Anomalous Origin of the Coronary Artery from the Pulmonary Artery in Children and Adults: A Pictorial Review of Cardiac Imaging Findings

Abstract

Anomalous origin of the coronary artery from the pulmonary artery is a rare and potentially fatal congenital heart defect. Up to 90% of infants with an anomaly involving the left coronary artery die within the first year of life if left untreated. Patients who survive beyond infancy are at risk of sudden cardiac death. Cardiac CT and MRI are increasingly being used for the accurate diagnosis of this anomaly for prompt surgical restoration of the dual coronary artery system. Moreover, life-long imaging surveillance after surgery is necessary for these patients. In this pictorial review, multimodal cardiac imaging findings of this rare and potentially fatal coronary artery anomaly are comprehensively discussed, and representative images are provided to facilitate the understanding of this anomaly.

Keywords: Cardiac catheterization; Cardiac computed tomography; Cardiac magnetic resonance imaging; Coronary artery anomaly; Echocardiography.

Fig. 1. Initial chest radiography of the infant type of anomalous origin of the left coronary artery from the pulmonary artery.

A. An anteroposterior chest radiograph shows significantly enlarged cardiomediastinal shadow. B. A lateral chest radiograph shows bulging of the posterior cardiac border (white arrows) and the posteriorly displaced left main bronchus (black arrow) due to the enlargement of the left cardiac chambers. In addition, the engorged central pulmonary vessels are visualized.

Fig. 2. Preoperative cardiac catheterization and angiography of anomalous origin of the left coronary artery from the pulmonary artery.

A. Frontal selective right coronary artery angiography of the infant type demonstrates faint visualization of the left coronary artery draining into the main pulmonary artery (arrow). Notably, the inter-coronary collateral vessels are poorly developed. B. Frontal selective right coronary artery angiography of the adult type shows the dilated, tortuous right and left coronary arteries with well-developed inter-coronary collateral arteries. The origin of the left coronary artery is anomalously connected to the main pulmonary artery (arrows). C. Frontal pulmonary angiography reveals regurgitant flow into the left coronary artery (arrows) in the infant type of this anomaly.

Fig. 3. Preoperative transthoracic echocardiography of anomalous origin of the left coronary artery from the pulmonary artery.

A. A parasternal echocardiographic image shows an anomalous connection (arrow) of the left coronary artery to the lateral aspect of the proximal MPA in the infant type. B. A Doppler echocardiographic image reveals reversed flow (red color) in the left circumflex artery (arrows) in the infant type. C. Apical four-chamber echocardiographic image demonstrates characteristic inter-coronary collateral arteries (arrows) in the interventricular septum in the adult type. D, E. Apical four-chamber echocardiographic images showing the thinned, echogenic anterolateral papillary muscle (arrows in D) with ischemic damage-induced fibrosis and calcification. In addition, Doppler echocardiography (E) shows mitral regurgitation (red color). Of note, the LA and LV are enlarged. AA = ascending aorta, LA = left atrium, LV = left ventricle, MPA = main pulmonary artery, RV = right ventricle

Fig. 4. Preoperative cardiac CT of anomalous origin of the left coronary artery from the pulmonary artery.

A. A frontal color-coded volume-rendered CT image demonstrates the right coronary artery normally arising from the aortic sinus (red color) and the left coronary artery anomalously originating from the pulmonary sinus (blue color) in the infant type. B. A superior color-coded volume-rendered CT image shows the dilated, tortuous right coronary artery anomalously arising from the MPA (blue arrow) and the dilated, tortuous left coronary artery normally originating from the aortic sinus (red arrow) in the adult type of a rare variant. Dilated, tortuous epicardial branches are noted due to well-developed inter-coronary collateral flow. C, D. Short-axis (C) and long-axis (D) CT images reveal characteristic inter-coronary collateral arteries in the interventricular septum in the adult type. E. An axial CT image acquired for contrast bolus tracking shows calcific densities in the anterolateral papillary muscle of the LV (arrow) and cardiomegaly in the infant type. F. A short-axis late iodine enhancement CT image demonstrates delayed enhancement in the anterolateral wall (white arrows) and thinning of the anteroseptal wall of the LV with subendocardial calcification (black arrow). G, H. Oblique sagittal end-systolic (G) and end-diastolic (H) color-coded volume-rendered CT images show the LV volumes segmented using three-dimensional threshold-based approach for ventricular function assessment. AA = ascending aorta, LA = left atrium, LV = left ventricle, MPA = main pulmonary artery, RV = right ventricle

Fig. 5. Postoperative cardiac CT after reimplantation of the left coronary artery for treating anomalous origin of the left coronary artery from the pulmonary artery.

A. An oblique sagittal volume-rendered CT image shows the patent left coronary artery (arrow) reimplanted into the aorta in the infant type. B. An oblique frontal volume-rendered CT image reveals an anastomotic stenosis (arrows) of the reimplanted left coronary artery in the adult type. The coronary arteries remain dilated and tortuous. LA = left atrium, LV = left ventricle, RV = right ventricle

Fig. 6. Cardiac MRI of anomalous origin of the left coronary artery from the pulmonary artery.

A, B. Short-axis cine images show an anomalous connection (arrow in A, B) of the left coronary artery to the MPA with dark intensity due to the turbulent flow (arrow in B). C. Series of short-axis cine images used for ventricular function assessment. For ventricular volumetry, a simplified contouring method is usually used. D, E. Short-axis (D) and long-axis (E) late gadolinium enhancement images demonstrate subendocardial myocardial infarction in the anteroseptal wall of the LV (arrows). AA = ascending aorta, LA = left atrium, LV = left ventricle, MPA = main pulmonary artery, RA = right atrium, RV = right ventricle

Fig. 7. Stress-rest myocardial perfusion single photon emission CT of anomalous origin of the left coronary artery from the pulmonary artery.

A. Radionuclide myocardial perfusion study shows a large fixed perfusion defect in the anteroseptal wall of the LV. B. Radionuclide myocardial perfusion study shows a large partially reversible perfusion defect in the anteroseptal wall of the LV. LV = left ventricle