Hypertrophic cardiomyopathy (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. This 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 a nearby valve to become leaky. HCM can cause uneven muscle growth. This can cause the heart to pump in a disorganized way. Rarely, it can cause abnormal heart rhythms that can be fatal.

Normal Heart and Heart With Hypertrophic Cardiomyopathy
Hypertrophic Cardiomyopathy
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HCM may be caused by a gene that causes an abnormality in the heart muscle. It can be inherited or it can happen from changes in the genes over time.