Which heart sound is classically heard as a ventricular gallop in heart failure?

Which heart sound is classically heard as a ventricular gallop in heart failure?

• A. S4
• B. S1
• C. S3
• D. S2

Answer: (C)

The sound heard as a ventricular gallop in heart failure is S3. It comes from rapid, early diastolic filling of a compliant, often volume-loaded ventricle. When blood flows quickly from the left atrium into the left ventricle after S2, the sudden deceleration can cause vibrations of the ventricular wall and chordae tendineae, producing a low-frequency crackling sound that you hear best with the bell at the apex in the left lateral position, shortly after S2. In adults with heart failure, S3 indicates elevated filling pressures and a dilated or poorly contracting ventricle, and it can have prognostic implications. By contrast, S4 is a late diastolic sound from atrial contraction against a stiff ventricle (diastolic dysfunction), S1 is the sound of AV valve closure at the start of systole, and S2 is the semilunar valve closure sound; none of these describe the ventricular gallop heard in heart failure.

The sound heard as a ventricular gallop in heart failure is S3. It comes from rapid, early diastolic filling of a compliant, often volume-loaded ventricle. When blood flows quickly from the left atrium into the left ventricle after S2, the sudden deceleration can cause vibrations of the ventricular wall and chordae tendineae, producing a low-frequency crackling sound that you hear best with the bell at the apex in the left lateral position, shortly after S2. In adults with heart failure, S3 indicates elevated filling pressures and a dilated or poorly contracting ventricle, and it can have prognostic implications. By contrast, S4 is a late diastolic sound from atrial contraction against a stiff ventricle (diastolic dysfunction), S1 is the sound of AV valve closure at the start of systole, and S2 is the semilunar valve closure sound; none of these describe the ventricular gallop heard in heart failure.