Inherited heart conditions

Inherited heart conditions, also called inherited cardiac conditions (ICC), are a group of heart problems that pass down through families. Around 1 in 250 people worldwide have one, and they can affect people of any age.

Your body has over 20,000 genes. Genes are made up of DNA, and they work like instructions for the body.

You have 2 copies of each gene. One comes from your mother and one from your father. Inherited heart conditions are caused by a change in one or more of your genes, which is known as a gene variant.

If one of your parents has a gene variant, there's a 50% chance it will be passed on to you (inherited). If you do inherit it, there's also a 50% chance you could pass it on to each of your children.

If you don't inherit the gene variant, you can't pass it on to your children. Most inherited heart conditions follow this pattern.

Each person is affected by each gene variant differently. So you could have a gene variant and have no symptoms at all. But you can still pass it on to your children, and they may have symptoms.

If someone in your family is diagnosed with an inherited heart condition, or is thought to have one, it's important to make a family tree with a healthcare professional. This can help show whether the same condition is present in more than one family member.

If you're diagnosed with an inherited heart condition, your first-degree family members (parents, siblings and children) should be assessed for the same condition.

An inherited heart condition can cause symptoms like:

• dizzy spells
• blackouts, faints or fits (seizures)
• palpitations
• breathlessness
• chest pain

If you have had any of these symptoms, speak to your doctor or another healthcare professional.

An inherited heart condition can also cause cardiac arrest and sudden cardiac death. Some affected people have no symptoms at all. This means that sometimes a family only learns they're affected by an inherited heart condition after a sudden cardiac death.

Inherited heart conditions fall into 3 main groups:

Inherited cardiomyopathies are conditions that affect the heart muscle and can run in families. Three examples are:

• Hypertrophic Cardiomyopathy (HCM)
• Dilated Cardiomyopathy (DCM)
• Arrhythmogenic Cardiomyopathy (ACM)

Inherited channelopathies are conditions that affect the heart's electrical system and the way the heart beats. Some examples are:

• Long QT Syndrome
• Brugada Syndrome
• Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

Aortopathy is a condition that can affect the aorta, the main artery in the body. Two examples are:

• Marfan Syndrome
• Loeys-Dietz syndrome

Sudden Arrhythmic Death Syndrome (SADS) is when someone dies suddenly or unexpectedly and no clear cause can be found. SADS can happen when the heart develops an abnormal rhythm, known as an arrhythmia. This causes a cardiac arrest, where the heart stops beating.

A cardiac arrest is a medical emergency, so it's worth finding out more about what to do in a heart emergency. Cardiac Risk in the Young (CRY) has information on sudden cardiac death.

Testing for inherited heart conditions can differ from one person to the next. It is also planned around your needs and your family's needs.

To start, a specialist will ask you questions about yourself and your family history. After that, they may send you for heart tests, which can include:

• an ECG (electrocardiogram)
• an echocardiogram
• a 24 hour heart monitor
• an exercise tolerance test
• a cardiac MRI scan

Each inherited heart condition is managed and treated in its own way. Your doctor will choose treatment based on your symptoms and any test results.

Treatment may include:

• changes to your lifestyle
• medicine
• pacemakers or implantable cardioverter defibrillators (ICDs)
• heart transplantation (in rare cases)