Abstract
The blood of the coronary arteries is perfused differently from other organs mainly because of myocardial diastole, and it is particularly remarkable in the left coronary arteries. Furthermore, the coronary circulation can be autoregulated, but it is controlled by coronary peripheral vascular resistance, tissue pressure in the diastolic myocardium, and myocardium contractility. Imaging modalities cannot evaluate complex coronary hemodynamics, and thus indexes such as coronary flow pattern, time-averaged peak flow velocity (APV), coronary flow reserve (CFR), myocardial fractional flow reserve (FFRmyo), shear stress, and peripheral vascular resistance are useful. Giant coronary aneurysms and significant stenosis-related lesions become problematic in coronary artery lesions of Kawasaki disease. Coronary flow is turbulent and APV, CFR, and shear stress decrease, whereas peripheral vascular resistance increases in giant coronary aneurysms that are not complicated with significant stenosis-related lesions and in the distal parts of giant coronary aneurysms. Flow is also turbulent and APV, CFR, FFRmyo, and shear stress significantly decrease and peripheral artery resistance increases in the distal part of significant stenotic lesions. Both of these conditions mean that the endothelium of blood vessels becomes disordered and could adversely affect later vascular remodeling.
