Murmur characterisation

Question 1

How to describe a murmur

Answer 1

• timing
• grade
• point of maximal intensity (PMI)
• radiation
• character and shape

Question 2

Murmur grades

Answer 2

Grade 1: very quiet, localised

Grade 2: quieter than S1/S2

Grade 3: similar loudness to S1/S2

Grade 4: louder than S1/S2

Grade 5: palpable thrill on chest wall (i.e. can feel the vibration of the murmur when palpating the chest wall)

Grade 6: audible with stethoscope off the chest wall

Question 3

PMI

Answer 3

Where is it the loudest?
- L or R side?
- base or apex?
OR
- based on valve position (mitral/aortic/pulmonic/tricuspid)

Question 4

Radiation

Answer 4

Direction in which the murmur radiates
- cranially
- caudally
- dorsal
- ventral
- (can also radiate to the other side of the chest)

Question 5

Shape

Answer 5

Band/plateau
- sound is constant

Crescendo
- increasing intensity of the murmur

Decrescendo
- decreasing intensity of the murmur

Crescendo-decrescendo

Decrescendo-crescendo

Question 6

Character

Answer 6

• soft
• harsh
• musical
• buzzing
• blowing
• squeak

Question 7

Mitral regurgitation - signalment

Answer 7

• all age groups

Question 8

Mitral regurgitation - CS

Answer 8

• incidental -> collapse and sudden death

Question 9

Mitral regurgitation - murmur characterisation

Answer 9

Timing
- holosystolic
- pansystolic
- mid-late systolic

Grade
- 1-6/6

PMI
- left
- mitral valve

Radiation
- caudo-dorsally
- sometimes towards aortic valve

Character & shape
- band/plateau
- crescendo

Question 10

Tricuspid regurgitation - signalment

Answer 10

• all age groups
• racing TB and S

Question 11

Tricuspid regurgitation - CS

Answer 11

• incidental -> collapse & sudden deaht

Question 12

Tricuspid regurgitation - murmur characterisation

Answer 12

Timing
- holosystolic
- pansystolic

Grade
- 1-6/6

PMI
- right
- tricuspid valve

Radiation
- cranio-dorsally

Character & shape
- band/plateau
- crescendo

Question 13

Aortic regurgitation - signalment

Answer 13

• middle age to older

Question 14

Aortic regurgitation - CS

Answer 14

• commonly incidental, progressive, CS in older

Question 15

Aortic regurgitation - murmur characterisation

Answer 15

TIming
- holodiastolic
- pandiastolic

Grade
- 1-6/6

PMI
- left
- aortic valve

Radiation
- caudoventrally
- (often to the right as well)

Character & shape
- decrescendo
- musical

Question 16

Pulmonic insufficiency - prevalence, signs

Answer 16

• uncommon in horses
• common to see on doppler echocardiography
• rarely affects performance

Question 17

Well-tolerated murmurs

Answer 17

• physiological murmurs
• tricuspid and mitral regurgitation (without structural valvular lesions)
• slowly progressive aortic regurgitation in middle-aged horses

Question 18

Poorly-tolerated murmurs

Answer 18

• acute onset murmurs
  – ruptured chordae tendinae
  – bacterial endocarditis
  – valvular dz associated with myocardial dz
• murmur + concurrent arrhythmias
• progressive lesions

Question 19

Plan

Answer 19

• cardiovascular assessment
• characterise the murmur
• further investigation?
  – echocardiography
  – ± resting ECG
  – ± exercising ECG