The second heart sound (S2) is produced by the closure of the aortic and pulmonic valves. The sound produced by the closure of the aortic valve is termed A2, and the sound produced by the closure ...

A third heart sound, or S3, is a low-frequency, extra heart sound that may be heard with a stethoscope right after the normal ...

A diastolic murmur is an unusual “whoosh” sound in the heart that occurs during the period after S2 and before S1. The heart produces a diastolic murmur as the ventricles relax and fill with ...

The first heart sound, or S1, is the "lub" of a normal heartbeat. It's a high-pitched sound that occurs at the beginning of systole—when the heart pumps blood out of the heart into the lungs or ...

Four valves in the heart open and close at specific times to control blood flow. These valves are responsible for the “S1 and S2 sounds.” The heart has a beating phase called systole and a ...