Enlarged Heart (Cardiomegaly)
An enlarged heart (cardiomegaly) can have various causes. But it's usually caused by high blood pressure (hypertension) or coronary artery disease.
An enlarged heart may not pump blood effectively, resulting in congestive heart failure. Cardiomegaly may improve over time. But most people with an enlarged heart need lifelong treatment with medications.
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Types of Enlarged Heart
The heart enlarges in response to damage to the heart muscle. Up to a point, enlargement permits the heart to continue to pump blood normally. As enlargement progresses, though, the heart's pumping ability declines.
Dilated cardiomyopathy is the main type of cardiomegaly. In dilated cardiomyopathy, the walls of both the left and right side of the heart (ventricles) become thin and stretched. The result is an enlarged heart.
In the other types of enlarged heart, the heart's muscular left ventricle becomes abnormally thick:
- Left ventricular enlargement (hypertrophy) is usually caused by high blood pressure.
- Hypertrophic cardiomyopathy is an inherited (genetic) condition.
Generally speaking, the heart's pumping ability is better preserved when the enlarged heart is "thick" rather than "thin."
Causes of an Enlarged Heart
The most common causes of an enlarged heart are blockages in the heart's blood supply (coronary artery disease) and high blood pressure. An enlarged heart can have many other causes, including:
- Viral infection of the heart
- Abnormal heart valve
- Pregnancy, with enlarged heart developing around the time of delivery (peripartum cardiomyopathy)
- Kidney disease requiring dialysis
- Alcohol or cocaine abuse
- HIV infection
- Genetic and inherited conditions
Frequently, no cause for an enlarged heart is identified. This is known as idiopathic dilated cardiomyopathy.
Symptoms of an Enlarged Heart
Most often, an enlarged heart causes no symptoms. If an enlarged heart becomes unable to pump blood effectively, symptoms of congestive heart failure can develop:
- Shortness of breath (especially with exertion or when lying flat)
- Leg swelling
- Increased abdominal girth
- Weight gain
- Fatigue
- Palpitations or skipped heartbeats
Symptoms vary widely in people with an enlarged heart. Some may never have symptoms. Others may have mild symptoms that remain unchanged for years. And some may experience steadily worsening shortness of breath.
Diagnosis of an Enlarged Heart
An enlarged heart may be discovered after a person discusses symptoms of congestive heart failure with a doctor. Other times, it is discovered in someone without symptoms who gets a test for other reasons.
Echocardiography (ultrasound of the heart) is the preferred test to diagnose an enlarged heart. There is no pain or risk from an echocardiogram. It can accurately measure the heart's:
- size
- muscle thickness
- pumping function
In some cases, echocardiography can suggest potential causes for an enlarged heart.
Doctors may use various other tests to help diagnose an enlarged heart, such as:
History. Shortness of breath or other symptoms of congestive heart failure may provide initial clues to the presence of an enlarged heart.
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