S1 and S2 are the normal heart sounds you hear when the heart valves close. Heart murmurs are extra sounds that can be heard during systole, diastole, or as a continuous sound. S3 and S4 are abnormal ...

An S4 heart sound is a low-pitched sound that occurs toward the end of the diastole. In some cases, an underlying health condition, often one affecting the left ventricle, may cause the S4 heart sound ...

An S4 heart sound cannot be present during atrial fibrillation (atrial kick is required). An S3 heart sound cannot be present in the setting of severe mitral stenosis. An S3 heart sound can be present ...

A heart murmur is an extra sound that can occur between heartbeats as blood moves through the heart. In babies, it is usually not a cause for concern. Sometimes, however, it can indicate an underlying ...