Feline myocardial disease (Yr 4) Flashcards
what are the possible primary feline myocardial diseases?
hypertrophic cardiomyopathy
restrictive cardiomyopathy
non-specific cardiomyopathy
dilated cardiomyopathy (DCM)
what are some complication associated with feline hypertension?
ocular (retinal detachment) and CNS complications
what is the gross pathology of HCM?
concentric hypertrophy of LV (thickened walls)
what are some differentials of concentric hypertrophy in suspects HCM cases?
aortic stenosis
systemic hypertension
hyperthyroidism
chronic renal failure
how does stress effect the murmur heard with HCM?
gets louder (variable intensity)
what is the typical presentation of a HCM?
older, male, overweight
how do preclinical HCM cats present?
asymptomatic heart murmur
arrhythmias (diastolic gallops)
increased NT-proBNP or troponin
how do clinical HCM cases present?
dyspnoea/tachypnoea (CHF)
feline arterial thrombo-embolism (FATE)
syncope
open mouth panting
sudden death
how does FATE present?
purple footpads (if non-pigmented)
off-back legs
painful
what is the most common site of FATE?
saddle thrombus (to external iliac arteries)
how can feline HCM be classified?
A - predisposed
B1 - subclinical (normal or mild atrial enlargement)
B2 - subclinical (moderate/severe atrial enlargement)
C - current/previous CHF
D - refractory CHF
how does HCM hearts appear on radiographs?
enlarged heart size (over 2.5 rib spaces)
bulging left atrial appendage (DV view)
how can ECG be used for HCM cases?
show/diagnose presence of arrhythmias
show LV enlargement (tall R wave)
intraventricular conduction disturbances
what is the source of a murmur in HCM cases?
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)
what is a diastolic gallop?
detection of S3 and S4
what causes S3?
rapid deceleration of blood in left ventricle
what causes S4?
left ventricular filling associated with atrial contraction
how are HCM cats treated when they enter CHF?
diuretic (furosemide)
venodilator if life threatening pulmonary oedema
ACE inhibitors (benazepril)
angiotensin II receptor blockers (telmisartan)
thromboembolism prevention (clopidogrel)
why is clopidogrel given to HCM cats?
prevent thromboembolism formation (anti-platelet drug)
should you treat asymptomatic HCM cats?
can use beta-blockers to slow heart rate and improve diastolic function (no evidence of this having any effect)
can you use beta blockers in cases with CHF?
no!! never use beta blockers with CHF as they will accelerate CHF by blocking sympathetic drive and reducing cardiac output which is compensating
what needs to be excluded when diagnosing a cat with DCM?
taurine deficiency (asses response to taurine supplementation)
how do you treat a symptomatic cat with DCM?
warm and oxygen
drain pleural effusions
furosemide
ACE inhibitors
pimobendan
what are the two forms of restrictive cardiomyopathy?
myocardial
endomyocardial
what are the characteristics of restrictive cardiomyopathy?
normal LV wall measurements
normal LV chamber dimensions
normal LV systolic function
marked LA enlargement
poor diastolic function (restrictive)
how do cats with arrhythmogenic right ventricular cardiomyopathy present?
ventricular arhythmias
right sided congestive heart failure - ascites (rare occasion you get this in cats)
what does NT pro-BNP test for?
wall stretch
when should you start HCM cats on clopidogrel?
when they enter B2 (subclinical but with moderate/severe atrial enlargement)
