Feline myocardial disease (Yr 4)

Question 1

what are the possible primary feline myocardial diseases?

Answer 1

hypertrophic cardiomyopathy
restrictive cardiomyopathy
non-specific cardiomyopathy
dilated cardiomyopathy (DCM)

Question 2

what are some complication associated with feline hypertension?

Answer 2

ocular (retinal detachment) and CNS complications

Question 3

what is the gross pathology of HCM?

Answer 3

concentric hypertrophy of LV (thickened walls)

Question 4

what are some differentials of concentric hypertrophy in suspects HCM cases?

Answer 4

aortic stenosis
systemic hypertension
hyperthyroidism
chronic renal failure

Question 5

how does stress effect the murmur heard with HCM?

Answer 5

gets louder (variable intensity)

Question 6

what is the typical presentation of a HCM?

Answer 6

older, male, overweight

Question 7

how do preclinical HCM cats present?

Answer 7

asymptomatic heart murmur
arrhythmias (diastolic gallops)
increased NT-proBNP or troponin

Question 8

how do clinical HCM cases present?

Answer 8

dyspnoea/tachypnoea (CHF)
feline arterial thrombo-embolism (FATE)
syncope
open mouth panting
sudden death

Question 9

how does FATE present?

Answer 9

purple footpads (if non-pigmented)
off-back legs
painful

Question 10

what is the most common site of FATE?

Answer 10

saddle thrombus (to external iliac arteries)

Question 11

how can feline HCM be classified?

Answer 11

A - predisposed
B1 - subclinical (normal or mild atrial enlargement)
B2 - subclinical (moderate/severe atrial enlargement)
C - current/previous CHF
D - refractory CHF

Question 12

how does HCM hearts appear on radiographs?

Answer 12

enlarged heart size (over 2.5 rib spaces)
bulging left atrial appendage (DV view)

Question 13

how can ECG be used for HCM cases?

Answer 13

show/diagnose presence of arrhythmias
show LV enlargement (tall R wave)
intraventricular conduction disturbances

Question 14

what is the source of a murmur in HCM cases?

Answer 14

left ventricular hypertrophy causes septal bulge
causing systolic anterior motion of mitral valve (mitral valve sucked towards the bulge) narrowing the outflow tract and causing mitral regurgitation
(gives itself a form of aortic stenosis)

Question 15

what is a diastolic gallop?

Answer 15

detection of S3 and S4

Question 16

what causes S3?

Answer 16

rapid deceleration of blood in left ventricle

Question 17

what causes S4?

Answer 17

left ventricular filling associated with atrial contraction

Question 18

how are HCM cats treated when they enter CHF?

Answer 18

diuretic (furosemide)
venodilator if life threatening pulmonary oedema
ACE inhibitors (benazepril)
angiotensin II receptor blockers (telmisartan)
thromboembolism prevention (clopidogrel)

Question 19

why is clopidogrel given to HCM cats?

Answer 19

prevent thromboembolism formation (anti-platelet drug)

Question 20

should you treat asymptomatic HCM cats?

Answer 20

can use beta-blockers to slow heart rate and improve diastolic function (no evidence of this having any effect)

Question 21

can you use beta blockers in cases with CHF?

Answer 21

no!! never use beta blockers with CHF as they will accelerate CHF by blocking sympathetic drive and reducing cardiac output which is compensating

Question 22

what needs to be excluded when diagnosing a cat with DCM?

Answer 22

taurine deficiency (asses response to taurine supplementation)

Question 23

how do you treat a symptomatic cat with DCM?

Answer 23

warm and oxygen
drain pleural effusions
furosemide
ACE inhibitors
pimobendan

Question 24

what are the two forms of restrictive cardiomyopathy?

Answer 24

myocardial
endomyocardial

Question 25

what are the characteristics of restrictive cardiomyopathy?

Answer 25

normal LV wall measurements
normal LV chamber dimensions
normal LV systolic function
marked LA enlargement
poor diastolic function (restrictive)

Question 26

how do cats with arrhythmogenic right ventricular cardiomyopathy present?

Answer 26

ventricular arhythmias
right sided congestive heart failure - ascites (rare occasion you get this in cats)

Question 27

what does NT pro-BNP test for?

Answer 27

wall stretch

Question 28

when should you start HCM cats on clopidogrel?

Answer 28

when they enter B2 (subclinical but with moderate/severe atrial enlargement)