Which of the following is NOT true regarding the S3 heart sound?

The S3 heart sound, often referred to as a "physiological" or "ventricular" gallop, typically occurs just after the S2 heart sound during the rapid filling phase of the ventricles. This sound occurs at the end of the rapid filling phase, which is associated with the heart's diastolic function. Being low-pitched, it can be best heard with the bell of the stethoscope, indicating that it is formed by blood rushing into the ventricles under specific conditions.

The statement that it is heard before the S1 heart sound is not accurate. The S1 heart sound marks the beginning of ventricular systole as the mitral and tricuspid valves close. Since S3 occurs after S2 and before S1, it is important to understand the sequence of heart sounds during the cardiac cycle to grasp the correct timing of S3 in relation to S1 and S2. Therefore, the assertion that S3 is heard before S1 does not align with the established physiology of the heart sounds.