Pathophysiology Quiz: Valve Stenosis Vs Regurgitation
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Valve Stenosis Vs RegurgitationQuestion 1 of 20

During a physical examination, a systolic murmur is heard. The patient is asked to squat from a standing position, which increases venous return and systemic vascular resistance. If the murmur's intensity increases significantly with this maneuver, which valvular lesion is the most likely cause?

Aortic stenosis
Mitral valve prolapse
Hypertrophic obstructive cardiomyopathy
Atrial septal defect
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Pathophysiology Quiz

Pathophysiology Quiz: Valve Stenosis Vs Regurgitation

Practice Valve Stenosis Vs Regurgitation in Pathophysiology with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

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This quiz focuses on Valve Stenosis Vs Regurgitation, giving you a quick way to practice the rules, question types, and explanations that matter most for Pathophysiology.

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Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

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Question 1

During a physical examination, a systolic murmur is heard. The patient is asked to squat from a standing position, which increases venous return and systemic vascular resistance. If the murmur's intensity increases significantly with this maneuver, which valvular lesion is the most likely cause?

  1. Aortic stenosis (correct answer)
  2. Mitral valve prolapse
  3. Hypertrophic obstructive cardiomyopathy
  4. Atrial septal defect
Explanation: Squatting increases both venous return (preload) and systemic vascular resistance (afterload). For aortic stenosis, the increased preload results in a larger stroke volume being forced across the stenotic valve, increasing turbulence and murmur intensity. In contrast, the murmurs of hypertrophic obstructive cardiomyopathy and mitral valve prolapse characteristically decrease in intensity with squatting.

Question 2

Both severe mitral regurgitation (MR) and severe aortic regurgitation (AR) can lead to elevated mean left atrial pressure (LAP). Which statement most accurately describes the difference in the primary mechanism causing this elevation?

  1. In MR, mean LAP is elevated due to direct retrograde flow during systole; in AR, it's elevated due to increased LVEDP impeding atrial emptying. (correct answer)
  2. In both conditions, the elevated mean LAP is primarily a result of left atrial volume overload from the pulmonary veins.
  3. In MR, the LAP elevation is primarily during diastole, while in AR, the LAP elevation is primarily during systole.
  4. In MR, LAP rises due to poor left atrial compliance, while in AR, LAP rises due to increased left atrial contractility.
Explanation: The mechanisms are distinct. In MR, the left atrium is directly exposed to high systolic pressure from the left ventricle, causing a large regurgitant 'v' wave and raising the mean LAP. In AR, the left ventricle becomes volume overloaded, leading to a high left ventricular end-diastolic pressure (LVEDP). This high diastolic pressure in the ventricle creates increased resistance to left atrial emptying during late diastole, causing blood to back up and raising the mean LAP.

Question 3

Aortic stenosis severity is best assessed by valve area rather than gradient because:

  1. Gradient is fixed in severe AS
  2. Gradient defines the orifice
  3. Gradient depends on flow (correct answer)
  4. Valve area depends on gradient
Explanation: A valve area calculation takes flow into account, while pressure gradient rises and falls with stroke volume and cardiac output. In low-flow states a hemodynamically severe valve can show a misleadingly low gradient, so area is the more reliable severity measure. The tempting wrong answer is "gradient is fixed in severe AS" - it isn't, because gradient is flow-dependent.

Question 4

In chronic severe mitral regurgitation, how do total LV and forward stroke volumes compare?

  1. Total normal, forward low
  2. Total low, forward low
  3. Total high, forward normal
  4. Total high, forward low (correct answer)
Explanation: In severe mitral regurgitation, each systole the LV must eject both the forward blood and the regurgitant volume back into the left atrium, so total LV stroke volume is high. However the regurgitant portion never reaches the body, so forward stroke volume is low. The tempting error is thinking total stroke volume stays normal with just forward flow low, but the LV increases total output to compensate for the leak.

Question 5

A wide pulse pressure with a low diastolic aortic pressure most directly reflects:

  1. Systolic outflow obstruction
  2. Diastolic aortic-to-LV flow (correct answer)
  3. Systolic LV-to-LA flow
  4. Diastolic LA-to-LV obstruction
Explanation: In aortic regurgitation, blood leaks backward from the aorta into the left ventricle during diastole, so aortic diastolic pressure falls and pulse pressure widens. The tempting wrong answer is systolic outflow obstruction, which narrows pulse pressure by slowing ejection rather than lowering diastolic pressure.

Question 6

Which finding identifies mitral stenosis, not regurgitation?

  1. LA pressure rises in systole
  2. Diastolic LA-LV gradient (correct answer)
  3. Eccentric LV volume overload
  4. Wide pulse pressure and runoff
Explanation: In mitral stenosis the valve fails to open fully, so left atrial pressure stays high and a gradient across the valve exists during diastolic filling. LA pressure rising in systole is the tempting distractor, but that points to mitral regurgitation, where blood leaks back into the atrium during ventricular systole.

Question 7

In acute severe aortic regurgitation, LV end-diastolic pressure rises steeply mainly because:

  1. The LV has no time to remodel (correct answer)
  2. The LV dilates and remodels
  3. Diastolic time lengthens
  4. Systolic ejection is blocked
Explanation: In acute aortic regurgitation, the regurgitant volume suddenly hits a noncompliant LV that has not had time to remodel or dilate. This steep rise in LVEDP reflects the sudden volume load on an unprepared chamber. The tempting wrong answer is LV dilation and remodeling, but that is a chronic compensation, not the acute cause.

Question 8

In a patient with isolated, severe mitral stenosis, what are the expected long-term effects on left ventricular end-diastolic volume (LVEDV) and left ventricular stroke work, assuming no other comorbidities?

  1. Increased LVEDV and increased stroke work.
  2. Normal or decreased LVEDV and decreased stroke work. (correct answer)
  3. Increased LVEDV and decreased stroke work.
  4. Normal or decreased LVEDV and increased stroke work.
Explanation: Mitral stenosis obstructs filling of the left ventricle from the left atrium. This leads to chronic under-filling of the left ventricle, resulting in a normal or decreased left ventricular end-diastolic volume (preload). According to the Frank-Starling mechanism, a lower preload leads to a lower stroke volume. Since stroke work is a function of stroke volume and pressure, the reduced stroke volume leads to decreased left ventricular stroke work. The left ventricle is said to be 'protected' in mitral stenosis.

Question 9

Both severe mitral regurgitation (MR) and severe aortic regurgitation (AR) can lead to elevated mean left atrial pressure (LAP). Which statement most accurately describes the difference in the primary mechanism causing this elevation?

  1. In MR, mean LAP is elevated due to direct retrograde flow during systole; in AR, it's elevated due to increased LVEDP impeding atrial emptying. (correct answer)
  2. In both conditions, the elevated mean LAP is primarily a result of left atrial volume overload from the pulmonary veins.
  3. In MR, the LAP elevation is primarily during diastole, while in AR, the LAP elevation is primarily during systole.
  4. In MR, LAP rises due to poor left atrial compliance, while in AR, LAP rises due to increased left atrial contractility.
Explanation: The mechanisms are distinct. In MR, the left atrium is directly exposed to high systolic pressure from the left ventricle, causing a large regurgitant 'v' wave and raising the mean LAP. In AR, the left ventricle becomes volume overloaded, leading to a high left ventricular end-diastolic pressure (LVEDP). This high diastolic pressure in the ventricle creates increased resistance to left atrial emptying during late diastole, causing blood to back up and raising the mean LAP.

Question 10

The pressure gradient across a stenotic valve is measured to be 40 mmHg at rest and increases to 90 mmHg during exercise. According to the Gorlin equation, where flow is proportional to the square root of the pressure gradient (Flow∝ΔPFlow \propto \sqrt{\Delta P}), this change implies that the cardiac output has approximately:

  1. Remained the same.
  2. More than tripled.
  3. Doubled.
  4. Increased by 50%. (correct answer)
Explanation: When you encounter questions about stenotic valves and pressure gradients, you're dealing with the relationship between cardiac output, valve area, and the pressure difference across the valve. The Gorlin equation tells us that flow through a stenotic valve is proportional to the square root of the pressure gradient: Flow∝ΔPFlow \propto \sqrt{\Delta P}. Let's work through this systematically. At rest, the pressure gradient is 40 mmHg, so flow is proportional to 40≈6.32\sqrt{40} \approx 6.32. During exercise, the gradient increases to 90 mmHg, making flow proportional to 90≈9.49\sqrt{90} \approx 9.49. The ratio of exercise flow to rest flow is 9.496.32≈1.5\frac{9.49}{6.32} \approx 1.5, meaning cardiac output increased by approximately 50%. Looking at the wrong answers: Choice A suggests cardiac output remained the same, which ignores the clear increase in pressure gradient that must accompany increased flow through the fixed stenotic valve. Choice B claims output "more than tripled" - this would require a much larger pressure gradient increase since (90/40)(\sqrt{90}/\sqrt{40}) is only 1.5, not over 3. Choice C suggests doubling occurred, but our calculation shows 1.5 times the original flow, not 2 times. The correct answer is D: cardiac output increased by 50%. Remember this key principle: with a fixed stenotic valve area, small increases in cardiac output create disproportionately large increases in pressure gradients. This is why patients with severe stenosis develop symptoms during exercise - their hearts work much harder to achieve modest increases in output.

Question 11

A 72-year-old male with severe aortic stenosis undergoes cardiac catheterization. Which pressure measurement pattern is most consistent with his diagnosis during ventricular systole?

  1. Peak left ventricular pressure of 180 mmHg and peak aortic pressure of 175 mmHg.
  2. Peak left ventricular pressure of 180 mmHg and peak aortic pressure of 110 mmHg. (correct answer)
  3. Peak left ventricular pressure of 110 mmHg and peak aortic pressure of 180 mmHg.
  4. Peak left ventricular pressure of 180 mmHg and mean left atrial pressure of 30 mmHg.
Explanation: Aortic stenosis creates an obstruction to outflow from the left ventricle. To eject blood across the stenotic valve, the left ventricle must generate a significantly higher pressure than the pressure in the aorta. A large systolic pressure gradient (in this case, 180 - 110 = 70 mmHg) between the left ventricle and the aorta is the hemodynamic hallmark of severe aortic stenosis.

Question 12

The pressure-volume loop of a patient with a valvular heart disease shows an abolition of the isovolumetric contraction phase, with the systolic ejection phase beginning immediately after mitral valve closure at a low pressure. The loop is also significantly wider, indicating increased preload. This pattern is characteristic of:

  1. Aortic stenosis
  2. Pulmonic stenosis
  3. Mitral regurgitation (correct answer)
  4. Aortic regurgitation
Explanation: In mitral regurgitation, the left ventricle has two outlets for ejection: the high-pressure aorta and the low-pressure left atrium. As soon as left ventricular pressure exceeds left atrial pressure (which happens very early in systole), regurgitant flow begins. This eliminates the period where both the mitral and aortic valves are closed and pressure rises without a volume change, i.e., the isovolumetric contraction phase. The volume overload also makes the loop wider.

Question 13

A patient is diagnosed with coexisting moderate aortic stenosis (AS) and moderate mitral regurgitation (MR). What is the expected combined effect of these two lesions on left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV)?

  1. Both LVESV and LVEDV will be decreased.
  2. LVESV will be increased, but LVEDV will be decreased.
  3. Both LVESV and LVEDV will be increased. (correct answer)
  4. LVESV will be decreased, but LVEDV will be increased.
Explanation: Aortic stenosis increases afterload, which makes it harder for the ventricle to eject blood, leading to incomplete emptying and an increased left ventricular end-systolic volume (LVESV). Mitral regurgitation is a volume overload lesion; the regurgitant volume returns to the LV during diastole, adding to the normal filling volume and thus increasing the left ventricular end-diastolic volume (LVEDV). The increased LVESV from AS also contributes to a higher LVEDV. The effects are additive.

Question 14

In a patient with isolated, severe mitral stenosis, what are the expected long-term effects on left ventricular end-diastolic volume (LVEDV) and left ventricular stroke work, assuming no other comorbidities?

  1. Increased LVEDV and increased stroke work.
  2. Normal or decreased LVEDV and decreased stroke work. (correct answer)
  3. Increased LVEDV and decreased stroke work.
  4. Normal or decreased LVEDV and increased stroke work.
Explanation: Mitral stenosis obstructs filling of the left ventricle from the left atrium. This leads to chronic under-filling of the left ventricle, resulting in a normal or decreased left ventricular end-diastolic volume (preload). According to the Frank-Starling mechanism, a lower preload leads to a lower stroke volume. Since stroke work is a function of stroke volume and pressure, the reduced stroke volume leads to decreased left ventricular stroke work. The left ventricle is said to be 'protected' in mitral stenosis.

Question 15

The pressure-volume loop of a patient with a valvular heart disease shows an abolition of the isovolumetric contraction phase, with the systolic ejection phase beginning immediately after mitral valve closure at a low pressure. The loop is also significantly wider, indicating increased preload. This pattern is characteristic of:

  1. Aortic stenosis
  2. Pulmonic stenosis
  3. Mitral regurgitation (correct answer)
  4. Aortic regurgitation
Explanation: In mitral regurgitation, the left ventricle has two outlets for ejection: the high-pressure aorta and the low-pressure left atrium. As soon as left ventricular pressure exceeds left atrial pressure (which happens very early in systole), regurgitant flow begins. This eliminates the period where both the mitral and aortic valves are closed and pressure rises without a volume change, i.e., the isovolumetric contraction phase. The volume overload also makes the loop wider.

Question 16

A patient is diagnosed with coexisting moderate aortic stenosis (AS) and moderate mitral regurgitation (MR). What is the expected combined effect of these two lesions on left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV)?

  1. Both LVESV and LVEDV will be decreased.
  2. LVESV will be increased, but LVEDV will be decreased.
  3. Both LVESV and LVEDV will be increased. (correct answer)
  4. LVESV will be decreased, but LVEDV will be increased.
Explanation: Aortic stenosis increases afterload, which makes it harder for the ventricle to eject blood, leading to incomplete emptying and an increased left ventricular end-systolic volume (LVESV). Mitral regurgitation is a volume overload lesion; the regurgitant volume returns to the LV during diastole, adding to the normal filling volume and thus increasing the left ventricular end-diastolic volume (LVEDV). The increased LVESV from AS also contributes to a higher LVEDV. The effects are additive.

Question 17

The pressure gradient across a stenotic valve is measured to be 40 mmHg at rest and increases to 90 mmHg during exercise. According to the Gorlin equation, where flow is proportional to the square root of the pressure gradient (Flow∝ΔPFlow \propto \sqrt{\Delta P}), this change implies that the cardiac output has approximately:

  1. Remained the same.
  2. More than tripled.
  3. Doubled.
  4. Increased by 50%. (correct answer)
Explanation: When you encounter questions about stenotic valves and pressure gradients, you're dealing with the relationship between cardiac output, valve area, and the pressure difference across the valve. The Gorlin equation tells us that flow through a stenotic valve is proportional to the square root of the pressure gradient: Flow∝ΔPFlow \propto \sqrt{\Delta P}. Let's work through this systematically. At rest, the pressure gradient is 40 mmHg, so flow is proportional to 40≈6.32\sqrt{40} \approx 6.32. During exercise, the gradient increases to 90 mmHg, making flow proportional to 90≈9.49\sqrt{90} \approx 9.49. The ratio of exercise flow to rest flow is 9.496.32≈1.5\frac{9.49}{6.32} \approx 1.5, meaning cardiac output increased by approximately 50%. Looking at the wrong answers: Choice A suggests cardiac output remained the same, which ignores the clear increase in pressure gradient that must accompany increased flow through the fixed stenotic valve. Choice B claims output "more than tripled" - this would require a much larger pressure gradient increase since (90/40)(\sqrt{90}/\sqrt{40}) is only 1.5, not over 3. Choice C suggests doubling occurred, but our calculation shows 1.5 times the original flow, not 2 times. The correct answer is D: cardiac output increased by 50%. Remember this key principle: with a fixed stenotic valve area, small increases in cardiac output create disproportionately large increases in pressure gradients. This is why patients with severe stenosis develop symptoms during exercise - their hearts work much harder to achieve modest increases in output.

Question 18

During a physical examination, a systolic murmur is heard. The patient is asked to squat from a standing position, which increases venous return and systemic vascular resistance. If the murmur's intensity increases significantly with this maneuver, which valvular lesion is the most likely cause?

  1. Aortic stenosis (correct answer)
  2. Mitral valve prolapse
  3. Hypertrophic obstructive cardiomyopathy
  4. Atrial septal defect
Explanation: Squatting increases both venous return (preload) and systemic vascular resistance (afterload). For aortic stenosis, the increased preload results in a larger stroke volume being forced across the stenotic valve, increasing turbulence and murmur intensity. In contrast, the murmurs of hypertrophic obstructive cardiomyopathy and mitral valve prolapse characteristically decrease in intensity with squatting.

Question 19

How does the primary hemodynamic burden of aortic stenosis (AS) fundamentally differ from that of mitral regurgitation (MR) in its effect on the left ventricle?

  1. AS imposes a primary pressure overload, while MR imposes a primary volume overload. (correct answer)
  2. AS primarily increases preload by restricting outflow, while MR primarily increases afterload.
  3. Both AS and MR impose a primary pressure overload on the left ventricle.
  4. Both AS and MR impose a primary volume overload on the left ventricle.
Explanation: Aortic stenosis creates a high resistance to ejection, forcing the left ventricle to generate very high pressures to maintain cardiac output; this is a classic pressure overload state, leading to concentric hypertrophy. Mitral regurgitation allows a portion of the ejected blood to return to the left atrium, which is then returned to the left ventricle in the next diastole. This recycling of blood imposes a volume overload on the ventricle, leading to dilation and eccentric hypertrophy.

Question 20

A patient with acute severe mitral regurgitation secondary to a ruptured chorda tendineae is in cardiogenic shock. How would the left atrial and left ventricular hemodynamics in this acute setting most significantly differ from those in a patient with chronic, compensated severe mitral regurgitation?

  1. In acute MR, left atrial pressure will be markedly higher, and left ventricular end-diastolic volume will be normal or only slightly increased. (correct answer)
  2. In acute MR, left atrial pressure will be near normal, but left ventricular end-diastolic volume will be massively increased.
  3. In acute MR, both left atrial pressure and left ventricular end-diastolic volume will be lower than in chronic MR.
  4. In acute MR, left atrial compliance is high, allowing it to accept the regurgitant volume with minimal pressure change.
Explanation: The key difference between acute and chronic regurgitation is chamber compliance. In acute MR, the normal-sized, non-compliant left atrium cannot handle the sudden large regurgitant volume, causing a massive spike in left atrial pressure, which leads to pulmonary edema. The left ventricle has not had time to dilate, so its end-diastolic volume is near normal. In chronic MR, the LA and LV have gradually dilated, increasing their compliance to accommodate the extra volume with a much smaller rise in pressure.