Long intramural left coronary artery confined to the left sinus of Valsalva with diastolic deformation: a case report.

Background: Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital anomaly. The most frequently reported and surgically treated form involves origin of a coronary artery from the opposite sinus that follows an interarterial course, often termed 'malignant'. In contrast, AAOCA arising from the appropriate sinus without an interarterial course is uncommon, and its clinical significance and optimal management remain poorly defined. Case summary: A 12-year-old girl with exertional syncope during physical activity was referred to our hospital. Contrast-enhanced computed tomography revealed an anomalous origin of the left coronary artery from the left sinus of Valsalva with an acute-angle take-off and an intramural segment. Intravascular ultrasound (IVUS) confirmed an intramural course within the aortic wall and demonstrated luminal deformation, with the lumen appearing more elliptical at end-diastole. Because of exertional syncope and a substantial intramural segment, surgical unroofing was performed without postoperative aortic valve dysfunction. Conclusion: This report describes a rare variant of AAOCA characterized by a long intramural course confined to the left sinus of Valsalva without an interarterial course. Despite the absence of a typical malignant course, the patient had symptoms suggestive of myocardial ischaemia. Multimodality imaging played a key role in diagnosis and surgical planning, while IVUS provided complementary structural and dynamic information by demonstrating luminal changes. Surgical unroofing may therefore be considered for symptomatic paediatric patients with a substantial intramural segment even without an interarterial course.