Enlargement of the heart. Cardiomegaly may take the form of hypertrophy (thickening) of the heart muscle or of dilatation (increase in volume) of 1 or more of the heart chambers. Hypertrophy occurs in conditions in which the heart has to work harder than normal to pump blood around the body. These include hypertension, pulmonary hypertension, and one type of cardiomyopathy. Dilatation of a heart chamber may be due to heart valve incompetence (failure of a valve to close properly after a contraction) such as occurs in aortic insufficiency.
Symptoms may not occur until the heart has enlarged to the point where it cannot cope with additional stress. Its reduced pumping efficiency leads to heart failure, with symptoms of breathlessness and ankle swelling. Cardiomegaly is diagnosed by physical examination, chest X-ray, and ECG. Treatment is directed at the underlying cause.
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