From Cyanosis to Extensive Systemic‐to‐Pulmonary Collaterals Formation: A Case With an Iatrogenic Connection of the Inferior Vena Cava to the Left Atrium

ABSTRACT Atrial septal defect (ASD) is a prevalent congenital heart abnormality that can be effectively repaired through either surgical or interventional procedures. We decide to describe a 50‐year‐old male with a history of dyspnea, cyanosis, and hypoxemia. A remarkable past medical history is that he underwent surgical correction of an ASD at the age of 6. Because of an initial misdiagnosis of Eisenmenger syndrome, he recently received palliative therapy, including therapeutic phlebotomy. Subsequent coronary computed tomography angiography (CTA) revealed systemic‐to‐pulmonary collaterals (SPCs) and an iatrogenic diversion of the inferior vena cava (IVC) to the left atrium (LA). A contrast study in transesophageal echocardiography confirmed the IVC's aberrant pathway to the LA. The diagnostic pathway and rationale behind these findings underscore the significance of multimodality imaging and reevaluation of the initial diagnostic impression.