The Medical Minute: The causes and symptoms of a silent heart attack

It's possible to have a heart attack and not even know it.

Maybe it's because you're stoic when it comes to pain and fatigue. Or maybe you write off your symptoms as heartburn or indigestion. It's even possible that your own body is kicking up its reserves to mask symptoms of what is happening inside.

No matter the reason, it's important to know about the causes of unrecognized, or silent, heart attacks and how to prevent them.

Dr. Charles Chambers, a cardiologist at Penn State Hershey Heart and Vascular Institute, says the big five risk factors for acute heart attacks also apply when it comes to the silent variety: high cholesterol, high blood pressure, diabetes, smoking and genetics.

While typical heart attack symptoms include chest pain that radiates up the neck and down the arm, sweatiness, shortness of breath and nausea, the silent variety flaunt their presence less, especially among women and diabetics.

“Women often experience chest pain differently, such as fatigue or tiredness, and not the typical pressure in the center of their chest,” Chambers says. “Diabetics may have damaged nerve fibers and therefore may have less ability to sense pain.”

In acute heart attacks, blood clots form quickly and cause an artery to close. In silent ones, the collateral coronary arteries may have time to grow and form connections that mute typical heart attack symptoms and can protect the heart muscle from more serious damage.

Often, those who experience silent heart attacks don't even realize something significant happened. They simply feel unwell or strangely fatigued and don't know why. Or, they may have no symptoms at all. It isn't until medical professionals do an electrocardiogram (EKG) and note damaged tissue on the heart muscle that the diagnosis can be made.

Damaged heart tissue evolves into scar tissue, but Chambers says it is possible to have normal heart function after a small heart attack, depending on how much of the heart is damaged.

“We are all born with more heart muscle than we need to do the activities of daily living,” he says. “The importance of diagnosing a silent one is that once you have had one, it increases your risk of having another heart attack.”

Being aware of your personal risk factors, addressing them and receiving regular medical care are the best ways to prevent heart attacks, silent or otherwise.

Chambers adds – if in doubt, check it out.

“The same nerve fibers that supply the heart also supply the chest wall muscle, the lungs and food pipe,” Chambers says. “All those organs can give you pain, so sometimes it's hard to differentiate between that and a heart attack.”

The Medical Minute is a weekly health news feature produced by Penn State Milton S. Hershey Medical Center. Articles feature the expertise of Penn State Hershey faculty physicians and staff, and are designed to offer timely, relevant health information of interest to a broad audience.

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