Acute coronary syndromes (ACS) are one of the leading causes of death and morbidity in industrialized countries. Typical presentation includes acute chest pain, cardiac troponin elevation and possibly associated electrocardiogram abnormalities. In great majority of the cases, myocardial infarction (MI) is due to atherosclerosis, usually with plaque rupture and consequent vessel occlusion. However, a minority of patients may suffer an MI for a range of other rare reasons such as coronary vasospasm, coronary thrombosis in situ or embolization from a distal source, hypercoagulable states, spontaneous coronary dissection, some coronary anomalies including coronary bridges and inflammatory states.