RT Book, Section A1 Doherty, Gerard M. SR Print(0) ID 58106317 T1 Cardiomyopathy, Ischemic T2 Quick Answers Surgery YR 2010 FD 2010 PB The McGraw-Hill Companies PP New York, NY SN LK accesssurgery.mhmedical.com/content.aspx?aid=58106317 RD 2024/11/09 AB • Normal coronary blood flow: 1 mL per gram of myocardium per minute• Oxygen extraction from coronary bed: 75% at rest, 100% during stress• Coronary flow primarily during diastole• Mean coronary resistance is 3-6 times the totally vasodilated value, implying extreme vasodilator reserve• Atherosclerosis progression: Intimal incorporation of lipids → expanding plaque with fibrosis and calcification → finally rupture of plaque causing thrombosis → acute infarction• Subtotal occlusions important in pathogenesis of unstable angina• Usual pattern-Short, proximal stenoses of left coronary artery-In right coronary artery, disease more diffuse, involving proximal and middle portions of artery-Patients with type 1 diabetes mellitus have diffuse disease• Blood flow may be adequate at rest; exercise and stress may produce ischemia• Acute coronary insufficiency (angina pectoris): Immediate decrease in myocardial work• After only 15 minutes of reversible ischemia, may take 24-48 hrs for complete recovery