heart sounds Flashcards
1
Q
when is S1 heard?
A
- when the mitral and tricuspid valves close at the beginning of ventricular systole
2
Q
where is S1 best heard?
A
in the apex
3
Q
where do you listen for mitral stenosis?
A
in the apex area over the mitral valve
4
Q
how do you enhance the intensity of S1 in mitral stenosis?
A
by rolling the patient onto their left hand side
5
Q
what can cause a quiet S1?
A
- low CO
- poor left ventricular function
- rheumatic mitral regurgitation
- long P-R interval (first degree heart block)
6
Q
what can cause a loud S1?
A
- increased CO
- large SV
- mitral stenosis
- short P-R interval
- atrial myxoma (rare)
7
Q
what can cause a variable S1?
A
- AF
- extrasystoles
- complete heart block
8
Q
when is S2 heard?
A
- closure of aortic and pulmonary valves at the end of systole
9
Q
where is S2 best heard?
A
at the left sternal edge
10
Q
why does S2 splitting occur?
A
- because left ventricular contraction slightly precedes that of the right ventricle so that the aortic valves close before the pulmonary valve
- the splitting increases at end-inspiration because increased venous filling of the right ventricle further delays pulmonary valve closure
- lub d-dub
11
Q
when might the aortic component of S2 be quiet or absent?
A
- in calcific aortic stenosis
- aortic regurgitation
12
Q
when might the aortic component of S2 be loud?
A
- systemic hypertension
13
Q
when might the pulmonary component of S2 be loud?
A
- pulmonary hypertension
14
Q
when would wide splitting of S2 but normal resp variation occur?
A
- right bundle branch block
- pulmonary hypertension
15
Q
when would fixed splitting of S2 with no variation in resp occur?
A
- atrial septal defect
