heart valves and sounds; valvular and congenital heart defects

Question 1

Cause of s1 sound

Answer 1

vibration of AV valves as they close at the beginning of systole

Question 2

duration of s1 sound

Answer 2

0.14s

Question 3

frequency s1 sound

Answer 3

25-45Hz

Question 4

cause of s2 sound

Answer 4

vibrations associated with closure of semi lunar valves at the end of systole

Question 5

where does s2 occur on ECG?

Answer 5

after the T wave

Question 6

duration of s2

Answer 6

0.11s

Question 7

frequency of s2

Answer 7

50Hz

Question 8

why does s1 have a longer duration than s2?

Answer 8

SL valves are tauter than A-V valves, so they vibrate for a shorter period of time

Question 9

why does s2 have higher frequency than s1?

Answer 9

• tautness of semilunar valves compared to less taut A-V
• greater elastic coefficient of the taut arterial walls, which provides the principal vibrating chambers for the second sound, in comparison with the much looser, less elastic ventricular chambers, which provide the vibrating system for the first heart sound

Question 10

aortic valve produces a loud sound in…?

Answer 10

systemic hypertension

Question 11

pulmonary valve produces a loud sound in…?

Answer 11

pulmonary hypertension

Question 12

cause of s3 heart sound

Answer 12

oscillation of blood back and forth in the ventricles initiated by in-rushing blood from the atria

Question 13

when does s3 occur?

Answer 13

middle third of diastole

Question 14

duration of s3

Answer 14

0.1s

Question 15

frequency of s3

Answer 15

20-30Hz

Question 16

where does s3 become loud and audible?`

Answer 16

• aortic regurgitation
• cardiac failure
• cardiomyopathy

Question 17

where does s3 occur in ECG?

Answer 17

between T and P wave

Question 18

causes of 4th heart sound

Answer 18

inrush of blood into the ventricles

Question 19

in what condition is 4th sound audible?

Answer 19

• left ventricular hypertrophy
• long standing hypertension
• aortic stenosis

Question 20

when does s4 occur

Answer 20

last third of diastole (just before s1)

Question 21

what is rheumatic fever?

Question 22

how does rheumatic fever affect heart valves?

Question 23

which valve is most affected in rheumatic fever?

Question 24

what is stenosis and regurgitation?

Question 25

what causes aortic stenosis murmurs?

Question 26

what causes aortic regurgitation murmurs?

Question 27

what causes mitral stenosis murmurs?

Question 28

what causes mitral regurgitation murmurs?

Question 29

classify the murmurs as systolic or diastolic