📝 Step 6 — 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 patient has reduced ventricular filling because the heart rate is markedly increased. Which phase is most affected?

Options:
Early ventricular systole
Late ventricular systole
Ventricular diastole
Atrial depolarization
Isovolumetric contraction

Correct Answer:
Ventricular diastole

Explanation:
Diastole is the main filling period of ventricles and is shortened significantly during tachycardia.

MCQ 2
Question:
During isovolumetric ventricular contraction, ventricular pressure rises but blood is not ejected because:

Options:
Atria are still contracting
All cardiac valves are closed
Semilunar valves remain open
Ventricular volume is increasing
Aortic pressure is falling rapidly

Correct Answer:
All cardiac valves are closed

Explanation:
In isovolumetric contraction, AV valves have closed but semilunar valves have not yet opened, so volume remains constant.

MCQ 3
Question:
Aortic valve stenosis mainly produces left ventricular hypertrophy due to:

Options:
Volume overload during diastole
Reduced atrial contraction
Pressure overload during ejection
Backflow into left atrium
Failure of venous return

Correct Answer:
Pressure overload during ejection

Explanation:
Aortic stenosis increases resistance to outflow, so the left ventricle contracts against high pressure.

MCQ 4
Question:
A patient has mitral valve incompetence. Which hemodynamic change is expected during ventricular systole?

Options:
Blood enters pulmonary trunk
Blood returns to left atrium
Blood enters right atrium
Blood returns to left ventricle
Blood enters coronary sinus

Correct Answer:
Blood returns to left atrium

Explanation:
Mitral regurgitation allows systolic backflow from left ventricle to left atrium.

MCQ 5
Question:
Which structure-function relationship best explains prevention of AV valve prolapse?

Options:
Cusps attach to papillary muscles through chordae tendineae
Semilunar valves attach to ventricular trabeculae
Aortic cusps attach directly to atrial myocardium
Papillary muscles open valves during diastole
Chordae tendineae contract to eject blood

Correct Answer:
Cusps attach to papillary muscles through chordae tendineae

Explanation:
Papillary muscles and chordae tendineae prevent AV valve cusps from bulging into atria during systole.

MCQ 6
Question:
A soft additional sound is heard just after S2 during rapid ventricular filling. Which sound is most likely present?

Options:
S1
S2
S3
S4
Opening click

Correct Answer:
S3

Explanation:
S3 occurs early in diastole during rapid ventricular filling and may indicate volume overload in adults.

MCQ 7
Question:
Which ECG-cardiac cycle relationship is most accurate?

Options:
P wave occurs after ventricular contraction
QRS complex precedes ventricular systole
T wave occurs during atrial systole
PR interval produces second heart sound
ST segment represents atrial filling

Correct Answer:
QRS complex precedes ventricular systole

Explanation:
Electrical depolarization of ventricles occurs before mechanical ventricular contraction.

MCQ 8
Question:
A patient with severe pulmonary congestion due to mitral valve disease develops breathlessness. The main mechanism is:

Options:
Reduced systemic venous pressure
Increased pulmonary venous pressure
Reduced right atrial filling
Increased aortic compliance
Reduced coronary sinus flow

Correct Answer:
Increased pulmonary venous pressure

Explanation:
Mitral valve disease increases left atrial pressure, which is transmitted backward to pulmonary veins.

MCQ 9
Question:
During ventricular ejection, which pressure relationship is required?

Options:
Atrial pressure exceeds ventricular pressure
Ventricular pressure exceeds arterial pressure
Venous pressure exceeds atrial pressure
Arterial pressure exceeds ventricular pressure
Atrial pressure exceeds arterial pressure

Correct Answer:
Ventricular pressure exceeds arterial pressure

Explanation:
Semilunar valves open when ventricular pressure rises above aortic or pulmonary arterial pressure.

MCQ 10
Question:
The high oxygen requirement of cardiac muscle is best explained by:

Options:
Poor mitochondrial content
Continuous contractile activity
Predominant anaerobic metabolism
Low coronary blood flow
Limited ATP requirement

Correct Answer:
Continuous contractile activity

Explanation:
Cardiac muscle contracts continuously and depends mainly on aerobic metabolism for ATP production.

MCQ 11
Question:
Atrial systole becomes especially important when ventricular filling time is reduced because it:

Options:
Initiates ventricular relaxation
Completes late ventricular filling
Closes the semilunar valves
Produces ventricular repolarization
Prevents ventricular ejection

Correct Answer:
Completes late ventricular filling

Explanation:
Atrial contraction contributes the final portion of ventricular filling, especially when diastole is shortened.

MCQ 12
Question:
Which abnormality is most likely to produce a diastolic murmur?

Options:
Mitral regurgitation
Aortic stenosis
Mitral stenosis
Pulmonary stenosis
Tricuspid regurgitation

Correct Answer:
Mitral stenosis

Explanation:
Mitral stenosis obstructs flow from left atrium to left ventricle during diastole.

MCQ 13
Question:
Aortic regurgitation mainly increases ventricular workload because it causes:

Options:
Systolic pressure overload
Diastolic volume overload
Reduced atrial pressure
Reduced venous return
Right atrial dilatation

Correct Answer:
Diastolic volume overload

Explanation:
Aortic regurgitation allows blood to return to the left ventricle during diastole, increasing end-diastolic volume.

MCQ 14
Question:
Which sequence best represents normal valve events in one cardiac cycle?

Options:
AV opening → AV closure → semilunar opening → semilunar closure
Semilunar opening → AV opening → AV closure → semilunar closure
AV closure → AV opening → semilunar closure → semilunar opening
Semilunar closure → semilunar opening → AV opening → AV closure
AV opening → semilunar closure → AV closure → semilunar opening

Correct Answer:
AV opening → AV closure → semilunar opening → semilunar closure

Explanation:
This sequence matches ventricular filling, isovolumetric contraction, ejection, and relaxation.

MCQ 15
Question:
Sympathetic stimulation increases cardiac output mainly by increasing:

Options:
AV valve thickness
Ventricular filling only
Heart rate and contractility
Pulmonary venous resistance
Diastolic valve closure

Correct Answer:
Heart rate and contractility

Explanation:
Sympathetic activity increases SA node firing and myocardial contractile force.

MCQ 16
Question:
Which finding best explains turbulent blood flow in valvular disease?

Options:
Smooth laminar flow through normal cusps
Narrowed or incompetent valve opening
Reduced electrical conduction only
Normal ventricular relaxation
Low cardiac muscle oxygen use

Correct Answer:
Narrowed or incompetent valve opening

Explanation:
Stenosis and regurgitation disturb normal flow and generate turbulence, producing murmurs.

MCQ 17
Question:
During isovolumetric relaxation, ventricular volume remains unchanged because:

Options:
Atria are contracting forcefully
AV and semilunar valves are closed
Semilunar valves are fully open
Ventricles are actively ejecting blood
Aortic pressure is below ventricular pressure

Correct Answer:
AV and semilunar valves are closed

Explanation:
After semilunar valve closure and before AV valve opening, all valves are closed, so volume does not change.

MCQ 18
Question:
A stiff hypertrophied ventricle produces an additional sound during atrial contraction. Which sound is expected?

Options:
S1
S2
S3
S4
Ejection click

Correct Answer:
S4

Explanation:
S4 is produced when the atrium contracts against a stiff, poorly compliant ventricle.

MCQ 19
Question:
Failure of chordae tendineae attached to the mitral valve most likely causes:

Options:
Mitral regurgitation
Aortic stenosis
Pulmonary stenosis
Tricuspid stenosis
Aortic regurgitation

Correct Answer:
Mitral regurgitation

Explanation:
Rupture of chordae allows mitral valve prolapse during systole, causing backflow into the left atrium.

MCQ 20
Question:
Reduced coronary perfusion impairs cardiac mechanical function mainly because:

Options:
Cardiac muscle depends heavily on aerobic ATP production
Cardiac muscle stores large oxygen reserves
Cardiac contraction depends mainly on anaerobic glycolysis
Cardiac valves require direct oxygen supply
Cardiac output is independent of ATP availability

Correct Answer:
Cardiac muscle depends heavily on aerobic ATP production

Explanation:
The myocardium relies on continuous aerobic ATP production; ischemia rapidly reduces contractile function.

📌 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.