American Board of Internal Medicine (ABIM) Certification Practice Exam

If the mean gradient for aortic stenosis is 25 mm Hg, what severity does it indicate?

1. Mild aortic stenosis

2. Moderate aortic stenosis

3. Severe aortic stenosis

4. Very severe aortic stenosis

The correct answer is: Moderate aortic stenosis

A mean gradient of 25 mm Hg in the context of aortic stenosis typically indicates moderate severity. The grading of aortic stenosis based on mean gradients helps clinicians understand how significant the obstruction to blood flow is. Mild aortic stenosis is usually associated with a mean gradient of less than 20 mm Hg, while severe aortic stenosis usually presents with a mean gradient above 40 mm Hg. A mean gradient in the range of 20–40 mm Hg is generally classified as moderate. Therefore, a mean gradient of 25 mm Hg falls within this moderate range, indicating that the obstruction is significant but not yet severe, which aligns with the assessment provided in the question. Understanding these classifications allows for better management decisions regarding interventions and monitoring of patients with aortic stenosis.