Cardiovascular physiology: S1 heart sound
S1 is caused by closure of mitral and tricuspid valves
Causes of a loud S1
Causes of a quiet S1
The diagram below demonstrates the cardiac cycle in relation to the heart sounds.
Causes of a loud S1
- mitral stenosis
- left to right shunts
- short PR interval, atrial premature beats
- hyperdynamic states
Causes of a quiet S1
- mitral regurgitation
The diagram below demonstrates the cardiac cycle in relation to the heart sounds.
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