Abstract
Coronary microvascular disease (CMD) makes reference to the anatomically and functionally disorders affecting vascular compartments (<400 mm diameter), covering a broad range of clinical conditions in which the structure and function of the coronary microcirculation is affected. CMD is characterized by an impaired coronary flow reserve (cut-off values of 2.0-2.5) or an abnormally index of coronary microvascular resistance (IMR >25) and/or focal or diffuse vasoconstriction during acetylcholine challenge, with an important role in myocardial perfusion. The aim of this work is to review CMD, definition, clinical manifestations, diagnosis method (non invasive and invasive approach) and the role of CMD in the main cardiomiophaties, such as Hypertrophic cardiomiopathy, none idiomatic dilated cardiomiopathy and infiltrative miocardiophaty.