There are four types of cardiomyopathy. Each type can be caused by genetic factors, environmental influences, or a combination of both genetics and environment.
Dilated cardiomyopathy (DCM) is characterized by an enlargement of the left ventricle chamber of the heart. DCM can be related to coronary artery disease (ischemic) or may arise purely from a defect in the cardiac muscle itself (non-ischemic). DCM usually begins as an enlarged heart and may progress into diminished functionality of the heart, and as the disease progresses, can lead to congestive heart failure.
Among patients diagnosed with DCM, over half of those with non-ischemic cardiomyopathy can be attributed to a genetic cause. More than 30 different genes have been associated with DCM, and genetic testing is available for a number of these genes.
In the cases of inherited DCM, there may be a family history of DCM (“enlarged heart”) or congestive heart failure. DCM can also be associated with life-threatening irregular heart rhythms (arrhythmias), which can be treated and prevented. Because of the risk of irregular heart rhythms, it is important to identify family members at risk. A family history of sudden death may be an indicator that some family members have DCM.
Hypertrophic cardiomyopathy (HCM) is characterized by a thickening of the heart walls, which interferes with the heart’s ability to pump. This condition can lead to congestive heart failure. Many people with HCM also have irregular heart rhythms (arrhythmia).
Thickening can occur in several places: The wall of the heart’s left ventricle, the wall of the right ventricle or the septum (the wall between the left and right ventricles). In some cases, thickening occurs in more than one location.
HCM can cause irregular heart rhythms — a problem that can be life-threatening — but can be prevented with device or medical management. So, it is important to identify the problem and take steps to help prevent it. A family history of sudden cardiac death or fainting may suggest the presence of HCM and the need for diagnostic testing.
Nearly 70 percent of HCM cases are due to genetic causes. Our Cardiovascular Genetics Clinic offers genetic testing for many of the genes that cause hypertrophic cardiomyopathy.
Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy
Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by an enlargement of primarily the right ventricle of the heart with a change in the consistency of the heart tissue. ARVD/C can also affect the left ventricle with a similar change in the cells that occupy the heart (called “fibrofatty infiltration”). ARVD/C can also be associated with life-threatening irregular heart rhythms such as ventricular tachycardia. Cardiologists at UChicago Medicine can treat these irregular heart rhythms with medication or other interventions.
Restrictive cardiomyopathy is characterized by normal left ventricular size but diastolic dysfunction. Restrictive cardiomyopathy that is infiltrative (amyloidosis, hemochromatosis, glycogen storage disease) can have a genetic component, for which genetic testing is available.