Many conditions cause an enlarged heart including damage from cardiovascular disease, inborn heart defects and genetic disorders, problems with the heart valves, high blood pressure, infections and inflammatory diseases, toxins and primary diseases of the heart muscle (cardiomyopathies). In most cases of an enlarged heart (also known as cardiomegaly), the heart wall is thinned and balloons outward. Less often, the heart wall becomes abnormally thick leading to an overall enlargement of the heart. Cardiomegaly may cause symptoms, which sometimes give clues to the underlying condition.
Shortness of Breath
Shortness of breath can be a symptom of cardiomegaly. It characteristically occurs during activity or while lying down and usually indicates some degree of heart failure. With worsening heart failure, this symptom is triggered by decreasing levels of activity. In severe heart failure, shortness of breath becomes continuous.
Dizziness, Lightheadedness and Fainting
The brain is exquisitely sensitive to reductions in blood flow and insufficient oxygen delivery. With an enlarged heart and mild to moderate heart failure, blood flow to the brain reduces when the demands on the heart increase with physical activity. Dizziness, lightheadedness or fainting can occur as a result. With worsening heart failure, these symptoms may result from marginal exertion or getting up to a standing position.
Fatigue and Weakness
Fatigue, weakness and a reduced capacity for activity occur with heart enlargement leads to heart failure. The poorly performing heart becomes unable to keep up with the body's needs when active; causing persistent tiredness and weakness.
Chest Pain
Chest pain--also known as angina--may occur with an enlarged heart. Angina is provoked when the heart does not receive sufficient oxygen, usually because of inadequate blood flow. Angina pain can include chest pressure, tightness, aching or gnawing. It may spread to the arm, shoulder or neck. New onset chest pain is an urgent medical situation as it may signal a heart attack.
Heart Palpitations
Heart palpitations describe a symptom wherein you suddenly become aware of your heartbeat, which may feel as if it is beating too hard, too fast or irregularly. This symptom may occur because heart arrhythmias (an abnormal heart rhythm) and cardiomegaly frequently travel together. Heart enlargement may cause an arrhythmia by interfering with the electrical conducting system, which carries the signals that coordinate the heartbeat. Conversely, some arrhythmias may cause heart enlargement.
Tissue Swelling
An enlarged, weakened heart has lost some of its pumping capacity. Thus, the blood moves through the body sluggishly, and fluid leaks out of the blood vessels into the tissues. This manifests as swelling in the feet, ankles and lower legs in someone who is upright. The pull of gravity contributes to where the fluid pools. The hands may also show swelling.
References
- "Robbins Pathologic Basis of Disease, 5th Edition"; Ramzi S. Cotran, M.D., et al, Editors; 1994
- "Harrison's Principles of Internal Medicine, 16th Edition"; Dennis L. Kasper, M.D., et al, Editors; 2004
- National Heart Lung and Blood Institute: What is Cardiomyopathy?
- Mayo Clinic: Enlarged Heart, Symptoms
- National Heart Lung and Blood Institute: Angina
