Hypertrophic Cardiomyopathy (HCM) is the most common inherited heart muscle condition. In HCM, the walls of the heart — most often the left ventricle — become abnormally thickened (hypertrophied), which can obstruct blood flow, cause the heart to pump less efficiently, and create dangerous arrhythmias.
HCM affects approximately 1 in 500 people and is a leading cause of sudden cardiac death in young people, including young athletes. Many people with HCM have no symptoms at all; others experience breathlessness, chest pain, palpitations, or blackouts. In some cases, the first sign of HCM is a cardiac arrest.
HCM is caused by mutations in genes that encode the proteins of the heart muscle, most commonly MYH7 and MYBPC3. It is inherited in an autosomal dominant pattern, meaning each first-degree relative of someone with HCM has a 50% chance of carrying the same gene variant.
Treatment depends on symptoms and risk profile and may include medication (beta-blockers, calcium channel blockers), a procedure called septal reduction therapy (to reduce obstruction), and ICD implantation for those at high risk of sudden cardiac arrest.
Family screening — with ECG, echocardiogram, and genetic testing — is strongly recommended for all first-degree relatives.