Abstract
Atrial septal defect (ASD) is a congenital heart defect that can be commonly found in adults. The coexistence of ASD with pulmonary alveolar proteinosis (PAP) has not been reported. We report the case of a 35-year-old male farmer who presented with progressive shortness of breath and was diagnosed with a large ostium secundum ASD, severe pulmonary artery hypertension (PAH) and biventricular dysfunction. Despite surgical closure of the ASD and intensive postoperative support, the patient developed profound haemodynamic instability and multi-organ failure, ultimately resulting in death. Histopathological examination of lung tissue revealed secondary PAP, which likely contributed to refractoriness of pulmonary hypertension and hypoxemia, complicating management. This report underscores the need for high suspicion of coexisting lung pathology, such as PAP, in ASD patients with disproportionate PAH, and highlights the complexities of perioperative management and the importance of individualised multidisciplinary care in such rare and challenging clinical scenarios.