Conditions + Treatments

What is cardiomyopathy?

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Contact the Cardiomyopathy Program

Cardiomyopathy is a disease of the heart muscle characterized by an abnormally large, thickened, and/or stiffened heart muscle.  It may affect only the heart’s lower chambers (ventricles) or both the lower and upper chambers (atria).

Cardiomyopathy causes damage to tissue surrounding the heart as well as heart muscle cells.  In severe cases, the heart becomes so weak that it cannot pump blood properly.  This can lead to heart failure and/ or irregular heartbeats (arrhythmias).

In some cases, cardiomyopathy also involves a buildup of scar tissue or fat within the heart muscle. Rarely, the heart muscle loses the ability to relax and blood cannot fill the heart properly.

Cardiomyopathy is very often a “time-will-tell” disease.  It can present in a multitude of ways and in each case, the progression of the disease can be unpredictable. Your child’s course of treatment and long-term outlook will depend greatly upon:

  • age
  • the underlying cause of the disease
  • the severity of the disease at the time of diagnosis
  • tolerance for specific medications or procedures
  • a family’s preferences for treatment

Information on the following pages will help you, your child and your family gain a better understanding of cardiomyopathy and a clearer picture of what to expect in the weeks and months ahead.

Different forms of cardiomyopathy

There are many different forms of cardiomyopathy. 

Dilated cardiomyopathy (DCM)

DCM, also called congestive cardiomyopathy, is the most common type and occurs when the main pumping chamber of the child’s heart muscle becomes too dilated or “stretched out.” Dilated cardiomyopathy renders the heart unable to pump blood effectively.

Hypertrophic cardiomyopathy (HCM) 

HCM also called hypertrophic obstructive cardiomyopathy, asymmetric septal hypertrophy or idiopathic hypertrophic subaortic stenosis. Unlike dilated cardiomyopathy, which makes the heart muscle stretched out, hypertrophic cardiomyopathy makes the heart muscle too thick. Usually, the thickening occurs in the muscle of the left ventricle in the heart, often involving the wall between the heart’s two ventricles.

Arrhythmogenic right ventricular cardiomyopathy (ARVC)

ARVC, also called arrhythmogenic right ventricular dysplasia, is a rare form of cardiomyopathy that affects only one in 5,000 people. This type of cardiomyopathy occurs when the muscle of the heart’s right ventricle is replaced by thick or fatty scar tissue. The scarring “scrambles” electrical signals within the heart and can impair the heart’s ability to pump blood.

Restrictive cardiomyopathy 

Restrictive cardiomyopathy is a a fourth, rare type of cardiomyopathy that causes the heart muscle to become excessively rigid or stiff. This makes it difficult for the ventricles of the heart to properly fill with blood.

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