Heart Sounds and Valves

Question 1

What does S1 correspond to?

Answer 1

1. Closing of the AV valves

2. “Lub” sound

Question 2

When does S1 occur?

Answer 2

At beginning of ventricular systole

Question 3

When does S2 occur?

Answer 3

At end of ventricular systole

Question 4

What does S2 correspond to?

Answer 4

1. Closing of semilunar valves

2. “Dub” sound

Question 5

Define S3

Answer 5

Weak rumbling sound occasionally heard during middle third of diastole
Sound of ventricles filling causing reverberation along ventricle walls

Question 6

What S3 sound can be heard with heart failure?

Answer 6

S3 gallop

Question 7

Until what age is S3 normal?

Answer 7

40

Question 8

Define S4

Answer 8

Very weak sound, if heard, abnl

Sound of atria contracting

Question 9

What do heart sounds result from?

Answer 9

1. Vibration of valves immediately after closure

2. Vibration of adjacent heart walls & major vessels

Question 10

What is the order of heart sounds if all 4 are present?

Answer 10

S4
S1
S2
S3

Question 11

Where do you auscultate to hear the aortic valve?

Answer 11

2nd intercostal space @ R sternal border

Question 12

Where do you auscultate to hear the pulmonic valve?

Answer 12

2nd intercostal space @ L sternal border

Question 13

Where do you auscultate to hear the tricuspid valve?

Answer 13

Over right ventricle (5th ICS left sternal border)

Question 14

Where do you auscultate to hear the mitral valve?

Answer 14

Over apex of left ventricle @ level of 5th ICS

Question 15

Define murmurs

Answer 15

Abnormal heart sounds produced by abnl patterns of blood flow in heart. May be from congenital condition or as a result of disease such as Rheumatic Fever.

Question 16

How can murmurs be described?

Answer 16

1. Timing of murmur relative to CC
   A. Systole shorter than diastole at nl HR
   B. systolic vs. diastolic
2. Intensity (loudness)
   A. Directly related to speed of blood flow, speed is determined by pressure gradient across valve
   Grade I-VI
3. Frequency (pitch)
   A. Also directly related to speed of blood flow at murmur’s origin

Question 17

What valves do rheumatic valvular lesions affect?

Answer 17

Usually affects mitral or aortic valves

Question 18

What is the pathophys of rheumatic valvular lesions?

Answer 18

1. Result from Rheumatic Fever (RF)
2. Large hemorrhagic & fibrinous lesions grow along the inflammed edges of heart valves
3. Usually occur on adjacent leaflets simultaneously so that the leaflets become stuck together
4. Lesions eventually become scar tissue, permanently fusing portions of leaflets
5. Leads to stenosis & regurgitation

Question 19

Define mitral valve stenosis

Answer 19

Incomplete opening of mitral valve during diastole, creating diastolic murmur

Question 20

What are common causes of mitral valve stenosis?

Answer 20

Most commonly the result of RF

congenital

Question 21

What are the characteristics of mitral valve stenosis?

Answer 21

1. Low-pitched (due to low velocity from narrowing of valve), rumbling murmur best heard at apex, left lateral decubitus position
   A. opening snap
   B. Heard in diastole
   C. Heard better with the bell than diaphragm

Question 22

Define mitral valve regurgitation

Answer 22

Incomplete closure of mitral valve

Question 23

What is the pathophys of mitral valve regurgitation?

Answer 23

1. Causes: RHD, ruptured chordae tendinae, papillary muscle dysfunction or dilation of LV or valve orifice

Question 24

What are the characteristics of mitral valve regurgitation?

Answer 24

1. High frequency systolic “blowing” murmur
   A. Holosystolic (pansystolic)
2. Transmitted strongest to LA (LA very deep in thorax)

Question 25

What can mitral valve diseases lead to?

Answer 25

Afib | pulmonary edema

Question 26

Murmurs are more common on which side of the heart?

Answer 26

Left

Question 27

What causes aortic stenosis?

Answer 27

Congenital valve malformation and acquired calcification of valve

Question 28

What are the characteristics of aortic stenosis?

Answer 28

1. Characterized by  resistance to ejection of blood from LV into aorta 2. Loud systolic ejection murmur 3. Occurs as a result of “nozzle effect” during systole 4. Turbulent blood flow against aortic walls causes the harsh murmur 5. Sometimes has an associated thrill over upper chest & neck

Question 29

Define aortic valve regurgitation

Answer 29

1. Incompetent aortic valve that allows blood to flow back to LV during diastole

Question 30

What are the causes of aortic valve regurgitation?

Answer 30

Causes are varied: RF, dilation of aorta, infective endocarditis, Marfan syndrome

Question 31

What are the characteristics of aortic valve regurgitation?

Answer 31

Holodiastolic murmur

Question 32

What is the result of aortic valve regurgitation and/or stenosis?

Answer 32

1. LV volume and pressure overload A. As valve deformity increases, regurg flow increases in LV, DBP falls, and LV progressively enlarges 2. LVH

Question 33

How can S1 and S2 be differentiated?

Answer 33

Listen to heart and feel carotid pulse at the same time. S2 is right after pulse