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What Is an Enlarged Heart?

An enlarged heart (cardiomegaly) means that the heart is bigger than normal. Your heart can become enlarged if the muscle works so hard that it thickens, or if the chambers widen. However, an enlarged heart isn’t a disease. It’s a symptom of a heart defect or condition that makes the heart work harder, such as cardiomyopathy, heart valve problems, or high blood pressure. An enlarged heart can’t pump blood as efficiently as a heart that’s not enlarged. This can lead to complications like stroke and heart failure. Here is what you need to know.


The heart enlarges because of damage to the heart muscle. Up to a point, an enlarged heart can still pump blood normally. As the condition progresses the heart's pumping ability declines.

Dilated cardiomyopathy is the main type of enlarged heart. The walls of both sides become thin and stretched. This enlarges your heart.

In some other types, the muscular left ventricle becomes very thick. High blood pressure may cause your left ventricle to enlarge. The thickening can also be inherited.

An enlarged heart keeps more of its pumping ability when it's "thick" rather than "thin."

Signs and Symptoms

Enlarged heart symptoms may not be present or go unnoticed at first as the condition slowly progresses. That’s why regular checkups are important to detect an enlarged heart. Make sure to see your doctor if you have any symptoms that can include:

Causes of enlarged heart

Some of the many causes of enlarged heart include:

  • coronary artery disease – fatty deposits or plaques build up inside one or more of the coronary arteries. This constant ‘silting’ is called atherosclerosis and it results in narrowing of the artery. This reduces the oxygen supply, which is the fuel for the pump.
  • high blood pressure– blood pumps with more force than usual through the arteries, which puts strain on the heart.
  • idiopathic dilated cardiomyopathy – this is the disease of the heart muscle, the cause of which is unknown. Enlarged or ‘dilated’ heart is one of the most common types of cardiomyopathy. The most common symptom patients get with cardiomyopathy is shortness of breath and swelling of the ankles.
  • myocarditis – an infection of the heart that is generally caused by a virus. A person may have a viral illness first and later have symptoms of congestive heart failure.


Often, these focus on the underlying cause, such as:

  • Coronary artery disease: Opening the blockages in the blood vessels that supply oxygen to the heart can improve blood flow to the heart muscle. If your heart is enlarged because of a blockage, its pumping may improve.
  • Hypertension: Controlling high blood pressure can prevent further damage. It can also make your heart work better.
  • Heart valve disease: Surgery or a less invasive procedure can sometimes repair or replace a damaged heart valve that is causing cardiomegaly.

Make sure to tell your doctor if you have a family history of similar conditions that can cause an enlarged heart, such as cardiomyopathy. If cardiomyopathy or other heart conditions are diagnosed early, treatments may prevent the disease from worsening. Your outlook depends on the underlying cause of your enlarged heart. Following the treatment plan your doctor recommends can help keep your heart healthy and prevent any further complications.