What characterizes an extra diastolic murmur?

What characterizes an extra diastolic murmur?

• A. Occurs during the opening of the stenotic mitral valve
• B. Occurs during closing of the aortic valve
• C. Occurs during systole
• D. Occurs during rapid ventricular filling

Answer: (A)

The key idea is that diastolic murmurs arise as blood flows through the valves during diastole. In mitral stenosis, the mitral valve is narrowed, so turbulent flow starts precisely when the valve opens in early diastole. That opening marks the onset of the diastolic murmur, often accompanied by an opening snap and a low-pitched rumble best heard at the apex with the patient in the left lateral position. This timing—beginning with the mitral valve opening—defines the extra diastolic murmur of mitral stenosis. Other timings don’t fit this pattern: a murmur tied to the aortic valve closing would relate to events around valve closure, not the opening across a stenotic mitral valve; systolic murmurs occur during systole, not diastole; and a murmur described as during rapid ventricular filling corresponds to a different diastolic phenomenon (often an S3) rather than the opening of a stenotic mitral valve.

The key idea is that diastolic murmurs arise as blood flows through the valves during diastole. In mitral stenosis, the mitral valve is narrowed, so turbulent flow starts precisely when the valve opens in early diastole. That opening marks the onset of the diastolic murmur, often accompanied by an opening snap and a low-pitched rumble best heard at the apex with the patient in the left lateral position. This timing—beginning with the mitral valve opening—defines the extra diastolic murmur of mitral stenosis.

Other timings don’t fit this pattern: a murmur tied to the aortic valve closing would relate to events around valve closure, not the opening across a stenotic mitral valve; systolic murmurs occur during systole, not diastole; and a murmur described as during rapid ventricular filling corresponds to a different diastolic phenomenon (often an S3) rather than the opening of a stenotic mitral valve.