Aortic stenosis (AS) can be a tricky condition. A lot of times, you won’t see or feel any symptoms. And as AS gets worse, symptoms can develop so slowly they’re hard to notice. 

“Symptoms can be subtle,” says Vuyisile Nkomo, MD. He is an American Heart Association expert and a Mayo Clinic cardiologist with a focus in echocardiography and heart valve disease. “Valve diseases are called silent killers because they aren’t really painful. They take a long time to develop. And as they go from trivial to mild to moderate to severe, they can really be stealthy.”

Here’s what happens with AS. One of the heart’s valves gets narrower. As it shrinks, it becomes harder for blood to pass through it and reach the rest of the body. That means your body doesn’t always get enough oxygen and nutrients.

Watch for these problems

As AS gets worse, you might notice these symptoms, according to the American Heart Association:

  1. Chest pain
  2. Rapid, fluttering heartbeat
  3. Trouble breathing or feeling short of breath
  4. Feeling dizzy or light-headed, or fainting
  5. Trouble walking short distances
  6. Swollen ankles or feet
  7. Problems sleeping or needing to sleep sitting up
  8. Lower activity level or a reduced ability to do normal activities

Some of these symptoms, like chest pain or trouble breathing, would likely grab your attention. But others are easier to ignore, especially if they develop slowly.

Pay attention to your energy level

Less energy could point to AS. “People not infrequently complain about fatigue. They can’t seem to keep up with their friends,” Nkomo says. “Any change in how much a person can do could potentially point to a valve problem.”

Of course, a lot of other factors could make you feel like you have less energy. You could be deconditioned and out of shape. You may be gaining weight. You might not feel like exercising because you have arthritis.

“All kinds of things can slow a person down, especially as they get older,” Nkomo says. “But if you’re slowing down, you should look to see whether aortic stenosis is the cause of that slowing down. If it is, correcting the aortic stenosis will make you feel better and live longer.”

Don’t dismiss a rapid or fluttering heartbeat

A rapid heartbeat can be another problematic AS symptom. It can be a sign of another heart condition called atrial fibrillation (AFib). AFib occurs when your heart beats irregularly. It can lead to heart complications. 

AFib can be present in 30 to 40% of people with AS. And more than 20% of older Americans have aortic stenosis. “It’s a very common combination,” Nkomo says. “When we run into this issue, we need to figure out where symptoms are coming from and how severe aortic stenosis is.”

Some people get AFib because of aortic stenosis. And some people have AFib first, then develop aortic stenosis later. “Both atrial fibrillation and aortic stenosis are common as we get older,” Nkomo says. “The tricky part is the symptoms of atrial fibrillation can be the same as the symptoms of aortic stenosis—shortness of breath, fatigue, and palpitations.” 

If you have both, it can be difficult to tell how severe your aortic stenosis is. AFib can make the severity of aortic stenosis appear milder on an echocardiogram, which is the standard screening test for AS. 

If you have AFib, your doctor might recommend a CT scan of your aortic valve. A CT scan can be important if your shortness of breath is getting worse, you’re slowing down, or you’re noticing other changes in your symptoms. With it, your doctor can get a clearer picture of what’s causing your symptoms.