In what condition is S4 typically heard?

S4, also known as the atrial sound or "gallop," is typically associated with conditions that involve decreased compliance of the left ventricle, leading to an increased left atrial pressure. This sound is produced when the atria contract forcefully to push blood into a stiff or hypertrophied ventricle, which is often seen in systemic hypertension, particularly when the heart undergoes structural changes as a response to increased workload.

In individuals with systemic hypertension, the left ventricle often becomes thicker (hypertrophy) as it works harder to pump against elevated pressures, thus reducing its compliance. As a result, when the left atrium contracts, the blood being forced into the stiff ventricle creates the S4 heart sound. This helps to identify the presence of underlying cardiovascular issues, such as long-standing hypertension, emphasizing the importance of assessing heart sounds during a cardiovascular examination.

While S4 can be detected in other circumstances and in various populations, its typical association with systemic hypertension makes this choice the most accurate within the context of this question.