What is an enlarged heart?

An enlarged heart (cardiomegaly) is an increase in the size of the heart. It is not strictly a disease, it is a sign that another health condition is affecting your heart. Some conditions – such as pregnancy – increase demand on the heart. Other conditions can thicken the heart wall muscle or stretch out the heart chambers (dilate) which makes the heart larger.


The heart can enlarge in two ways:

  1. Dilatation: The heart walls become thin, stretch out (dilate) and weaken. This enlarges the heart. Dilated cardiomyopathy can lead to heart failure, where the heart loses its ability to pump properly.
  2. Hypertrophy: The heart walls thicken causing the heart to become less efficient. This can happen in athletes and pregnant women, whose hearts undergo a high workload for long periods of time. Left ventricular hypertrophy (LVH) is the thickening of the muscle of the left lower heart chamber (ventricle) – the main pumping chamber of the heart. It can be caused by high blood pressure or aortic stenosis. 

The health conditions that can cause your heart to enlarge are:


People with cardiomegaly may not have any symptoms until their condition becomes more severe. The symptoms you may experience include:

  • shortness of breath
  • chest pain
  • heart palpitations (rapid, fluttering, or pounding heartbeat)
  • arrhythmia (irregular heartbeat)
  • dizziness
  • fainting
  • rapid exhaustion with physical activity
  • swelling

Your doctor will diagnose cardiomegaly by doing a physical exam and assessing your:

  • signs and symptoms
  • medical history
  • family history
  • test results

Some of the tests used to diagnose an enlarged heart are:


The treatment for cardiomegaly depends on the underlying medical condition that is causing the problem and how much your heart is enlarged. The goal of treatment is to control your symptoms and prevent further complications. Your treatment may include medications, surgery and lifestyle changes. You and your doctor will discuss the treatment options and decide what is best for you and your circumstances. 


Surgery and other procedures

You can lower your risk of developing other heart diseases and stroke by knowing and controlling your blood pressure, diabetes and blood cholesterol. It’s also important to lead a healthy lifestyle.

Talk to your doctor about the lifestyle changes that will benefit you the most.

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