Cardiovascular syste.m yr 3 — Past Paper Questions & Answers

Question 1

A 58-year-old male smoker with hypertension presents to the emergency department with crushing chest pain of 2 hours duration. An ECG shows ST-elevation in leads V1-V4. Which artery is MOST likely occluded?

Accepted Answer

Right coronary artery (RCA) — ST elevation in leads V1-V4 indicates an anterior myocardial infarction, which is typically caused by occlusion of the left anterior descending (LAD) artery.

Question 2

A 45-year-old woman with a history of streptococcal pharyngitis 3 weeks ago presents with fever, migratory polyarthritis, and a new cardiac murmur. Biopsy of the myocardium shows Aschoff bodies. What is the pathological hallmark of an Aschoff body?

Accepted Answer

Fibrinous pericarditis with neutrophilic infiltrate — Aschoff bodies are characteristic granulomatous lesions found in rheumatic fever, composed of fibrinoid necrosis, Anitschkow cells (caterpillar cells), and occasional multinucleated giant cells.

Question 3

A 72-year-old male with longstanding hypertension is found to have a dilated abdominal aorta measuring 6.2 cm on ultrasound. Which layer of the aortic wall is MOST affected in abdominal aortic aneurysm (AAA), and what is the key pathological mechanism?

Accepted Answer

Intima - atherosclerotic plaque erodes into the media — Abdominal aortic aneurysms primarily involve the media, where chronic inflammation and enzymatic degradation (especially by MMPs) lead to the destruction of elastin and collagen, weakening the vessel wall.

Question 4

A 50-year-old male undergoes autopsy after sudden cardiac death. The heart weighs 560 g (normal ~300 g). The left ventricle shows concentric wall thickening with a normal-sized chamber. Which hemodynamic condition is MOST likely responsible?

Accepted Answer

Chronic systemic hypertension (pressure overload) — Concentric left ventricular hypertrophy with a normal chamber size is a classic adaptation to chronic pressure overload, most commonly caused by systemic hypertension or aortic stenosis.

Question 5

A 66-year-old female with type 2 diabetes develops progressive exertional dyspnea. Echocardiography shows preserved ejection fraction (55%) but impaired diastolic filling. Which pathological process BEST explains this finding?

Accepted Answer

Myocardial fibrosis and hypertrophy causing impaired ventricular relaxation — Diastolic dysfunction (impaired ventricular relaxation) with preserved ejection fraction is often caused by myocardial hypertrophy and fibrosis, which reduce ventricular compliance.

Question 6

A 35-year-old male with Marfan syndrome presents with sudden severe back pain. CT angiography reveals aortic dissection extending from the ascending aorta to the iliac arteries. The dissection plane travels through which layer of the aortic wall?

Accepted Answer

Within the outer third of the media — Aortic dissection involves a tear in the intima, allowing blood to enter and propagate within the medial layer, creating a false lumen.

Question 7

A 60-year-old male with chronic renal failure develops calcific deposits in the medial layer of muscular arteries, visible on X-ray as 'tram-track' calcifications. This is BEST described as:

Accepted Answer

Hyaline arteriosclerosis — Mönckeberg medial calcific sclerosis is characterized by calcification within the media of muscular arteries, often seen in chronic kidney disease, and appears as "tram-track" calcifications on imaging.

Question 8

A 48-year-old male is diagnosed with infective endocarditis. The MOST common cause of subacute bacterial endocarditis on a previously damaged (rheumatic) valve is:

Accepted Answer

Streptococcus viridans (Streptococcus sanguinis) — Streptococcus viridans is the most common cause of subacute infective endocarditis, particularly affecting previously damaged heart valves.

Question 9

A 55-year-old female presents with episodic flushing, diarrhea, and wheezing. Echocardiography shows tricuspid valve thickening with regurgitation. Urinary 5-HIAA is elevated. Which pathological finding is expected on the tricuspid valve?

Accepted Answer

White fibrous plaques on the endocardial surface of the right heart — Carcinoid heart disease causes characteristic white fibrous plaques on the endocardial surface, especially of the right heart valves, leading to thickening and dysfunction.

Question 10

Which of the following pathological changes in a coronary artery plaque is MOST directly responsible for converting stable angina to an acute coronary syndrome?

Accepted Answer

Calcification reducing plaque elasticity — Plaque rupture or erosion with subsequent superimposed thrombosis is the critical event that converts stable angina into an acute coronary syndrome.

Question 11

A 68-year-old male develops a fever, new murmur, and splinter hemorrhages 3 weeks after a dental extraction. A TTE reveals a vegetation on the aortic valve. Which of the following peripheral signs is caused by septic emboli from infective endocarditis?

Accepted Answer

Osler nodes (painful nodules on finger pads) — Splinter hemorrhages are linear hemorrhages under the nail bed, caused by microemboli from infective endocarditis lodging in the capillaries.

Question 12

Pathological examination of a myocardial biopsy from a patient with dilated cardiomyopathy (DCM) would MOST likely show which of the following?

Accepted Answer

Diffuse myocyte hypertrophy with interstitial fibrosis and no disarray — Dilated cardiomyopathy is characterized by myocyte hypertrophy, myocyte loss, and interstitial fibrosis, leading to ventricular dilation and impaired systolic function.

Question 13

A 40-year-old female with mitral valve prolapse (MVP) is found to have leaflets that are thick, rubbery, and balloon into the left atrium on echocardiography. Histologically, the leaflets show expansion of the spongiosa layer with myxomatous material. This material consists PRIMARILY of:

Accepted Answer

Calcium hydroxyapatite deposits — Myxomatous degeneration in MVP is characterized by an accumulation of proteoglycans and glycosaminoglycans in the spongiosa layer of the valve leaflets.

Question 14

A 30-year-old male with AIDS presents with fever, night sweats, and weight loss. A cardiac mass is found on echocardiography. Biopsy reveals spindle cells with slit-like vascular spaces and surrounding red blood cells. What is the MOST likely diagnosis?

Accepted Answer

Rhabdomyoma — The histological description (spindle cells, slit-like vascular spaces, red blood cells) is characteristic of Kaposi sarcoma, a common malignancy in AIDS patients.

Question 15

A 55-year-old male presents with progressive exertional dyspnea and bilateral leg edema. He had an anterior STEMI 5 years ago. ECG shows LBBB. Echocardiography shows an EF of 22%, a dilated LV with global hypokinesis, and an apical thrombus. Which of the following complications is he at GREATEST risk for?

Accepted Answer

Ventricular wall rupture — An apical thrombus in a dilated, hypokinetic left ventricle significantly increases the risk of systemic embolization, such as stroke.

Question 16

A 62-year-old male with hypertension and hyperlipidemia undergoes coronary angiography and is found to have a 70% stenosis of the RCA. The stenosis is caused by a stable fibrous plaque. What histological feature of this plaque distinguishes it from a VULNERABLE plaque?

Accepted Answer

Presence of foam cells within the plaque — A thick fibrous cap with abundant smooth muscle cells and few macrophages is characteristic of a stable plaque, which is less prone to rupture than a vulnerable plaque.

Question 17

A 50-year-old female with systemic sclerosis (scleroderma) is found to have right heart failure on examination. Her PCWP is normal but PVR is markedly elevated. Which vascular pathology is MOST responsible for her pulmonary hypertension?

Accepted Answer

Multiple pulmonary emboli causing mechanical obstruction — Systemic sclerosis commonly causes pulmonary arterial hypertension (PAH) due to intimal fibrosis and medial hypertrophy of pulmonary arterioles, consistent with elevated PVR and normal PCWP.

Question 18

A 63-year-old male with known coronary artery disease develops a new harsh pansystolic murmur and signs of cardiogenic shock 4 days after a large inferior MI. Echocardiography shows severe mitral regurgitation. What is the MOST likely structural cause?

Accepted Answer

A rupture of the interventricular septum creating an acquired VSD — Papillary muscle rupture is a known mechanical complication of MI, typically occurring 3-7 days post-MI, leading to acute severe mitral regurgitation and cardiogenic shock.

Question 19

A 72-year-old male with constrictive pericarditis undergoes pericardiectomy. The resected pericardium shows dense fibrous thickening with areas of calcification. Which of the following hemodynamic features would be EXPECTED in this patient?

Accepted Answer

Elevated PCWP with normal RA pressure — Equalization of diastolic pressures (right atrial, right ventricular, pulmonary artery diastolic, and pulmonary capillary wedge pressures) is a hallmark hemodynamic finding in constrictive pericarditis.

Question 20

A 68-year-old male with a history of hypertension is found dead. Autopsy reveals a globular heart weighing 620 g, dilated four chambers, and flabby myocardium. There is no significant coronary artery disease. This pattern is MOST consistent with:

Accepted Answer

Hypertrophic cardiomyopathy — A globally dilated, flabby heart with four-chamber dilation and no significant coronary artery disease is the classic description of dilated cardiomyopathy.

Question 21

A 34-year-old female presents with a 2-week history of exertional dyspnea and ankle swelling. She delivered a healthy baby 6 weeks ago. Echocardiography shows a dilated LV with EF of 30%. Endomyocardial biopsy shows lymphocytic myocarditis. Which pathological mechanism is MOST likely responsible?

Accepted Answer

Plaque rupture in a coronary artery causing MI — The presentation (postpartum, dilated LV, low EF, lymphocytic myocarditis) is highly suggestive of peripartum cardiomyopathy, which is thought to have an autoimmune basis.

Question 22

A 52-year-old male with a history of hyperlipidemia undergoes femoral-popliteal bypass surgery. The resected arterial segment shows an advanced atherosclerotic plaque with central cholesterol clefts and calcification. The cholesterol clefts form because:

Accepted Answer

Calcium displaces cholesterol from lipoproteins in the plaque — Cholesterol is lipid-soluble and dissolves out during routine tissue processing (which involves alcohol and xylene), leaving behind characteristic empty, needle-shaped clefts in histological sections.

Question 23

A 42-year-old female with SLE develops pleuritic chest pain, friction rub, and ECG changes showing diffuse saddle-shaped ST elevation. She has no fever. Which pericardial finding would be expected?

Accepted Answer

Purulent (suppurative) pericarditis with neutrophilic exudate — SLE is a common cause of acute pericarditis, which typically presents pathologically as fibrinous pericarditis, often described as a 'bread-and-butter' appearance due to fibrin deposition.

Question 24

A 78-year-old female is found to have multiple 1–3 mm flat, wart-like, sterile vegetations along the line of closure of the mitral valve on the atrial surface. She has a history of metastatic pancreatic cancer. What is the MOST likely diagnosis?

Accepted Answer

Acute infective endocarditis — Sterile vegetations associated with malignancy (like pancreatic cancer) are characteristic of non-bacterial thrombotic endocarditis (NBTE), also known as marantic endocarditis.

Cardiovascular syste.m yr 3 — Past Paper Questions & Answers

Questions, Answers & Explanations