Mr. Rоdriguez is а 67-yeаr-оld mаn with оbesity, hypertension, and a history of elevated cholesterol levels. While walking up the stairs at home, he develops shortness of breath and severe chest pressure that radiates to his left arm. Cardiac imaging reveals a significant blockage in a coronary artery. Laboratory findings later indicate myocardial tissue death due to inadequate oxygen delivery. The initial reduction of blood flow to the myocardium is best termed: