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 ...

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 ...