Severe left atrium compression after percutaneous coronary intervention with perforation of a circumflex branch of the left coronary artery.

Coronary artery perforation is a rare complication of percutaneous coronary intervention, but can result in cardiac tamponade and is thus potentially life-threatening. This report describes a rare case of epimyocardial haematoma formation after coronary perforation resulting in a functional mitral stenosis in a patient with coronary bypass grafting in his history. Coronary artery perforations in patients who had previously undergone a coronary bypass grafting procedure, may lead to uncommon haematoma localizations with significant functional implications. A rapid surgical intervention can be life saving.