Acquired heart dz in cats Flashcards
Which heart diseases occur most in cats?
Cardiomyopathies
congenital dz
arrhythmias
What are the traditional cardiomyopathy classifications?
hypertrophic
dilated
restrictive
arrhythmogenic RV
unclassified
What is HCM?
hypertrophic cardiomyopathy
increased LV wall thickness
What can cause HCM?
hypertension
reduced preload
neoplastic infiltration
transient myocardial thickening
acromegaly
hyperthyroidism
What is RCM?
restrictive cardiomyopathy
normal LV wall thickness, LA dilation
What is a condition that can cause RCM?
hyperthyroidism
What is DCM?
Dilated cardiomyopathy
chamber dilation, systolic dysfunction
What can cause DCM?
dietary taurine deficiency
tachycardia-mediated
What is ARVC?
arrythmogenic RV
RA and RV dilation
What is the prevalence of HCM in cats?
15%
increases with age
1 in 7 clinically silent
Why are the LV walls thick in HCM?
In humans its mostly genetic mutation
What are 3 consequences to the heart of LV hypertrophy?
LV doesn’t relax (bad filling)
Stiff ventricle
= diastolic dysfunction
Poor myocardial perfusion
What are 3 clinical effects of cardiomyopathies in cats?
Pulmonary oedema
Intra-cardiac thrombus (dilated chamber is ideal for formation)
Arrhythmias
Which cats are prone to cardiomyopathies?
maine coons/ragdolls
mutations of myosin binding protein C
What is Dynamic LVOT obstruction?
SAM: Systolic Anterior Motion of the mitral leaflet/valve
What is the signalment for HCM?
male predisposition
before 6m or over 12y
pedrigree cats (maine coon, ragdoll, british shorthair, bengal, sphinx, etc)
What does a cat with a gallop heart tell us?
they have a higher risk
associated with a worse prognosis for their HCM
What are diagnosis tools for HCM in cats?
Xray (heart shouldnt be wider than 2 rib spaces, pulmonary oedema)
BP
Rule out hyperthyroidism
Echocardiography (LA enlargement)
Biomarkers
What does a cat with LA tell us?
HCM cats with bigger LA have a higher risk and worse survival rate
What are biomarkers for HCM?
Cardiac troponin-I (part of contractile apparatus and leak out with damage)
NT-proBNP (high in cats with LA dilation/myocardium stretch)
What are the stages of heart disease?
A: predisposed animal
B1 low risk: subclinical, have dz but no CS
B2 higher risk: subclinical, have dz but no clinical signs, high risk of developing
C: current/previous HCF/ATE
D: refractory HCF
What are the treatment options for asymptomatic (B1/B2) heart dz?
Low risk cats (no CS, no gallop, no arrhythmia, normal LA size, low biomarkers) -> No tx with follow up
What are the treatment options for dynamic LVOT obstruction (Stage B2)?
if angina (panting when playing)
atenolol (B-blocker)
What is the effect of atenolol on survival in cats with HCM?
Doesn’t improve survival but does improve quality of life
What are the 2 major risks with LA enlargement?
Risk of CHF
Risk of thromboembolism
What can we give to reduce the risk of thromboembolism (Stage B2)?
Anti-thrombotic medication: Clopidogrel, aspirin
Between Aspirin and Clopidogrel which anti-thrombotic medication helped survival rates (Stage B2)?
Clopidogrel
Standard to reduce risk of thromboembolism
What do we do with an acutely decompensated cat who we suspect has CHF (stage C))?
Minimal handling to decrease stress
Improve oxygenation
Potentially sedate to reduce stress
Furosemide to effect (loop diuretic to try and clear pulmonary oedema)
Echocardiogram (B lines = artifact)
Monitor renal function and electrolytes
What medications can we give to eliminate abnormal fluid retention (Stage C)?
Furosemide
ACE inhibitor? (no proven benefit)
Spironolactone
What medications can we give to a cate with refractory CHF (Stage D)?
increased furosemide
spironolactone
replace furosemide with torasemide?
Pimobendan?
What are the tx for asympotmatic, normal LA?
No tx
atenolol for LVOTO
What are the tx for asymptomatic, big LA?
Clopidogrel
What are the tx for CHF?
Furosemide
Clopidogrel
Spironolactone (if cat can tolerate more meds)
Ace inhibitor?
What are the tx for poor systolic function?
Pimobendan
