overall resistance across various vascular beds compared to ACE inhibitors. Diuretics, on the other hand, help lower blood pressure primarily through fluid reduction, which alters blood volume rather than directly impacting vascular resistance.

Understanding the distinct mechanisms of these medications highlights why ACE inhibitors stand out in the context of lowering vascular resistance.