SCAD (spontaneous coronary artery dissection): symptoms, causes, treatment and recovery

The BHF explains that SCAD happens when one or more of the inner layers of a coronary artery tears away from the outer layer. Blood can flow into the space between the layers, reducing or blocking the flow of blood through the artery. This can lead to a heart attack, or in very rare cases a cardiac arrest where the heart stops beating.

Beat SCAD, the UK patient charity, describes a bruise (sometimes called a tear) developing in the artery wall, creating a "false lumen" that compresses the artery and prevents normal blood flow. It says SCAD can, very rarely, be fatal, and that it is under-diagnosed.

The BHF lists the symptoms of SCAD, which can feel similar to angina or a heart attack.

• chest pain

• tightness or pain in the arms, neck, jaw, upper back or stomach

• feeling dizzy or lightheaded

• feeling tired or out of breath

• feeling sick or being sick

• feeling sweaty or clammy

The BHF says to call 999 if you have chest pain or any of the symptoms above. People with SCAD often ignore symptoms, especially if they appear fit and healthy and have no history of cardiovascular risk factors, but it is important to get checked out so it can be diagnosed as early as possible.

Beat SCAD notes that chest pain in young, fit people with no history of risk factors is often dismissed as anxiety, panic attacks, indigestion or gall stones, and that the longer blood flow is reduced, the higher the chance of permanent damage to heart muscle. The NHS says do not drive yourself to A&E for a suspected heart attack, and the person you speak to at 999 will give you advice.

The BHF says we do not yet know what causes SCAD or why it happens, and it often happens out of the blue. It cannot currently be predicted or prevented. Beat SCAD says some associations have been described with pregnancy and the period after delivery, menopause, fibromuscular dysplasia, hereditary connective tissue disorders, and extreme emotional stress or extreme exercise.

The BHF notes that people who have had SCAD will often have fibromuscular dysplasia, a rare condition affecting medium-sized arteries, making them weak or stiff. Beat SCAD says research has identified genetic variants that confer a higher risk, but it is not caused by a single gene in the way hereditary diseases are.

The BHF says SCAD most commonly occurs in women aged between 45 and 53 and that at least 80% of people with SCAD are women. Beat SCAD says it has been reported across a wide age range (18 to 84) with an average age of 50, and that around 10% of patients are male. Many people have few or none of the traditional risk factors for heart disease such as high cholesterol, smoking or diabetes.

The BHF says SCAD can happen during, or soon after, pregnancy. Beat SCAD says around 10% of patients have their SCAD around the time of pregnancy, and that 21 to 27% of heart attacks in pregnancy and 50% of post-partum coronary events are reportedly due to SCAD. It publishes a leaflet on pregnancy-related SCAD (P-SCAD) and a specialist referral service.

The BHF says SCAD is usually diagnosed after the event, once you reach hospital. Tests include blood tests, an ECG, a coronary angiogram and a CT scan. Beat SCAD adds that the ECG can look normal in some SCAD patients, that blood tests measure troponin, a protein released during a heart attack, and that you may have an echocardiogram to show how well the heart is functioning. It says current best practice is for patients to be monitored in hospital for at least five days because most recurrent SCADs occur during early follow-up.

The BHF says treatment varies depending on your condition and how severe the symptoms are. Conservative treatment, without invasive procedures, is recommended when the condition is stable, and you will usually be given medicines. Most people have a coronary angiogram first.

Beat SCAD says the first few weeks and months can feel like a rollercoaster and recovery is not linear, with plenty of rest important at first. It describes recovery as a marathon rather than a sprint. It says recent studies show that virtually all SCADs heal by themselves between three and six months after the event, and that ongoing chest pain is common among patients during the first year or so.

The BHF says cardiac rehabilitation can help you get back to normal, and to speak to your GP if you have not been offered it. A SCAD diagnosis can be frightening, especially if you find out after an emergency, and many people feel anxious, panicky or depressed afterwards. The BHF encourages talking about these feelings with a loved one, your GP, a cardiac rehab nurse or a counsellor, and mentions support communities for people with SCAD.

Beat SCAD says around 10% of patients will have more than one SCAD, but research suggests the outcomes are good. It says controlling blood pressure and stress is important, and that many patients find it helpful to be referred to a SCAD specialist.

SCAD is treated as an emergency through 999 and NHS hospital cardiology services, and follow-up and cardiac rehabilitation are available on the NHS. Beat SCAD describes a clinic referral service for people who would like a SCAD specialist opinion. Some people also see a private cardiologist for follow-up, but acute care follows the emergency pathway.