Medical school pathology lecture. Pathology of myocardial infarction.

1. "Man often becomes what he believes himself to be. Mahatma Gandhi 1869-1948, Indian Political Leader

2. Pathology of Myocardial Infarction: Dr. Venkatesh M. Shashidhar Associate Professor & Head of Pathology

4. Coronary Thrombosis With Infarction

6. No Q wave - Q wave Why spared?

7. Coronary Atherosclerosis with Thrombosis -(MI)

8. Coronary Atherosclerosis

13. Morphology - Gross & Microscopic Time (approx) GROSS MICROSCOPY Up to 4 hour None None (loss of glycogen/LDH) 4 - 24 hours Gradually developing pale centre dark mottling at periphery. Oedematous. Beginning coagulation necrosis contraction bands. Eosinophilia, pyknotic nuclei, Oedema, acute inflammatory cells. 3-7 days Clearly visible Yellow rubbery centre with haemorrhagic border Obvious necrosis of muscle and plenty of Neutrophils hemorrhage few macrophages & early granulation tissue. 1-3 weeks Infarcted area pale, thin yellow, red gray border. (loss of tissue mass) Granulation tissue, macrophages prominent capillaries, fibroblasts. 3-6 weeks (permanent) Small Silvery scar becoming tough and white Replacement of granulation tissue by dense fibrosis

14. Myocardial Infarction – 3-7 day Pale centre Hemorrhagic periphery

15. Recent MI – 3-7 day. Pale centre Hemorrhagic periphery MI – Papillary M LV RV Papillary Muscle

16. Myocardial Infarction ? Recent ? old 1-3wk - Thin wall, white, thin hemorrhagic periphery

17. MI - Triphenyl Tetrazolium Cl. Stain for LDH . old MI recent MI & Hemorrhage

20. Myocardial Infarction ? time Old & Recent

21. Normal Myocardium: Capillary-RBC My. Neucleus IC disc

22. MI 18hr loss of nucleus, contraction bands. C.Bands

23. MI 18-24 hr loss of nucleus, contaction bands, coagulative necrosis.

24. MI 1day loss of nucleus, contraction bands, few neutrophils. C.Bands Neutro

25. MI 2-3 day – Marginal inflammation. Dead Live

26. MI 1-2 day Hemorrhage & contraction bands in reperfusion injury.

27. MI 1-2 day Hemorrhage & contraction bands in reperfusion injury. MI with reperfusion. A Gross and B microscopy: Following streptokinase therapy. (triphenyl tetrazolium chloride-stained transverse section; posterior wall at top.) B, Myocardial necrosis with hemorrhage and contraction bands, visible as hypereosinophilic bands spanning myofibers (arrow).

28. MI 1-3 day – Plenty of Neutrophils.

29. MI 1-3 wk – Granulation tissue, capillaries.

30. MI 3-6wk - Scar, inflam, outer viable myocardium Live My. Scar.

31. MI >6-Years - Collagen Scar no inflammation.

32. Morphology - Gross & Microscopic Time (approx) GROSS MICROSCOPY Up to 4 hour None None (loss of glycogen) 4 - 24 hours Gradually developing pale centre dark mottling at periphery. Oedematous. Beginning coagulation necrosis contraction bands. Eosinophilia, pyknotic nuclei, Oedema, acute inflammatory cells. 3-7 days Clearly visible Yellow rubbery centre with haemorrhagic border Obvious necrosis of muscle and plenty of Neutrophils hemorrhage few macrophages & early granulation tissue. 1-3 weeks Infarcted area pale, thin yellow, red gray border. (loss of tissue mass) Granulation tissue, macrophages prominent capillaries, fibroblasts. 3-6 weeks (permanent) Small Silvery scar becoming tough and white Replacement of granulation tissue by dense fibrosis

34. Complications of MI: A Anterior myocardial rupture . B Rupture ventricular septum C Rupture papillary muscle. D Fibrinous pericarditis (dark, rough) E Thinning and mural thrombus. F a neurysm

35. MI - Rupture

36. MI – 3 days ? diagnosis

37. MI – Papillary muscle Rupture

39. Old MI – Ventricular Aneurysm Aneurysm

40. Old MI – Ventricular Aneurysm After an infarct, stretching of collagenous scar causing aneurysmal bulging of the ventricular wall ( V ).

41. MI – Rupture & Tamponade

43. "Slow down and enjoy life. It's not only the scenery you miss by going too fast, you also miss the sense of where you are going and why." Eddie Cantor 1892-1964, Comedian

60. Our progress towards success begins with a simple fundamental question...? Where am I going...?

61. Laboratory Diagnosis

62. Self Study Cases & Questions: Nice video of Pathogenesis of Acute MI online: http://pri-med.com/PMO/Home.aspx (Select “Pathogenesis of Acute MI” from list)