Myocardial Ischemia, Injury & Infarction Chapter 15 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS

Outline Coronary Artery Circulation Coronary Artery Disease Acute Coronary Syndromes Acute Myocardial Syndrome

Coronary Artery Disease/Risk Factors Family History Gender Race Age Cigarette Smoking Diabetes Mellitus Hypertension Elevated Cholesterol Obesity Lack of Exercise Stress Cocaine Use

Pathophysiology of CAD Phase 1: Appearance of an atheromatous Plaques Phase 2:Formation of thrombus on the surface of the plaque after erosion or rupture –Erosion: endothelial covering of the plaque is torn away –Rupture: fibrous cap is weakened/surge of blood pressure/vasospasm Phase 3: Resolution or Occlusion

Myocardial Ischemia, Injury & Infarction Results from the failure of local CA to supply sufficient oxygenated blood to the myocardial tissue. –Occlusion or obstruction:atherosclerotic CA with blood clots –CA Spasm caused by constriction of smooth muscle in the wall of the CA. –Other reasons such as arrhythmia, PE, Hypotension or shock –Increased Myocardial workload –Decreased level of oxygen in blood delivered to the myocardium