Hypertrophic cardiomyopathy
Also called: HCM
An inherited condition in which the heart muscle becomes abnormally thick, most often in the septum. It can obstruct outflow from the heart and is a leading cause of sudden cardiac death in young athletes.
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About 1 in 500 people.
What happens in the body
Mutations in sarcomere proteins (e.g. MYH7, MYBPC3) cause disorganised, thickened muscle fibres and scarring, which stiffen the ventricle and create electrical instability.
Causes
- Inherited mutations in heart muscle protein genes (autosomal dominant)
Risk factors
- Family history of HCM or sudden cardiac death
Symptoms
- Breathlessness
- Chest pain
- Palpitations
- Dizziness or fainting, especially during exercise
- Often no symptoms
Diagnosis — tests and examinations
- ECG
- Echocardiography showing wall thickness ≥15 mm
- Cardiac MRI
- Genetic testing and screening of relatives
- Holter monitoring for arrhythmias
Treatment
Medicines and medical treatment
- Beta-blockers or verapamil
- Mavacamten (cardiac myosin inhibitor) for obstructive HCM
- Anticoagulation for atrial fibrillation
Operations and procedures
- Implantable cardioverter-defibrillator for those at high risk of sudden death
- Septal myectomy (surgery) or alcohol septal ablation to relieve obstruction
Self-care, home remedies and lifestyle
- Discuss sport participation with a specialist
- Avoid dehydration
- Screen first-degree relatives
Possible complications
- Sudden cardiac death
- Atrial fibrillation and stroke
- Heart failure
Prevention
- Family screening enables early detection
Outlook
Most people have a normal or near-normal life expectancy with modern management.
When to see a doctor
See a doctor for fainting during exercise or a family history of sudden death under 50.
Sources and further reading
These sources cover this condition. They have not been checked against every statement on this page.
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