📝 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 coronary artery is occluded for a prolonged period. The affected cardiac muscle initially loses contractility and later progresses to irreversible cell death. Which cellular event best explains this transition?

Options:
Reduced glycogen storage with preserved membrane integrity
Increased fatty acid oxidation with stable mitochondria
Mitochondrial damage with calcium influx
Enhanced aerobic metabolism with lactate clearance
Improved sodium pump activity with cell shrinkage

Correct Answer:
Mitochondrial damage with calcium influx

Explanation:
Prolonged ischemia causes ATP depletion, ion pump failure, calcium influx, mitochondrial damage, and irreversible myocyte injury.

MCQ 2

Question:
A 62-year-old man with inferior wall infarction is hypotensive and has ongoing chest pain. Nitrate therapy is being considered. Which action is most appropriate?

Options:
Give nitrate immediately to all patients with infarction
Use nitrate before checking blood pressure
Replace reperfusion therapy with nitrate infusion
Use nitrate as the only antithrombotic treatment
Avoid nitrate until hemodynamic status is assessed

Correct Answer:
Avoid nitrate until hemodynamic status is assessed

Explanation:
Nitrates may worsen hypotension. In MI, they are used for pain only when blood pressure and clinical status allow.

MCQ 3

Question:
A patient treated for myocardial infarction develops recurrent chest pain three days later. The physician wants a biomarker that can help assess reinfarction. Which marker is more useful in this setting?

Options:
Cardiac troponin T
Creatine kinase-MB
C-reactive protein
Serum lactate dehydrogenase
Plasma fibrinogen

Correct Answer:
Creatine kinase-MB

Explanation:
CK-MB returns to baseline earlier than troponin, so it may help detect reinfarction after a recent MI.

MCQ 4

Question:
A patient suddenly collapses five days after an acute myocardial infarction. Autopsy shows hemopericardium and cardiac tamponade. Which pathological process most directly explains this complication?

Options:
Dense collagen deposition in the infarcted wall
Early neutrophilic margination in capillaries
Fatty replacement of necrotic myocardium
Macrophage digestion of dead muscle fibers
Calcification of damaged coronary plaques

Correct Answer:
Macrophage digestion of dead muscle fibers

Explanation:
At 3–7 days, macrophages remove necrotic tissue, weakening the infarct wall and predisposing to rupture.

MCQ 5

Question:
Which finding in a patient with acute myocardial infarction most strongly suggests a need for urgent high-risk assessment?

Options:
Persistent ischemic pain with dynamic ECG change
Mild dyspepsia after taking aspirin
Brief atypical pain with normal biomarkers
Localized tenderness over the chest wall
Isolated anxiety with stable vital signs

Correct Answer:
Persistent ischemic pain with dynamic ECG change

Explanation:
Persistent pain with evolving ECG changes suggests ongoing ischemia and high-risk ACS requiring urgent assessment.

MCQ 6

Question:
Aspirin’s antiplatelet effect continues for several days after a single dose. Which property best explains this duration?

Options:
Reversible inhibition of platelet ADP receptors
Competitive blockade of thrombin receptors
Direct neutralization of circulating fibrinogen
Activation of endothelial prostacyclin release
Irreversible inhibition of platelet cyclooxygenase

Correct Answer:
Irreversible inhibition of platelet cyclooxygenase

Explanation:
Aspirin irreversibly inhibits platelet COX-1, and platelets cannot synthesize new enzyme because they lack nuclei.

MCQ 7

Question:
A patient with ACS is prescribed clopidogrel. A reduced response is suspected because of variable metabolic activation. Which feature of clopidogrel explains this problem?

Options:
Direct factor Xa inhibition
Antithrombin III activation
Prodrug requiring hepatic activation
Immediate fibrin clot dissolution
Vitamin K receptor blockade

Correct Answer:
Prodrug requiring hepatic activation

Explanation:
Clopidogrel is a prodrug and requires hepatic activation, so response can vary among patients.

MCQ 8

Question:
A patient with acute coronary syndrome has a past history of transient ischemic attack. Which P2Y12 inhibitor should be avoided because of bleeding risk in this setting?

Options:
Clopidogrel
Prasugrel
Ticagrelor
Aspirin
Dipyridamole

Correct Answer:
Prasugrel

Explanation:
Prasugrel is avoided in patients with previous stroke or TIA due to increased bleeding risk.

MCQ 9

Question:
During PCI for high-risk ACS, a drug is selected to block fibrinogen-mediated cross-linking of activated platelets. Which drug group has this action?

Options:
P2Y12 receptor blockers
Cyclooxygenase inhibitors
Vitamin K antagonists
GP IIb/IIIa inhibitors
Direct thrombin inhibitors

Correct Answer:
GP IIb/IIIa inhibitors

Explanation:
GP IIb/IIIa inhibitors block the final common pathway of platelet aggregation by preventing fibrinogen bridging.

MCQ 10

Question:
A patient receiving unfractionated heparin develops thrombocytopenia and new limb ischemia. Which mechanism best explains this paradoxical thrombosis?

Options:
Platelet-activating antibodies against heparin complex
Suppression of vitamin K-dependent factor synthesis
Direct destruction of fibrin by excess plasmin
Reduced thromboxane production in platelets
Irreversible blockade of ADP receptors

Correct Answer:
Platelet-activating antibodies against heparin complex

Explanation:
Heparin-induced thrombocytopenia is immune-mediated and can cause thrombosis despite a low platelet count.

MCQ 11

Question:
A patient is shifted from unfractionated heparin to low molecular weight heparin. Which feature explains why routine aPTT monitoring is generally not required?

Options:
Complete oral absorption
Marked inhibition of platelets
Direct inhibition of vitamin K
Rapid reversal by vitamin K
Predictable anticoagulant response

Correct Answer:
Predictable anticoagulant response

Explanation:
LMWH has better bioavailability and a more predictable dose response than unfractionated heparin.

MCQ 12

Question:
A patient with heparin-induced thrombocytopenia requires anticoagulation. Which drug is most suitable because it directly inhibits thrombin?

Options:
Rivaroxaban
Argatroban
Warfarin
Aspirin
Streptokinase

Correct Answer:
Argatroban

Explanation:
Argatroban is a direct thrombin inhibitor and can be used in heparin-induced thrombocytopenia.

MCQ 13

Question:
A patient started on warfarin develops painful skin necrosis early in therapy. Which early change best explains this complication?

Options:
Excess thromboxane generation by platelets
Direct activation of factor Xa
Rapid fibrin clot breakdown
Transient protein C depletion
Increased plasminogen activation

Correct Answer:
Transient protein C depletion

Explanation:
Warfarin initially reduces protein C, producing a temporary hypercoagulable state that may cause skin necrosis.

MCQ 14

Question:
A patient on stable warfarin therapy is prescribed metronidazole. A few days later, his INR is markedly raised. Which explanation is most likely?

Options:
Increased vitamin K intake
Enhanced platelet aggregation
Reduced warfarin metabolism
Accelerated clotting factor synthesis
Direct reversal of anticoagulation

Correct Answer:
Reduced warfarin metabolism

Explanation:
Some drugs such as metronidazole inhibit warfarin metabolism, increasing anticoagulant effect and bleeding risk.

MCQ 15

Question:
A patient taking warfarin suddenly starts consuming large amounts of green leafy vegetables daily. Which effect is most expected?

Options:
Reduced anticoagulant effect
Increased thrombolytic activity
Enhanced heparin sensitivity
Direct platelet inhibition
Improved fibrin breakdown

Correct Answer:
Reduced anticoagulant effect

Explanation:
Vitamin K-rich foods can reduce warfarin effect; patients should keep vitamin K intake consistent.

MCQ 16

Question:
A thrombolytic drug is administered to a patient with STEMI. Which adverse effect requires the greatest concern during treatment?

Options:
Mild gastric irritation
Reversible tinnitus
Transient dry cough
Peripheral ankle edema
Intracranial bleeding

Correct Answer:
Intracranial bleeding

Explanation:
The most feared complication of thrombolytic therapy is intracranial hemorrhage.

MCQ 17

Question:
A patient develops fever, hypotension, and allergic features after receiving a fibrinolytic drug. Which agent is most classically associated with antigenicity?

Options:
Alteplase
Streptokinase
Tenecteplase
Reteplase
Dabigatran

Correct Answer:
Streptokinase

Explanation:
Streptokinase is antigenic and may cause allergic reactions because it is derived from streptococcal proteins.

MCQ 18

Question:
An unconscious patient with STEMI requires emergency PCI. No relatives are immediately available, and delay may threaten life. Which approach best reflects the consent principle?

Options:
Delay all intervention until written consent is obtained
Perform only non-invasive treatment until family arrives
Ask a junior staff member to sign for the patient
Proceed in the patient’s best interest with documentation
Cancel reperfusion because consent is unavailable

Correct Answer:
Proceed in the patient’s best interest with documentation

Explanation:
In life-threatening emergencies, treatment may proceed in the patient’s best interest when delay is dangerous, with clear documentation.

MCQ 19

Question:
A patient has rest chest pain, ST depression, and raised troponin. There is no ST elevation. Which approach is most appropriate at basic 3rd-year level?

Options:
Antiplatelet and anticoagulant therapy with risk assessment
Immediate thrombolysis without further assessment
Only analgesia and discharge after symptom relief
Long-term warfarin as the sole emergency treatment
No antithrombotic therapy if ECG lacks ST elevation

Correct Answer:
Antiplatelet and anticoagulant therapy with risk assessment

Explanation:
NSTEMI requires antiplatelet therapy, anticoagulation, monitoring, and risk-based invasive planning rather than routine thrombolysis.

MCQ 20

Question:
A patient develops embolic stroke weeks after a large anterior myocardial infarction. Echocardiography shows a clot attached to the ventricular wall. Which mechanism best explains its formation?

Options:
Acute bacterial invasion of endocardium
Primary platelet failure after aspirin use
Stasis over akinetic infarcted myocardium
Excess oxygen delivery to scarred tissue
Rapid dissolution of ventricular fibrin

Correct Answer:
Stasis over akinetic infarcted myocardium

Explanation:
Large infarcts can cause akinetic ventricular segments, leading to mural thrombus formation and systemic embolization.

📌 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.