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 ...

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 ...

Healthcare providers listen to the heart's rhythm and ... closes to prevent backflow into the left atrium. S3 (gallop) is an abnormal heart sound. It is not usually present but may be heard ...