Types of Inherited Heart Condition

Inherited heart conditions result from faulty genes passed down through families. They arise from small changes in the instructions written in your DNA — but from such small changes, the effects can be far-reaching.

Why the heart is vulnerable

The heart is an extraordinary organ, working continuously from before birth until the end of life. Its function depends on muscular chambers, a precisely timed electrical system, and an intricate network of blood vessels all working in coordination. With a mechanism that complex, there are many points at which an inherited fault can express itself. Grouping these conditions into types makes them far easier to understand.

Cardiomyopathies

Cardiomyopathies are conditions affecting the structure and function of the heart muscle itself. Heart muscle fibres do much more than contract like the muscles in your arms — they must be flexible enough to fill with blood and strong enough to eject it, in a precisely timed sequence.

Hypertrophic cardiomyopathy (HCM)

The heart muscle thickens abnormally, most often in the wall between the ventricles. A thickened chamber simply cannot hold as much blood, and in some cases the thickening obstructs outflow. People with HCM may experience breathlessness, chest pain, palpitations, light-headedness or fainting — classically during or just after exertion. It affects roughly 1 in 500 people and is a leading cause of sudden cardiac death in young athletes.

Dilated cardiomyopathy (DCM)

In many ways the opposite: the chambers stretch and thin, filling with blood but lacking the strength to pump it all out. This progressively leads to heart failure, with breathlessness, fatigue and swelling of the ankles, legs and abdomen.

Arrhythmogenic right ventricular cardiomyopathy (ARVC)

Heart muscle is gradually replaced by fatty and fibrous tissue, disrupting both pumping and electrical conduction, and predisposing to dangerous rhythms.

Arrhythmias

The heart maintains its coordinated pumping motion through a tightly controlled electrical system. Impulses travel across the atria, pause briefly, then sweep through the ventricles — this is exactly what an ECG records. Inherited faults in the ion channels that carry those impulses can disrupt the rhythm.

Long QT syndrome

The heart takes longer than normal to electrically recharge between beats. This can trigger a dangerous rhythm causing fainting, seizures or sudden death, often provoked by exercise, emotional stress, or sudden loud noises. Certain medications can also prolong the QT interval, so people with this diagnosis are given a list of drugs to avoid.

Brugada syndrome

Affects sodium channels in heart cells and can cause dangerous ventricular rhythms, characteristically during sleep or fever.

Catecholaminergic polymorphic ventricular tachycardia (CPVT)

Impulses fire extremely rapidly in response to exercise or adrenaline, and at those speeds the heart cannot function as a pump. It can lead to loss of consciousness or sudden death.

Inherited high cholesterol

Cholesterol is an essential building block of cells. In excess, it accumulates as fatty deposits in artery walls — atherosclerosis — which can restrict or block blood flow.

Familial hypercholesterolaemia (FH)

An inherited condition in which cholesterol is not cleared efficiently from the bloodstream, causing very high levels from birth and greatly accelerating artery narrowing. It affects around 1 in 250 people, yet the large majority remain undiagnosed. It may cause no symptoms at all, though some people develop fatty deposits around the eyes or in tendons. It is highly treatable once identified, which is what makes the diagnostic gap so significant.

Warning signs

Speak to your GP if you experience unexplained fainting (especially during exercise), palpitations, breathlessness disproportionate to activity, or chest pain on exertion — and particularly if there is a family history of heart problems or sudden unexplained death under the age of 40.

Getting assessed

Diagnosis may involve an ECG, echocardiogram, cardiac MRI, exercise testing, an ambulatory monitor or genetic testing. Where a condition is confirmed, NHS inherited cardiac conditions clinics offer cascade testing so close relatives can be screened too.

Rightangled's DNA tests assess genetic markers associated with cardiovascular risk, with results reviewed by our clinical team, which includes GPhC-registered independent prescribers, and medical oversight from our doctor, Dr Abdullah. A consumer genetic test is a screening and awareness tool, not a substitute for specialist diagnostic testing — if you have a strong family history, ask your GP for a referral to an inherited cardiac conditions clinic.

The British Heart Foundation also runs a Genetic Information Service helpline on 0300 456 8383.

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Related reading: how heart conditions can be inherited.

This article is for general information and does not replace personalised medical advice.