Figure 1.

Etiologies of chest pain without obstructive CAD.
This figure illustrates the varying pathophysiologic mechanisms of chest pain without obstructive CAD grouped into three broad categories: non-cardiac; cardiac ischemic; and cardiac non-ischemic. The contribution of multiple potential pathophysiologies to cardiac syndrome X is highlighted. Microvascular angina overlaps partially with cardiac syndrome X as shown, but has a narrower pathophysiologic basis which is cardiac ischemic in nature..