Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle (myocardium) becomes abnormally thick (hypertrophied). The thickened heart muscle can make it harder for the heart to pump blood.

Hypertrophic cardiomyopathy often goes undiagnosed because many people with the disease have few, if any, symptoms. In a small number of people with HCM, the thickened heart muscle can cause shortness of breath and problems in the heart's electrical system, resulting in life-threatening abnormal heart rhythms (arrhythmias).

Fortunately, people with hypertrophic cardiomyopathy often lead normal lives with no significant problems.

Symptoms Causes Risk factors Complications Prevention

Signs and symptoms of hypertrophic cardiomyopathy include:

  • Shortness of breath, especially during exercise
  • Chest pain, especially during exercise
  • Fainting, especially during exercise or exertion
  • Dizziness
  • Fatigue
  • Sensation of rapid, fluttering or pounding heartbeats (palpitations)
  • Heart murmur, which a doctor might detect while listening to your heart

When to see a doctor

A number of conditions can cause shortness of breath and heart palpitations. It's important to get a prompt, accurate diagnosis and appropriate care. See your doctor if you experience any symptoms associated with hypertrophic cardiomyopathy.

Call 911 or your local emergency number if you experience any of the following symptoms for more than a few minutes:

  • Rapid or irregular heartbeat
  • Difficulty breathing
  • Chest pain

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use