LAUSR

https://e-kcj.org The coronary arterial system consists of large epicardial coronary arteries (>500 μm), prearterioles (100–500 μm), and intramural arterioles (<100 μm). Each component of the coronary arterial system plays a unique role in maintaining coronary blood flow. In the absence of obstructive stenosis, epicardial coronary arteries mainly serve as capacitance vessels with little resistance (up to 10%) to coronary blood flow. Coronary vascular resistance is mostly controlled by prearterioles (up to 25%) and arterioles (up to 55%) by altering myogenic constriction and vascular tone in response to mechanical, neural, and metabolic stimuli. Namely, coronary microcirculation is the main site for myocardial blood flow regulation beyond the epicardial coronary arteries.1)2)