Cardiomyopathy Dr Rob Hicks Cardiomyopathy affects the structure of the heart and diminishes its ability to function effectively.

In this article

What is it? Dilated cardiomyopathy Hypertrophic cardiomyopathy

Restrictive cardiomyopathy Arrhythmogenic right ventricular cardiomyopathy

What's the treatment? Advice and support

There are four types of cardiomyopathy:

• Dilated cardiomyopathy (DCM)
• Hypertrophic cardiomyopathy (HCM)
• Restrictive cardiomyopathy (RCM)
• Arrhythmogenic right ventricular cardiomyopathy (ARVC)

Each has different causes and symptoms (see below).

With DCM, the muscular walls of the heart become stretched or dilated. This causes the heart to become larger and the heart muscle weaker, making it unable to pump as well as it should.

Symptoms include tiredness and shortness of breath while exercising or resting. People with the condition may also have heart palpitations, fainting episodes, chest pain and notice their ankles becoming swollen.

DCM isn't common, but it's the commonest form of cardiomyopathy. It affects people of any age, although it's most common between the ages of 20 and 60. It affects men and women, but men are two to three times more likely to develop it.

Although it isn't entirely clear why people develop DCM, there are several possible reasons. It may follow a viral or other infection of the heart, or be part of an autoimmune process where, for an unknown reason, the body attacks itself. Certainly, alcohol and drug misuse, and exposure to certain chemicals and pesticides, can cause the problem. In some cases it runs in families.

In HCM, also known as hypertrophic obstructive cardiomyopathy, the muscular walls of the heart become thickened. This prevents the heart from filling up with blood properly and stops it being pumped from the heart.

People with this condition may become short of breath, experience chest pains and palpitations, and may often faint. Sadly, sudden death is sometimes the first indication that HCM was present.

Approximately one person in 500 has HCM. Its exact cause is unknown, although it's usually inherited. Screening is offered to families of those with the condition.

A particular dilemma arises when a young person with a keen interest in sports is diagnosed with HCM. Long-term training is associated with an increased risk of the heart ventricle wall becoming thickened, which would exacerbate the problem.

This is caused by stiffening of the heart muscles. It's most common in the tropics, where it's often due to scarring (fibrosis) of the heart muscle that occurs for no apparent reason.

In the UK, the most common cause is a condition called amyloid, where abnormal proteins are deposited in parts of the body - in this case the heart muscle.

ARVC occurs when heart muscle is damaged and is gradually replaced with fat and scar tissue. Although its name suggests it only affects the right area of the heart, it can affect both sides.

It's inherited and is more common in males. It usually presents itself in teenage and younger adult years.

ARVC may cause symptoms of palpitations, fainting, chest pain and shortness of breath, caused by abnormal electrical heart rhythms or weakening of the heart's ability to pump.

The first manifestation of the condition may be sudden death, which is associated with young people involved in intense exercise or sporting activity.

Most people with symptoms related to heart function will have an electrocardiogram, chest x-ray and echocardiogram, which allows the structure and function of the heart to be studied. From these tests, the diagnosis of cardiomyopathy is made.

Treatment aims to relieve symptoms and prevent complications. Medication may be used to control the symptoms of heart failure, to treat and prevent arrhythmias (irregular heart rhythms), and to lessen the risk of blood clots forming.

Cardioversion, a pacemaker or an implantable defibrillator may be used to treat and control certain types of arrhythmia.

People with HCM are sometimes offered surgery to remove parts of the thickened heart muscle.

When the symptoms of cardiomyopathy aren't well controlled by medication and a person's quality of life is affected, heart transplantation may be considered.

Cardiomyopathy Association

Tel: 0800 018 1024
Email: info@cardiomyopathy.org
Website: www.cardiomyopathy.org

This article was last medically reviewed by Dr Rob Hicks in November 2007