This document presents a case study of a 45-year-old woman who underwent device closure of an eccentric atrial septal defect, which led to complications including pericardial and left-sided pleural effusion due to injury during the procedure. Despite the challenges posed by the eccentric nature of the defect and subsequent complications, the patient was managed conservatively and discharged symptom-free after six days. The study emphasizes the technical difficulties and the need for close monitoring during and after similar procedures.