Ischemic Heart Disease Group of diseases Most common cause of death in developed countries Terminology: 1.Angina pectoris 2.Myocardial infarction 3.Sudden cardiac death 4.Chronic ischemic heart disease –Coronary artery disease –Acute coronary disease

Ischemic Heart Disease Common in older adults: –>60 in males –>70 in females –M>F Fisk factors: hypertension, Diabetes, smoking, high cholesterol, genetic factors Factors reducing the risk: regular exercise, alcohol.

Ischemic Heart Disease Pathogenesis: –Atherosclerosis of coronary arteries –Stenosis (narrowing) of the lumen Mild, moderate, sever “critical” >75% stenosis –Changes in atheromatous plaques: 1.Acute plaque change: –fissuring, hemorrhage, rupture with embolism –Usually occurs in moderate stenosis –How does it occur? –Metalloproteinase from macrophages, T-cell activation, hemodynamic trauma

Ischemic Heart Disease Pathogenesis: –Changes in atheromatous plaques: 2. Coronary artery thrombosis –Complete occlusion resulting in infarction –Incomplete occlusion resulting in unstable angina –Embolization 3. Coronary artery vasospasm –Other pathology: Emboli from aorta or valves vasculitis Severe hypotension Left ventricular hypertrophy

Angina Pectoris Intermittent chest pain caused by transient reversible myocardial ischemia 1.Typical “stable” angina Episodic chest pain Crushing sub-sternal Radiate to left arm Due to fixed atherosclerotic narrowing Usually with critical stenosis >75% Relieved by rest or nitroglycerin

Angina Pectoris Intermittent chest pain caused by transient reversible myocardial ischemia 2. Prinzmetal (variant) angina: Occurs at rest, awaken the patient from sleep Due to coronary artery spasm 3. Unstable angina: Increase in frequency of angina With less and less exercise Last longer Due to acute changes in atheromatous plaque or thrombosis

Myocardial Infarction Myocardial necrosis caused by local ischemia In the US 1.5 million cases with 500,000 deaths per year Age group year, M:F 4:1

Myocardial Infarction Pathogenesis: –Coronary artery thrombosis –Necrosis of cardiac muscle after minutes of complete occlusion –Necrosis begins in the subendothelial zone –Depends on the vessel involved: Left anterior descending (40-50%): anterior and apical area of the LV with anterior 2/3 rd of septum Right coronary artery (30-40%): posterior and basal area of the LV, posterior 1/3 rd of the septum Circumflex artery: lateral wall of the LV

Myocardial Infarction Morphology: –12 h: no change –12-18 h: coagulative necrosis –18-24 h: neutrophils –3 days: peak of inflammation –If reperfusion occurs it results in hemorrhage –4-7 days: well-defined pale region, with macrophages, and fibroblasts –10 days: granulation tissue –4 weeks: collagen depsition –8 weeks: scar

Myocardial Infarction Complications: –Left ventricular failure (60%) –Cardiogenic shock (10%) –Papillary muscle dysfunction/infarction/rupture –Rupture of LV (4-8%) –Mural thrombi (15%) –Ventricular aneurysm –Acute pericarditis

Myocardial Infarction Clinical: –Sever, crushing sub-sternal chest pain –Radiate to neck, jaw, shoulder and left arm –Last for hours –Dyspnea due to pulmonary edema –If large(>40%) leads to cardiogenic shock –“silent” MI in diabetics and elderly –ECG changes –Elevated CK, troponin, LDH –25% death due to arrhythmia

Chronic Ischemic Heart Disease Development of progressive congestive heart failure as a consequence of long-term ischemia Usually with Moderate-severe coronary artery stenosis Pervious MI and scarring Dilated heart

Sudden Cardiac Death Excluding: homicide, suicide, trauma and toxins Causes: heart disease, pulmonary embolism, rupture aortic aneurysm, CNS Ischemic heart disease is the most common cause Death due to ventricular arrhthmia