Shigesato Inoue, Akihiro Jo, Hiroyuki Kumazoe, Kentaro Wakamatsu
A 40-year-old man presented with right-sided pulmonary infiltrates mimicking pneumonia. Imaging and transesophageal echocardiography revealed unilateral pulmonary edema (UPE) from acute severe mitral regurgitation (MR) due to chordal rupture. Unilateral infiltrates with rapid deterioration warrant early echocardiographic evaluation.