Lecture 13 - Heart Sounds & Murmurs

Question 1

describe S1 sounds

Answer 1

• “lub”
• closure of mitral and tricuspid valves

Question 2

describe S2 sounds

Answer 2

• “dub”
• closure of aortic and pulmonic valves

Question 3

Split S1 sound

Answer 3

• asynchronous AV valve closure
• can be normal in larger dogs
• bundle branch block, VPCs, dyssynchrony of ventricle contraction

Question 4

Split S2 sound

Answer 4

• async closure of aortic/pulmonic valves
• inspiration increases venous return and ejection time
• prolonged RV ejection (PS, PH) or LV ejection (AS, SHTN)

Question 5

S3 Gallops
a. what is it?
b. when is it heard?
c. is it always abnormal?

Answer 5

• low-pitched during diastole
• passive blood-filling ventricle and impacting on wall
• abnormal in small animals, can be DCM
• sometimes normal in horses

Question 6

S4 Gallops
a. what is it?
b. when is it heard?
c. is it always abnormal?

Answer 6

• low-pitched during diastole
• atrial contraction (“kick”) due to thickened left ventricle
• abnormal in small animals (HCM)

Question 7

T/F: both S3 and S4 sounds would be heard in early diastole

Answer 7

FALSE - only S3, S4 in late diastole

Question 8

mid-systolic click

Answer 8

• extra “click” in systole between S1 and S2
• MV prolapse (tense chordae tendinae)

Question 9

when would heart sounds be increased?

Answer 9

hyperdynamic state (fever, anemia, pimobendan use)

Question 10

when would heart sounds be decreased?

Answer 10

myocardial dysfunction

Question 11

when would heart sounds be muffled?

Answer 11

presence of effusion

Question 12

T/F: laminar flow occurs up to a critical velocity and then becomes turbulent flow

Answer 12

TRUE

Question 13

turbulent flow occurs because of what 2 things

Answer 13

1. change in direction
2. increase in velocity

Question 14

define heart murmur

Answer 14

prolonged audible vibration of turbulent flow in the heart

Question 15

what are the 4 general causes of heart murmurs

Answer 15

1. high velocity
2. decreased blood viscosity (anemia)
3. large stroke volume
4. turbulence in flow

Question 16

murmurs are described by what

Answer 16

1. location
2. timing and duration (within cardiac cycle)
3. intensity
4. frequency or pitch

Question 17

the point of maximal intensity in cats is

Answer 17

sternal or parasternal

Question 18

what is the PMI for the mitral valve

Answer 18

5th intercostal space, left side, elbow height

Question 19

what is the PMI for the aortic valve

Answer 19

4th intercostal space, left side, craniodorsal to mitral

Question 20

what is the PMI for the pulmonic valve

Answer 20

3rd intercostal space, left side, armpit

Question 21

what is the PMI for the tricuspid valve

Answer 21

5th intercostal space; right side, point of elbow

Question 22

systolic murmur

Answer 22

between S1 and S2
occurs during ventricular ejection when AV valves should be closed

Question 23

diastolic murmur

Answer 23

occurs when ventricles are filling/relaxing and aortic/pulmonic valves should be closed

Question 24

continuous murmur

Answer 24

heard throughout systole and diastole

Question 25

grade 1 murmur

Answer 25

soft, heard with difficulty, one location (focal)

Question 26

grade 2 murmur

Answer 26

soft, heard in one location but does not radiate from PMI (focal), readily heard

Question 27

grade 3 murmur

Answer 27

moderately loud murmur readily heard and radiates slightly, regional

Question 28

grade 4 murmur

Answer 28

loud murmur that radiates widely and can be heard on both sides of thorax

Question 29

grade 5 murmur

Answer 29

very loud associated with palpable precordial thrill felt on one side of thorax

Question 30

grade 6 murmur

Answer 30

heard with stethoscope lifted off thorax wall, radiates

Question 31

crescendo

Answer 31

gradually increases to peak intensity

Question 32

decrescendo

Answer 32

gradually tapers from initial peak

Question 33

Diamond

Answer 33

builds to peak and tapers off

Question 34

plateau

Answer 34

equal in intensity throughout

Question 35

what is responsible for timing and opening of valves

Answer 35

pressure gradients

Question 36

stenosis

Answer 36

valves do not open fully/properly due to the narrowing of path, so the heart works harder

Question 37

regurgitation

Answer 37

valves do not close properly and resulting in leaky valves where blood flows backward

Question 38

if _____ and _____ are increased, cardiac work increases

Answer 38

volume; pressure

Question 39

eccentric hypertrophy

Answer 39

increased volume from valve insufficiency

Question 40

concentric hypertrophy

Answer 40

increased pressure from stenosis

Question 41

eccentric hypertrophy leads to ____ of chamber and concentric hypertrophy leads to ____ of walls

Answer 41

dilation; thickening

Question 42

T/F: diastolic pressure is increased in concentric hypertrophy

Answer 42

FALSE

Question 43

what type of murmur decreases stroke volume

Answer 43

mitral valve regurgitation

Question 44

T/F: mitral valve regurgitation is a common left apical systolic murmur in dogs

Answer 44

TRUE

Question 45

systolic murmur

Answer 45

AV valves

Question 46

diastolic murmur

Answer 46

aortic and pulmonic valves

Question 47

shunt

Answer 47

abnormal mixing of blood in heart or great vessels

Question 48

what 3 conditions cause volume overload to the left side of the heart

Answer 48

1. patent ductus arteriosus
2. ventricular septal defect
3. atrial septal defect

Question 49

T/F: PDA is a continuous murmur

Answer 49

TRUE

Question 50

T/F: in a ventricular septal defect, where flow is left to right, a patient may be cyanotic

Answer 50

FALSE - blood will be oxygenated

Question 51

an increase in pulmonary circulation increases what two things?

Answer 51

1. venous return
2. left ventricle volume

Question 52

what is a rare defect in animals that allows the mixing of blood from the atria

Answer 52

atrial septal defect