Cardiomyopathy can be the result of a viral infection in the heart or a congenital heart defect.
Cardiomyopathy changes and weakens the heart muscle. The weakened heart muscle may become thin and larger, weakening the heart and its ability to pump effectively. The heart eventually goes into a state of pump failure and cannot supply the body with enough blood flow. Cardiomyopathy affects both sexes and all ages. It is usually a long-term disease.
There are three types of cardiomyopathy:
Dilated cardiomyopathy: Dilated cardiomyopathy causes the cavity of the heart to enlarge, weakening the entire heart muscle and causing it to pump poorly. Researchers believe this condition may be related to a recent viral infection. Between 30-15 percent of people with dilated cardiomyopathy have a family history of the disease, which means it is likely genetic in these cases. Dilated cardiomyopathy is the most common form of the disease, and it affects males more than females. It can affect any age, but the average is 30 to 50 years old. It can be caused by chronic, excessive alcohol consumption, along with dietary deficiencies.
Hypertrophic cardiomyopathy: Hypertrophic cardiomyopathy occurs when the muscle mass of the left ventricle of the heart is larger than normal, or the wall between the two ventricles becomes enlarged and obstructs blood flow from the left ventricle. The heart is not able to relax properly between beats and fails to fill with blood. This type of cardiomyopathy can cause the heart muscle to increase in size, resulting in chest pain, difficulty breathing, fatigue and dizziness. Some people who have hypertrophic cardiomyopathy have cardiac arrhythmias, which can cause sudden death. This type of cardiomyopathy affects approximately one in 500 individuals and is usually inherited. It can affect people of all ages.
Restrictive cardiomyopathy: Restrictive cardiomyopathy occurs when the muscular wall of the heart becomes excessively rigid, impairing the filling of the ventricles with blood between heartbeats. The heart muscle can pump but cannot relax to fill with blood, causing high pressures in the heart and fluid buildup. This is the least common type of cardiomyopathy in the United States. It usually results from another disease. Restrictive cardiomyopathy can also be caused by genetic factors.
Viral infections that infect the heart or coronary artery disease are major causes of cardiomyopathy. The disease also can be the result of another disease or its treatment, such as complex congenital heart defects, nutritional deficiencies, uncontrollably fast heart rhythms, Duchenne muscular dystrophy and certain types of chemotherapy. When cardiomyopathy is a genetic condition, it is caused by abnormalities in genes or chromosomes at birth. The cause of cardiomyopathy also can be unknown.
Symptoms include fatigue, difficulty breathing, weight gain, swelling and chest pain. Cardiomyopathy can result in heart failure. In some cases, an individual may have no symptoms, but the disease will be detected on an abnormal echocardiogram or a cardiac MRI.
Tests to diagnose cardiomyopathy include:
Chest X-ray – A radiograph or picture of the heart and lungs including blood vessels, ribs and bones of the spine
Echocardiogram (also called echo) – This test uses sound waves to assess the function and structure of the heart muscle and valves
Electrocardiogram (EKG/ECG) – A test that records the electrical activity of the heart
Cardiac MRI (cardiac magnetic resonance imaging or CMR) – A noninvasive, sophisticated imaging procedure that uses large magnets and a computer to produce detailed images of the structure and function of the heart while it is beating
BNP testing (B-type natriuretic peptide) – This test detects a hormone released from the ventricles in response to increased wall tension that occurs with heart failure
Cardiac catheterization with biopsy – A procedure to obtain a sample of heart muscle tissue for biopsy to check for signs of infection and inflammation. The tissue sample is obtained via cardiac catheterization, in which a long, thin tube (catheter) is inserted in an artery or vein in the groin, arm or neck, and then threaded to the heart.
Treatment of cardiomyopathy is focused on managing symptoms, halting the progression of the disease and preventing complications. Treatment specifics depend on the type of cardiomyopathy.
- Medications – Vasodilators, anticoagulants and antiarrhythmic drugs may be prescribed
- Surgery and procedures – Heart transplantation may be necessary if the condition is serious and the patient is otherwise healthy
- Medications – Beta-blockers, calcium-channel blockers and antiarrhythmic medications may be prescribed
- Surgery and procedures – Alcohol ablation, a nonsurgical treatment
- Medications – Diuretics, blood pressure medication and drugs to control heart rhythm may be prescribed
Genetic testing is possible for some patients and families with cardiomyopathy. The Medical Genetics Program at The Ohio State University Wexner Medical Center provides genetic consultations to patients and their family members who may have or be at risk of a genetic condition. We will assist you and your family in deciding if testing is right for you. Usually genetic testing involves having a blood sample drawn and should begin with a family member who has the condition in question. Our Medical Genetics Program staff will discuss any concerns you may have about genetic testing, such as the cost and insurance coverage, as well as the possible benefits of genetic testing for you and your family.