(Cardiomyopathy, Hypertrophic—Adult; HCM—Adult; Idiopathic Hypertrophic Subaortic Stenosis—Adult; Asymmetric Septal Hypertrophy—Adult; ASH—Adult; HOCM—Adult; Hypertrophic Obstructive Cardiomyopathy—Adult)
Pronounced: hi-per-TRO-fik car-DEE-o-my-AH-pah-thee
by Diana Kohnle
Hypertrophic cardiomyopathy, or HCM, is a form of cardiomyopathy. This is a condition in which the heart muscle thickens due to genetic problems with the muscle’s structure. As the muscle thickens, it must work harder to pump blood, which strains the heart muscle. Sometimes, the thickened muscle gets in the way of the blood leaving the heart and causes a blockage. This blockage can cause the neighboring heart valve, called the mitral valve, to become leaky. HCM can cause uneven muscle growth which can cause the heart to pump in a disorganized way. Rarely, it can cause abnormal heart rhythms that can even be fatal.
There are three main types of cardiomyopathy:
HCM can occur in people of all ages. But, it is usually most severe when it occurs in younger people. The diagnosis is only made in people who do not have other causes of cardiomyopathy (eg, amyloidosis, sarcoidosis, coronary or valvular heart disease, etc.)
Those with HCM are at an increased risk of sudden death. However, many individuals with HCM live a normal, healthy life with very few symptoms.
Causes of HCM include:
In people over age 60, HCM is likely to be caused by or related to high blood pressure.
These factors increase your chance of developing this condition. Tell your doctor if you have any of these risk factors:
These symptoms can be caused by some of the side effects of the condition, including arrhythmias (abnormal heart beats). The blocked or reduced blood flow is usually the cause of symptoms like dizziness, fainting, and difficulty breathing.
Your doctor will ask about your symptoms and medical history, and perform a physical exam.
Tests may include the following:
Treatment focuses on controlling symptoms and preventing complications. Talk with your doctor about the best treatment plan for you. Treatment options include:
Medications may be used to help maintain proper and regular heart function. These may include beta-blockers and calcium channel blockers.
If you have an arrhythmia, you may need anti-arrhythmic drugs. You may also need blood-thinning medication.
The thickened portion of the heart muscle is cut and removed. This may be needed if you have a severely blocked blood flow from the heart.
If the mitral valve is leaking, surgery may also be done to repair or replace the mitral valve.
Alcohol Septal Ablation
Alcohol is injected into the arteries of the thickened portion of the heart. This helps to reduce the blockage in the heart and improve blood flow out of the heart.
Implantable Cardioverter Defibrillators (ICD)
This ICD is implanted if you are at heightened risk for sudden death.
To help reduce your chances of getting HCM, take the following steps:
American Heart Association
Canadian Cardiovascular Society
Heart and Stroke Foundation of Canada
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Last reviewed September 2013 by Michael J. Fucci, DO