Cardiomyopathy is heart muscle disease. It damages the muscle tone of the heart and reduces its ability to pump blood to the rest of the body. Approximately 500,000 Americans have cardiomyopathy, many of whom are undiagnosed. Cardiomyopathy is a leading cause of heart failure and the most common reason for needing a heart transplant. Cardiomyopathy is dangerous because it often goes unrecognized and untreated. It frequently affects young people. There are four main types of cardiomyopathy: dilated or congestive cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, and ischemic cardiomyopathy.
Dilated (or congestive) cardiomyopathy is the most common form of cardiomyopathy. It weakens the walls of the chambers of the heart. In most cases, its cause is unknown (idiopathic).
Hypertrophic cardiomyopathy, although rare in general, is the second most common form of cardiomyopathy. It causes a thickening of the heart's walls. It is most often an inherited disease, although the cause is not always clear. It can affect people of all ages. The enlarged heart muscle obstructs the circulation of blood.
Restrictive cardiomyopathy is rare in the United States. It restricts the heart from stretching properly, reducing the amount of blood that can fill the heart's chambers.
Ischemic cardiomyopathy is the loss or weakening of heart muscle tissue caused by a reduction of oxygen-rich blood flow to the heart muscle. The ischemia usually results from coronary artery disease and heart attacks. Treatment for ischemic cardiomyopathy is similar to that for other forms of cardiomyopathy, with special attention given to treating the underlying coronary artery disease. Patients whose hearts have been seriously damaged by ischemic cardiomyopathy may need a heart transplant.
Although cardiomyopathy is one of the less frequent forms of heart disease, it is important to be aware of the role that heredity plays in the disease and to be familiar with its symptoms. Patients should check their family medical history to learn their risk.
The warning signs for cardiomyopathy include unexplained shortness of breath, bloating, fainting, and chest pain. Drinking too much alcohol, a poor diet, and exposure to toxins can all contribute to the progression of cardiomyopathy.
Cardiomyopathy is diagnosed and treated by a team of physicians in cardiovascular diseases, cardiac surgery, genetics, and specialists from other areas as needed. Tests used to diagnose cardiomyopathy include a complete history and physical examination, blood tests, chest x-rays, echocardiograms, Holter monitoring, exercise stress testing, and coronary catheterization or angiography.
Treatment options depend on the severity of symptoms and are intended to decrease stress on the heart and relieve symptoms. Options may include medication, surgery, or the implantation of a pacemaker or automatic defibrillator. Certain medications can help relax the heart and reduce the degree of obstruction, allowing the heart to pump more efficiently. Beta blockers and calcium channel blockers are common families of drugs that are prescribed. Antibiotics are used to prevent bacterial endocarditis. When medication no longer relieves symptoms, surgery may be indicated. The risk of open heart surgery depends on the patient's age and general health. Surgical treatments vary with the type of cardiomyopathy.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/Cardiomyopathy.cfm
American Heart Association www.americanheart.org/presenter.jhtml?identifier=4468
Mayo Clinic www.mayoclinic.org/hypertrophic-cardiomyopathy/index.html
Updated December 2009