FAQ

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a rare inherited arrhythmia syndrome in which the heart is structurally normal but specific triggers — particularly physical exertion or emotional stress — can provoke dangerous ventricular arrhythmias. These can cause palpitations, blackouts, or sudden cardiac arrest.

CPVT is caused by mutations affecting calcium regulation within heart muscle cells, most commonly in the RYR2 gene. It typically presents in childhood or adolescence and can cause sudden cardiac arrest in young people who appear otherwise completely healthy. A standard resting ECG may be normal; an exercise stress test often reveals the characteristic bidirectional ventricular tachycardia.

Treatment includes beta-blockers to reduce the risk of arrhythmias triggered by adrenaline, strict avoidance of competitive and high-intensity exercise, and in many cases ICD implantation. Some patients are also treated with flecainide.

Because CPVT is inherited, family screening is essential following a diagnosis. First-degree relatives should be assessed with an exercise stress test as well as a resting ECG and echocardiogram, as the resting ECG may appear entirely normal even in affected individuals.

Hypertrophic Cardiomyopathy (HCM) is the most common inherited heart muscle condition. In HCM, the walls of the heart — most often the left ventricle — become abnormally thickened (hypertrophied), which can obstruct blood flow, cause the heart to pump less efficiently, and create dangerous arrhythmias.

HCM affects approximately 1 in 500 people and is a leading cause of sudden cardiac death in young people, including young athletes. Many people with HCM have no symptoms at all; others experience breathlessness, chest pain, palpitations, or blackouts. In some cases, the first sign of HCM is a cardiac arrest.

HCM is caused by mutations in genes that encode the proteins of the heart muscle, most commonly MYH7 and MYBPC3. It is inherited in an autosomal dominant pattern, meaning each first-degree relative of someone with HCM has a 50% chance of carrying the same gene variant.

Treatment depends on symptoms and risk profile and may include medication (beta-blockers, calcium channel blockers), a procedure called septal reduction therapy (to reduce obstruction), and ICD implantation for those at high risk of sudden cardiac arrest.

Family screening — with ECG, echocardiogram, and genetic testing — is strongly recommended for all first-degree relatives.

Brugada Syndrome is an inherited heart condition in which the heart’s electrical system malfunctions despite the heart having a normal structure. It is caused by mutations affecting sodium channels in heart cells — most commonly in the SCN5A gene — and produces a characteristic pattern on an ECG. People with Brugada Syndrome are at risk of dangerous ventricular arrhythmias (abnormal heart rhythms), which can cause sudden cardiac arrest, most often at rest or during sleep.

Brugada Syndrome is more common in men and in people of South-East Asian descent. It may be diagnosed after an unexplained cardiac arrest, after an abnormal ECG is found incidentally, or through family screening following a diagnosis in a relative.

The main treatment for those considered at high risk is an ICD (implantable cardioverter defibrillator), which can detect and terminate life-threatening arrhythmias. Certain medications and substances — including some antidepressants, sodium channel-blocking drugs, and large amounts of alcohol — can trigger arrhythmias in Brugada Syndrome and should be discussed with your cardiologist.

Because Brugada Syndrome is inherited, first-degree relatives (parents, siblings, and children) of anyone diagnosed should be offered cardiac screening.

If your cardiac arrest was caused by or is suspected to be related to an inherited heart condition, it is important that your first-degree relatives — parents, siblings, and children — are offered cardiac screening. This is recommended regardless of whether they have symptoms, as many inherited cardiac conditions produce no warning signs until a serious arrhythmia occurs.

You do not need to wait for your relatives to develop symptoms before seeking assessment. Proactively identifying a condition in a family member — before an event occurs — could save their life.

In the UK, inherited cardiac conditions are managed by specialist cardiac genetics or inherited cardiac conditions (ICC) services, often based at regional cardiac centres. Your cardiologist or electrophysiologist should be able to refer you and your relatives to the appropriate service. The process typically begins with a detailed family history, followed by investigations such as ECG, echocardiogram, exercise testing, and in some cases genetic blood testing.

The charity Cardiac Risk in the Young (CRY) and the British Heart Foundation also provide information and support for families affected by inherited cardiac conditions.

It depends on the cause. Cardiac arrest itself is not directly inherited — but many of the conditions that cause it can run in families.

If your cardiac arrest was caused by an inherited condition such as Hypertrophic Cardiomyopathy (HCM), Long QT Syndrome, Brugada Syndrome, or Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT), there is a significant chance that first-degree relatives (parents, siblings, and children) may carry the same genetic variant and be at increased risk themselves. In some conditions, the risk to first-degree relatives is as high as 50%.

If your cardiac arrest was caused by coronary artery disease (blocked arteries), there is an increased familial risk of heart disease, though this is due to a combination of genetic and lifestyle factors rather than a single gene.

If no cause was identified (idiopathic ventricular fibrillation), inherited channelopathies are sometimes present without a detectable structural abnormality, and family screening may still be recommended.

Your cardiologist or electrophysiologist should discuss family screening with you following your cardiac arrest. If they have not, ask them directly. The process typically involves first-degree relatives having an ECG, echocardiogram, and in some cases genetic testing.

Some heart problems do run in families but that does not mean all family members will have the same problems or need the same type of therapy. Be sure to talk to your doctor for more information.