07 Jun You can have a heart attack and never know about it
It’s a shocking reality for millions of people across the country: They go for a routine physical exam only to find out they’ve had a heart attack that happened days, weeks or months earlier.
About half of all heart attacks are silent, meaning the symptoms are so subtle, the person didn’t even know they had one, according to a study in the journal Circulation. Yet a silent heart attack is identical to a normal heart attack in all other respects. “As a critical care cardiologist, to me silent heart attacks are actually scarier, because when people have symptoms, they know to seek care right away,” says Dr. Evelina Grayver, director of the coronary care unit at North Shore University Hospital in Manhasset, New York.
The danger of the silent heart attack is that it’s discovered after the fact, often by a routine echocardiogram, or EKG, so it’s too late for doctors to repair damage to the heart. And, according to the study in Circulation, having one tripled the chances of dying from heart disease later in life. It also increased the risk of premature death from any cause.
Doctors say just figuring out that you’ve had a silent heart attack is a positive move, because you can discuss with your cardiologist how to manage your risk factors going forward.
A heart attack happens when an artery to the heart is blocked, often by a clot, so blood and oxygen can’t pass through to supply the heart. Sometimes this causes pain and pressure in the chest, producing a typical heart attack with classic symptoms. But sometimes, symptoms are more unexpected, such as pain in the jaw, arms, neck, teeth or abdomen. Another common symptom, particularly in women, is extreme fatigue.
Many people don’t know to look for these lesser-known symptoms, and they may attribute them to a passing annoyance or something to mention next time they visit a doctor. “They might have symptoms like fatigue or mild shortness of breath, which they can attribute to something and everything else other than a heart attack,” Grayver says. Plus, people with diabetes may not feel any symptoms at all if they have nerve damage and aren’t sensitive to pain.
Silent heart attacks are typically discovered by a primary care physician who performs a routine EKG in an exam room to test the heart’s electrical activity. The doctor will get a reading of a “Q wave” from the EKG, meaning an absence of electrical impulse in a part of the heart. That indicates part of the heart muscle has been damaged from lack of blood and oxygen and formed scar tissue. “Once there is a scar, you have missed the boat,” says Dr. Maliakal Joseph Anto, chief of cardiology at Syosset Hospital in New York and assistant professor of medicine at Hofstra University. “Patients have to get to the emergency room for help within about the first hour. If you wait too long, the damage is done.”
If a heart attack is detected and a patient makes it to a hospital quickly, a surgeon will open up the blocked vessel and restore blood flow before damage becomes permanent.
Once they’re told they’ve had a silent heart attack, patients are generally shocked and upset, Anto says. But if they think back, they sometimes can pinpoint when it happened. “When you look back in retrospect, a patient will have felt an extreme sense of fatigue or remember profuse sweating,” Anto says. “It may have occurred, and the patient may not have paid attention to it.”
The key is thinking about risk factors and how to manage them in order to avoid having a second heart attack, since those who have had one heart attack are at increased risk for another. Risk factors patients ought to be aware of include smoking, being overweight and having high cholesterol, high blood pressure or family history of heart disease. “The most important thing an individual can do is to know yourself and understand risk factors,” says Dr. Ali Rahimi, a cardiologist with Kaiser Permanente Atlanta. “Never let a symptom get old. If something is different, let your doctor know. If you used to be able to go up and down stairs easily and now you can’t, let your doctor know. If you have new shortness of breath or chest pain with exertion, you should let your doctor know.”
Doctors can perform further tests to look at the rest of the heart, such as a stress test, angiogram, CT scan or cardiac catheterization to examine the structure and function of the heart and make a plan going forward.
Some people who’ve suffered a silent attack may find they have a condition called “silent ischemia,” which means shortage of blood and oxygen to the heart from gradual accumulation of plaque in the arteries. Doctors can, when appropriate, open up arteries or prescribe medicine to help control that, as well as other conditions that could lead to another heart attack.
Silent heart attacks are dangerous, but knowing what they are and how to find out if you’ve had one are the first steps. “We teach people that taking care of the heart is a two-way street between the doctor and patient,” Grayver says. “The patient needs to understand the importance of a low-cholesterol diet, exercise and weight management.”