May also be called: Enlarged Heart; Macrocardia; Megalocardia; Cardiac Enlargement

Cardiomegaly (kar-dee-oh-MEG-uh-lee) is the medical term for an enlarged heart.

More to Know

The heart is the key organ in the circulatory system. This strong muscle has to pump blood to all parts of the body thousands of times a day. To do this well, the heart has to be in good shape, just like any other muscle.

An enlarged heart can be a sign that it's weak and out of shape due to an underlying medical condition. Cardiomegaly may happen in people who have:

• high blood pressure
• had a previous heart attack
• diseases that affect the heart valves or heart muscle
• an abnormal heartbeat (arrhythmia)
• a congenital heart condition

Someone with an enlarged heart might have symptoms such as shortness of breath, chest pain, or swelling in the legs.

When a condition like high blood pressure causes the heart to work harder, the heart muscle grows thicker and larger. The heart also can enlarge when its walls are stretched and become thin. Over time, both of these weaken the heart.

If cardiomegaly is found, tests will be done to find and treat its cause. Not treating the condition causing cardiomegaly can lead to heart failure and other serious problems.

Keep in Mind

Sometimes, such as with athletes and pregnant women, cardiomegaly is normal and reversible, meaning that the heart can go back to its normal size. Other cases could be a sign of a serious heart condition that could quickly become life threatening. Successfully treating the condition causing the heart to enlarge will often treat the cardiomegaly as well.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.