The formation of ventricular aneurysm is a late complication of a large transmural myocardial infarction (MI). The scarred thinned ventricular wall bulges out during systole. Ventricular aneurysm may be further complicated by formation of mural thrombus, arrhythmias, and heart failure. The image shows an old posterior myocardial infarction with aneurysm of the thinned posterior wall. The patient was a 62 y/o male with biventricular hypertrophy who was in biventricular failure with an ejection fraction of 10%. Image copyright: pathorama.ch.