Emergency Medical Technician (EMT) Basic Certification Practice Exam

Which of the following best describes the role of nitroglycerin in cardiac care?

1. Decreases heart rate

2. Relaxes coronary arteries and reduces workload

3. Increases myocardial oxygen demand

4. Increases fluid retention

The correct answer is: Relaxes coronary arteries and reduces workload

Nitroglycerin plays a crucial role in cardiac care primarily by relaxing the coronary arteries and reducing the workload of the heart. This medication is a vasodilator, meaning it causes blood vessels to widen, which increases blood flow to the heart muscle. By doing so, it helps alleviate the symptoms of angina (chest pain) that occur due to insufficient blood flow or oxygen to the heart. When nitroglycerin is administered, it lowers the resistance against which the heart must pump (afterload), thereby reducing the amount of work the heart has to do. This reduction in workload not only helps relieve chest pain but also decreases myocardial oxygen demand, allowing the heart muscle to function more efficiently during episodes of stress or exertion. The relaxation of the coronary arteries enhances blood supply to the heart muscle itself, improving oxygen delivery where it's needed most. In contrast, options that refer to decreasing heart rate, increasing myocardial oxygen demand, or increasing fluid retention do not accurately reflect the effects of nitroglycerin. The medication does not primarily function to lower heart rate or increase oxygen demand; rather, it aims to relieve cardiac stress and improve oxygen delivery. Likewise, nitroglycerin is not associated with increasing fluid retention, which is more common with other