Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a heart condition that causes the heart muscle to be thicker than normal (hypertrophy). Most of the time, the muscle involved is in the left ventricle, which is the chamber that pumps blood with oxygen to the body. Hypertrophic cardiomyopathy is typically inherited through a gene mutation (abnormal DNA code) that is passed through a family, but not all family members are necessarily affected. It is not uncommon for the thickened muscle to not be present until teenage years.

HCM is associated with two major problems/risks. Since the muscle cells in the heart are abnormal, even at a microscopic level, the electrical conduction in the heart can be irregular and cause abnormal heart rhythms. These abnormal rhythms can sometimes be dangerous and cause the heart to stop beating (cardiac arrest). The thickened heart muscle can also block the flow of blood out of the heart if it is severely thickened. This can cause a decrease in blood flow and oxygen to the body, which can be dangerous. The risk of both of these is thought to be higher with competitive sports, which is why diagnosis in athletes is important to avoid sudden cardiac arrest.

HCM can be managed primarily with medicine and educated decisions on sports activity (some sports may be restricted). For more severe cases, more aggressive treatment may be necessary. This can include the placement of an implantable cardiac defibrillator (ICD) or surgical removal of the thickened muscle.