Information for Family Members

Inherited Cardiomyopathy in Families

If a family member is suspected or known to have an inherited cardiomyopathy, there may be a risk that you have the same heart condition. It is important to see a cardiologist for a heart check, even if you aren’t experiencing any symptoms. It is routine for relatives considered at-risk of developing an inherited cardiomyopathy to be periodically seen by a cardiologist for heart tests, this is called clinical screening.

You can see your regular GP for a referral to a cardiologist (heart doctor) for clinical screening.

Family of four hugging.

How is Inherited Cardiomyopathy passed through families?

Genetic information is shared between families. If a family member is suspected to have an inherited cardiomyopathy, there is a risk that you may have the same heart condition.

For an inherited cardiomyopathy to develop, one copy of a gene that is involved in your heart function may contain a genetic change (variant) that stops the heart from working as it should. The genetic variant changes the instructions sent out to the body, causing a cardiomyopathy.

Example of gene changes leading to cardiomyopathy. Left example shows two copies of the same gene one has a change which leads to cardiomyopathy. This is what the genetics of someone with cardiomyopathy would look like. Right hand side shows two genes without a cardiomyopathy gene change. Showing what the genetics of someone unaffected by cardiomyopathy would look like.

Clinical Screening for Family Members

If you have a family member with a cardiomyopathy it is important to see a cardiologist for clinical screening.

Clinical screening involves tests that look at the current condition of your heart. These tests are done by a cardiologist (heart doctor) who will look at the structure, electrical rhythm and function of your heart. These tests should be completed by a cardiologist who has expertise in inherited heart conditions.

The cardiologist will make a decision about how often at-risk family members should have clinical screening. Their decision will be based on the relative’s age, family history of the heart problem, and the clinical findings from the first screening.

If a genetic change (variant) has been found that explains your family’s cardiomyopathy, cascade genetic testing may be offered to other family members. This is a process of identifying who in the family does or does not have the same genetic variant as the index person. It can help clarify who needs ongoing clinical screening with a cardiologist.

Choosing to have cascade genetic testing is a personal decision. Discussing the possible consequences and results with friends, family and a genetic counsellor can help with your decision. There can also be factors to consider regarding life insurance.

It is important you speak to a genetic counsellor before any genetic testing. Your GP can refer you to genetic services or cardiac genetic service.

Image describes the different test types to diagnose cardiomyopathy. Taking a family history: Usually a three generation family history will be taken to find any clues to whether your cardiomyopathy runs in your family. You will typically be asked about family members' age, their health and if they have died at what age and the cause of death. Electrocardiogram (ECG): An ECG is a recording of the electrical activity of your heart, and can identify any unusual heart rhythms or extra heartbeats. The test involves placing ECG nodes (stickers) across your chest, arms and legs, and takes 5 minutes to complete. Echocardiogram (Echo): An echocardiogram (Echo) looks at the structure, size, and function (contraction and blood flow) of your heart. An echo uses wave sounds (ultrasound) to make a picture of your heart. This test takes around 30-40 minutes. Exercise stress test (Stress ECG): This test is done while exercising to see how your heart responds when it has to work harder than normal. For this test you will have an ECG while either on a treadmill or a bike. You will start the exercise test at an easy pace and increase the level of exertion. This test takes about 30-40 minutes to complete. Holter Monitor: A Holter monitor is a small device that records the heart’s electrical activity over a few hours or days. The device can be carried around your neck or waist and is connected to ECG electrodes (small patches that will stick to your chest). The monitor will take approximately 15 minutes to fit and will need to be returned at the completion of the test. Cardiac Magnetic Resonance (CMR) Imaging: CMR imaging takes detailed pictures of your heart structure and can see any changes to the tissues that make up the heart muscle. CMR looks at parts of the heart that may not be clearly visible on other tests such as an echocardiogram. You will lie very still on a bed that moves into a large cylinder (MRI machine). The scan takes approximately 45 minutes.

If you have clinical screening as an at-risk relative and nothing is found (i.e., the heart is structurally normal and has a normal rhythm), there is the possibility you do not have the same heart problem as your family. However, we cannot rule out the risk that you could develop disease in the future and so periodic check-ups are important.

It is important that all first-degree family members continue to have clinical screening on a regular basis. Some cardiomyopathies can present later in life. How often a person should be checked is based on their cardiologist’s advice, their current age, and will often be 1-3 yearly.