Your heart can become enlarged because of a congenital problem or conditions like high blood pressure or a heart attack.
An enlarged heart is a layman’s term describing when the overall size of your heart is bigger than it should be. Medically, it’s referred to as cardiomegaly, and often it’s first spotted on a routine chest X-ray. Additional testing is then needed to figure out the cause.
An enlarged heart is usually a precursor to heart failure.
The heart swells in size due to one of two reasons, says Zubin Eapen, MD, associate professor of medicine at Duke University and director of the Duke Heart Failure Same-Day Access Clinic in Durham, North Carolina. “Either the chambers of the heart have become dilated, or enlarged, or else the heart walls have become abnormally thickened,” he says.
When the Heart Chamber Becomes Dilated
For those of us a little rusty on our anatomy: the heart has four chambers; the top two are the left and right atria, the bottom two are the left and right ventricles. “Usually, enlarged hearts involve the left ventricle, the heart’s main pumping chamber,” says Dr. Eapen.
Sometimes an enlarged heart develops because of a structural defect or other congenital condition. But usually it’s because the heart is weakened — from coronary artery disease, muscle damage from a previous heart attack, or one of the most common causes, hypertension, or high blood pressure.
“If your blood pressure is higher than it should be, it means your heart has to pump harder than normal to move blood throughout your body,” Eapen says. “So the actual walls or the muscle of the left ventricle become abnormally thick to compensate for the extra work.” In other words, you heart is just like any other muscle in the body that bulks up when it’s forced to do heavy lifting.
A thickened heart muscle, however, is just a stopgap measure. “If hypertension is not controlled, over time the heart muscle starts to get weaker, and that can result in symptoms like shortness of breath, swelling in the lower extremities and abnormal weight gain as a result of fluid retention,” Eapen says.
Essentially an enlarged heart is a red flag alerting you that if you don’t make some changes, you may be headed for heart failure.
With alcohol or drug abuse, which can also cause the heart to enlarge, “often there’s not that natural progression where the heart slowly thickens over time and then starts to get weaker. In some of those cases, we see dilation of the cavity of the heart without the heart muscle thickening first.” In those instances, patients may hear the term dilated cardiomyopathy, which means the heart muscle walls are much thinner than normal.
What Puts You at Risk for an Enlarged Heart?
Any of the following can also increase your risk for developing an enlarged heart:
- High blood pressure Pressure higher than 140/90 puts you at an increased risk of developing an enlarged heart.
- A family history of enlarged hearts or cardiomyopathy If a parent or sibling has had an enlarged heart, you may be more susceptible to developing the condition.
- Coronary artery disease and heart attack A buildup of plaque in the arteries can obstruct blood flow, and may lead to a heart attack. When part of the muscle dies, your heart has to pump harder to move blood through your body, which can cause it to enlarge.
- Congenital heart disease If you’re born with certain conditions that affect the structure of your heart, you may be at higher risk.
- Disease of the heart valves The heart has four valves — aortic, mitral, pulmonary and tricuspid — that open and close to direct blood flow through your heart. Conditions that damage the valves may cause the heart to enlarge.
Prevention Steps You Can Take Today
Eapen says the take-home message, first and foremost, is to control your risk factors for heart disease: make sure blood pressure is well controlled, lose excess weight, avoid excessive drug or alcohol use. He recommends checking out the American Heart Association’s Life Simple 7, seven steps you can take to improve your heart health.
According to Clyde Yancy, MD, chief of the division of cardiology-medicine at Northwestern University’s Feinberg School of Medicine in Chicago, and a past president of the American Heart Association, “One in five Americans will develop heart failure. If we can raise awareness, we can drive people to early detection and earlier treatment.”
Even vague symptoms like feeling tired all the time, or listlessness, warrant a doctor’s appointment, he says — especially if you know you have high blood pressure or have had a previous heart attack. According to the National Heart, Lung, and Blood Institute, your doctor can pick up some important clues just from listening to your heart and lungs with a stethoscope. After that, depending on your history and symptoms, your physician can decide whether subsequent tests, such as an electrocardiogram (ECG or EKG), echocardiogram, or other type of imaging is in order.