Clinical Pearls & Morning Reports
Published May 31, 2023
A diagnosis of ALCAPA (anomolous left coronary artery originating from the pulmonary artery) in adulthood is extremely rare. Read the NEJM Clinical Problem-Solving Article here.
Q: When does ALCAPA typically manifest?
A: Coronary-artery anomalies are congenital defects that are characterized by an abnormal origin or course of any of the three main epicardial coronary arteries. ALCAPA manifests primarily in infancy and is often fatal if not surgically corrected. The incidence of ALCAPA is estimated to be 1 case per 300,000 live births; the incidence of survival into adulthood without surgery is 10 to 15%.
Q: How does ALCAPA present in adults?
A: Although ALCAPA is rare, especially in adults, it can manifest in adulthood if collateralization of the left coronary artery from the right coronary artery is sufficient to allow for retrograde perfusion of the left ventricle. Common presenting symptoms in patients in whom the diagnosis is made in adulthood include fatigue, dyspnea, angina, arrhythmias, myocardial infarction, and sudden cardiac death. In a series of cases of ALCAPA that were diagnosed in adulthood, the average age at presentation was 41 years, 14% of the patients were asymptomatic at presentation, and 12% of all cases were diagnosed at autopsy.
A: When numerous collaterals develop, continuous retrograde flow from the right coronary artery to the deoxygenated left coronary artery and to the low-pressure, deoxygenated pulmonary arterial tree can cause coronary steal syndrome. This syndrome may confer a predisposition to a diffusely hypokinetic left ventricle or to dysfunction of the papillary muscle and left ventricular lateral wall, thereby leading to mitral regurgitation.
A: ALCAPA is associated with a high risk of sudden cardiac death; as such, surgical correction is generally recommended. After the age of 50 years, the risk of sudden death seems to decline, and the risk of surgery may outweigh its benefits. The technique that is currently recommended for the correction of ALCAPA is translocation of the left coronary artery, a procedure in which a system of two coronary arteries is created. Another approach — the Takeuchi technique — involves the creation of an aortopulmonary window and an intrapulmonary tunnel in order to connect the anomalous left coronary artery to the aorta with the use of a flap of native pulmonary arterial tissue. However, the Takeuchi technique is no longer routinely used owing to the recognition of severe late complications, including intrapulmonary tunnel obstruction and leak, stenosis of the main pulmonary artery, and aneurysm formation in a coronary artery.