Figure 2.

Comparison of current arterial obstruction‐ischemia concept of atherosclerosis, as shown in (a) and (b) (adapted from Lanza et al.29 with a permission from Wolters Kluwer Health) and (c) our concept. In the stenosis of (a) epicardial (Epi) artery, the territory supplied (gray area) results in regional contractile dysfunction (P1 and P2 indicate blood pressure proximal and distal to obstructive vessels), whereas in the case of (b) microvascular alterations, myocardial ischemia is considered localized only in small myocardial areas (small circles; a and b indicate dysfunctional microvessels). In these concepts, contractile abnormalities are results. (c) Our energy demand‐supply model (adapted from conceptual framework of Kamiya and Takahashi78 with a permission from The American Physiological Society); if the sum of tissue‐microcirculation units, as described here as Nb₀ (rt), decrease, the diameters of daughter branches and the mother branch have to decrease. In other words, if metabolic demand of myocardium decreases (because of mitochondrial dysfunction), its blood supply would decrease, therefore, the diameter of supplying conduit vessel decreases adaptively. Endo, endocardial.