Feline Cardiomyopathy Flashcards
List the phenotypes of feline cardiomyoopathy
- hypertrophic cardiomyopathy
- restrictive cardiomyopathy (endomyocardial and myocardial forms)
- dilated cardiomyopathy
- arrhythmogenic cardiomyopathy
- nonspecific phenotype
List 6 inciting causes to develop HCM phenotype
- hyperthyroidism
- systemic hypertension
- glucocorticoid administration
- reduced preload
- neoplastic infiltration
- transient myocardial thickening
- acromegaly
How are Stage B1 and B2 cardiomyopathies in cats differentiated?
by the risk of developing ATE or CHF and LA size is commonly used as a surrogate for this risk
other echo findings used as surrogate: LV and LA systolic dysfunction, degree of LV hypertrophy
How is Stage D defined (i.e., cut-off value for therapeutic dose)
CHF unresponsive to medical management - > 6 mg/kg/day PO Furosemide required
What is the prevalence of HCM in the general cat population versus in older cats?
general 15%
older 29%
List pedigree cats predisposed to HCM
Ragdoll, Maine Coon, Norwegian Forest Cat, british shorthair, persian, bengal, birman
In what gene have mutations for HCM been identified?
MyBPC3
List risk factors for cats with HCM developing ATE or CHF
- presence of gallop sound or arrythmia
- LA enlargement moderate to severe
- severe hypertrophy of LV wall
- systolic dysfunction of LV/decreased FS%
- spontaneous echo contrast
- clot within left atrial appendage
- regional wall thinning or hypokinesis
- restrictive diastolic filling
IS DLVOTO a negative prognostic indicator?
No
How common are murmurs in cats with subclinical HCM versus healthy cats without HCM?
80% versus 30-45%
How common is a gallop sound in subclinical HCM cats?
3-20%
List clinical findings that make CHF more likely in a cat presenting with respiratory distress
- murmur
- audible arrhythmia
- temp < 37.5
- HR >200
- RR > 80
How specific is the valentine-shaped heart for HCM in cats?
not specific
How do you use pleural fluid for NT-proBNP assays?
have to dilute it 1:1 in saline
What is the prognostic value of cTnI in cats with HCM?
prognostic for risk of cardiovascular death
When are ECGs recommended in cats with HCM?
only if episodes of collapse/syncope observed
How common is LV hypertrophy in cats with systemic hypertension?
85%
Does hyperthyroidism itself cause severe HCM?
no, usually preexisting mild HCM that’s exacerbated
hyperthyroidism on its own will cause only mild HCM
What is the recommendation for measuring serum thyroxine levels in cats with suspected heart disease?
> 6 years measure
Describe the recommendation for how to measure left ventricular wall thickness
right parasternal short or long axis, measure interseptal and free wall
end-diastolic
normal: < 5 mm
> 6 mm –> hypertrophied
measure 3 times (3 cardiac cycles) and get average
How do you assess for blood stasis on echocardiogram?
Doppler LA appendage flow velocity
For a normally-sized cat, what is the normal end-diastolic LV wall thickness, what is considered indicative of hypertrophy?
< 5 mm normal
over 6 mm elevated
List all measurements on echo that are part of the standard-of-care to evaluate for HCM
M-mode
* IVSd
* LVFWd
* LVIDd, LVIDs, FS%
* LA FS%
2D
* * IVSd
* LVFWd
* LVIDd, LVIDs
* LA/Ao
* LA diameter from RP long axis view
What is the treatment recommendation for HCM stage B1?
no treatment in general
may consider beta-blocker (atenolol) if DLVOTO present
