Anomalous left coronary artery from the pulmonary artery

Anomalous left coronary artery from the pulmonary artery (ALCAPA), also known as Bland-White-Garland syndrome (BWG), is a rare congenital coronary artery anomaly and is considered one of the most serious of such anomalies.

There are two forms based on onset of disease each of which has different manifestations and outcomes 5:

  • infantile type
    • infants experience myocardial infarction and congestive heart failure
    • 90% die within the 1st year of life
  • adult type
    • manifests in adults
    • results to chronic myocardial ischaemia and dysrhythmias
    • cause of sudden cardiac death 

This abnormality only accounts for 0.25-0.5% of all congenital cardiac anomalies 3.

Associations

It is often an isolated anomaly but can be associated with other cardiac anomalies in ~ 5% of cases 3,7:

In the infantile type, ALCAPA presents typically when infants are 1-2 months old (see pathology below).

ALCAPA results when the left main coronary artery arises from the pulmonary trunk instead of the ascending aorta. The function of the left main coronary arterial territory then often requires extensive collateral formation from the right coronary artery.

In the first month of life, physiologic pulmonary hypertension tends to preserve antegrade blood flow within the left coronary artery, and infants usually remain asymptomatic.

As pulmonary pressures drop, left-to-right shunting from the higher pressure left coronary arterial system to the lower pressure pulmonary arterial system begins to occur, and patients become symptomatic.

Cardiac CT

ECG-gated cardiac CT allows direct visualisation of anomalous left main coronary arterial origin from the posterior aspect of the pulmonary artery. The right coronary artery may be unusually dilated and tortuous with evidence of collateral formation. Intercoronary collateral arteries along the external surface of the heart or within the interventricular septum may also be seen.

Prognosis depends significantly on the extent of collateral formation, however, most infants die within the 1st year of birth 4. Death is usually due to circulatory insufficiency from left ventricular dysfunction or mitral valve incompetence, myocardial infarction, or life-threatening cardiac dysrhythmias 3. Early surgical repair is potentially curative. The Takeuchi procedure involves creation of an aortopulmonary window and an intrapulmonary tunnel that baffles the aorta to the ostium of the anomalous left coronary artery.

Congenital coronary artery anomalies
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Article information

rID: 9750
Section: Pathology
Synonyms or Alternate Spellings:
  • ALCAPA
  • Bland-White-Garland syndrome
  • Bland-White-Garland syndrome (BWG)
  • ALCAPA syndrome

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Cases and figures

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    Dilated cardiomyo...
    Case 1: with dilated cardiomyopathy
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    Case 2: cardiac CT with ALCAPA
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    Case 3
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