Case presentation
An 8-year-old boy presented with symptoms of shortness of breath, palpitations, and markedly reduced exercise tolerance following an upper respiratory tract infection 20 days ago. His medical history was notable only for a diagnosis of infantile exanthema, characterised by maculopapular rashes and fever, at the age of 1. On admission, the patient’s blood pressure was 114/74 mmHg, heart rate 128 beats per minute, respiratory rate 24 breaths per minute, and oxygen saturation 98% on room air. He was 142 cm tall and weighed 41 kg with no evidence of growth restriction. Physical examination revealed a loud holosystolic murmur throughout the precordium, particularly at the apex, while the lungs were clear.
Electrocardiography showed sinus tachycardia with a rate of 124 beats per minute. Echocardiography revealed a dilated left atrium, enlarged left ventricle, and left ventricle ejection fraction of 61%. Severe mitral regurgitation, moderate tricuspid regurgitation, and the systolic pulmonary artery pressure estimated at 84 mmHg were also presented (Figure S2 and S3). The initiations of right (4.4 mm) and left (5.0 mm) coronary arteries were slightly dilated, both appearing to arise from the aorta. Coronary artery CT (Figure 1) demonstrated a stripe shadow in the region of the anterior interventricular sulcus, suggestive of the left coronary artery, with its upper end closely related to the pulmonary artery root. Laboratory studies were nearly all normal, including the vasculitic test. Angiography (Figure 1 and Figure S4) revealed a large, dilated, and tortuous right coronary artery arising from the aorta, which supplied the left coronary system through little collaterals. No left coronary artery was identified arising from the aorta or the pulmonary artery following contrast media injection.
( a ). Coronary computed tomography angiography image: proximal left main trunk ended blindly. Coronary computed tomography angiography showed a stripe shadow (black arrow) in the anterior interventricular groove without enhancement seeming to be left coronary artery (LCA). ( b ). Coronary angiography: right coronary artery (RCA) origin of the aorta (AO). Coronary angiography only revealed a dilated and tortuous RCA with little collaterals without any signs of LCA.
Based on these findings, we considered mitral regurgitation and heart failure due to myocardial ischaemia, primarily caused by left coronary artery lesions, although the exact lesion was unclear. Takayasu’s arteritis, congenital left main coronary artery atresia (LAMCAA), and anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) were considered as potential diagnoses. The patient was subsequently transferred to the operating room for coronary artery bypass grafting or revascularization and mitral valve repair. Intraoperative transesophageal echocardiography revealed some weak blood flow signals of the left coronary artery from pulmonary artery root, confirming that the left coronary artery originated from the left-posterior sinus of the pulmonary artery. The mean pulmonary artery pressure and aorta pressure measured during the operation were 48 mmHg and 59 mmHg. The patient underwent successful left coronary artery reimplantation to the aorta and mitral valve repair. Since the surgery, he has not suffered any dyspnoea and fatigue.
Discussion
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital cardiovascular defect that is often misdiagnosed as valvular heart disease. Reference Khanna, Torigian, Ferrari, Bross and Rosen1 This abnormality manifests in two types: the infant type and the adult type, each with distinct clinical features and outcomes. In infants with little or no coronary collateral circulation, ALCAPA typically presents with congestive heart failure and mitral regurgitation secondary to myocardial infarction. Without surgical intervention, up to 90% of infants will die within weeks or months of birth. Reference Wesselhoeft, Fawcett and Johnson2 In contrast, although adults with ALCAPA develop significant collateral circulation, it is insufficient to adequately supply the left ventricle and fully oxygenated blood flows into the main pulmonary artery. This can lead to sudden cardiac death due to fatal arrhythmias. Reference Leong, Borges, Henry and Butany3 Echocardiography is an important examination that often reveals cardiac enlargement, mitral regurgitation, and hyperechoic papillary muscles. It is typically diagnosed through angiography or echocardiography, which can directly visualise the left coronary artery originating from the main pulmonary artery or demonstrate retrograde flow from the left coronary artery to the main pulmonary artery. Reference Xiao, Jin and Han4
In this case, angiography and echocardiography did not reveal any typical retrograde blood flow in left coronary artery from the pulmonary artery, which led to confusion and a misdiagnosis. The detailed diagnostic process is given in Figure S1. This patient could have developed severe mitral regurgitation due to myocardial ischaemia after birth, but it did not result in fatal consequences. In a short period, the severe mitral regurgitation caused pulmonary hypertension, increasing pressure above systemic pressure. This led to antegrade flow in the anomalous left coronary artery from the main pulmonary artery, similar to what occurs in neonatal life. This was confirmed intraoperatively by weak antegrade flow in TEE and significantly increased pulmonary artery pressure. While this prevented severe deterioration of LV function, heart failure symptoms progressed rapidly with increased physical activity or the development of pulmonary infections.
Sedky et al. reported a similar case of a 1.5-year-old male child with ALCAPA and severe mitral regurgitation. Reference Sedky, Hosny, Donya, AbdElsalam and Yacoub5 Echocardiography revealed antegrade flow in the left coronary artery. However, the origin of the left coronary artery was far from its typical position, which helped the surgeons easily identify the anomaly. In addition, other cases of ALCAPA describing antegrade flow in the left coronary artery have also been reported in patients with associated conditions such as patent ductus arteriosus or ventricular septal defect. Reference Awasthy, Marwah, Sharma and Dalvi6,Reference Suzuki, Ittleman and Gogo7 Similar to previous ALCAPA cases, antegrade flow in the left coronary artery due to elevated pulmonary artery pressure reverses the classic “coronary steal” phenomenon. However, in patent ductus arteriosus/ventricular septal defect-associated ALCAPA, left-to-right shunts directly increase pulmonary artery pressure. In our case, pulmonary artery hypertension was indirectly caused by MR, a mechanism rarely reported in isolated ALCAPA. Moreover, patients with patent ductus arteriosus/ventricular septal defect often undergo earlier intervention due to heart failure in the infant period. Our case presented with delayed symptoms after infection in an older age, raising diagnostic difficulties in patients without shunts to clinicians. To our knowledge, this is the first report of ALCAPA with antegrade flow without other comorbidities (patent ductus arteriosus/ventricular septal defect). For this child, as pulmonary vascular resistance falls and the development of coronary collaterals after birth, retrograde flow from the left coronary artery to pulmonary artery makes subendocardial hypoperfusion. Myocardial ischaemia triggers tethering in the papillary muscles and restricted motion of the leaflet, resulting in mitral regurgitation and left ventricular dysfunction. When the time prolongs further, the end result is the volume overload, dilatation of the mitral annulus, worsening mitral regurgitation, pulmonary venous hypertension and, finally, pulmonary hypertension and tricuspid regurgitation. Elevated pulmonary vascular pressure decreases the retrograde flow in the left coronary artery and makes the flow antegrade again as in the infant period. These atypical presentations of antegrade flow in the left coronary artery can bring diagnostic challenges to clinicians.
Surgical treatments for ALCAPA include left coronary artery ligation with coronary artery bypass grafting, Takeuchi operation, and left coronary artery reimplantation. However, treatment for mitral valve regurgitation at the same time remains controversial. It is believed that mitral regurgitation is associated with myocardial ischaemia in ALCAPA patients. Some centres advocated against mitral valve repair or replacement, arguing that mitral regurgitation would be reduced following reconstruction of the coronary circulation. Reference Brown, Ruzmetov, Parent, Rodefeld and Turrentine8,Reference Yuan and Jing9 However, in our centre, we recommend performing mitral valve surgery and left coronary artery reimplantation simultaneously. In our centre, we believe that early mitral valve repair surgery may improve cardiac function and reduce the incidence of perioperative complications and risks of reoperation. We advocate that infants and young children with severe mitral regurgitation will undergo mitral valve repair at the time of coronary artery revascularization. Preoperative mild or moderate mitral regurgitation will be improved after reperfusion alone. However, for older children and adults, mitral valve repair or replacement will be performed in those with moderate or severe mitral regurgitation. Although coronary perfusion is recovered, significant valve regurgitation will not regress without surgery. But it is noticeable that mitral valve replacement at first surgery should be implemented with caution for children. A total of 42 patients accepted surgery for ALCAPA from January 2017 to March 2025 in our centre. Following our centre protocol, 6 young children (average age 1.3 years) with severe preoperative mitral regurgitation underwent MVP simultaneously, and all children were discharged uneventfully. About 5 children (average age 1.5 years) with mild or moderate mitral regurgitation had ALCAPA procedure alone, and the degree of mitral regurgitation improved or remained stable during follow-up. For old children or adults, we advocate that moderate to severe regurgitation requires surgical intervention. About 2 children (average age 9.6 years) and 4 adults had MVP, and an 8-year-old child of them had to accept MVR (St. Jude mechanical valve) at half a year after first discharge for aggravation of regurgitation.
This case underscores the imperative to suspect ALCAPA in children presenting with unexplained heart failure and severe mitral regurgitation, even when classic imaging signs (e.g. retrograde left coronary artery flow) are absent. Clinicians should consider abnormal hemodynamics (e.g. pulmonary artery hypertension) that may mask typical findings. Selective left and right heart angiography remain necessary for paediatric cases with diagnostic uncertainty.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S1047951125100978.
Acknowledgements
The authors would like to thank all staff members in the department of cardiovascular surgery of West China Hospital. The authors sincerely thank Dr Changping Gan, for his contributions to the study design and performance.
Financial support
This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Competing interests
The authors have no conflict of interests.
Ethical standards
This research does not involve any human and/or animal experimentation.
