fig3

Figure 3. Endothelial dysfunction is the primary pathological change in CMD. In normal microvessels, the compensation mechanism includes eNOs and NO increase and ET-1 decrease. In CMD, the decompensation mechanism includes decreased NO and eNOS, and increased ET-1 and FFA. MVO is a more severe condition that always occurs when microemboli (small black block) clog microvessels with inflammation and platelet aggregation. MVO always leads to micro-infarcts (big black shadow). CMD: Coronary microvascular dysfunction; eNOS: endothelial nitric oxide synthase; NO: nitric oxide; ET-1: endothelin-1; FFA: free fatty acids; MVO: microvascular obstruction.