Family Nurse Practitioner Exam

Which test is used to determine the severity of arterial blockage?

1. Electrocardiogram

2. Ankle-brachial index (ABI)

3. Computed tomography (CT) scan

4. Magnetic resonance imaging (MRI)

The correct answer is: Ankle-brachial index (ABI)

The Ankle-Brachial Index (ABI) is the most appropriate test for assessing the severity of arterial blockage, particularly in the context of peripheral arterial disease (PAD). This simple but effective test measures the ratio of the blood pressure in the patient's ankle to the blood pressure in their arm. By comparing these two values, healthcare providers can determine how well blood is flowing to the limbs. A low ABI indicates reduced blood flow, which can signify moderate to severe arterial blockage. This test is non-invasive, and its specificity and sensitivity make it a valuable tool for detecting lower limb ischemia. It's particularly useful in identifying asymptomatic patients who may have significant arterial disease. In contrast, an electrocardiogram primarily evaluates the electrical activity of the heart and is useful for diagnosing arrhythmias and myocardial ischemia but does not assess peripheral circulation. A computed tomography (CT) scan can visualize the anatomy of blood vessels and may assess blockages, but it is typically used for more complex cases or when detailed imaging is necessary, rather than as a routine screening tool for arterial blockage severity. Similarly, a magnetic resonance imaging (MRI) scan provides comprehensive imaging of soft tissues but is not specifically designed for arterial function assessments in the same way the ABI measures flow in the