Physiologically Split S2 Lesson #667

patient thorax when auscultating by stethoscope

patient position during auscultation
The patient was supine during auscultation.


Closure of the aortic valve followed by the closing of the pulmonic valve generates the second heart sounds (S2). Careful observation of the intensity and splitting of the S2 can indicate the presence of several cardiac abnormalities.

In this recording, we present normal physiological S2 splitting. The splitting varies between zero and eighty milliseconds over the respiratory cycle. The S2 aortic component (S2A) precedes the S2 pulmonic component (S2P).



Physiologically Split S2

Authors and Sources

Authors and Reviewers


? v:3 | onAr:0 | onPs:2 | tLb:0 | pv:1
uStat: False | db:0 | cc: | tar: False
| cDbLookup # 0 | pu: False | pl: System.Collections.Generic.List`1[System.String]
em: | newuser: False

An error has occurred. This application may no longer respond until reloaded. Reload 🗙