Signs of a silent heart attack are mild or unusual symptoms that people often ignore: indigestion-like discomfort, unexplained fatigue, mild shortness of breath, a cold sweat, nausea or discomfort in the jaw, back or arm. Many silent heart attacks are discovered later on an EKG or echocardiogram. They still damage the heart and raise the risk of another heart attack.
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Board-certified cardiologist · Katy & Sugar Land, TX
Fellowship-trained in cardiovascular disease, interventional cardiology, echocardiography and advanced heart failure and transplant cardiology. Former Assistant Professor of Cardiology at McGovern Medical School.
What is a silent heart attack?
A silent heart attack, sometimes called a silent myocardial infarction, is a heart attack with symptoms so mild, brief or unusual that the person does not realize what happened. Blood flow to part of the heart muscle is still blocked, and heart muscle is still damaged. The difference is that the warning signs are missed.
Silent heart attacks are not rare. Research suggests they may account for a substantial share of all heart attacks, and they are more common in people with diabetes, older adults and women.
Signs of a silent heart attack
Looking back, many people recall symptoms they brushed off:
- Chest discomfort that felt like indigestion or heartburn, or mild pressure that faded.
- Unusual fatigue or feeling run down for no clear reason.
- Mild shortness of breath, especially with activity.
- Discomfort in the upper back, jaw, neck or arm that seemed like a pulled muscle.
- A cold sweat, nausea or lightheadedness that passed.
- Flu-like symptoms or a sense of being unwell.
- Trouble sleeping or unexplained anxiety.
The NHLBI notes that heart attack symptoms vary widely and some people have few or none.
- Chest discomfort, pressure or “indigestion” lasting more than a few minutes or returning
- Shortness of breath, cold sweat, nausea or lightheadedness with or without chest pain
- Pain in the jaw, neck, back, arms or upper stomach with any of the above
Who is at risk for a silent heart attack?
- People with diabetes, because nerve damage can reduce the ability to feel heart pain. Learn about diabetes and heart disease.
- Older adults.
- Women, who more often have less typical symptoms. See heart attack symptoms in women.
- People with high blood pressure, high cholesterol, kidney disease, obesity or a smoking history.
- People with a family history of early heart disease.
How a silent heart attack is found
Most silent heart attacks are discovered weeks, months or even years later, when a test shows evidence of past heart muscle damage:
- An EKG may show “Q waves” or other patterns of an old heart attack. If you were told your EKG was abnormal, follow up with a cardiologist.
- An echocardiogram can show a region of heart muscle that does not move normally.
- Nuclear stress imaging or cardiac MRI can show scarred heart muscle.
- Blood tests can detect a recent heart attack, but troponin levels return to normal within days.
Why a silent heart attack matters
A silent heart attack is not a harmless heart attack. It signals that coronary artery disease is present, and untreated it raises the risk of another heart attack, heart failure and dangerous heart rhythms. Because the person did not get treatment at the time, they also miss the medicines and lifestyle changes that protect the heart afterward.
What to do if you think you had one
If you are told you may have had a silent heart attack, or you recall symptoms that worry you, see a cardiologist. Evaluation typically includes an echocardiogram to check pumping strength, testing for ongoing reduced blood flow such as a stress test, and a review of risk factors. Treatment often includes medicines to protect the heart and arteries, such as aspirin when appropriate, statins and blood pressure medicines, plus blood sugar control, quitting smoking, regular activity and cardiac rehabilitation. Some patients need cardiac catheterization and stenting.
Preventing a heart attack, silent or not
Know your numbers for blood pressure, cholesterol and blood sugar; do not smoke; stay active most days; eat a heart-healthy diet; and keep regular checkups. A coronary calcium scan can help some adults with intermediate risk understand how much plaque they have. Talk with a preventive cardiology specialist about your personal plan.
Heart evaluation in Katy and Sugar Land
If an EKG showed signs of a possible old heart attack, or you have been ignoring symptoms that now worry you, Advanced Cardiology can help. Dr. Khalid evaluates patients at our Katy and Sugar Land offices with EKG and echocardiogram testing in the office and stress testing arranged as needed.
Katy office: 410 W Grand Pkwy S, Suite 4D, Katy, TX 77494
Sugar Land office: 7102 Tarrington Ave, Suite 505, Sugar Land, TX 77479
Phone: (713) 258-6111
We also see patients from Fulshear, Richmond, Rosenberg, Stafford, Missouri City and west Houston.
Told your EKG shows an old heart attack?
Get a full cardiology evaluation and a plan to protect your heart. Request a visit in Katy or Sugar Land.
Having symptoms right now? Call 911. Do not wait for an appointment.
Frequently asked questions
What are the signs of a silent heart attack?
Mild chest discomfort that feels like indigestion, unusual fatigue, mild shortness of breath, cold sweat, nausea, and discomfort in the jaw, back or arm. Symptoms are often brief and dismissed.
How do you know if you had a silent heart attack?
Usually through a later test, such as an EKG, echocardiogram, nuclear stress test or cardiac MRI, that shows signs of past heart muscle damage.
Who is most likely to have a silent heart attack?
People with diabetes, older adults, women, and people with high blood pressure, high cholesterol, kidney disease or a smoking history.
Is a silent heart attack dangerous?
Yes. It damages heart muscle and signals coronary artery disease. It raises the risk of another heart attack, heart failure and rhythm problems, especially if untreated.
Can an EKG detect a silent heart attack?
Often, yes. An EKG may show patterns of an old heart attack, but not always. An echocardiogram or stress imaging can provide more information.
What should I do if I think I had a silent heart attack?
See a cardiologist for evaluation. If you have symptoms now, such as chest discomfort or breathlessness, call 911.
Trusted health resources
- Heart Attack: Symptoms, National Heart, Lung, and Blood Institute (NIH)
- Heart Attack: Diagnosis, National Heart, Lung, and Blood Institute (NIH)
- Heart Attack, MedlinePlus, U.S. National Library of Medicine
- Coronary Artery Disease, MedlinePlus, U.S. National Library of Medicine
Medical disclaimer: This article is for general education and is not a diagnosis or a substitute for care from your own doctor. If you think you may be having a heart attack, stroke or another emergency, call 911 right away.
