Which heart sound is associated with heart failure?

The S3 gallop, also known as a third heart sound, is commonly associated with heart failure, particularly in cases of volume overload. This sound occurs due to the rapid filling of the ventricles during the early diastolic phase of the cardiac cycle. In individuals with heart failure, the ventricles are often stiff or dilated due to increased pressure and fluid retention, which leads to abnormal filling patterns.

When fluid accumulates in the heart as a result of heart failure, it can cause the ventricles to fill more rapidly than normal. The S3 sound is a reflection of this rapid ventricular filling and is often heard best with the patient in a left lateral decubitus position using the bell of the stethoscope.

In contrast, S1 and S2 heart sounds are primarily associated with the closure of the heart valves during systole and diastole, respectively, and do not directly indicate heart failure. S4 gallop, while indicative of stiff or hypertrophied ventricles and often seen in certain types of heart failure, is more commonly associated with conditions that lead to left ventricular hypertrophy, such as hypertension, rather than the volume overload typically seen in heart failure. Thus, the S3 gallop serves as a