Question

Following is true regarding opening snap:

• A. It is a high-pitched diastolic sound.
• B. It is due to opening of stenosed aortic valve.
• C. It indicates pulmonary arterial hypertension.
• D. It precedes the aortic component of second heart sound.

Hint:

The opening snap comes from a stenotic mitral valve snapping open, right after S2, not before it.

Answer 1

The Correct Option is A

Step 1: Understanding the Question.
The opening snap is an extra heart sound classically linked to mitral stenosis, and the question asks which statement about it is correct.

Step 2: Key Concept.
In mitral stenosis, the mitral valve leaflets are thickened and fused but still mobile enough to dome open. When left atrial pressure forces the stenotic valve open in early diastole, the sudden tensing of the leaflets creates a sharp, high-pitched sound called the opening snap, heard just after the second heart sound (S2).

Step 3: Detailed Explanation.
Option (1) it is a high-pitched diastolic sound: this matches the description of the opening snap exactly, since it is a sharp, high-pitched sound occurring in early diastole.
Option (2) it is due to opening of stenosed aortic valve: this is incorrect, since the opening snap comes from the mitral valve, not the aortic valve.
Option (3) it indicates pulmonary arterial hypertension: this is incorrect, since the opening snap is a marker of mitral stenosis, not of pulmonary artery pressure.
Option (4) it precedes the aortic component of second heart sound: this is incorrect, since the opening snap actually comes after S2, not before it. The gap between A2 and the opening snap (the A2-OS interval) is used clinically, and a shorter interval points to more severe mitral stenosis.

Step 4: Final Answer.
The opening snap is a high-pitched diastolic sound.
\[ \boxed{\text{It is a high-pitched diastolic sound}} \]