Coronary artery anomalies: types, symptoms, tests and treatment

The coronary arteries are the blood vessels that supply the heart muscle itself. Normally the right coronary artery arises from the right-hand side of the aorta and the left coronary artery arises from the left side. Cleveland Clinic describes an anomalous coronary artery as one that did not form correctly before birth, so that it is in the wrong place or starts from the wrong place.

It says the artery may start from the wrong part of the aorta (the most common situation), from part of a different coronary artery, or from the pulmonary artery, and that up to 1% of the population has an anomalous coronary artery. Most cases are not dangerous, but occasionally the anomaly leads to not enough blood flow reaching the heart muscle.

Cardiac Risk in the Young, a UK charity, uses the term coronary artery anomalies (CAAs) to cover differences in the origin or the course of a coronary artery, and notes that they have been identified as the underlying cause in up to 17% of sudden cardiac deaths in the young athletic populations reported in registries.

The anomalies differ in how likely they are to cause problems. Cleveland Clinic groups them as follows.

Many anomalies produce no symptoms and are found incidentally during a scan or echocardiogram done for another reason. When symptoms do occur they are usually related to exertion. Cleveland Clinic lists chest pain with physical activity, fainting during activity, breathlessness during activity and a heart murmur. In babies with ALCAPA, signs include pain or irritability, crying while feeding and heart failure.

Chest pain, fainting or palpitations during or straight after exercise should not be put down to being unfit, particularly in a young person. A first episode needs a medical assessment. Collapse with unresponsiveness and abnormal or absent breathing is a cardiac arrest: call 999, start CPR and use a defibrillator if one is available. Cleveland Clinic advises adults to go to the emergency department for chest pain with shortness of breath, and parents to seek help if a baby cries often, is too pale or breathes too quickly.

Cleveland Clinic says the cause is unknown. The anomaly arises in the first month or so of pregnancy when the coronary arteries are forming, and the clinic says researchers have not found evidence that it is hereditary. Nothing a parent did causes it, and it cannot be prevented.

Because a physical examination can be normal, the diagnosis rests on imaging. Cleveland Clinic lists CT angiography, chest X-ray, transthoracic echocardiogram, ECG, heart MRI, cardiac catheterisation and a stress test as tests used for anomalous coronary arteries.

Cardiac Risk in the Young notes that routine screening of athletes with a consultation and a resting 12-lead ECG does not identify structural abnormalities such as coronary artery anomalies, and that a resting echocardiogram added to screening may be the first time an anomaly is identified or suspected. It adds that echocardiographic assessment of the coronary arteries needs specific skills, which are part of the British Society of Echocardiography congenital accreditation.

In the NHS, referral is usually through a GP or paediatrician to cardiology, with congenital heart disease services involved for children and for adults with congenital heart disease. A normal ECG does not rule an anomaly out.

Cleveland Clinic says providers recommend surgery for certain people, with or without symptoms, who have an anomalous origin of the left coronary artery, but suggest it only for some people with an anomalous right coronary artery who have symptoms. Most adults with an anomalous right coronary artery do not need surgery.

It lists the surgical approaches as moving the artery and reattaching it to the aorta or the correct sinus, coronary unroofing (opening the top of an artery that comes from the wrong sinus), pulmonary artery translocation, using a tissue patch to enlarge the artery, coronary bypass grafting and stenting. Complications include bleeding, blood clots, injury to a coronary artery and a leaky aortic valve. It says that after surgery a child may stay in hospital for several days, may take aspirin for three months and may return to sport after three months.

If surgery is not a good option, a clinician may recommend limiting physical activity, and may prescribe medicines such as beta-blockers or diuretics to ease the heart workload. Cleveland Clinic says activity needs to be limited only if the anomaly puts a person at risk of cardiac arrest, and that those considered low risk may not need surgery and can be as active as they like.

The outlook depends on the type. Cleveland Clinic says the outlook is good if ALCAPA is treated before problems happen, but that untreated ALCAPA in babies carries a 90% chance of being fatal. For AAOCA it says surgery removes symptoms and protects against sudden death, and that limiting physical activity may also help.

Because the anomaly is present from birth it does not change without surgery, so regular follow-up with repeat tests is the norm. A decision about sport should be made with a cardiologist who has experience of congenital heart disease and who can explain the specific risk of the artery involved.

This guide is information, not a risk assessment. Sources for this condition are limited in the UK, so one of the sources below is from a US centre and its surgical figures may not match UK practice.