Introduction: Atherosclerotic coronary artery thrombosis is the most common cause of acute myocardial infarction.
Clinical picture: A 30-year-old lady presented with acute peripartum massive anterior ST segment myocardial infarction and cardiogenic shock. This was due to acute Stanford type A aortic dissection with the intimal flap occluding the left coronary ostium. The initial diagnosis was not apparent. Echocardiography confirmed the diagnosis.
Treatment and outcome: She underwent emergency surgical repair (Bentall procedure). Pathology confirmed underlying idiopathic cystic medial degeneration.
Conclusion: A high index of clinical suspicion is required in acute myocardial infarction presenting without traditional cardiovascular risk factors.