Cardiovascular Pathology MCQs: Rheumatic OmpathStudy

MOUNT KENYA UNIVERSITY MEDICAL SCHOOL BACHELOR OF MEDICINE AND BACHELOR OF SURGERY DEPARTMENT OF PATHOLOGY CAT 2 — END OF SEMESTER 2 UNIT CODE: MBPA 3512A UNIT TITLE: CARDIOVASCULAR SYSTEM PATHOLOGY --- 1. A 58-year-old male smoker with hypertension, crushing chest pain 2 hrs, ST-elevation in leads V1–V4. Which artery is MOST likely occluded? A. Right coronary artery (RCA) B. Left anterior descending artery (LAD) C. Left circumflex artery (LCx) D. Posterior descending artery (PDA) E. Diagonal branch of the LAD Answer: B V1–V4 = anterior/anteroseptal leads → territory of the LAD RCA → inferior leads (II, III, aVF); LCx → lateral leads (I, aVL, V5–V6) 2. 45-year-old woman, strep pharyngitis 3 weeks ago, migratory polyarthritis, new murmur, Aschoff bodies on biopsy. Pathological hallmark of an Aschoff body? A. Fibrinous pericarditis with neutrophilic infiltrate B. Granuloma with central fibrinoid necrosis, Anitschkow cells, and multinucleated giant cells C. Coagulative necrosis surrounded by lymphocytes D. Caseous necrosis with epithelioid macrophages E. Amyloid deposits in the interstitium Answer: B Aschoff body = pathognomonic lesion of acute rheumatic fever/rheumatic carditis Central fibrinoid necrosis surrounded by activated macrophages ( Anitschkow cells — "caterpillar cells," owl-eye nuclei) and multinucleated giant cells (Aschoff giant cells) 3. 72-year-old male, longstanding HTN, AAA 6.2 cm. Which layer MOST affected, and key mechanism? A. Intima — atherosclerotic plaque erodes into the media B. Media — destruction of elastin and collagen by matrix metalloproteinases (MMPs) C. Adventitia — inflammatory infiltrate causing external compression D. Intima — fibromuscular hyperplasia narrows the lumen E. Media — cystic medial degeneration with mucoid deposits Answer: B AAA pathogenesis centers on the media : chronic inflammation (often atherosclerosis-driven) upregulates MMPs that degrade elastin/collagen, weakening the wall and allowing dilation (E) describes Marfan-type dissection pathology, not typical atherosclerotic AAA 4. 50-year-old, sudden cardiac death, heart 560g, concentric LV wall thickening, normal-sized chamber. Most likely hemodynamic cause? A. Chronic mitral regurgitation B. Chronic aortic regurgitation C. Chronic systemic hypertension (pressure overload) D. Large ventricular septal defect (volume overload) E. Tricuspid stenosis Answer: C Concentric hypertrophy with normal chamber size = pressure overload (hypertension, aortic stenosis) Volume overload lesions (MR, AR, VSD) cause eccentric hypertrophy with chamber dilation 5. 66-year-old female, T2DM, exertional dyspnea, EF preserved (55%), impaired diastolic filling. Best explanation? A. Dilated cardiomyopathy with global systolic dysfunction B. Myocardial fibrosis and hypertrophy causing impaired ventricular relaxation C. Pericardial constriction limiting ventricular filling D. Severe aortic stenosis reducing stroke volume E. Mitral regurgitation causing left atrial dilation Answer: B Classic HFpEF picture in diabetes: diabetic cardiomyopathy causes myocardial fibrosis/hypertrophy → stiff, poorly compliant ventricle → impaired relaxation despite preserved EF 6. 35-year-old male, Marfan syndrome, aortic dissection ascending aorta to iliacs. Which layer does the dissection plane travel through? A. Between the intima and media (subintimal) B. Within the outer third of the media C. Between the media and adventitia D. Within the adventitia E. Through the full thickness of the aortic wall Answer: B Marfan-associated dissection results from cystic medial degeneration (loss of elastin/smooth muscle, mucoid pools) The dissection plane classically splits within the outer third of the media 7. 60-year-old, chronic renal failure, calcific deposits in the media of muscular arteries, "tram-track" on X-ray. Best description? A. Atherosclerosis of large elastic arteries B. Mönckeberg medial calcific sclerosis C. Hyaline arteriolosclerosis D. Hyperplastic arteriolosclerosis E. Fibromuscular dysplasia Answer: B Mönckeberg sclerosis: calcification of the media of muscular arteries, common in elderly/diabetics/CKD; does not narrow the lumen (unlike atherosclerosis) 8. 48-year-old, infective endocarditis on a previously damaged (rheumatic) valve. Most common cause of subacute bacterial endocarditis? A. Staphylococcus aureus B. Streptococcus viridans (S. sanguinis) C. Enterococcus faecalis D. Staphylococcus epidermidis E. HACEK organisms Answer: B Low-virulence oral streptococci ( viridans group ) classically infect already-damaged/deformed valves → indolent, subacute course S. aureus causes acute IE, often on normal valves 9. 55-year-old female, flushing, diarrhea, wheezing, elevated urinary 5-HIAA, tricuspid thickening/regurgitation. Expected tricuspid valve finding? A. Fibrinous vegetations along the line of closure B. White fibrous plaques on the endocardial surface of the right heart C. Calcific nodules on the aortic surface of leaflets D. Large friable ve