When living with a complex medical condition like aortic stenosis, you may find yourself with more questions than answers. You might be wondering, “How does my cardiologist (heart doctor) know how severe my aortic stenosis is? What does this mean for my treatment options?”

Your aortic stenosis grade refers to how severe your condition is. In this article, we’ll cover the key features your cardiologist looks at to determine your grade and how it’s measured. We’ll also discuss what your stage and grade mean for your treatment options and outlook.

What Is Aortic Stenosis?

Aortic stenosis is a disease that can restrict blood flow to the rest of the body. Your heart works hard to pump oxygen-rich blood to the rest of your body. Your left ventricle (one of the lower chambers of your heart) is responsible for pumping blood from your heart to your aorta — the largest blood vessel in your body. Your aorta carries blood out to your organs and tissues.

The aortic valve sits between the left ventricle and the aorta, opening and closing tightly to control blood flow. This valve is made of three tissue flaps that stop blood from flowing back into your heart, a process known as aortic regurgitation.

With age, a person’s aortic valve can begin to narrow, thereby limiting the amount of blood flowing through it. This is known as aortic stenosis (or aortic valve stenosis). According to the American Heart Association, more than 13 percent of American adults over the age of 75 live with this condition.

Other causes and risk factors of aortic stenosis include:

• Valve scarring from infection, inflammation, or disease
• Valve calcification (buildup of calcium deposits)
• Bicuspid aortic valve (being born with two tissue flaps instead of three)
• Risk factors for heart disease, including hypertension (high blood pressure) and high cholesterol levels

While some people are asymptomatic, meaning they show no signs of aortic stenosis, those who have symptoms may experience:

• Shortness of breath
• Syncope (fainting)
• Angina (chest pain)
• Dizziness
• Heart palpitations (fast-beating or fluttering heart)

How Is Aortic Stenosis Stage Determined?

If you’re experiencing symptoms of aortic stenosis, your doctor may refer you to a cardiologist, who’ll run a series of tests to figure out what’s causing them. Once you’re diagnosed with aortic stenosis, your cardiologist will use the test results to determine the stage or severity of the condition.

Echocardiography

Echocardiography is one of the primary tests that doctors use to diagnose and evaluate aortic stenosis. Also known as a cardiac ultrasound, echocardiography uses sound waves that bounce off your heart to create pictures of how your heart works in real time.

Echocardiography helps your healthcare team gather important information, including:

• Your valve anatomy (what the aortic valve looks like)
• If you have other types of valve disease
• If there are other abnormalities, such as widening of the aorta
• How much blood your left ventricle pumps out to your body with each heartbeat

Doppler Echocardiography

A Doppler echocardiogram is a specific tool used to measure the valve’s hemodynamics, or the speed and direction of blood through your heart and across the valves. Doctors will take several key measurements using a Doppler echocardiogram, including the aortic valve maximum velocity, mean gradient, and valve area.

These medical terms can be quite complicated. Here, we’ll break them down into simpler concepts to help you better understand your condition.

Aortic Valve Maximum Velocity

The aortic valve maximum velocity is a measurement of the speed at which blood flows across the aortic valve. When you have aortic stenosis, your aortic valve is narrowed. Your left ventricle tries to pump the same amount of blood through a smaller space in the valve, which increases the blood flow’s speed. The higher your aortic valve maximum velocity, the more severe your aortic stenosis. Normal aortic maximum velocity is less than 2 meters per second.

Mean Gradient

The aortic valve opens and closes to allow blood from the left ventricle to flow through. When you have aortic stenosis and the valve narrows, less blood can pass through. This causes more pressure to build up between the left ventricle and the aorta.

The difference in pressure between these two areas — known as the pressure gradient — can tell your cardiologist how severe your aortic stenosis is. Aortic stenosis grading takes into account your mean transvalvular gradient (mean gradient) — that is, the average pressure across the aortic valve between the left ventricle and aorta.

Like your blood pressure, the mean gradient is measured in millimeters of mercury (mm Hg). Normally, a healthy aortic valve has minimal, if any, mean gradient. A high gradient is a sign of more severe aortic stenosis.

Aortic Valve Area

The aortic valve area refers to the size of your aortic valve when it’s open. A healthy aortic valve area is between 3 and 4 square centimeters. As your aortic stenosis progresses, the valve begins to narrow, and the area becomes smaller. The smaller your aortic valve area, the more severe your aortic stenosis.

Other Tests

To better understand aortic stenosis and check for other issues in the heart or blood vessels, some people may need additional tests, including:

• Chest X-ray
• Stress test
• CT scan
• MRI scan
• Cardiac catheterization

After you have a confirmed diagnosis of aortic stenosis, your cardiologist will use the test results to determine the stage or severity of the condition. Your stage will affect what treatments you receive.

What Are the Stages of Aortic Stenosis?

There are four stages of aortic stenosis:

• Stage A — At risk of aortic stenosis
• Stage B — Progressive aortic stenosis
• Stage C — Asymptomatic severe aortic stenosis
• Stage D — Symptomatic severe aortic stenosis

Stage A Aortic Stenosis

In stage A aortic stenosis, you have risk factors for aortic stenosis, but don’t have any symptoms or changes to how your blood flows through your heart. The aortic maximum velocity is normal in stage A. You may have some aortic valve sclerosis (stiffening) or other changes to your aortic valve.

Stage B Aortic Stenosis

Stage B aortic stenosis is mild to moderate valve disease. In stage B, you don’t have any symptoms. However, you do have some changes to your aortic valve and blood flow that can cause problems.

Mild to moderate valve calcification can change how the aortic valve works, increasing the aortic valve maximum velocity and pressure gradient. Your doctor can use these measurements to determine your aortic stenosis severity.

In stage B aortic stenosis, the heart chamber has to work extra hard to pump blood through a smaller valve. This can cause changes to the left ventricle of the heart.

Stage C Aortic Stenosis

Stage C aortic stenosis is when aortic stenosis is severe, but doesn’t cause any symptoms. In stage C, calcification makes the aortic valve opening shrink to 1 square centimeter or less. Stage C aortic stenosis is broken down into two substages — C1 and C2.

Stage D Aortic Stenosis

If you have symptoms of aortic stenosis, you have stage D aortic stenosis. Just like stage C, the valve in your heart gets very hard and only opens a tiny bit — about 1 square centimeter or less.

This stage is broken down into three substages:

• D1 — The valve is very narrow, and the heart might be too thick or weak. You may also experience pulmonary hypertension (high blood pressure in the lungs).
• D2 — The heart can’t pump as well as it normally does.
• D3 — The heart walls are too thick, so the heart can’t fill up with blood properly.

What Your Aortic Stenosis Stage Means

Your cardiologist will use your aortic stenosis severity to create your treatment plan. For mild or moderate aortic stenosis, your cardiologist may recommend making lifestyle changes, like eating a heart-healthy diet and keeping physically active.

It’s important that you take steps to prevent or slow down your condition from progressing to heart failure. Your cardiology provider may prescribe medications for you to take better care of your cardiovascular health. These can include cholesterol and blood pressure medications or medications to help regulate your heart rhythm.

Severe aortic stenosis can be life-threatening and requires surgery to replace the damaged heart valve. Surgeries may include a transcatheter aortic valve replacement or a surgical aortic valve replacement. Replacing the valve can treat your symptoms and help prevent heart failure. Your doctor can further discuss these options with you and help determine which may be the most appropriate.

Talk With Others Who Understand

On MyHeartDiseaseTeam, the social network for people with heart disease and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with heart disease.

What questions do you have about aortic stenosis and grading? How is your aortic stenosis graded? Share your experience in the comments below, or start a conversation by posting on your Activities page.