Increased S4 heart sound can be indicative of which condition?

The presence of an increased S4 heart sound, also referred to as an "atrial gallop," is primarily associated with conditions that involve reduced ventricular compliance or increased atrial pressure. The S4 sound is produced by the vibrations of the ventricles filling with blood during the late diastolic phase, specifically when the atria contract to push blood into a stiff or hypertrophied ventricle. This phenomenon is often seen in conditions such as left ventricular hypertrophy and longstanding hypertension.

While options that mention left ventricular hypertrophy and heart failure could also involve an S4 sound, the increased intensity of the S4 specifically highlights the prevalence of an atrial gallop due to conditions directly causing decreased compliance of the left ventricle. In healthy individuals, the S4 is typically not present, but its increase signifies an adaptative hemodynamic change in response to underlying cardiac issues. Thus, recognizing the S4 as indicative of an atrial gallop is crucial for diagnosing underlying problems related to atrial contraction and left ventricular stiffness.