heart sounds

Question 1

what is the first heart sound, S1 due to?

Answer 1

closure of the mitral and tricuspid valves

Question 2

what is the second heart sound, S2 due to?

Answer 2

closure of the aortic and pulmonary valves

Question 3

what is S3 due to?

Answer 3

ventricular filling

S3 is normal in children, but normally silent in adults - can be a sign of pathology

Question 4

what murmur is heard in aortic valve stenosis? what are the causes of aortic valve stenosis?

Answer 4

Crescendo-decrescendo murmur – heard between S1 and S2

causes:
- degenerative - senile calcification
- congenital - bicuspid valve formation
- chronic rheumatic fever - inflammation - commissural fusion

Question 5

what murmur is heard in aortic valve regurgitation? causes of AVR?

Answer 5

early decrescendo diastolic murmur – heard after S2

causes:
- aortic root dilation - leaflets pulled apart
- valvular damage - endocarditis rheumatic fever

Question 6

what murmur is heard in mitral valve regurgitation? causes of MVR?

Answer 6

holosystolic murmur – heard between S1 and S2

causes:
- myxomatous degeneration weakens tissue and leads to prolapse
- damage to papillary muscle after heart attack
- left sided heard failure leads to LV dilation which can stretch valve
- Rheumatic fever can lead to leaflet fibrosis which disrupts seal formation

Question 7

what sound is heard in mitral valve stenosis? causes of MVS?

Answer 7

diastolic rumble - snap as valve opens – heard after S2

causes:
- rheumatic fever