Question:hard
A 50 yr old female presented with dyspnoea and chest pain. Which of the following proves that she has aortic stenosis rather than aortic regurgitation?
A 50 yr old female presented with dyspnoea and chest pain. Which of the following proves that she has aortic stenosis rather than aortic regurgitation?
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AS = pressure (afterload) overload; AR = volume (preload) overload. Recall which type of work costs the myocardium more oxygen (Laplace's law).
Updated On: Jun 22, 2026
- Increase in myocardial oxygen consumption is seen with increased pressure work than volume
- Aortic stenosis causes reduced pressure at aortic valve
- Workload has nothing to do with myocardial oxygen consumption
- Increase in preload more than afterload than after load
Show Solution
The Correct Option is A
Solution and Explanation
Frame the whole question around a single physiological idea: pressure work is metabolically far more "expensive" for the heart than volume work.
First, classify the two valve lesions by the type of load they impose:
• Aortic stenosis → the LV pushes blood through a narrowed valve → it must build a high intraventricular pressure → pressure (afterload) overload.
• Aortic regurgitation → blood leaks back in diastole → the LV fills with extra volume each beat → volume (preload) overload.
Next, recall what determines oxygen use by the myocardium. The dominant factor is ventricular wall stress, given by Laplace's law \[\sigma = \frac{P \times r}{2h}\] where $P$ is intraventricular pressure, $r$ the radius and $h$ the wall thickness. Because oxygen consumption tracks wall stress (plus heart rate and contractility), a rise in developed pressure costs much more oxygen than simply moving more blood volume at the same pressure.
Therefore the statement "increase in myocardial oxygen consumption is seen with increased pressure work more than volume work" is the one that fingerprints aortic stenosis (the pressure-overload lesion).
Quickly discard the rest: AS produces a high - not reduced - transvalvular pressure gradient (so the "reduced pressure" option is wrong); workload absolutely does drive myocardial O$_2$ demand (so that denial is wrong); and a preload-greater-than-afterload picture describes the volume overload of regurgitation, not stenosis.
Hence option A is correct.
First, classify the two valve lesions by the type of load they impose:
• Aortic stenosis → the LV pushes blood through a narrowed valve → it must build a high intraventricular pressure → pressure (afterload) overload.
• Aortic regurgitation → blood leaks back in diastole → the LV fills with extra volume each beat → volume (preload) overload.
Next, recall what determines oxygen use by the myocardium. The dominant factor is ventricular wall stress, given by Laplace's law \[\sigma = \frac{P \times r}{2h}\] where $P$ is intraventricular pressure, $r$ the radius and $h$ the wall thickness. Because oxygen consumption tracks wall stress (plus heart rate and contractility), a rise in developed pressure costs much more oxygen than simply moving more blood volume at the same pressure.
Therefore the statement "increase in myocardial oxygen consumption is seen with increased pressure work more than volume work" is the one that fingerprints aortic stenosis (the pressure-overload lesion).
Quickly discard the rest: AS produces a high - not reduced - transvalvular pressure gradient (so the "reduced pressure" option is wrong); workload absolutely does drive myocardial O$_2$ demand (so that denial is wrong); and a preload-greater-than-afterload picture describes the volume overload of regurgitation, not stenosis.
Hence option A is correct.
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