Hypertrophic cardiomyopathy Health Article

Definition

Hypertrophic cardiomyopathy (HCM) is a condition in which the heart muscle becomes thick. The thickening makes it harder for blood to leave the heart, forcing the heart to work harder to pump blood.

Alternative Names

Cardiomyopathy - hypertrophic (HCM); IHSS; Idiopathic hypertrophic subaortic stenosis; Asymmetric septal hypertrophy; ASH; HOCM; Hypertrophic obstructive cardiomyopathy

Causes, incidence, and risk factors

Hypertrophic cardiomyopathy is often asymmetrical, meaning one part of the heart is thicker than the other parts. The condition is usually passed down through families (inherited). It is believed to be a result of several problems (defects) with the genes that control heart muscle growth.

Younger people are likely to have a more severe form of hypertrophic cardiomyopathy. However, the condition is seen in people of all ages.

Symptoms

• Chest pain
• Dizziness
• Fainting, especially during exercise
• Heart failure (in some patients)
• High blood pressure (hypertension)
• Light-headedness, especially after activity or exercise
• Sensation of feeling the heart beat (palpitations)
• Shortness of breath

Other symptoms that may occur are:

• Fatigue, reduced activity tolerance
• Shortness of breath when lying down

Some patients have no symptoms. They may not even realize they have the condition until it is found during a routine medical exam.

The first symptom of hypertrophic cardiomyopathy among many young patients is sudden collapse and possible death. This is caused by very abnormal heart rhythms (arrhythmias). Hypertrophic cardiomyopathy is a major cause of death in young athletes who seem completely healthy but die during heavy exercise.

Signs and tests

The health care provider will perform a physical exam and listen to the heart and lungs with a stethoscope. Listening with a stethoscope may reveal abnormal heart sounds or a murmur. These sounds may change with different body positions.

The pulse in your arms and neck will also be checked. The doctor may feel an abnormal heartbeat in the chest.

Tests used to diagnose heart muscle thickness, problems with blood flow, or leaky heart valves (mitral valve regurgitation) may include:

• 24-hour Holter monitor (heart monitor)
• Cardiac catheterization
• Chest x-ray
• ECG
• Echocardiography (the most common test) with Doppler ultrasound
• MRI of the heart
• Transesophageal echocardiogram (TEE)

Blood tests may be done to rule out other possible diseases.

If you are diagnosed with hypertrophic cardiomyopathy, your health care provider may recommend that your close blood relatives (family members) be screened for the condition.