The coronary slow flow phenomena or “cardiac syndrome Y”: A review

Myocardial infarction in young individuals is a rare event that is seldom due to atherosclerotic coronary artery diseases, except in the setting of familial hyperlipidemias with accelerated atherosclerosis. Potential etiologies of myocardial injury in young patients are various, but non-coronary pathologies causing direct myocardial injury e.g. viral myocarditis, account for the majority of cases. Coronary artery diseases causing myocardial infarction in young patients represent a challenge to any treating physician; they mostly fall into the category of “coronary artery vasomotor disorders”. The coronary slow flow phenomena or as more recently called “cardiac syndrome Y” is a relatively poorly understood microvascular coronary artery disorder caused by increased microvascular coronary artery resistance to flow that may result in myocardial infarction at rest in young individuals, the diagnosis can be especially challenging. The unique characteristics of the CSFP/CSY prompted the call for a separate classification within coronary artery vasomotor disorders. In this review we discuss in brief non-atherosclerotic coronary artery disorders, highlighting key clinical features, then we move to an in depth review of the CSFP/CSY including its: Epidemiology, pathophysiology, diagnosis prognosis and management.