Hypertrophic cardiomyopathy (HCM) is a genetic condition affecting the heart muscle. HCM causes the heart muscle wall to become abnormally thick or “hypertrophied” and most often affects the left ventricle. The left ventricle is the chamber of the heart responsible for pumping oxygen-rich blood to the body. HCM can make it difficult for the heart to pump enough blood, especially during exercise. It may also affect the heart’s electrical system and lead to development of abnormal heart rhythms (arrhythmias) that increase the risk for sudden cardiac death.
HCM is the most common type of inherited heart muscle disease and affects 1 in every 500 people.
Some people with HCM lead normal and healthy lives. For others, HCM can cause a wide range of symptoms from shortness of breath and exercise intolerance to more severe problems like chest pain and loss of consciousness. In the most severe cases, HCM may lead to heart failure and sudden death.
HCM is s an inherited disorder triggered by genetic variants that cause the heart muscle to grow abnormally thick.
HCM is suspected based on a person’s symptoms, family history, and results of diagnostic testing. The most commonly used test to diagnose HCM is the echocardiogram, a non-invasive test that uses sound waves to visualize the heart structure and function.
Genetic testing for HCM is performed to help confirm a suspected diagnosis.
Genetic testing may also help distinguish HCM from other diseases that cause thickening of the heart walls.
HCM can be treated through a combination of medication to control the heartbeat, lifestyle modifications, and in some cases, surgery may be recommended to improve blood flow out of the heart or insert an implantable cardiac defibrillator (ICD) to monitor and reestablish typical heartbeat.
Genetic testing for HCM may help accurately distinguish HCM from other diseases that cause thickening of the heart, which can have a vastly different clinical course and require different therapies.
Once the genetic cause of HCM is identified in an individual, genetic testing for other family members may be indicated to assess their risk for HCM and the need for possibly life-saving treatment. Family testing is important because relatives may be at risk regardless of whether or not they are experiencing any symptoms.
Your physician will assist you in identifying and arranging for the appropriate genetic test(s). If you have specific questions or concerns about the testing, your physician may refer you to a genetic counselor to discuss further. Once you are ready to proceed with genetic testing, you will need to submit either a blood or saliva sample.
Idiopathic hypertrophic subaortic stenosis (IHSS)
Muscular subaortic stenosis