Anomalous left coronary artery from the pulmonary artery (ALCAPA, Bland-White-Garland syndrome or White-Garland syndrome) is a rare congenital anomaly occurring in approximately 1 in 300,000 liveborn children. The diagnosis comprises between 0.24 and 0.46% of all cases of

congenital heart disease A congenital heart defect (CHD), also known as a congenital heart anomaly, congenital cardiovascular malformation, and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital he ...

. The anomalous left coronary artery (LCA) usually arises from the

pulmonary artery A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and ...

instead of the

aortic sinus An aortic sinus, also known as a sinus of Valsalva, is one of the anatomic dilations of the ascending aorta, which occurs just above the aortic valve. These widenings are between the wall of the aorta and each of the three cusps of the aortic va ...

. In fetal life, the high pressure in the pulmonic artery and the fetal shunts enable oxygen-rich blood to flow in the LCA. By the time of birth, the pressure will decrease in the pulmonic artery and the child will have a postnatal circulation. The myocardium, which is supplied by the LCA, will therefore be dependent on collateral blood flow from the other coronary arteries, mainly the RCA. Because the pressure in RCA exceeds the pressure in LCA a

collateral circulation Collateral circulation is the alternate Circulatory system, circulation around a blocked blood vessel, artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to redundancy (engi ...

will increase. This situation ultimately can lead to blood flowing from the RCA into the LCA retrograde and into the pulmonary artery, thus forming a left-to-right shunt.

Signs and symptoms

The development of symptoms in ALCAPA depends heavily on the amount of collateral development. When few collaterals are present, the myocardium will not get enough oxygen and will become ischemic. The symptoms in an infant with ALCAPA include signs of heart failure such as

dyspnea Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that ...

and

tachypnea Tachypnea, also spelt tachypnoea, is a respiratory rate greater than normal, resulting in abnormally rapid and shallow breathing. In adult humans at rest, any respiratory rate of 1220 per minute is considered clinically normal, with tachypnea b ...

, but sometimes the development is more subtle and the first sign of ischemia can be crying during feeding, sweating, failure to thrive and irritability. Approximately 90% of patients die within the first year if left untreated. Patients having a significant collateral circulation can live to adulthood in rare cases, but often insufficient circulation will cause them to develop chronic ischemia, having a risk for sudden cardiac arrest, heart failure or malignant arrhythmia. The mechanism of patient survival to adulthood is not fully understood.

Diagnosis

Historically ALCAPA was diagnosed with conventional

angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfo ...

. Today

echocardiography Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an ec ...

is easily used. It can provide direct visualisation of the anomalous coronary artery and other associated structural abnormalities, and it can also assess myocardial function. The use of pulse and color-flow doppler can sometimes visualise reversal flow in the pulmonic artery. Other non-invasive methods used are

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

(CT) as well as

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

(MRI), which enable a direct visualisation of the arteries as well as the myocardial viability.

Surgery

Surgery is indicated in all patients with ALCAPA independent of symptoms, since reconnection of the anomalous left coronary artery to the aortic root is crucial to the perfusion of the myocardium dependent on that vessel. Several surgical techniques have been described in ALCAPA repair, including reimplantation of the left coronary artery into the aorta, creation of an intra-pulmonary buffer (Takeuchi procedure), and bypass grafting. Establishment of a dual coronary system is the preferred method and if possible reimplantation of the artery is the approach of choice. Surgery on the

mitral valve The mitral valve ( ), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two Cusps of heart valves, cusps or flaps and lies between the atrium (heart), left atrium and the ventricle (heart), ...

at the same time as ALCAPA correction is controversial. Even if surgery is carried out in adulthood, reestablishment of a two-coronary system can make malignant arrhythmia disappear.

Outcome and management

No difference in long-term mortality or left ventricle function has been shown between the different techniques to re-establish a two-coronary system. An exception is the ligation of the anomalous left coronary artery, which has a higher mortality. The development of surgical techniques and restoring of two-artery circulation has dramatically increased survival. Close long-term follow-up of these patients is necessary, to diagnose a recurrent left ventricle dysfunction, but also to better understand the natural evolution of a corrected heart.

References

External links

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