A heart within the heart--a rare congenital cause of an embolic stroke.

The authors report the case of an 87-year-old lady who presented with a right middle cerebral artery territory infarct in whom the authors diagnosed a probable ruptured blood cyst attached to her anterior mitral valve leaflet, with the use of trans-thoracic and trans-oesophageal echocardiography. Embolic strokes are recognised as a rare complication of intracardiac blood cysts, with very few cases previously reported. Echocardiography was first used to identify a blood cyst in 1983 and remains an excellent modality to diagnose this rare condition.