Normal Heart Sounds

First and Second Heart Sounds - Normal and Unsplit - Auscultation Lesson

This is a normal first and second heart sound at 60 beats per minute. You are auscultating at the Mitral valve area (Apex). The first heart sound has slightly greater intensity than the second heart sound.

The first heart sound is produced by the closing of the mitral and tricuspid valve leaflets.
The second heart sound is produced by the closing of the aortic and pulmonic valve leaflets.
The second heart sound is unsplit when the subject is holding his or her breath at peak expiration.

Listen

The patient's position is supine.

Visualize

Observe

The first heart sound is produced by the closing of the mitral and tricuspid valve leaflets. The second heart sound is produced by the closing of the aortic and pulmonic valve leaflets.