Functional mitral stenosis, atrial fibrillation and heart failure secondary to left atrial compression by the formation of a localised periatrial haematoma after cardiac resuscitation.

A 53-year-old male patient was diagnosed with progressive dyspnoea after primary coronary intervention of circumflex lesion. Resuscitation was performed in the follow-up period due to the development of asystole. Control angiography showed patentstent without perforation signs and echocardiography revealed prominent compression of the left atrium by a periatrialmass. Magnetic resonance imaging (MRI) was performed for differential diagnosis. The MRI revealed an isolated periatrial haematoma compressing the left atrium and obliterating the mitral valve orifice. Haematoma formation had most probably occurred after resuscitation, since the initial echocardiogram was normal. After a one week follow-up, there had been no decrease in the size of the haematoma, and surgery was proposed. Left atrial compression by the formation of a periatrial haematoma related to resuscitation has not been reported before. It can cause atrial fibrillation and rapidly progressive heart failure. A more accurate diagnosis could be made using an MRI study.