Imaging findings of subaortic membrane stenosis associated with patent ductus arteriosus: a rare case report

Introduction: Subaortic membrane stenosis is an uncommon congenital abnormality that may accompany other anomalies, such as patent ductus arteriosus (PDA), resulting in diagnostic and therapeutic difficulties. Subaortic stenosis frequently coexists with other congenital abnormalities. The prevalence of concomitant abnormalities is 50–65%, predominantly occurring with patent ductus arteriosus in 34% of instances. The reported prevalence varies from 6.1 per 10,000 live births to 6–6.5% among all individuals with congenital cardiac disease. This case report aims to present a rare instance of subaortic membrane stenosis linked to patent ductus arteriosus, highlighting the need for multimodality imaging, especially CT angiography, in verifying the diagnosis and directing care. Case description: A 19-year-old female complains of easy fatigability for the past 6 months. The result of electrocardiography was sinus rhythm, LVH with multiple PVCs. Chest X-ray showed cardiomegaly with pulmonary congestion accompanied by pulmonary plethora. After echocardiography patient was diagnosed with PDA and subaortic membrane stenosis. From the Cardiac CT and Calcium Scoring, also Pulmonary CT Angiography revealed a hypodense linear structure located on the inferior aspect of the aortic valve, predominantly on the right leaflet, which confirms the diagnosis of Subaortic membrane stenosis with PDA. Conclusion: CT Angiography can provide valuable preoperative information in patients with subaortic membrane stenosis, where detailed knowledge of the surgical site is desired.