A third heart sound, or S3, is a low-frequency, extra heart sound that may be heard with a stethoscope right after the normal S1 and S2 heart sounds. S1 and S2 are the "lub-dub" sounds of a heartbeat ...

The S3 heart sound occurs as the mitral valve opens and allows blood to fill the left ventricle passively. The sound happens as a result of blood striking the left ventricle during early diastole. An ...

There are a few common extra heart sounds that the clinician may encounter. These include ejection sounds that occur with pulmonic or AS heard in early systole, “clicks” that are heard in mitral or ...

The third heart sound (S3), also known as the "ventricular gallop," occurs just after S2 when the mitral valve opens allowing passive filling of the left ventricle. The S3 sound is actually produced ...