In this Q&A, Amy Sarma, MD, a cardiology fellow at Massachusetts General Hospital's Corrigan Minehan Heart Center, shares insights into the causes and symptoms of a silent heart attack, how they differ for men and women, and what you can do to help prevent it from happening.

Q. What is a silent heart attack?

A. The term “silent heart attack” describes the situation in which evidence of a prior heart attack is picked up during medical testing in a patient who did not realize that they have had a heart attack. Many people do not experience the typical chest discomfort that most people think of when they imagine what is like to have a heart attack, and this is how these heart attacks can be missed. For example, we know that patients with diabetes are at higher risk for heart disease, but they are also more likely to experience atypical chest pain or no chest pain at all when having a heart attack.

We also know that there are different mechanisms by which patients can have heart attacks. While the end result is inadequate blood flow to a portion of the heart resulting in damage, there are many different ways that this can happen.

Silent heart attacks have real consequences, and we are learning to take them just as seriously as heart attacks that manifest with traditional symptoms.

Q. What are the symptoms?

A. Patients don’t experience symptoms during a silent heart attack. However, patients might feel the after-effects of the damage from a heart attack, particularly symptoms of heart failure that can include:

  • New difficulty breathing
  • Fluid accumulation (i.e. swelling), particularly in the legs
  • Fatigue
Q. Are the symptoms different for men than women?

A. We are still learning about the differences between men and women with respect to heart attacks, but while all patients can experience atypical symptoms, women—particularly young women—may be less likely to experience traditional symptoms and therefore may not recognize that they are having a heart attack. It is important for both patients and doctors to consider the possibility of a heart attack in patients, especially those who have risk factors for heart disease.

Q. What can cause a silent heart attack? Are the causes different for men than women?

A. The causes of silent heart attacks are the same as those that cause heart attacks with symptoms. The most common cause of a heart attack is a blockage in a blood vessel that compromises blood supply to the portion of the heart that depends on that blood vessel. However, there are many different ways that blood flow to the heart can be compromised and women may be at higher risk for some of the less common mechanisms, which include:

  • Spontaneous coronary artery dissection, or SCAD (when a spontaneous tear forms in the wall of a blood vessel compromising blood flow)
  • Coronary vasospasm (a temporary, sudden spasm of a coronary artery that can impair blood flow)
  • Microvascular disease (disease of small blood vessels supplying the heart)

Because less is known about less common mechanisms, these causes are harder to identify and treat. There is still so much to learn about how to improve cardiovascular care in women, and this is a focus of Mass General's Corrigan Women’s Heart Health Program.

Q. What should someone do during a silent heart attack?

A. By definition, silent heart attacks are those that patients do not know they are experiencing. However, because we know that many patients do not experience the traditional symptoms of a heart attack, people should keep an open mind and seek medical care if they are experiencing new symptoms. Regardless of whether or not symptoms are from a heart attack, it is always important to bring them to medical attention so that doctors can determine the cause and provide appropriate treatment. Anyone who thinks that they may be experiencing a heart attack should call 911 and seek immediate care.

Q. Are there any ways to prevent a silent heart attack?

A. Yes, ways to reduce your risk of having any type of heart attack include:

  • Eating a healthy diet
  • Maintaining an active lifestyle
  • Maintaining a healthy weight
  • Not smoking
  • Following up with doctors regularly

Doctors can help people identify whether someone may be at higher risk for developing heart disease and can help treat some of these risk factors—like high blood pressure, high cholesterol and diabetes. Women with a history of pre-eclampsia may also be at increased risk for heart disease.

It is very important that patients who already have heart disease or have had a heart attack see a cardiologist (a doctor who specializes in diseases of the heart) regularly to care for their hearts. Patients who have had a heart attack are at particularly high risk for another heart attack, and a cardiologist can help patients reduce this risk.