fig1

Figure 1. The structure of coronary microvessels and the main mechanisms of CMD. The large artery (> 500 μm diameter) is at the proximal end, the prearteriole and the arteriole (500-10 μm diameter) are in the middle part, and the capillary (< 10 μm diameter) is at the distal end. The middle and distal arterial systems mainly provide coronary resistance, nutrient exchange and other functions. The middle and distal arterial systems and venous systems of the same magnitude constitute the coronary microvessels. The mechanisms that affect the local areas of CMD include endothelial dysfunction, inflammation, oxidative stress, left ventricular hypertrophy, microcirculation resistance and mitochondrial abnormalities. CMD: Coronary microvascular dysfunction.