Hypertrophic Cardiomyopathy (HCM)
Overview
Plain-Language Overview
Hypertrophic Cardiomyopathy (HCM) is a condition that affects the heart muscle, causing it to become abnormally thick. This thickening mainly involves the left ventricle, which is responsible for pumping blood to the rest of the body. The thickened muscle can make it harder for the heart to pump blood efficiently, leading to symptoms like shortness of breath, chest pain, and sometimes fainting. It can also cause irregular heart rhythms, which may be dangerous. HCM is often inherited and can affect people of all ages, sometimes leading to sudden cardiac events.
Clinical Definition
Hypertrophic Cardiomyopathy (HCM) is a genetic cardiac disorder characterized by asymmetric left ventricular hypertrophy without an obvious cause such as hypertension or valvular disease. The core pathology involves myocyte hypertrophy, myofibrillar disarray, and interstitial fibrosis, typically caused by mutations in sarcomeric protein genes such as MYH7 and MYBPC3. This hypertrophy leads to diastolic dysfunction and may cause left ventricular outflow tract (LVOT) obstruction due to systolic anterior motion of the mitral valve. Clinically, HCM is significant for its association with heart failure, arrhythmias, and sudden cardiac death, especially in young adults and athletes.