Ostium Secundum Atrial Septal Defect: A Case Report with Review of Literature

Background: Atrial septal defect (ASD) is a congenital cardiac abnormality, representing roughly 10% of all congenital heart problems. The ostium secundum type is the truly familiar form, characterised by a deficit in the fossa ovalis. A significant proportion of instances, sometimes diagnosed in childhood, remain asymptomatic and undiscovered for the whole of a patient's life. Case Presentation: An incidental discovery of a multi-fenestrated ostium secundum-type atrial septal defect was made during routine cadaveric dissection of a 60-year-old male cadaver. Five distinct fenestrations were observed within and around the fossa ovalis area of the interatrial septum, located in its superior, central, and inferior segments a configuration characteristic of the 'swiss-cheese' septal variety. The fossa ovalis boundary was discernible as a fibrous ring, however the floor and adjacent septum secundum tissue were significantly perforated. This individual has no recorded history of congenital heart disease. Conclusion: This case highlights the clinical and anatomical importance of multi-fenestrated ostium secundum atrial septal defect, a morphological variety characterised by numerous distinct perforations instead of the anticipated singular central opening. The observed 'swiss-cheese' pattern has significant implications during surgical intervention, since it frequently prevents conventional single-device transcatheter closure and may require surgical patch repair. This case underscores the significance of cadaveric dissection in revealing intricate congenital abnormalities that may remain asymptomatic during a affected population life. KEYWORDS: Atrial septal defect. Ostium secundum, multi-fenestrated atrial septal defect, Cadaveric dissection.