Cardiac Pathology (IHD, Myocardial Infarction, Valvular, Endocarditis) MCQs

Pathology · 105 free questions with answers & explanations.

1. A patient dies 5 days after transmural myocardial infarction. Autopsy shows yellow softening of the necrotic myocardium with a neutrophilic infiltrate and early macrophage invasion. This corresponds to which phase of MI healing?
2. A 60-year-old patient with rheumatic heart disease presents with acute stroke. Echocardiography shows mitral stenosis. Valvular vegetations at autopsy are small (1-2 mm), firm, and located on the line of closure of both mitral and tricuspid valve leaflets on the atrial surface. These findings characterize:
3. In acute myocardial infarction, coagulation necrosis becomes histologically apparent at 12–24 hours. At approximately what time post-infarction do neutrophil infiltration peak and then transition to macrophage-dominated phagocytosis?
4. Libman-Sacks endocarditis is a non-infective endocarditis characteristically seen in systemic lupus erythematosus. The vegetations in Libman-Sacks endocarditis are pathologically distinguished from acute rheumatic fever (Aschoff body-associated) endocarditis by:
5. A 55-year-old hypertensive woman undergoes autopsy following sudden cardiac death. The left ventricle shows concentric hypertrophy, and histology reveals myocyte disarray, interstitial fibrosis, and thickened intramural coronary arterioles. No obstructive epicardial coronary artery disease is found. Which molecular pathway is most central to the pathogenesis of pressure overload-induced cardiac hypertrophy?
6. A 28-year-old intravenous drug user is found to have Staphylococcus aureus bacteremia and right-sided endocarditis affecting the tricuspid valve. Vegetation pathology shows abundant neutrophils, fibrin, and gram-positive cocci. Which virulence factor of S. aureus is most critical for initiating valvular colonization?
7. A 60-year-old woman with advanced ovarian carcinoma develops a murmur. Echocardiography reveals small, sterile, firm vegetations on multiple valves bilaterally, particularly on the line of valve closure. She has no fever and blood cultures are negative. Vegetation histology shows fibrin and platelets without neutrophils. What is this condition and its pathological basis?
8. A 60-year-old man dies 3 days after an acute MI. Autopsy shows a large area of necrosis in the left ventricular wall with surrounding hyperemia. Histology shows loss of nuclei, wavy myofibers with cytoplasmic eosinophilia, and prominent neutrophilic infiltration. No macrophages are seen. This time-course of histological changes corresponds to:
9. In acute rheumatic fever, Aschoff bodies are pathognomonic cardiac lesions. The cells at the center of these granulomatous lesions are Anitschkow cells ('caterpillar cells'). Anitschkow cells are best described as:
10. In infective endocarditis, the HACEK group of organisms (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella) have a characteristic feature that distinguishes them from Streptococcus viridans in terms of diagnosis. This feature is:
11. A patient with myocardial infarction dies 72 hours after onset. Autopsy shows a yellow-tan soft area with a rim of hyperemia. Microscopically, the area shows coagulative necrosis with ghost cell outlines and prominent neutrophilic infiltration. Which specific landmark microscopic finding distinguishes this stage from the 1-week appearance?
12. A patient with rheumatic mitral stenosis has LA thrombus. Histologically, mitral valve leaflets show Aschoff nodules. The characteristic Aschoff cell (Aschoff giant cell) is derived from which cell lineage?
13. A patient with HACEK organism endocarditis (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella) develops large vegetations with septic emboli. Libman-Sacks endocarditis differs from infective endocarditis in that it:
14. Grossly, a transmural myocardial infarction of 4 days' duration would show which characteristic finding?
15. Non-bacterial thrombotic endocarditis (NBTE, marantic endocarditis) is characterized by sterile vegetations. Which histological feature distinguishes its vegetations from those of infective endocarditis?
16. In hypertrophic cardiomyopathy (HCM), the most common causative genetic mutation involves:
17. A 52-year-old diabetic man dies 5 days after an anterior myocardial infarction. Autopsy shows a yellow-white necrotic center with a red-brown hyperemic border, and softening of the myocardium. Histologically, the infarcted area contains ghost cardiomyocytes, polymorphonuclear infiltrate being replaced by mononuclear cells, and early granulation tissue at the margins. At this time point (day 5), which is the most dangerous mechanical complication that can occur?
18. Libman-Sacks endocarditis is the non-infective endocarditis associated with SLE. Which distinguishing feature separates it from acute rheumatic fever (RF) endocarditis regarding the location of vegetations?
19. A pathologist examining a cardiac biopsy from a patient with suspected cardiac allograft rejection identifies Quilty lesions. These represent:
20. In a patient with acute myocardial infarction, coagulation necrosis is the predominant early histological pattern. The transition from reversible to irreversible injury occurs at approximately what time threshold in experimental models?
21. Libman-Sacks endocarditis is the non-infectious endocarditis characteristic of SLE. The vegetations differ from infective endocarditis in which key histopathological feature?
22. Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomere proteins. The most commonly mutated gene in familial HCM is:
23. A 63-year-old woman develops free wall rupture 4 days after an anterior STEMI treated with thrombolysis. Post-mortem reveals coagulation necrosis with prominent neutrophilic infiltration, early macrophage ingestion, and beginning of granulation tissue. This temporal morphological pattern corresponds to which stage of myocardial infarction?
24. A 28-year-old intravenous drug user has fever, regurgitant murmur, and septic pulmonary emboli. Blood cultures grow Staphylococcus aureus. Echocardiography reveals a vegetation on the tricuspid valve. In infective endocarditis caused by S. aureus, the virulence mechanism allowing initial valve colonization without pre-existing valve damage involves which surface protein?
25. Histology of a cardiac allograft biopsy 3 years after transplantation shows concentric intimal hyperplasia in coronary arteries with smooth muscle cell proliferation and lymphocytic infiltration of vessel walls without significant luminal thrombus. This finding represents:
26. Libman-Sacks endocarditis is characterized by sterile vegetations. Which of the following accurately describes its pathological features compared to infective endocarditis?
27. In hypertrophic cardiomyopathy (HCM), the causative mutations are predominantly in genes encoding sarcomeric proteins. The most common genetic mutation causing HCM involves:
28. A 50-year-old man dies 8 hours after the onset of crushing chest pain. Autopsy reveals occlusive coronary thrombus over an atherosclerotic plaque. Which of the following accurately describes the earliest detectable histological change versus the first macroscopic change in the infarcted myocardium at this time point?
29. In libman-Sacks endocarditis associated with antiphospholipid syndrome, which of the following best describes the pathology and its clinical relevance compared to infective endocarditis?
30. In hypertrophic cardiomyopathy (HCM), sarcomeric mutations most commonly affect myosin heavy chain (MYH7) or myosin binding protein C (MYBPC3). How do gain-of-function sarcomeric mutations cause the characteristic diastolic dysfunction and fibrosis in HCM?
31. A patient dies 4 days after an acute anterior STEMI. At autopsy, a pericardial friction rub had been heard on day 2. Microscopic examination of the infarct zone at this stage would most likely show:
32. Libman-Sacks endocarditis in SLE characteristically involves which cardiac structures and has what distinctive pathological feature that helps distinguish it from infective endocarditis?
33. Autopsy of a patient who died 4 days after an acute MI shows a large area of yellow-tan softened myocardium surrounded by a hyperaemic border with neutrophilic infiltration giving way to macrophage infiltration. Coagulative necrosis is confirmed. Which temporal event in the pathologic healing sequence corresponds to peak risk of free wall rupture?
34. A patient with a prosthetic aortic valve develops fever and bacteraemia with Staphylococcus epidermidis within 60 days of surgery. Echocardiogram shows a perivalvular abscess. This is best classified as which form of infective endocarditis?
35. In rheumatic mitral stenosis, fibrosis of the mitral leaflets leads to a 'fish-mouth' or 'buttonhole' orifice. What is the primary microscopic change in the mitral valve in acute rheumatic carditis that leads to this chronic deformity?
36. A 65-year-old man with anterior STEMI died 4 days after onset. Autopsy of the heart would most likely show which histological and gross changes?
37. Libman-Sacks endocarditis is associated with antiphospholipid antibody syndrome and SLE. Which cardiac valvular pathology pattern distinguishes Libman-Sacks from rheumatic endocarditis and infective endocarditis?
38. Arrhythmogenic cardiomyopathy (ARVC/ACM), now classified as arrhythmogenic cardiomyopathy in WHO 2022, most commonly results from mutations in which molecular complex, and what is the mechanistic link between these mutations and the fibro-fatty replacement of the myocardium?
39. A patient dies 4 days after a large anterior STEMI. Autopsy shows a soft, gelatinous, yellow-tan zone of myocardium with scattered neutrophilic infiltrates and beginning macrophage infiltration. What is the key structural change that poses the greatest risk for mechanical complications at this time?
40. In non-bacterial thrombotic endocarditis (NBTE, marantic endocarditis), vegetations are characteristically located on which valve surface and composed of which material?
41. A 55-year-old man dies 4 days after an anterior STEMI. Autopsy shows a transmural infarct with abundant neutrophilic infiltration, wavy fiber change, and beginning coagulation necrosis. At this stage, which complication is most feared due to enzymatic digestion of the myocardial wall?
42. Pathological examination of a cardiac valve removed during surgery for infective endocarditis shows large, irregular, destructive vegetations with underlying valve leaflet necrosis. Gram stain of the vegetation shows Gram-positive cocci in clusters. The underlying valvular predisposing lesion most commonly associated with S. aureus endocarditis is:
43. A 60-year-old man dies 5 days after a large anterior MI. Autopsy reveals a free wall rupture of the left ventricle with hemopericardium. Which histological process was occurring in the necrotic myocardium that predisposed to rupture at this specific time point?
44. Libman-Sacks endocarditis in SLE characteristically shows vegetations on which surface of which valve, and which complement-related laboratory finding is associated with active disease?
45. A patient dies 10 days after acute myocardial infarction. Autopsy shows a ventricular free wall rupture with haemopericardium. Histologically, the infarcted zone shows maximal neutrophilic infiltration at this timepoint. Which pathological process is responsible for rupture?
46. Nonbacterial thrombotic endocarditis (NBTE, marantic endocarditis) is characterized by sterile vegetations at the line of valve closure. Which clinical setting is it MOST associated with?
47. A 60-year-old man dies 4 days after an acute anterior STEMI. At autopsy, the infarcted myocardium shows yellow-gray softening with a hyperemic border. Histologically, there is coagulative necrosis with abundant neutrophil infiltration. Which complication is MOST feared at this stage?
48. Libman-Sacks endocarditis is characterized by sterile verrucous vegetations on BOTH surfaces of the mitral valve leaflets. This finding is MOST specifically associated with which condition?
49. A 45-year-old IV drug user presents with fever and a new tricuspid regurgitation murmur. Echocardiography shows a large vegetation on the tricuspid valve. Blood cultures grow Staphylococcus aureus. What histological feature MOST distinguishes subacute from acute infective endocarditis?
50. On autopsy of a patient who died 5 days after an acute myocardial infarction, the affected myocardium shows yellow-white necrotic tissue with a red-haemorrhagic border. Microscopically, which finding is MOST expected at this stage?
51. Libman-Sacks endocarditis, characterised by small sterile vegetations on both surfaces of the mitral valve leaflets, is pathognomonically associated with which systemic condition?
52. A 28-year-old intravenous drug user develops fever, new-onset right-sided heart failure, and multiple pulmonary septic emboli. Blood cultures grow Staphylococcus aureus. The valve MOST commonly affected in IV drug user–associated infective endocarditis is the:
53. A 60-year-old man dies 4 days after acute myocardial infarction. Autopsy shows a yellow, soft, necrotic center surrounded by hyperemic rim in the anterior wall. Histology would MOST likely show:
54. Libman-Sacks endocarditis, characteristically seen in SLE, predominantly involves which cardiac valves and surfaces?
55. The MOST common causative organism in subacute infective endocarditis affecting a previously abnormal (but not prosthetic) valve is:
56. In acute myocardial infarction, the first histologically detectable change on routine H&E staining typically appears at:
57. Libman-Sacks endocarditis is characterised by small, sterile vegetations on cardiac valves. This form of non-bacterial thrombotic endocarditis is most specifically associated with which autoimmune condition?
58. A 35-year-old IV drug user develops fever and a new pansystolic murmur. Blood cultures grow Staphylococcus aureus. Echocardiography shows bulky, friable vegetations on the tricuspid valve. The mechanism by which infective endocarditis vegetations form on cardiac valves is:
59. In a transmural myocardial infarction, the first histological change detectable on light microscopy after 4-6 hours is:
60. Libman-Sacks endocarditis in SLE characteristically produces vegetations on:
61. Dilated cardiomyopathy caused by coxsackievirus B myocarditis involves molecular mimicry. The cardiac autoantigen mimicked by the viral capsid protein is:
62. At autopsy, a patient who died 5 days after an acute MI shows a soft, yellow-tan infarct with a neutrophilic infiltrate and beginning macrophage infiltration. Which additional finding is expected at this stage?
63. Nonbacterial thrombotic endocarditis (NBTE, marantic endocarditis) is characteristically associated with which clinical setting?
64. A 60-year-old man dies 4 days after an anteroseptal MI. Autopsy shows a soft, yellow-tan area in the anterior wall with neutrophilic infiltrate and early granulation tissue at the margins. The risk of free wall rupture is highest at which time window post-MI?
65. A 25-year-old intravenous drug user presents with fever, new systolic murmur, and multiple septic pulmonary emboli on CT. Blood cultures grow Staph aureus. The most likely valve affected and the mechanism is:
66. Rheumatic mitral stenosis results from recurrent streptococcal pharyngitis triggering an autoimmune response. The cardiac lesion in acute rheumatic fever—Aschoff bodies—consists of:
67. A 60-year-old man dies 5 days after acute myocardial infarction. At autopsy, there is a soft, yellow-tan area of myocardial necrosis surrounded by a hyperemic zone. The predominant infiltrating cell type at this stage is:
68. Libman-Sacks endocarditis, a non-infective endocarditis, is characteristically seen in which condition and has what unique morphologic feature?
69. Hypertrophic cardiomyopathy (HCM) most commonly involves a mutation in the gene encoding which sarcomeric protein?
70. A 55-year-old man dies 4 days after an anterior MI. Autopsy shows a rupture of the interventricular septum. What pathological process at 4 days explains this complication?
71. Libman-Sacks endocarditis is pathognomonic of which condition, and which heart valve surface does it preferentially affect?
72. In libman-Sacks endocarditis associated with SLE, vegetations are characteristically located on:
73. In acute myocardial infarction, neutrophilic infiltration of the infarcted zone is first seen at approximately:
74. A 55-year-old man dies 4 days after an acute anterior MI. Autopsy shows free wall rupture. Histologically, the infarcted zone at this time would show:
75. A 25-year-old IV drug user develops fever and tricuspid valve vegetations on echo, growing S. aureus. Histology of infective endocarditis vegetations shows:
76. The MOST reliable indicator of healed rheumatic myocarditis on histology is:
77. In acute myocardial infarction, irreversible cell injury occurs after approximately 20–40 minutes of severe ischemia. Which ultrastructural feature on electron microscopy is the EARLIEST marker of irreversible myocardial injury?
78. A 65-year-old man with a 3-week-old anterior STEMI treated with thrombolysis presents with fever, chest pain worse on leaning forward, and a pericardial friction rub. This late post-MI complication is best explained by:
79. In non-bacterial thrombotic endocarditis (NBTE / marantic endocarditis), vegetations most commonly occur on which valvular surface and in which patient populations?
80. A 55-year-old man dies 4 days after an anterior MI. Autopsy reveals a soft, yellowish area in the anterior wall with neutrophilic infiltrate. Which structural complication is MOST likely to occur at this time?
81. Libman-Sacks endocarditis is characterized by which histological feature and is most associated with which condition?
82. In acute rheumatic carditis, the pathognomonic histological finding in the myocardium is:
83. A 65-year-old man dies 4 days after acute myocardial infarction. At autopsy, the infarcted zone of the left ventricle shows yellow-tan softening. Histologically, which finding is most characteristic at this stage?
84. A 30-year-old IV drug user develops high fever, new aortic regurgitation murmur, and multiple peripheral embolic events. Blood cultures grow Staphylococcus aureus. Which of the following valvular lesions best describes infective endocarditis?
85. Dilated cardiomyopathy (DCM) is the most common cardiomyopathy worldwide. The most common identifiable genetic cause involves mutations in which protein?
86. A 75-year-old man with a prosthetic mitral valve develops fever, new regurgitant murmur, and multiple cerebral emboli 2 months post-implantation. Blood cultures grow coagulase-negative Staphylococci. The most likely type of prosthetic valve endocarditis is:
87. A 60-year-old man dies 5 days after an acute myocardial infarction. Autopsy reveals a soft, yellowish area in the left ventricle with a thin, friable wall. Microscopically, abundant neutrophil infiltration was seen 2 days ago. What is the predominant cellular change seen at day 5 post-MI that creates the highest risk of ventricular free wall rupture?
88. Libman-Sacks endocarditis (non-bacterial thrombotic endocarditis) is a cardiac complication of SLE. It differs from infective endocarditis by its characteristic location of vegetations. Where are the vegetations located in Libman-Sacks endocarditis?
89. Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death in young athletes. The underlying histological finding that predisposes to lethal arrhythmias in HCM is best described as:
90. On histology of a myocardial infarct, which finding is FIRST to appear and at what time after coronary occlusion?
91. Non-bacterial thrombotic endocarditis (NBTE/marantic endocarditis) most characteristically features:
92. Hypertrophic cardiomyopathy (HCM) is pathologically characterized by which histological finding on endomyocardial biopsy?
93. At 48 hours after a massive anterior myocardial infarction, the area of infarction shows coagulation necrosis with 'ghost outlines' of myocytes and a rim of neutrophilic infiltrate at the periphery. Which of the following complications is most likely to occur at this stage?
94. Which of the following best describes the pathogenesis of mitral valve prolapse (MVP) at the molecular level?
95. Libman-Sacks endocarditis is a nonbacterial thrombotic endocarditis most classically associated with which condition, and which valvular surface is preferentially involved?
96. A patient dies 4 days after an acute anterior myocardial infarction. At autopsy, the infarct zone shows yellow softening with a red hyperemic border. On microscopy, which combination of findings is expected?
97. Libman-Sacks endocarditis is a non-infective endocarditis associated with systemic lupus erythematosus. Its characteristic vegetations differ from those in infective endocarditis by:
98. Hypertrophic obstructive cardiomyopathy (HOCM) most commonly results from mutations in which sarcomeric protein?
99. A 52-year-old obese man with hypertension and hypercholesterolemia dies suddenly. Autopsy reveals a ruptured atherosclerotic plaque in the proximal left anterior descending coronary artery with overlying occlusive thrombus. The plaque has a large lipid core occupying >40% of plaque volume, a thin fibrous cap infiltrated by macrophages, and minimal calcification. Which of the following features MOST contributed to plaque vulnerability and rupture?
100. A 65-year-old man with a history of hypertension presents to the emergency department with sudden onset of tearing chest pain radiating to the back. CT angiography reveals a dissecting hematoma within the media of the aorta extending from the aortic root to the descending thoracic aorta. Histology of the aortic wall shows loss of smooth muscle cells and elastic fibers in the media with pooling of basophilic ground substance. What is this histological finding called?
101. A 6-year-old child presents with fever for 12 days, bilateral non-purulent conjunctivitis, strawberry tongue, erythema of the palms and soles, a cervical lymph node 2 cm in diameter, and a diffuse macular rash on the trunk. Echocardiography shows dilatation of the left anterior descending coronary artery. Which of the following accurately describes the vascular lesion in this condition?
102. A 70-year-old woman dies following a 3-week illness of progressive cardiac failure. At autopsy, the heart weighs 680 g (normal ~350 g). The left ventricular wall is dilated and thinned rather than hypertrophied. Microscopically, there is interstitial fibrosis, myocyte hypertrophy with large nuclei, and scattered areas of replacement fibrosis without significant coronary atherosclerosis. Which of the following diagnoses best fits this pathological pattern?
103. Dilated cardiomyopathy (DCM) is the most common cardiomyopathy leading to heart failure. The most frequent genetic cause of familial DCM involves mutation in which gene?
104. Hypertrophic cardiomyopathy (HCM) is most commonly caused by mutations in sarcomeric proteins. The most frequently mutated gene encodes:
105. Hypertrophic cardiomyopathy most commonly results from mutations in genes encoding which structural protein?