📝 Step 5 — KMU Past Papers & Exam Learning

This section contains KMU-style past paper questions designed to strengthen conceptual understanding. Focus on understanding explanations rather than memorizing answers.

🎯 How to Study KMU Past Papers

• Read the question carefully.
• Think about the answer before looking.
• Read the explanation slowly.
• Understand the reasoning behind the correct answer.
• Revise difficult questions again.

MCQ 1
Question:
A 70-year-old man with chronic left ventricular failure dies after progressive respiratory deterioration. Microscopy of the lungs shows alveolar macrophages containing coarse golden-brown pigment. The pigment is derived from:

Options:
Degraded surfactant phospholipids
Extravasated red blood cells
Necrotic bronchial epithelium
Inhaled carbon particles
Pulmonary vascular fibrin

Correct Answer:
Extravasated red blood cells

Explanation:
Chronic pulmonary venous congestion causes repeated alveolar hemorrhage. Macrophages ingest red cells and accumulate hemosiderin, forming heart-failure cells.

MCQ 2
Question:
A patient with chronic congestive cardiac failure develops centrilobular hepatic congestion. Which region of the hepatic lobule is most vulnerable to hypoxic injury?

Options:
Periportal hepatocytes
Bile duct epithelium
Zone 2 hepatocytes
Centrilobular hepatocytes
Portal venous endothelium

Correct Answer:
Centrilobular hepatocytes

Explanation:
Zone 3 hepatocytes lie farthest from the oxygen-rich portal blood supply and are most affected by venous congestion and reduced perfusion.

MCQ 3
Question:
A patient with severe aortic stenosis develops heart failure after years of compensatory adaptation. Which structural response would have occurred initially?

Options:
Concentric ventricular hypertrophy
Four-chamber ventricular dilation
Marked biatrial enlargement
Right ventricular fatty replacement
Diffuse endocardial amyloid deposition

Correct Answer:
Concentric ventricular hypertrophy

Explanation:
Chronic pressure overload increases wall stress and produces parallel addition of sarcomeres, resulting in concentric left ventricular hypertrophy.

MCQ 4
Question:
A patient with long-standing mitral regurgitation develops progressive cardiac enlargement. Which adaptive pattern best reflects chronic volume overload?

Options:
Reduced ventricular chamber size
Septal myofiber disarray
Concentric wall thickening
Restrictive ventricular filling
Eccentric ventricular hypertrophy

Correct Answer:
Eccentric ventricular hypertrophy

Explanation:
Volume overload causes chamber dilation with sarcomeres added in series, producing eccentric hypertrophy.

MCQ 5
Question:
A patient with acute left ventricular failure develops severe hypoxemia. Which change most directly impairs gas exchange?

Options:
Increased alveolar surfactant production
Fluid accumulation within alveoli
Reduced bronchial mucus secretion
Decreased pulmonary capillary flow
Increased lymphatic drainage

Correct Answer:
Fluid accumulation within alveoli

Explanation:
Raised pulmonary hydrostatic pressure drives fluid into the interstitium and alveoli, increasing diffusion distance and producing ventilation–perfusion mismatch.

MCQ 6
Question:
A man with chronic alcohol misuse presents with progressive exertional dyspnea. Echocardiography shows globally reduced ventricular contraction and enlarged cardiac chambers. Which mechanism is most consistent with his condition?

Options:
Infiltration producing ventricular stiffness
Sarcomeric mutation causing septal thickening
Toxic myocardial injury causing dilation
Pressure overload causing concentric hypertrophy
Pericardial fibrosis limiting filling

Correct Answer:
Toxic myocardial injury causing dilation

Explanation:
Alcohol can directly damage cardiac myocytes and produce dilated cardiomyopathy with systolic dysfunction and chamber enlargement.

MCQ 7
Question:
A patient with restrictive cardiomyopathy has severe systemic congestion despite near-normal ventricular chamber size. Which pressure change is expected?

Options:
Reduced atrial filling pressure
Reduced pulmonary venous pressure
Increased ventricular compliance
Reduced systemic venous pressure
Increased diastolic filling pressure

Correct Answer:
Increased diastolic filling pressure

Explanation:
A stiff ventricle requires higher filling pressure to accept blood, producing atrial enlargement and pulmonary or systemic venous congestion.

MCQ 8
Question:
A patient with heart failure has cold extremities, reduced urine output and confusion without marked peripheral edema. Which pathophysiological component is dominant?

Options:
Forward failure with tissue hypoperfusion
Backward failure with venous congestion
Isolated pulmonary capillary leakage
Primary sodium loss from the kidneys
Excessive ventricular compliance

Correct Answer:
Forward failure with tissue hypoperfusion

Explanation:
Reduced cardiac output causes inadequate perfusion of the kidneys, brain and peripheral tissues, producing oliguria, confusion and cool extremities.

MCQ 9
Question:
A patient with acute pulmonary edema is given intravenous furosemide. In addition to diuresis, which early effect may improve symptoms before major urine loss occurs?

Options:
Coronary vasoconstriction
Increased aldosterone secretion
Venodilation with reduced preload
Increased ventricular afterload
Suppression of myocardial contractility

Correct Answer:
Venodilation with reduced preload

Explanation:
Intravenous loop diuretics can produce early venodilation, reducing venous return and pulmonary capillary pressure before substantial diuresis occurs.

MCQ 10
Question:
A patient receiving high-dose furosemide develops hearing impairment. Which additional drug would further increase the risk of this complication?

Options:
Spironolactone
Amiloride
Hydrochlorothiazide
Gentamicin
Acetazolamide

Correct Answer:
Gentamicin

Explanation:
Loop diuretics and aminoglycosides are both ototoxic, so concurrent use increases the risk of hearing damage.

MCQ 11
Question:
A patient with heart failure and recurrent gout is started on hydrochlorothiazide. Which mechanism contributes to worsening hyperuricemia?

Options:
Increased uric acid production by the liver
Reduced urate secretion in the proximal tubule
Increased filtration of urate at the glomerulus
Enhanced urate breakdown in renal tissue
Reduced intestinal elimination of uric acid

Correct Answer:
Reduced urate secretion in the proximal tubule

Explanation:
Thiazides compete with uric acid for proximal tubular secretion and may also increase urate reabsorption through volume contraction.

MCQ 12
Question:
A patient receiving a thiazide diuretic develops muscle weakness and ventricular ectopic beats. Which electrolyte disturbance is the most likely cause?

Options:
Hypermagnesemia
Hypernatremia
Hypokalemia
Hypercalcemia
Hyperphosphatemia

Correct Answer:
Hypokalemia

Explanation:
Thiazides increase distal sodium delivery and potassium loss, predisposing to weakness and cardiac arrhythmias.

MCQ 13
Question:
A patient with glaucoma and metabolic alkalosis is prescribed acetazolamide. Which acid–base disturbance may develop during therapy?

Options:
Respiratory alkalosis
Metabolic acidosis
Respiratory acidosis
Metabolic alkalosis
Mixed respiratory alkalosis

Correct Answer:
Metabolic acidosis

Explanation:
Carbonic anhydrase inhibition increases urinary bicarbonate loss, lowering plasma bicarbonate and producing a hyperchloremic metabolic acidosis.

MCQ 14
Question:
A patient taking acetazolamide develops renal stones. Which urinary change promotes this adverse effect?

Options:
Reduced urinary bicarbonate
Reduced urinary sodium
Increased urinary acidity
Reduced urinary calcium
Increased urinary alkalinity

Correct Answer:
Increased urinary alkalinity

Explanation:
Bicarbonate loss makes the urine alkaline, which favors precipitation of calcium phosphate and stone formation.

MCQ 15
Question:
Mannitol is considered for a patient with raised intracranial pressure who also has severe left ventricular failure. Why should it be used cautiously?

Options:
It causes marked potassium retention
It initially expands extracellular volume
It directly depresses myocardial contractility
It blocks aldosterone receptors
It produces severe bradycardia

Correct Answer:
It initially expands extracellular volume

Explanation:
Mannitol draws water into the intravascular compartment before excretion, which can increase preload and worsen pulmonary congestion.

MCQ 16
Question:
A patient with heart failure is prescribed amiloride. Which renal transport process is inhibited?

Options:
Sodium–potassium–chloride cotransport
Sodium–chloride cotransport
Carbonic anhydrase activity
Epithelial sodium channels
Na⁺/K⁺ ATPase in cardiomyocytes

Correct Answer:
Epithelial sodium channels

Explanation:
Amiloride blocks epithelial sodium channels in the collecting duct, reducing sodium reabsorption and potassium secretion.

MCQ 17
Question:
A patient with chronic heart failure is receiving an ACE inhibitor, spironolactone and a potassium supplement. Which complication is most likely?

Options:
Severe hypocalcemia
Hyperuricemia
Ototoxicity
Metabolic alkalosis
Hyperkalemia

Correct Answer:
Hyperkalemia

Explanation:
ACE inhibition and aldosterone blockade both reduce potassium excretion; additional potassium supplementation further increases the risk.

MCQ 18
Question:
A patient with chronic heart failure has a regular pulse of 52 beats/min and first-degree AV block. Which drug should be reviewed because it may further slow AV nodal conduction?

Options:
Mannitol
Digoxin
Acetazolamide
Furosemide
Hydrochlorothiazide

Correct Answer:
Digoxin

Explanation:
Digoxin increases vagal activity and slows conduction through the AV node, potentially worsening bradycardia or heart block.

MCQ 19
Question:
A patient with severe digoxin toxicity has hyperkalemia and a life-threatening arrhythmia. Which intervention directly neutralizes circulating drug molecules?

Options:
Intravenous magnesium sulfate
Oral activated charcoal alone
Digoxin-specific antibody fragments
Intravenous calcium chloride
Temporary sodium restriction

Correct Answer:
Digoxin-specific antibody fragments

Explanation:
Digoxin immune Fab binds free digoxin and rapidly reduces its pharmacological and toxic effects in severe poisoning.

MCQ 20
Question:
A student performs a SWOT analysis before managing a simulated heart-failure emergency. Limited time and an unstable patient are identified. These factors belong to which category?

Options:
Strengths
Weaknesses
Learning outcomes
Opportunities
Threats

Correct Answer:
Threats

Explanation:
Threats are external circumstances that may interfere with performance, such as time pressure, patient instability and resource limitations.

📌 Important Exam Strategy

KMU examinations often test integrated understanding rather than isolated facts. Focus on linking anatomy, embryology, histology, and clinical concepts when reviewing questions.

✅ Revision Tip

If you can explain the reason behind the correct answer without looking at notes, your concept is strong.