Cardiac Murmurs in Large Animals

Question 1

murmurs not associated with valve pathology

Answer 1

physiological (flow) murmurs in horses

functional/physiological valve regurgitation in horses

Question 2

murmurs associated with valve pathology

Answer 2

valve degeneration (can be 2ndry to ventricular dilation)
bacterial endocarditis
valve prolapse
ruptured chordae tendineae

Question 3

murmurs from congenital abnormalities

Answer 3

VSD (ventricular septal defect)
PDA (patent ductus arteriosis)
valvular dysplasia

Question 4

cardiac auscultation - what to listen to

Answer 4

timing
intensity
point of max intensity (PMI)
pitch + quality
radiation
precordial thrill

Question 5

echocardiography - uses

Answer 5

confirmation of diagnosis
asses severity
prognosis

Question 6

electrocardiography

Answer 6

little value in murmur assessment in horse + farm animals

identify concurrent arrythmias

Question 7

2D + M-mode echocardiography

Answer 7

valve structure + function
chamber size
myocardium
monitor progression

Question 8

doppler echocardiography

Answer 8

spectral + colour flow
semi-quantitative assessment of valvular regurgitation
volume + velocity of regurgitant jets

Question 9

aortic flow murmurs

Answer 9

common
quiet
local radiation only
PMI aortic valve/heart base
effect of exercise on murmur variable
normal in fit horses

Question 10

ventricular flow murmurs

Answer 10

less common
short duration
high pitched squeak/whoop
between S2 and 3
PMI heart base or AV valves
normal in young Tbs in training

Question 11

valve regurgitation in horses

Answer 11

mainly Tb horses in training
in 30% horses in training
mitral > tricuspid > aortic
severity varies - non-progressive or associated with valve pathology

Question 12

mitral regurgitation

Answer 12

significance + auscultation vary with cause
incr intensity + radiation with severity
plateau shaped
radiates caudodorsally
can cause sudden death due to pulmonary artery rupture

Question 13

tricuspid regurgitation

Answer 13

significance + auscultation vary with cause
incr intensity + radiation with severity
plateau shaped
radiates craniodarsally

Question 14

aortic regurgitation

Answer 14

often due to endocardiosis
more common in older horses
causes left ventricular overload + left sided heart failure
take pulse to check if systolic/diastolic
PMI - aortic valve

Question 15

mitral regurgitation may be significant if

Answer 15

associated with poor performance
resting tachycardia
abnormal pulse quality, slow CRT
LSHF
arrhythmias, esp atrial fibrillation
> grade 4
wide radiation

Question 16

tricuspid regurgitation may be significant if

Answer 16

associated with poor performance 
resting tachycardia
abnormal pulse
RSHF
arrhythmias, esp atrial fibrillation
> grade 4
wide radiation

Question 17

aortic regurgitation may be significant if

Answer 17

associated with poor performance 
resting tachycardia
bounding arterial pulse
slow CRT
LSHF
arrhythmias, esp atrial fibrillation

Question 18

degenerative valvular disease

Answer 18

commonest form of valve pathology

many valve regurgitations in horses not associated with obvious valve patholgy

Question 19

bacterial endocarditis

Answer 19

2ndary to bacteriaemia
prompt treatment vital as large proliferative lesions may develop
less return to normal valve function if left

Question 20

bacterial endocarditis - ruminants - causes

Answer 20

liver abcess
traumatic reticulitis
metritis
mastitis
navel abscess
"joint ill"

Question 21

bacterial endocarditis - horses

Answer 21

site of sepsis often not identified

septic jugular thrombophlembitis

Question 22

bacterial endocarditis - diagnosis

Answer 22

clinical signis - congestive heart failure, fever, cardiac murmur, tachycardia, tachynoea
lab data - hyperfibrinogenaemia, anaemia + leucocytosis
blood culture

Question 23

bacterial endocarditis - treatment

Answer 23

broad spectrum antibiotics based on sensitivity

Question 24

bacterial endocarditis - prognosis

Answer 24

guarded even after bacteriological cure
permanent structural damage to valve
some lesions recover
septic emboli may shed to distant sites - lungs + kidney

Question 25

valve prolapse

Answer 25

can affect any valve
may cause audible murmur
considered to be physiological rather than pathological phenomenon
non-progressive regurgitation
diagnosis - echo

Question 26

ruptured chordae tendinae

Answer 26

spontaneous or 2ndary to infl or degenerative changes in the chordae
more common in mitral valve - higher pressure
sudden death/acute heart failure

Question 27

changes in ventricular size

Answer 27

AV valve regurge cna develop 2ry to - severe ventricular dilation, cardiomyopathy + myocardial disease, aortic regurge + LV volume overload
mitral/tricuspid regurgitation appear later

Question 28

congenital abnormalities

Answer 28

VSD
PDA
valve dysplasia

Question 29

VSD

Answer 29

ventricular septal defect
commonest congenital cardiac defect in LA's
defect in dorsal part of the septum
2 murmurs create a "diagonal" murmur
RHS murmur with LV to RV shunt
LHS murmur with RV overload

Question 30

PDA

Answer 30

patent ductus arteriosis
in normal foals until 7-10 days old
blood flows along PDA in systole + diastole - continuous murmur
grade 3-5, wide radiation

Question 31

valve dysplasia

Answer 31

uncommon in LA’s

rarely well tolerated + usually part of complex congenital cardiac disease