Diagnosing Congenital Diaphragmatic Eventration Presenting With Transient Cardiac Dextroposition in an Adult: A Case Report and Literature Review.

Congenital diaphragmatic eventration (CDE) is a rare developmental anomaly characterized by abnormal elevation of an intact hemidiaphragm due to deficient muscular development. Although often asymptomatic in adults, it may present with respiratory or gastrointestinal complaints. We report a 65-year-old man with congenital left hemidiaphragmatic eventration associated with gastric displacement and colonic interposition. He initially presented with chest pain and was found to have cardiac dextroposition. Multimodality imaging, including fluoroscopy, demonstrated a transient rightward cardiac displacement that became more apparent after postprandial gastric distention and regressed as gastric decompression occurred. This dynamic finding suggests that gastrointestinal distention and associated mass effect can exacerbate mediastinal displacement in patients with CDE. This case highlights the importance of considering congenital diaphragmatic anomalies in adults with atypical chest symptoms and emphasizes the value of dynamic imaging in clarifying reversible cardiac displacement.