On occasion the first heart sound can be made up of two separate sounds separated by a very small interval (20-30 milliseconds).

The Mitral component (caused by closure of the Mitral valve) comes first and is louder than the Tricuspid component (caused by closure of the Tricuspid valve).

A minimally split first heart sound is a normal variation of the first heart sound.

After reviewing the sound, use the waveform and anatomy tabs for more information about this sound.

First Heart Sound (Minimally Split)
Position: Tricuspid
Maneuver: Supine
Chestpiece: Diaphragm