Figure 3.

Mechanisms of coronary macrovascular and microvascular dysfunctions. Normal structure and function of coronary macro- and microcirculation is composed by epicardial arteries, pre-arterioles, arterioles, and capillaries. Epicardial spasm typically occurs in the epicardial arteries. On the contrary, coronary microvascular circulation can be subject to impaired coronary vasodilatation due to endothelial and non-endothelium-dependent factors and to microvascular spasm disorder. These phenomena lead to coronary microvascular dysfunction which supports a systemic vascular disease due to vasoconstriction or impaired vasodilatation.