Hypertrophic Cardiomyopathy Center

About Hypertrophic Cardiomyopathy

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Hypertrophic Cardiomyopathy

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What is Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy (HCM), also known as hypertrophic obstructive cardiomyopathy (HOCM) and idiopathic hypertrophic subaortic stenosis (IHSS), is a genetic disease that occurs when the muscle of the left ventricle of the heart becomes thicker than normal. In patients with hypertrophic cardiomyopathy, the heart muscle is often stiff and relaxes poorly.

This makes it difficult for the heart to pump blood to the rest of the body and requires higher pressures than normal to expand the inflow of blood. The amount of blood that the heart can hold is then reduced as a result of the disease, which limits the amount of blood that can flow to the rest of the body. Hypertrophic cardiomyopathy can also affect the heart's mitral valve, causing blood to leak backward through the valve.

Normally, the heart wall measures from 0.08 to 1.2 cm in width. In hypertrophic cardiomyopathy, the heart wall measures 1.3 cm or greater. The pattern of muscle thickening varies by individual and is identified using an echocardiogram (ultrasound of the heart).

The distribution of muscle thickening in patients with hypertrophic cardiomyopathy is variable:

In 70% of individuals affected by hypertrophic cardiomyopathy, there is an increase of pressure called "obstruction" that occurs either at rest, or with exercise when the blood is ejected out of the pumping chamber of the heart. If this pressure increase is present, the term "hypertrophic obstructive cardiomyopathy" is used.

In addition, when cells from the hypertrophic cardiomyopathy heart muscle are viewed under a microscope, they will most often show an abnormal pattern called "myocardial cell disarray." The hypertrophic cardiomyopathy heart muscle cells align in a disorganized pattern, and this can result in irregular heart rhythms and problems with the electrical system.

Hypertrophic Cardiomyopathy Causes

Hypertrophic cardiomyopathy is also called familial hypertrophic cardiomyopathy, as it is typically an inherited disorder. Several disease-causing mutations in the genes encoding protein of the cardiac sarcomere are the cause of the majority of the cases.

It can affect men and women of all ages, and symptoms can appear in childhood or adulthood. It is estimated that one out of 500 people has the gene for hypertrophic cardiomyopathy. One-half of children with the disease have a parent or sibling with varying degrees of left ventricular muscle or ventricular wall enlargement, although relatives may or may not have symptoms.

However, hypertrophic cardiomyopathy may also be acquired resulting from high blood pressure or aortic stenosis (narrowing or obstruction of the aortic valve causing restricted blood flow). In fact, nearly one-half of deaths due to hypertrophic cardiomyopathy occur during or after physical activity. Sudden death occurs due to lethal heart rhythm disturbances (ventricular fibrillation and ventricular tachycardia). It is the most common cause of sudden cardiac death in athletes as a result of structural heart changes in response to intense training.

In general, patients with hypertrophic cardiomyopathy should refrain from particularly strenuous or competitive athletics, avoid heavy lifting, and always warm up and cool down before and after any exercise.

Hypertrophic Cardiomyopathy Symptoms

Symptoms may occur at any stage in a person's life, even though the condition may have been present for some time.

The following are the most common symptoms of hypertrophic cardiomyopathy. However, each patient may experience symptoms differently. Symptoms may include:

Other forms of familial cardiomyopathy:

Hypertrophic Cardiomyopathy Diagnosis

While hypertrophic cardiomyopathy has typically been recognized by its structure (hypertrophy), the electrical functions of the heart are also adversely affected. Cardiologists use a variety of diagnostic tools, such as an electrocardiogram, echocardiogram, heart monitor, MRI, and other tests to examine the heart and make a diagnosis.

Hypertrophic Cardiomyopathy Treatment

It is very possible to live a long and active life with hypertrophic cardiomyopathy. Although there is no cure for the disease, there is much we can do to help. Treatment options aim to improve heart function, relieve symptoms, and prevent complications. Those who have few or now symptoms may require only monitoring.

Learn more about the following treatment options for hypertrophic cardiomyopathy:

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