Which heart sound is typically associated with congestive heart failure (CHF)?

The third heart sound, known as S3, is typically associated with congestive heart failure (CHF). It is often referred to as a "ventricular gallop" and occurs just after S2. The presence of an S3 sound indicates that there is increased filling pressure in the ventricles, which can occur due to volume overload and reduced ventricular compliance, characteristics commonly seen in CHF.

In patients with CHF, the rapid filling of the ventricles during early diastole can lead to the generation of this sound. It is often best heard when a patient is lying in a left lateral position. When assessing a patient, the presence of S3 can provide valuable insight into the severity of heart failure and ventricular function, signaling a need for further evaluation and potential intervention.

On the other hand, S1 and S2 are normal heart sounds associated with the closure of heart valves during the cardiac cycle, while S4, or "atrial gallop," typically occurs in conditions where there is stiffness in the ventricles, indicating a different pathological state often linked to conditions such as hypertension or left ventricular hypertrophy rather than CHF specifically.