Where is S3 heart sound typically associated?

The S3 heart sound, often referred to as a "physiological S3," is typically associated with conditions that involve volume overload of the ventricles, making congestive heart failure the most relevant association. In congestive heart failure, the heart's ability to pump blood is impaired, leading to an increase in left ventricular filling pressures. This results in the sound of turbulent blood flow as the ventricles fill with blood. The S3 sound usually occurs in early diastole and is heard best at the apex of the heart with the patient in a lateral decubitus position.

While an S3 can occasionally be heard in healthy young individuals or during pregnancy due to high blood volume states, its presence in older adults is often indicative of underlying cardiac dysfunction, particularly heart failure. This differential is important to understand, as it emphasizes the S3 sound as a marker for potential heart failure.

In contrast, options like chronic atrial fibrillation and myocardial infarction may involve different heart sounds or clinical presentations. Atrial fibrillation commonly leads to an irregular rhythm but does not specifically correlate with an S3 sound, which reflects diastolic filling dynamics. Myocardial infarction can create other abnormal sounds, such as gallops or rubs, but