Is Aortic Stenosis Hereditary?

Disclaimer: This article is for informational purposes only and is not intended to diagnose any conditions. LifeDNA does not provide diagnostic services for any conditions mentioned in this or any other article.

Overview

As people live longer, heart-related conditions are becoming more common and more serious. Among them is a disease that often goes unnoticed until it’s advanced, yet it’s one of the most frequent reasons older adults need heart valve surgery.

It tends to affect men more than women, and its risk increases sharply with age, impacting over 2% of people above 60, and nearly 10% of those over 80. This condition is called aortic stenosis, where a narrowing of the heart’s main valve restricts blood flow and forces the heart to work harder.

It may be present at birth or develop gradually over time due to calcium buildup. Without treatment, especially after symptoms begin, the outlook may be life-threatening, with up to half of untreated patients dying within two years. While surgery may help, it isn’t without risks, and there are still no medications proven to slow or stop the disease. That’s why researchers are urgently working to better understand aortic stenosis and find safer, more effective ways to treat it.

What Is Aortic Stenosis?

Aortic stenosis is a heart condition where the aortic valve becomes too narrow. This valve acts as a gateway, allowing blood to flow from the heart to the rest of the body. When the opening is too tight, it makes it harder for blood to pass through.

Because of this, the heart has to pump much harder to move blood forward. Over time, this extra effort can strain the heart and affect how well it functions. Aortic stenosis can be present at birth or develop later in life, often due to calcium buildup on the valve.

Symptoms of Aortic Stenosis

Aortic stenosis (AS) may develop slowly over time, and many people may not notice any symptoms in the early stages. However, as the valve becomes more narrowed and the heart struggles to pump blood effectively, symptoms can begin to appear, especially during physical activity. These signs often suggest that the condition has become moderate to severe.

Here are the most common symptoms and what they mean:

Shortness of breath: When the valve is too narrow, it limits how much oxygen-rich blood can reach the body during movement or exercise. This can make even simple tasks feel exhausting and cause you to feel out of breath quickly.
Chest pain or pressure: The heart must work much harder to push blood through the tight valve. This increased effort can reduce blood flow to the heart muscle itself, leading to pain, tightness, or pressure in the chest.
Fatigue: With less blood being pumped out to the body, your muscles and organs don’t get the oxygen and nutrients they need. This can leave you feeling unusually tired, even after light activity or rest.
Dizziness or fainting: During exertion, the narrowed valve may not allow enough blood to reach the brain. This can lead to lightheadedness or fainting spells, which are serious warning signs that the heart is under strain.
Heart palpitations or irregular heartbeat: As the heart struggles to keep up with the body’s needs, it may beat irregularly or feel like it’s racing or fluttering. This is the heart’s way of trying to compensate for the restricted blood flow.

These symptoms are signs that the heart is under stress. If left untreated, severe aortic stenosis can be life-threatening, especially once symptoms appear. That’s why early detection and proper management are so important.

What Causes Aortic Stenosis?

1. Congenital Causes

Some people are born with aortic stenosis. This type accounts for about 3% to 6% of all heart problems present at birth. The narrowing that blocks blood flow from the heart can occur in different areas, below the valve (subvalvar), at the valve itself (valvar), or just above it (supravalvar).

In many cases, children with aortic stenosis also have other heart defects, such as a patent ductus arteriosus (a blood vessel that stays open after birth), aortic coarctation (a narrowed part of the aorta), or a ventricular septal defect (a hole between the heart’s lower chambers). These additional heart problems are found in about 15% to 20% of children with aortic stenosis.

A common related condition is bicuspid aortic valve, where the valve has only two flaps instead of the usual three. In newborns, severe narrowing can lead to critical aortic stenosis, where blood flow to the body becomes dangerously low. This is a medical emergency that requires urgent treatment. In older children and teens, aortic stenosis or bicuspid aortic valve may cause few or no symptoms, but there is still a risk of sudden death if the valve narrowing is moderate to severe, even if the person feels completely fine.

2. Genetic Factors

Aortic stenosis, particularly when caused by BAV, often runs in families. Studies show that up to 89% of BAV cases are inherited, although no single gene explains it entirely. Instead, many genes likely play a role, often in combination. Some of the key genes linked to valve development include:

NOTCH1 – Mutations in this gene are associated with BAV and aortic aneurysms.
GATA4, GATA5, and GATA6 – These genes help guide early valve formation, and their mutations can cause valve malformations and calcification.
Nkx2.5 – Works with GATA genes to support heart development and may contribute to valve disease when altered.

These genes affect how the valve forms in the womb. When disrupted, they can lead to long-term problems such as BAV, valve narrowing, and associated conditions like aortic dilation.

3. Age-Related and Degenerative Causes

In people over 75, aortic stenosis is usually by age-related wear and tear. It affects over 25% of those over age 65 and becomes more severe with age. The most common cause in older adults in developed countries is calcification from aging, not rheumatic disease. Several health and lifestyle factors increase the risk of age-related AS:

High LDL (bad) cholesterol: LDL stands for low-density lipoprotein. It carries cholesterol through your blood, but too much of it can build up in your arteries and heart valves. This buildup contributes to hardening and narrowing, including in the aortic valve.
Smoking: Smoking damages blood vessels and increases inflammation in the body. It speeds up the aging and calcification of the aortic valve, while also raising the risk of heart disease in general.
High blood pressure (hypertension): When your blood pressure is too high, your heart has to work harder to pump blood. Over time, this extra pressure can wear out the aortic valve and promote stiffness or thickening of the valve tissue.
Diabetes or high blood sugar: Uncontrolled blood sugar levels can damage blood vessels and lead to inflammation. This can affect how the valve tissue repairs itself and may encourage calcium buildup on the valve.
Metabolic syndrome: This is a group of conditions that often happen together, including high blood pressure, high blood sugar, excess belly fat, and abnormal cholesterol levels. Having metabolic syndrome raises your risk of heart disease and accelerates the calcification of the aortic valve.

How Is Aortic Stenosis Diagnosed?

Diagnosing aortic stenosis (AS) begins with a careful medical evaluation. Because symptoms can take years to appear—or may be mistaken for other conditions—doctors use a combination of physical exams and heart tests to confirm the diagnosis and understand how severe the narrowing is.

Here are the most common steps involved:

Physical examination: A doctor listens to your heart using a stethoscope. A heart murmur, which sounds like a whooshing or swishing noise, can be a sign of turbulent blood flow through a narrowed valve.
Echocardiogram (echo): This is the most important test for diagnosing AS. It uses sound waves (ultrasound) to create images of the heart. It shows how well the valve is opening and how blood is moving through the heart.
Electrocardiogram (ECG or EKG): This test measures the electrical signals in your heart. It can help detect signs of heart strain or thickening of the heart muscle caused by AS.
Chest X-ray: A chest X-ray gives a picture of the heart and lungs. It can show if the heart is enlarged or if there’s fluid in the lungs, both of which may be related to AS.
Cardiac catheterization: In some cases, especially before surgery, doctors may perform this test to get a detailed look at the heart and measure pressure inside the chambers. A thin tube (catheter) is inserted into a blood vessel and guided to the heart.
Exercise or stress testing: This test checks how the heart performs under physical stress. It’s often used when symptoms are unclear or to assess how well the heart tolerates activity.

These tests help doctors determine the severity of aortic stenosis and decide on the best treatment plan, whether it’s regular monitoring, medication for related conditions, or valve replacement.