Which heart sound is associated with heart failure?

The S3 gallop is particularly associated with heart failure and represents increased volume and pressure in the ventricles during diastole. This sound occurs due to the rapid filling of blood into a dilated ventricular chamber, often seen in cases of left ventricular dysfunction. The S3 sound is best heard when the patient is in the left lateral decubitus position and indicates volume overload, which is a hallmark of heart failure.

In contrast, S1 is the sound created by the closure of the mitral and tricuspid valves at the beginning of ventricular contraction, while S2 is associated with the closure of the aortic and pulmonic valves at the end of ventricular systole. The S4 gallop, on the other hand, is linked to conditions such as hypertensive heart disease or ischemic heart disease and arises from atrial contraction against a stiff or hypertrophied ventricle, which is not as directly connected to heart failure as the S3 sound. Therefore, the S3 gallop serves as a significant clinical marker for heart failure and helps guide diagnosis and treatment decisions.