Murmurs

Question 1

what are the aims of investigating heart murmurs in horses?

Answer 1

determine significance of performance, risk of collapse and progression

Question 2

where is the apex beat of the horses heart?

Answer 2

over the mitral valve

Question 3

what causes S1?

Answer 3

shutting of the AV valves (mitral/tricuspid)

Question 4

what causes S2?

Answer 4

shitting of the seminar valves (aortic/pulmonic)

Question 5

what causes S4?

Answer 5

atrial contraction

Question 6

when is S4 heard in the cardiac cycle

Answer 6

just before S1

Question 7

what causes S3?

Answer 7

end of rapid passive ventricular filling

Question 8

what is S3 heard?

Answer 8

just after S2

Question 9

what correlates to S4 on an ECG?

Answer 9

P wave

Question 10

what causes a P wave?

Answer 10

depolarisation of the atrium

Question 11

what causes the QRS complex?

Answer 11

depolarisation of ventricles

Question 12

what causes the T wave?

Answer 12

repolarisation of ventricles

Question 13

why does mitral valve regurgitation cause a load S3?

Answer 13

blood flows back into the atrium so the atrium becomes very full with blood, then when the ventricle relaxes there is a higher pressure of blood rushing into the ventricle (very rapid filling)

Question 14

is diastole or systole shorter?

Answer 14

systole is shorter

Question 15

as heart rate increases does the length of diastole or systole decrease?

Answer 15

systole (becomes harder to tell if a murmur is diastolic os systolic)

Question 16

what causes murmurs?

Answer 16

turbulent flow of blood

Question 17

what influences Reynolds number?

Answer 17

velocity, diameter of vessel, density, viscosity

Question 18

what number influences turbulence?

Answer 18

Reynolds

Question 19

what is Reynolds number?

Answer 19

(velocity x diameter x density) / viscosity

Question 20

how does the diameter of the vessel influence the turbulence of blood?

Answer 20

large vessels have more turbulence

Question 21

why do foals often have flow murmurs?

Answer 21

they are relatively anaemic, so the viscosity of the blood is lower so there is more turbulence to blood

Question 22

how are murmurs graded?

Answer 22

1 - barely audible
2 - quite than S1/S2
3 - as loud as S1/S2
4 - louder than S1/S2
5 - very loud and palpable thrill
6 - audible with stethoscope off of chest

Question 23

how can the timings of murmurs be described?

Answer 23

(early, mid, late, pan, holo) - systolic, diastolic, continuous

Question 24

what does pan- mean when describing murmurs?

Answer 24

covers over the normal heart sounds

Question 25

what do we use to describe murmurs?

Answer 25

grade timing point of maximum intensity radiation shape quality

Question 26

how can the shape of a murmur be described?

Answer 26

plateau crescendo (get louder) decrescendo (get quieter)

Question 27

what are the two categories of murmurs?

Answer 27

physiological/functional pathological

Question 28

when are flow murmurs heard?

Answer 28

early/mid systole

Question 29

are flow murmurs normal?

Answer 29

yes - physiological murmurs

Question 30

where can flow murmurs be localised to?

Answer 30

heart base

Question 31

what vessel are flow murmurs associated with?

Answer 31

aorta

Question 32

when are filling murmurs heard?

Answer 32

early diastole (between S2 and S3)

Question 33

what are the two main physiological murmurs?

Answer 33

flow and filling

Question 34

what age animals are filling murmurs heard in?

Answer 34

young, fit animals

Question 35

what kind of sound does a filling murmur make?

Answer 35

squeak

Question 36

what is the most common pathological murmur of horses?

Answer 36

mitral/tricuspid regurgitation

Question 37

what is the timing of a mitral valve regurgitation murmur?

Answer 37

holo/pansystolic

Question 38

what is the point of maximal intensity of mitral valve regurgitation murmur?

Answer 38

heart apex

Question 39

what is does if you find a grade 1-2 mitral valve regurgitation murmur?

Answer 39

monitor for progression

Question 40

what is does if you find a dare 3-6 mitral valve regurgitation murmur?

Answer 40

investigate further (echo)

Question 41

why are right sided murmurs less of a concern then left side?

Answer 41

lower pressure in the right side

Question 42

what aged horses are ventricular septal defect murmur usually detected in?

Answer 42

young horses

Question 43

which side of the heart are ventricular septal defect murmur loudest on?

Answer 43

right

Question 44

what is the timing of ventricular septal defect murmurs?

Answer 44

pansystolic

Question 45

why does a faster/louder ventricular septal defect murmur give a better prognosis?

Answer 45

means there is a smaller defect and the pressure difference is still large meaning the horse hasn't gone into heart failure

Question 46

what age horses are aortic insufficiency/regurgitation murmurs seen in?

Answer 46

older horses (degenerative disorder)

Question 47

what is the timing of insufficiency/regurgitation murmurs?

Answer 47

holodiastolic

Question 48

what is the point of maximal intensity of insufficiency/regurgitation murmurs?

Answer 48

heart base

Question 49

what does a insufficiency/regurgitation murmur sound like?

Answer 49

moaning (teenage murmur) uhhhh

Question 50

what causes a continuous murmur?

Answer 50

patent ductus arteriosus

Question 51

where is the ductus arteriosus?

Answer 51

between the aorta and pulmonary artery

Question 52

when is a patent ductus arteriosus murmur normal?

Answer 52

foals up to 5 days old

Question 53

what is the point of maximal intensity of patent ductus arteriosus murmur?

Answer 53

heart base

Question 54

what are the main pathological murmurs?

Answer 54

mitral/tricuspid regurgitation ventricular septal defect aortic regurgitation patent ductus arteriosus

Question 55

what are the two differentials for left systolic murmurs?

Answer 55

mitral regurgitation aortic flow

Question 56

what are the two differentials for left diastolic murmurs?

Answer 56

aortic regurgitation ventricular filling

Question 57

what are the two differentials for right systolic murmurs?

Answer 57

tricuspid regurgitations ventricular septal defect