INFORMATION & RESOURCES
WHAT IS AN ANOMALOUS CORONARY ARTERY
Anomalous aortic origin of a coronary artery (AAOCA) is an abnormality of the origin or the course of a coronary artery. An AAOCA is congenital, which means it is present at birth, however it is often diagnosed later in childhood/adolescence and many people may never even know they have it. An AAOCA may sometimes be referred to as a type of CAA (coronary artery anomaly) or ACA (anomalous coronary artery).
AAOCA affects approximately 0.3% of the population, and appears about three times more often in boys than girls. AAOCA can be associated with ischemia (decreased blood flow to the heart), which can lead to sudden cardiac arrest (SCA) and sudden cardiac death (SCD) following exercise/exertion. AAOCA is the second leading cause of SCD in young athletes in the United States.
The normal anatomy of the coronary arteries consists of a right coronary artery and a left coronary artery, both of which arise from the aorta (the biggest vessel in the body) and provide blood and oxygen to the heart. These two coronary arteries originate from typical areas on the aorta called sinuses of Valsalva.
With AAOCA, the origins of a
coronary artery arise from the
opposite sinus. If an artery is
connected from the wrong side,
its path can get routed around or
through the heart in a way that
can inhibit blood flow, especially
during exercise when the
arteries fill with more blood.
Depending on which coronary
artery takes off from the wrong
sinus and the path it takes will
influence how much a patient is
affected and whether they are at
an increased risk for SCD.
MAIN TYPES OF AAOCA
Anomalous Aortic Origin of the Right Coronary Artery (AAORCA) - Right coronary artery arises from the left side of the aorta
Anomalous Aortic Origin of the Left Coronary Artery (AAOLCA) - Left coronary artery arises from the right side of the aorta
Interarterial - The coronary artery’s course runs between the two great arteries – the aorta and the pulmonary artery (the artery that takes blood to the lungs to receive oxygen).
Intramyocardial - Also referred to as intraseptal - this is when a coronary artery has a course inside the heart muscle for a specific length.
Intramural - The first part of the coronary artery runs within the aortic wall and may increase risk for ischemia (decreased blood flow to the heart muscle).
Other - Other courses may include varying routes and include retroaortic, retrocardiac and prepulmonic to describe where the anomalous artery runs.
AAORCA has been found to be approximately six times more prevalent than AAOLCA according to recent studies. Current data shows AAORCA has an occurrence of 0.06-0.9% and AAOLCA of 0.03-0.15%. AAOLCA typically carries a higher risk, although certain AAORCA can pose risks as well. Interarterial AAOCA and especially interarterial AAOLCA is thought to be associated with an increased risk of SCD. However, identifying which AAOCA patients are high risk and may benefit from surgical repair can still be challenging overall.
As mentioned, AAOCAs are congenital, meaning they are present at birth. At this time no specific cause has been identified. There may be a hereditary component to the condition and siblings are often also tested, but more studies must be done to confirm this link.
SYMPTOMS AND DIAGNOSIS
About half of all AAOCA patients are asymptomatic and are diagnosed incidentally while undergoing workup for unrelated issues. For those experiencing symptoms, such symptoms most usually occur during or after exercise/exertion and can include chest pain, heart palpitations, syncope (fainting), dizziness, difficulty breathing or shortness of breath. In some cases the first symptoms can also include SCA (sudden cardiac arrest) or SCD, which may present without warning.
Many children and adolescents are first given an electrocardiogram (ECG or EKG) as part of a standard sports physical exam. An ECG measures the electrical activity of the heart, and an abnormal ECG can help lead to further investigation to diagnose an AAOCA. However, most AAOCA patients have a normal ECG or with nonspecific abnormalities and therefore echocardiogram is an essential diagnostic tool.
An echocardiogram (echo), which is an ultrasound of the heart, can help detect an AAOCA by providing a view of the coronary arteries. More detailed imaging is usually necessary once a suspected AAOCA has been determined. Such imaging is usually done by cardiac magnetic resonance imaging (CMRI) or computerized tomographic angiography (CTA) to generate a more accurate image of the heart and coronary arteries.
Other tests include exercise stress tests to help determine adequacy of blood supply to the cardiac muscle. A typical exercise stress test is done with a patient running on a treadmill or stationary bike while being monitored for signs of ischemia and other metrics.
Treatment varies depending on type of AAOCA, symptom history and other lifestyle factors.
Recommendations can include observation alone, exercise restriction, surgical repair or a combination of these.
In terms of exercise restriction, recommendations vary by patient and care provider. A return to competitive sports post surgery is also considered case by case and factors in such things as remaining asymptomatic, negative stress tests and other key determining factors.
It is important to note, there are many unknowns with AAOCA, including its true prevalence in the population. The exact mechanisms leading to SCD and the absolute determinants of risk for SCD are not completely understood. Furthermore, the effects of different management strategies including surgery and exercise restriction are still being studied.
LIVING WITH AAOCA -
FOR THE PATIENT AND THE PARENT
An initial diagnosis of AAOCA is often very confusing and anxiety producing for both patient and parent. With the uncertainties surrounding the condition, the psychological impact can be profound. Currently, risk stratification and optimal patient management are very much still being determined. Decisions as to if and when to undergo surgical intervention, the lack of long-term studies, safely participating in sports/exercise and the management of daily life are just a few of the challenges faced. Many AAOCA programs include trained psychologists who can help patients and families deal with this diagnosis and the management thereof. Furthermore, connecting with other AAOCA patients
and families can help bring some shared experiences and comfort to a challenging situation.
In addition, various centers across the country have created AAOCA registries to track and examine the outcomes of patients with the condition. A centralized registry for patients 30 and younger with almost 50 participating institutions also exists through the Congenital Heart Surgeons’ Society (CHSS). Such registries can benefit patients and families by providing additional resources and data to improve care for AAOCA patients.
For those newly diagnosed or wishing to understand more about AAOCA, there are several resources available through some leading centers across the U.S., which specialize in AAOCA. In addition, various journal articles and other scientific literature are available through a variety of databases, some of which are listed below.
Texas Children’s Hospital
Children’s Hospital of Philadelphia
Boston Children’s Hospital
Nemours / A.I. duPont Hospital for Children
Lurie Children’s Hospital of Chicago
Cincinnati Children’s Hospital
The National Center for Biotechnology Information (NCBI)
The NCBI which is a division of the National Library of Medicine (NLM) at the National Institutes of Health (NIH) includes the world's largest repository of medical and scientific abstracts, full-text articles, books and reports. Search all databases on the NCBI for “AAOCA” to find various scientific literature on AAOCA
American College of Cardiology
Enter “AAOCA” on the site’s search bar to bring up relevant articles by experts and researchers in the field
Cleveland Clinic - Making Sense of AAOCA