You are reading the radiologist’s report on your chest x-ray when you notice the word “cardiomegaly.” You look it up and learn that it means “enlarged heart.” You immediately call your doctor to ask if something is seriously wrong with your heart.
The answer is…not necessarily.
“An enlarged heart is not a disease in itself,” says Cleveland Clinic heart failure cardiologist Arianne Agdamag, MD. “It could be due to normal adaptive changes or your body’s reaction to an underlying disease process.”
What Is an Enlarged Heart?
You can’t feel an enlarged heart. It is usually an incidental finding on an x-ray or computed tomography (CT) scan of the chest that was ordered for an unrelated problem—for example, a lung issue.
“I tell patients ‘cardiomegaly’ means the chambers of their heart are enlarged, its walls are thickened, or they have a combination of both,” Dr. Agdamag says.
Enlarged Heart Symptoms
An enlarged heart discovered incidentally will be asymptomatic. Conversely, some people experience symptoms that can be caused by an enlarged heart. These symptoms may include:
- Shortness of breath
- Palpitations
- Dizziness
- Lightheadedness
- Fatigue
- Irregular heartbeat
What Causes an Enlarged Heart?
There are multiple reasons why a heart will enlarge. Regardless of whether you are experiencing symptoms, it’s important to identify the underlying cause, so it can be addressed.
Common causes of cardiomegaly include:
- Chronic hypertension
- End-stage kidney disease
- Coronary artery disease
- Narrowed (stenosed) or leaky (regurgitant) heart valves
- Abnormal heart rhythm
- Hyperthyroidism
- Cardiomyopathies such as hypertrophic obstructive cardiomyopathy
- Genetics
- Amyloidosis (a disease that deposits amyloid protein in the heart muscle)
- Hemochromatosis (a disease that deposits iron in the heart muscle)
- Congenital heart disease
- Certain lung diseases
Some of these conditions force the heart to pump harder to supply the body with oxygenated blood. Just like a bicep that grows with exercise, the heart muscle grows larger to compensate for the higher resistance or the higher volume it encounters.
Other conditions increase the amount of blood in the body or cause blood to back up in the heart. This process forces chambers of the heart to grow larger to accommodate the extra volume.
Amyloidosis, hemochromatosis, and other cardiomyopathies cause the walls of the heart to thicken and become stiff.
Not all causes of cardiomegaly are abnormal or dangerous. Some normal conditions can cause a heart to enlarge, including:
- Pregnancy, because a pregnant woman’s heart pumps blood for her fetus as well as for herself.
- Athletic training, because athletes’ hearts work hard on a regular basis.
How Is an Enlarged Heart Diagnosed?
Chest x-rays and CT scans may provide the first indication that a heart may be enlarged, but they are not precise enough for physicians to make a diagnosis with confidence.
“An initial diagnosis of cardiomegaly can be erroneous, so it needs to be confirmed. For this purpose, we use echocardiography, which is a reliable modality for verifying whether or not a heart is enlarged,” Dr. Agdamag says.
An echocardiogram also enables measurement of the left ventricular internal diameter in diastole (LVIDD). This test measures the size of the left ventricle (the heart’s main pumping chamber) between contractions, when it is filled with blood. The measurement can then be compared to normal ventricle size in men and women to determine whether the left ventricle has dilated (enlarged) or its walls have become thicker (hypertrophied).
After an echocardiogram has been performed, a cardiac magnetic resonance imaging (MRI) scan may be ordered. “An MRI will allow us to further characterize the tissue, provide precise measurements, and assess for causes of heart enlargement,” Dr. Agdamag says.
How Is an Enlarged Heart Treated?
Cardiomegaly is managed by treating the underlying cause with medications, interventional procedures, surgery, and lifestyle changes.
For example, you may need medications to lower your blood pressure, help your heart contract, reduce the risk of blood clots, eliminate excess fluid, prevent an abnormal heart rhythm, or raise your blood iron levels.
You may need to have a heart valve repaired or replaced or your heart revascularized with angioplasty and stenting or coronary artery bypass grafting (heart bypass surgery). A pacemaker may help your heart beat in a steady rhythm, or an implantable cardioverter-defibrillator may be necessary to restart your heart if it stops.
Can an Enlarged Heart Go Back to Normal?
Whether an enlarged heart can return to its normal size depends on the reason for enlargement and how far the underlying condition has progressed. After most pregnant women give birth, their hearts shrink back to normal. Athletes may find that their hearts shrink after they retire from their sport.
But for certain people with cardiomyopathies, their hearts may remain enlarged despite treatment. And, whether a heart affected by valve disease will shrink depends on how long cardiomegaly has been present. “If a leaky or stenosed heart valve is repaired or replaced before the heart is badly damaged, the heart may return to a normal size,” Dr. Agdamag says.
Possible Complications
An enlarged heart may or may not cause complications. When present, complications can include:
- Heart failure. “It’s the consequence of many untreated heart issues,” Dr. Agdamag says.
- Abnormal heart rhythms are a potential complication of hypertrophic obstructive cardiomyopathy.
- Blood clots. They are uncommon, but they can be associated with a low ejection fraction (the percentage of blood pumped out of the left ventricle with each heartbeat) or arrhythmia.
- It can occur from the common arrhythmia known as atrial fibrillation.
- Sudden cardiac death. It can result from a deadly arrhythmia, such as ventricular tachycardia.
How to Lower Your Risk of Enlarged Heart
You are at increased risk of heart enlargement if you have a family history of certain types of heart disease or you have high blood pressure.
Although you can’t change your family history, you can lower your personal risk of developing an enlarged heart by keeping your blood pressure and weight within normal parameters, eating a healthy diet, limiting alcohol intake, not smoking, and being physically active.
The Last Word
“Echocardiography is the initial test for evaluating cardiomegaly, so if it is seen on an x-ray or CT scan, make sure the diagnosis is confirmed with an echo,” Dr. Agdamag advises.
“Because appropriate treatment of cardiomegaly depends on the underlying cause, it is important to figure out the root cause,” she continues. “A cardiologist is the right physician for any form of heart enlargement, so you will need to see a cardiologist to have your diagnosis confirmed and receive early, appropriate treatment.”
