Basics
Description
The anomalous coronary artery arises from the pulmonary artery rather than the aorta. Most commonly, the anomalous left coronary artery arises from the pulmonary artery in a condition known as ALCAPA or Bland-White-Garland syndrome. �
Epidemiology
Incidence
Very rare anomaly, occurring in 0.25% of congenital heart disease �
Prevalence
The majority of patients present in infancy at approximately 2 months of age (when pulmonary vascular resistance is falling). There are case reports of patients presenting as late as the 4th-7th decades of life. �
Pathophysiology
- In the fetal and neonatal period, pulmonary artery pressure is increased owing to elevated pulmonary vascular resistance. This elevated pulmonary artery pressure provides antegrade flow from the pulmonary artery through the anomalous coronary artery.
- As pulmonary vascular resistance drops, pulmonary arterial pressure drops. When the diastolic blood pressure in the pulmonary artery decreases below myocardial perfusion pressure (or diastolic aortic pressure), pulmonary run-off "steals"� blood from the myocardium, resulting in myocardial ischemia of the anterolateral left ventricular wall and mitral valve papillary muscle dysfunction.
- The fact that the left ventricle is perfused with desaturated blood plays a less important role than the overall perfusion-related imbalance between myocardial oxygen demand and supply.
Etiology
- Abnormal septation of the conotruncus into the aorta and pulmonary artery
- Persistence of the pulmonary buds and involution of the aortic buds that usually eventually form the coronary arteries
- As-yet-unspecified genetic predisposition
Diagnosis
History
- Typically presents with paroxysms of poor feeding, pallor, tachypnea, respiratory distress, and diaphoresis
- Irritability, crying, appearance of being in pain (especially after meals)
- Can be asymptomatic
- Can be symptomatic in infancy and then gradually improve (with the development of adequate coronary collateralization)
- Older children and adults may have dyspnea, syncope, or angina pectoris.
- Sudden death
Physical Exam
- Signs of congestive heart failure (CHF) such as cachexia, tachycardia, tachypnea, lethargy, diaphoresis
- Signs of low cardiac output such as pallor, diminished peripheral pulses and perfusion
- Gallop rhythm
- Loud P2 component of S2 (if left ventricular heart failure raises pulmonary arterial pressure)
- Murmur of mitral regurgitation or a continuous murmur reminiscent of a coronary arteriovenous fistula
- Diagnosis should be entertained in any infant presenting with cardiomegaly or perplexing cardiorespiratory symptoms.
Diagnostic Tests & Interpretation
Imaging
- Chest radiograph: cardiomegaly, pulmonary edema
- Electrocardiography: anterolateral infarct pattern in an infant (Q in I, aVL, V4-V6), abnormal R-wave progression in precordial leads
- Echocardiogram: attachment of coronary artery to pulmonary artery by 2-dimensional imaging. Doppler interrogation shows flow passing from coronary artery to great artery rather than vice versa (if pulmonary vascular resistance has fallen).
- Dilation of the right coronary artery
- Left ventricular function impairment, wall motion abnormalities, and dilation
- Mitral regurgitation
- Echogenic papillary muscles
- Coronary CT angiography
- Excellent diagnostic modality for older patients with slower heart rates, allowing better resolution
- Emerging CT technology is allowing this technique to be used in infancy with lower radiation doses and excellent resolution.
- Nuclear imaging: Thallium myocardial perfusion imaging shows reduced uptake in ischemic regions.
- Cardiac catheterization: Angiographic and hemodynamic parameters may correlate with degree of cardiovascular dysfunction.
- Low cardiac output
- High left atrial filling pressures
- Pulmonary arterial hypertension
- Aortic root angiography shows passage of contrast medium from normally connected right coronary artery to the left coronary arterial system to the pulmonary artery.
- Pulmonary artery angiogram shows reflux of contrast medium into the left coronary artery and/or a "negative wash-in"� of unopacified blood flowing from left coronary to pulmonary artery.
Differential Diagnosis
- Cardiomyopathy
- Myocarditis
- Coronary artery fistula
- Left ventricular failure from other causes
- Mitral valve regurgitation
- Respiratory distress from other causes
- Colic
Treatment
General Measures
The first priority is to safely institute supportive care measures while expeditiously planning for surgical intervention. �
Surgery/Other Procedures
- Direct reimplantation of the left coronary artery into the aorta using a button of pulmonary arterial tissue and/or an extension-tube graft of anterior and posterior pulmonary arterial wall tissue sewn into a narrow cylinder to avoid tension, distortion, and stenosis of the coronary
- Creation of an aortopulmonary window and tunnel that directs blood from aorta to the left coronary ostium (Takeuchi procedure).
- Ligation of the origin of the left coronary artery and reconstitution of flow with saphenous or internal mammary graft rarely used in the current era.
- Ligation of the origin of the left coronary artery (to prevent flow runoff into the pulmonary artery or "steal"�) is rarely ever used, even in very ill infants.
Inpatient Considerations
Initial Stabilization
- Attention to basic life support measures (airway, breathing, and circulation) and prompt referral to a pediatric cardiac center are indicated immediately on presentation.
- As myocardial ischemia can be worsened with traditional heart failure treatments such as oxygen administration, afterload reduction, and inotropic support, these therapies should be administered in consultation with a pediatric cardiac care center.
- An excess of procedures, interventions, and manipulation is poorly tolerated by this group of critically ill patients.
Ongoing Care
Prognosis
- Untreated, 90% of those who present in infancy will die before the age of 1 year, usually at 1 to 2 months of age (when pulmonary vascular resistance falls).
- Very few of those who present early improve spontaneously.
- Late results after surgery are excellent in many centers. Hospital mortality in larger selected series of these frequently moribund patients is ≤5%, with very little subsequent attrition.
- Mitral regurgitation usually improves after surgery establishes a patent dual-coronary system, but this may take 6-12 months to be fully realized. Follow-up evaluation is warranted, as mitral regurgitation may progress despite surgery, and valve repair may be required later.
Additional Reading
- Azakie �A, Russell �JL, McCrindle �BW, et al. Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic re-implantation: early survival, patterns of ventricular recovery and late outcome. Ann Thorac Surg. 2003;75(5):1535-1541. �[View Abstract]
- Bland �E, White �P, Garland �J. Congenital anomalies of the coronary arteries: report of an unusual case associated with cardiac hypertrophy. Am Heart J. 1933;8:787-801.
- Dodge-Khatami �A, Mavroudis �C, Backer �CL. Anomalous origin of the left coronary artery from the pulmonary artery: collective review of surgical therapy. Ann Thorac Surg. 2002;74(3):946-955. �[View Abstract]
- Ginde �S, Earing �M, Bartz �P, et al. Late complications after Takeuchi repair of anomalous left coronary artery from the pulmonary artery: case series and review of literature. Pediatr Cardiol. 2012;33(7):1115-1123. �[View Abstract]
- Keane �JF, Lock �JE, Fyler �DC, eds. Nadas' Pediatric Cardiology. Philadelphia, PA: WB Saunders; 2006.
- Lange �R, Vogt �M, Horer �J, et al. Long-term results of repair of anomalous origin of the left coronary artery from the pulmonary artery. Ann Thorac Surg. 2007;83(4):1463-1471. �[View Abstract]
- Michielon �G, Di Carlo �D, Brancaccio �G, et al. Anomalous coronary artery origin from the pulmonary artery: correlation between surgical timing and left ventricular function recovery. Ann Thorac Surg. 2003;76(2):581-588, discussion 588. �[View Abstract]
- Pelliccia �A. Congenital coronary artery anomalies in young patients: new perspectives for timely identification. J Am Coll Cardiol. 2001;37(2):598-600. �[View Abstract]
Codes
ICD09
- 746.85 Coronary artery anomaly
ICD10
- Q24.5 Malformation of coronary vessels
SNOMED
- 450301003 Anomalous origin of left coronary artery from pulmonary artery (disorder)
FAQ
- Q: How do you differentiate crying from the symptoms of myocardial ischemia from crying from colic?
- A: This is not easy, but clinical assessment should manifest the signs of CHF, shock, and low cardiac output, which are decidedly atypical for the usual patient with colic. If the patient is still feeding, the crying in patients with this lesion classically occurs after meals, when blood is shunted to the liver and intestines. This is not a highly sensitive finding, and concern should lead to further objective evaluation.