An unusual cause of right upper- and mid-zone infiltrates on chest x-ray.

Chest x-ray remains a critical investigation in patients who present with shortness of breath. We report a 60-year-old man who presented with shortness of breath, haemoptysis and respiratory failure, a raised white cell count, and right upper-and mid-zone infiltrates on chest x-ray. He developed progressive multiple organ failure despite aggressive intensive care management with antibiotics, ventilation and inotropes. As his haemodynamic instability continued to worsen, transthoracic, and subsequently transoesophageal, echocardiography revealed posterior mitral valve leaflet prolapse with severe mitral regurgitation. Mitral valve repair and annuloplasty led to eventual complete resolution of symptoms. The changes seen in the right upper and mid zones on initial chest x-ray were due to the mitral regurgitant jet being directed predominantly towards the right superior pulmonary vein. We report this case to highlight a rare but important cause of lobar oedema, and the usefulness of echocardiography in assessment of the patient with complex critical illness.