Cardiomyopathy

Cardiomyopathy is a heart muscle disease that makes it difficult for the heart to pump. There are different types of cardiomyopathy and treatments are available. Learn what you can do to manage your cardiomyopathy.

Cardiomyopathy is a disease of the heart muscle, causing the heart muscle to become enlarged, thick or rigid. In rare cases, the muscle tissue in the heart is replaced with scar tissue.

As cardiomyopathy worsens, the heart becomes weaker. It is less able to pump blood through the body and maintain a normal electrical rhythm. This can lead to heart failure and rhythm problems (arrhythmias).

Types of cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an excessive thickening of the heart muscle without any obvious cause.

Dilated cardiomyopathy (DCM) causes the heart to become dilated or enlarged. In the majority of cases it's not known why DCM occurs, but excessive alcohol intake is known to be a cause. Dilated cardiomyopathy may build up over several years and not cause significant problems. However, over time the enlarged heart gradually weakens. This is called heart failure.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disorder where the heart muscle cells are gradually replaced by fibrous and fatty tissue. This causes the heart to dilate and its pumping action to weaken. There's no known cause for this condition, but it has a tendency to run in families.

Restrictive cardiomyopathy (RCM): Restrictive cardiomyopathy causes the walls of the heart muscle to become stiff. This restricts the flow of blood through the heart, leading to problems with blood flow to the rest of the body. The cause is unknown, but it has been linked to rare metabolic conditions, and may also be caused by a genetic abnormality.

Takotsubo cardiomyopathy or broken heart syndrome, is a condition often triggered by physical or emotional stress. During a takotsubo event, the heart’s largest chamber (the left ventricle) swells and changes shape. This stops the heart pumping properly and reduces blood flow to the body.

Peripartum cardiomyopathy, also called postpartum cardiomyopathy, is a rare form of heart failure that affects women late in pregnancy or in the first few weeks or months after birth. The heart chambers become enlarged and the weakened heart muscle pumps blood less efficiently. The cause is unknown and may involve multiple factors.

Cardiomyopathy can be acquired or inherited. 'Acquired' means you weren't born with the disease but you developed it due to another disease, condition or factor. 'Inherited' means your parents passed the gene for the disease on to you.

In many cases, the cause of cardiomyopathy isn't known, but it can be caused by:

  • viral infections which cause inflammation of the heart muscle (known as myocarditis)
  • some cardiomyopathies run in families.
  • heavy drinking over several years. Read more about alcohol and the heart.

Our latest advice is that no amount of alcohol if good for your heart. This means, if you don’t currently drink any alcohol, don’t start drinking. If you do drink alcohol – it’s better to drink less.

If you’re worried about your drinking, talk to your doctor, nurse or health professional.

For free support, contact the Alcohol Drug helpline 24/7 on 0800 787 797 or visit support.alcohol.org.nz for a list of services available throughout Aotearoa.

Read more about alcohol and the heart.

The different types of the disease have different causes, signs, symptoms and outcomes.

Most people with heart-related symptoms will have heart tests like an electrocardiograph (ECG), chest x-ray and echocardiogram (echo). These tests check how your heart is working and what it looks like. Some blood tests may also be required. From these tests, the diagnosis of cardiomyopathy can be made. 

Management of cardiomyopathy is focused around relieving symptoms, preventing complications and maximising quality of life. The main focus is on symptom control with medication. These medications also help to control 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 hypertropic cardiomyopathy are sometimes offered surgery to remove parts of the thickened heart muscle.

When medication can’t adequately control the symptoms of cardiomyopathy, and a person's quality of life is affected, heart transplantation may be considered.

By way of control and prevention, making some simple lifestyle changes can go a long way to making a healthier life for you and your family.

The Cardiac Inherited Disease Group (CIDG) is a group of New Zealand medical professionals who aim to prevent sudden cardiac death due to inherited heart conditions. Visit www.cidg.org.nz to learn more about inherited cardiomyopathy.

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Visit the CIDG website