Question

Which one of the following is NOT the cause of wide pulse pressure?

• A. Severe aortic regurgitation
• B. Severe mitral regurgitation
• C. Severe tricuspid regurgitation
• D. Severe anemia

Hint:

Wide pulse pressure needs either aortic diastolic runoff or a high output state; think about which valve lesion never causes either.

Answer 1

The Correct Option is C

Step 1: Recall what pulse pressure means.
Pulse pressure is the difference between systolic and diastolic blood pressure. It widens whenever the stroke volume goes up, the systolic pressure goes up, or the diastolic pressure falls because blood runs off out of the arteries faster than normal.

Step 2: Analyze severe aortic regurgitation.
In aortic regurgitation, blood leaks back from the aorta into the left ventricle during diastole. This drop in diastolic pressure, together with a large stroke volume on the next beat, produces a classically wide pulse pressure with a bounding, collapsing pulse. So this is a true cause of wide pulse pressure.

Step 3: Analyze severe anemia.
Severe anemia lowers blood viscosity and forces the heart into a high output state to keep tissues supplied with oxygen. The higher stroke volume raises systolic pressure while diastolic pressure stays low, so pulse pressure widens. This is also a true cause.

Step 4: Analyze severe tricuspid regurgitation.
Tricuspid regurgitation is a right heart valve problem. Blood leaks back from the right ventricle into the right atrium, this mainly raises right atrial and venous pressure, but it does not act on the systemic arterial circuit the way aortic regurgitation does. It is not linked with a wide systemic pulse pressure.

Step 5: Analyze severe mitral regurgitation.
Mitral regurgitation lets some blood leak backward into the left atrium instead of going forward into the aorta on each beat. This can even reduce the forward stroke volume reaching the aorta, so it does not classically widen pulse pressure the way aortic regurgitation does, though it is a left heart lesion.

Step 6: Pick the best answer.
Among the choices, severe tricuspid regurgitation is a right sided lesion with no established link to systemic pulse pressure at all, making it the clearest answer to this EXCEPT question.

Step 7: Final answer.
\[ \boxed{\text{Severe tricuspid regurgitation}} \]