Hypertrophic cardiomyopathy (HCM) is a complex type of heart disease marked by thickening and stiffness of the heart muscle and heart valve changes. The normal heart muscle stretches easily when blood is filling the heart chambers. When the muscle thickens, it cannot stretch well and it can affect blood flow through the heart chambers.
Hypertrophy causes the wall that separates the left and right side of the heart (the septum) to thicken and obstruct blood flow leaving the main heart pumping chamber (left ventricle) to the aorta. This reduces the amount of blood reaching the body and can cause a “back-up” or congestion of blood in the circulatory system.
Hypertrophic cardiomyopathy may also affect the heart’s electrical system. Changes in the heart cells may impact the electrical signals that travel through your heart and cause an arrhythmia (abnormal heart rhythm).
HCM affects an estimated 600,000 to 1.5 million Americans, or one in 500 people. HCM is the most common cause of sudden cardiac death in people under age 30, especially in young professional athletes.
HCM is usually inherited or may be acquired as a result of high blood pressure or aging. There is a 50 percent chance that the children and siblings of those with hypertrophic cardiomyopathy will inherit the genetic mutation for the disorder. Those diagnosed with HCM may have genetic testing done and if an gene abnormality is found, family members can be tested. Close relatives are also urged to talk to their healthcare providers about getting screened for the disease with an echocardiogram.