Which heart sound is typically associated with heart failure?

The S3 heart sound, also known as the "third heart sound," is commonly associated with heart failure, particularly in cases of volume overload. This sound is produced during rapid ventricular filling, which occurs when the ventricles are unable to properly manage the blood returning from the atria. In healthy individuals, the S3 sound is usually not present; its presence in adults, especially if it is new or loud, can suggest underlying heart issues.

In heart failure, the ventricles may be dilated or stiff, leading to increased pressure and volume in the heart. As blood flows into the ventricles during diastole, an S3 sound can indicate that the heart is struggling to accommodate this volume. This sound is often described as a low-frequency "gallop," and its detection can help clinicians assess the severity of heart failure and other cardiac conditions.

The S1 sound marks the beginning of systole and is related to the closing of the mitral and tricuspid valves, while the S2 sound relates to the closing of the aortic and pulmonic valves at the end of systole. The presence of these sounds is less indicative of heart failure compared to the S3. The S4 heart sound typically reflects decreased compliance of the