Key takeaways

  • Aortic stenosis is a condition where the aortic valve becomes narrowed, forcing the left ventricle to work harder and eventually causing the heart muscle to thicken and stiffen over time.
  • Common causes include age-related calcium buildup on the valve in older adults and bicuspid aortic valve (a congenital condition) in younger people. Risk factors include high blood pressure, high cholesterol, smoking, and diabetes.
  • Evaluation is recommended for people with a heart murmur, symptoms like chest pain or fainting with exertion, a known bicuspid aortic valve, or older adults with new heart-related symptoms. Diagnosis is primarily made using an echocardiogram.

Aortic Stenosis is a condition where the aortic valve becomes narrowed. This makes it harder for blood to flow from the left ventricle (the heart’s main pumping chamber) into the aorta and out to the rest of the body.

Because the narrowed valve creates a constant blockage to blood flow, the left ventricle has to generate higher pressures to push blood through the aortic valve. Over time, this extra strain causes the heart muscle to thicken (a process called hypertrophy). The thickened muscle becomes stiffer, which can reduce the heart’s ability to relax and fill properly (diastolic dysfunction).

If the condition progresses without treatment, the heart muscle may weaken, leading to heart failure.

The most common cause of aortic stenosis is age-related calcification, which is the buildup of calcium on the aortic valve over time. This is most often seen in older adults.

In younger people who develop aortic stenosis, the most likely cause is a bicuspid aortic valve. This is a congenital (present at birth) condition in which the valve has two leaflets instead of the usual three.

Other risk factors for aortic stenosis include high blood pressure (hypertension), high cholesterol, smoking, and diabetes. Rheumatic heart disease, although less common in the United States, is another possible cause.

Aortic stenosis develops slowly and may not cause symptoms at first.

When symptoms do appear, they often include:

  • shortness of breath, especially during activity
  • chest pain
  • dizziness or fainting, particularly with exertion
  • fatigue
  • reduced ability to exercise
  • signs of heart failure, such as swelling in the legs

Evaluation is recommended for:

  • people with a systolic ejection murmur heard on a heart exam
  • people with with symptoms such as chest pain with activity, fainting (syncope), or shortness of breath (dyspnea)
  • people with a known bicuspid aortic valve
  • older adults (over age 65) with new heart-related symptoms
  • people with a history of rheumatic fever

Aortic stenosis is primarily diagnosed by an echocardiogram (an ultrasound of the heart). This test can:

  • measure the valve area
  • assess pressure gradients (the difference in blood pressure across the valve, which helps show how severe narrowing is)
  • evaluate the valve’s structure (tricuspid vs. bicuspid)
  • assess valve function (including the degree of calcification, narrowing, and any leakage, called regurgitation).
  • evaluate overall heart function

Additional tests may include:

  • a cardiac catheterization, if noninvasive test results are unclear or before valve replacement
  • computed tomography (CT) calcium scoring of the valve, in select cases
  • exercise testing in people without symptoms to check for symptoms during physical activity

Dr. Uzochukwu Ibe is an ABMS board certified internal medicine physician and a general cardiologist. He completed his fellowship in interventional cardiology in Ohio and now practices in Missouri.