New perspectives in slow coronary flow: a review and update

Since the first description of coronary slow flow by Tambe et al. until today, there have been many publications referring to this entity that is still a source of controversy. Also named in some point as "Y syndrome" it includes a broad spectrum of clinical presentation since angina to acute coronary syndrome or even ventricular arrhythmias and sudden death. Its pathophysiology is multifactorial and has not been completely elucidated yet, involving inflammatory factors, endothelial dysfunction, diffuse microvascular disease, atheromatosis and also metabolic, anatomical and even genetic factors. The diagnostic criteria have also evolved over the years. The main diagnostic test is by angiography, considering coronary slow flow within the spectrum of angina with non-obstructive coronary lesions, however, in recent years controversy has arisen about its true nature. Lately, there have been many studies published contemplating different aspects of this entity, referring either to its pathophysiology or to its diagnosis and treatment. In the present manuscript we make an updated review of coronary slow flow encompassing it in the current cardiological panorama.