Normal Heart Sounds

First and Second Heart Sounds - Normal and Unsplit Sounds

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.

First and Second Heart Sounds - Normal and Unsplit

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The recommended auscultation position for the stethoscope is the Mitral position. For this sound, use stethoscope's Diaphragm.

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The recommended patient position is Supine

Phonocardiogram

This waveform plots sound amplitude on the vertical axis against time on the horizontal axis.

Heart Animation

Lessons

1	First and Second Heart Sounds - Normal and Unsplit
2	First Heart Sound (Minimally Split)
3	Second Heart Sound - Physiologically Split #1
4	Third Heart Sound - Physiologic
5	Innocent Murmur
6	Exercise - Heart Rate 120

Practice Drill

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CourseID	22
CourseCaseOrder	1
ID	13