Massive Pericardial Effusion in Down Syndrome with Supravalvar Pulmonary Stenosis Associated to Left Pulmonary Collapsep

Background: Pericardial effusion (PE) in Down syndrome (DS) patients usually occurs secondary to hypothyroidism, but we have no report of massive pericardial effusion in euthyroid Down syndrome patient with supravalvar pulmonary stenosis. Case Presentation:We reported an 11-month-old male with Down syndrome with massive pericardial effusion that had conservative management with levothyroxin who presented with cyanosis, respiratory distress and dominantly left upper lobe pulmonary collapse. There was no response to medical management by antibiotic therapy, O2 therapy with hood and chest physiotherapy after five days. Pericardiocentesis guided echocardiography performed on the sixth day after admission and 180 cc transudated pericardial fluids has extracted. Clinical and paraclinical findings were relieved dramatically 12-24 hour after pericardiocentesis. However, Angiography showed supravalvar pulmonary stenosis (SPS). Conclusion: We assume that the chronic compression effect of massive pericardial effusion may be a major cause of SPS.