The cardiovascular system part 1
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1. The document discusses atherosclerosis and ischemic heart disease. Atherosclerosis is a disease of large and medium arteries characterized by plaque buildup within the artery wall. 2. Risk factors for atherosclerosis include age, gender, family history, hyperlipidemia, hypertension, smoking, and diabetes. Grossly, plaques appear white to yellow and firm or soft. Microscopically, plaques contain macrophages, foam cells, cholesterol, and calcium. 3. Ischemic heart disease is caused by an imbalance between myocardial oxygen supply and demand. Myocardial infarction results from coronary artery occlusion and causes heart muscle cell death. On gross exam, infarcts appear yellow or hemorrhagic
The cardiovascular system part 1
- 1. The Cardiovascular System Part 1 By Dr. Varughese George Department of Pathology
- 4. Atherosclerosis • Introduction • Risk Factors • Gross Features • Microscopic Features • Complications
- 5. Atherosclerosis • A disease of large and medium-sized arteries. So we are talking about the aorta and its main branches: coronaries, internal and external iliac, carotids, & subclavian arteries. The organ arteries are rarely affected such as renal, splanchnic, upper extremity arteries. The intracerebral arteries & lower extremity arteries are the only exceptions. • Accumulation of fibrofatty plaques within the intima of blood vessels. • Produces irregular thickening of the wall and narrowing of the lumen.
- 6. Atherosclerosis • Introduction • Risk Factors • Gross Features • Microscopic Features • Complications
- 7. Non-Modifiable Risk Factors • Age – A dominant influence – Atherosclerosis begins in the young, but does not precipitate organ injury until later in life • Gender – Men more prone than women, but by age 60-70 about equal frequency • Family History – Familial cluster of risk factors – Genetic differences
- 8. Modifiable Risk Factors (potentially controllable) • Hyperlipidemia • Hypertension • Cigarette smoking • Diabetes Mellitus • Elevated Homocysteine • Factors that affect hemostasis and thrombosis • Infections: Herpes virus; Chlamydia pneumoniae • Obesity, sedentary lifestyle, stress
- 9. Atherosclerosis • Introduction • Risk Factors • Gross Features • Microscopic Features • Complications
- 10. Atheroma Aorta GROSS FEATURES: The atheromatous plaque in the coronary is eccentrically located bulging into the lumen from one side. The plaque lesion is white to yellowish-white and may have ulcerated surface. Cut section shows firm fibrous cap and central yellowish-white soft porridge-like core. Frequently, there is grittiness owing to calcification in the lesion.
- 11. Atheroma Aorta
- 12. Atherosclerosis • Introduction • Risk Factors • Gross Features • Microscopic Features • Complications
- 13. Atheroma Aorta MICROSCOPIC FEATURES : • The superficial luminal part of fibrous cap is covered by endothelium and is composed of smooth muscle cells,dense connective tissue and extracellular matrix. • The cellular area under the fibrous cap is composed of macrophages, foam cells and lymphocytes. • The deeper central soft core consists of extracellular lipid material, cholesterol clefts, necrotic debris and lipid laden foam cells. • Calcium salts are deposited in the vicinity of necrotic area and in the lipid pool deep in the thickened intima.
- 15. Atherosclerosis • Introduction • Risk Factors • Gross Features • Microscopic Features • Complications
- 16. Complications of Atherosclerosis COMPLICATED PLAQUES : Dystrophic Calcification ( brittle eggshell quality) Ulceration and Atheroemboli Plaque rupture with superimposed thrombus CLINICAL COMPLICATIONS: Ischemic Heart Disease (MIs) Cerebrovascular Accidents Atherothrombi (transient ischemic attacks & renal infarcts) Aneurysm formation. Peripheral Vascular Disease. Mesenteric artery occlusion.
- 18. Ischemic Heart Disease • Acute or chronic cardiac disability arising from imbalance between the myocardial supply and demand for oxygenated blood. " Ischaemia " refers to an insufficient amount of blood. The coronary arteries are the only source of blood for the heart muscle. If this coronary arteries are blocked, the blood supply will reduce. Chest pain: cardinal symptom of myocardial ischemia caused by coronary artery disease (CAD)
- 19. 19 Risk Factors Uncontrollable •Sex •Hereditary •Race •Age Controllable •High blood pressure •High blood cholesterol •Smoking •Physical activity •Obesity •Diabetes •Stress and anger
- 20. 20 Ischemic Heart Disease Classification – Myocardial infarction (MI) – Sudden cardiac death – Angina pectoris – Chronic Ischemic Heart Disease with Heart Failure
- 21. Myocardial Infarction • Introduction • Gross Features • Microscopic Features • Complications
- 22. Myocardial Infarction • Partial or total occlusion of one or more of the coronary arteries due to an atheroma, thrombus or emboli resulting in cell death (infarction) of the heart muscle. • Types – – Transmural Infarct – involves the entire thickness of the LV wall ischemic necrosis of > 50% of myocardial wall. – Subendocardial Infarct – multifocal areas of necrosis confined to the inner 1/3-1/2 of the left ventricular wall. ischemic necrosis of < 50% of myocardial wall. • Distribution of coronary artery thrombosis – – Left anterior descending artery - 45% – Right coronary artery – 35% – Left circumflex artery – 15%
- 23. Myocardial Infarction • Introduction • Gross Features • Microscopic Features • Complications
- 24. Acute Myocardial Infarction GROSS FINDINGS In a nonreperfused MI, the infarcted area is well defined at 2-3 days, with a central area of yellow discoloration surrounded by a thin rim of highly vascularized hyperemia. The arrow points to a transmural infarct in the posterior wall of the left ventricle, in this short axis slice through the left and right ventricular chambers.
- 25. Acute Myocardial Infarction GROSS FINDINGS In reperfused MI, the infarcted region appears red because of trapping of the red cells and hemorrhage from ruptured necrotic capillaries The infarct is diffusely hemorrhagic. There is a rupture track through the center of this posterior left ventricular transmural infarct.
- 26. Recent MI – 3-7 day. Hemorrhagic periphery LV RV
- 27. Healed Myocardial Infarct GROSS FEATURES The infarcted area is replaced by a thin, grey-white, hard, shrunken fibrous scar compared to adjacent uninvolved grey brown myocardium There is diffuse scarring (white) with marked thinning of the ventricle
- 28. Myocardial Infarction • Introduction • Gross Features • Microscopic Features • Complications
- 32. Healed Myocardial Infarct MICROSCOPIC FEATURES : There is replacement of an irregular area of the myocardium by dense fibrocollagenous tissue with foci of entrapped groups of myocardial fibres. The neighbouring myocardial fibres may show compensatory hypertrophy. The affected area of healed infarct shows old granulation tissue seen by infiltrate of some pigmented macrophages,lymphocytes and plasma cells and a few capillary sized blood vessels.
- 33. Myocardial Infarction • Introduction • Risk Factors • Gross Features • Microscopic Features • Complications
- 34. Complications of Myocardial Infarction • Cardiac Arrhythmias ‘sudden death’ • Congestive heart failure (pulmonary edema) • Cardiogenic Shock ( as > 40-50% of myocardium is necrotic) • Mural thrombosis with thromboembolization • Fibrinous pericarditis. • Cardiac rupture (most common 4-7 days post MI) – Ventricular free wall cardiac tamponade. – Interventricular septum left to right shunt. – Papillary muscle mitral insufficiency. • Ventricular aneurysm formation.
- 35. Chronic Ischemic Heart Disease • Introduction • Gross Features • Microscopic Features
- 36. Chronic Ischemic Heart Disease Chronic IHD is found in elderly patients of progressive ischaemia who have had repeated episodes of angina due to coronary disease.
- 37. Chronic Ischemic Heart Disease • Introduction • Gross Features • Microscopic Features
- 38. Chronic Ischemic Heart Disease Gross Features • The heart may be normal sized or hypertrophied. • The left ventricular wall shows foci of grey-white fibrosis.
- 39. Chronic Ischemic Heart Disease • Introduction • Gross Features • Microscopic Features
- 40. Chronic Ischemic Heart Disease Microscopic Features There are scattered areas of myocardial fibrosis, especially around arterioles (terminal branches of coronaries) in the interstitial tissue of the myocardium. The neighbouring myocardial fibres show variation in fibre size and changes of myocardial hypertrophy Areas of brown atrophy may be seen, i.e. presence of lipofuscin pigment in the myocardial fibres.