A 68-year-old woman being treated with hemodialysis for autosomal dominant polycystic kidney disease was admitted for progressive dyspnea over 6 months. On chest radiography, her cardiothoracic ratio had increased from 52.2% 6 months prior, to 71%, and echocardiography revealed diffuse pericardial effusion and right ventricular diastolic insufficiency. A resultant pericardial tamponade was thought to be the cause of the patient’s dyspnea, and therefore a pericardiocentesis was performed, with a total of 2,000mL of fluid removed.