Exam 4 - Feline Cardiac Disease Flashcards
T/F: approximately 15% of apparently healthy cats have cardiomyopathy
true
what is a murmur?
audible sound of turbulent blood flow
what causes a murmur?
valve regurgitation
outflow tract obstruction
congenital lesions - septal defects
why are murmurs an insensitive diagnostic test for detecting heart disease in a cat?
cats can have a murmur that is unrelated to heart disease
or a cat can have heart disease with no audible murmur
in cats a ______ is not always present with heart disease & and ______ is not always caused by heart disease
murmur
what do you do to diagnose a cat with heart disease?
detection of a murmur, gallop sound, arrhythmia on physical exam
arrhythmia on ECG
cardiomegaly on thoracic rads
echo - required to diagnose type of heart disease
what is the best test for detecting heart disease in a cat?
echo!!!
cardiomegaly on rads, arrhythmia on ECG, elevated NTproBNP in a cat with murmur/gallop/respiratory signs
what are some examples of things that can cause a heart murmur?
heart disease, hypertension, hyperthyroidism, age related, stress, anxiety, anemia, dehydration
when looking at a cat with suspected heart disease with an arrhythmia on ecg, what signs may indicate that is clinically significant?
tachycardia, weakness, collapse, pale mucus membranes, poor pulse quality, & systemic hypotension
need to rule out hyperthyroidism & electrolyte abnormalities
what medications can be used for a cat with ventricular arrhythmias?
atenolol - 6.25 mg/cat PO every 12 hours
sotalol - 10mg/cat PO every 12 hours
why do you need an echo in a cat with suspected cardiac disease?
investigate the cause of a murmur, assess ventricular systolic & diastolic function, look for atrial enlargement, & thrombus/stroke/assess embolic risk
what is a biomarker?
substance that is specific to the organ or tissue under study that is released in proportion to injury or disease
what is BNP?
b-type natriuretic peptide that is released by cardiac myocytes primarily in the ventricle in response to stretch
it is cleaved into 2 parts - inactive has a longer 1/2 life that can be measured in plasma or serum
why use a BNP assay on a cat?
species specific - useful for assessing dyspneic cats
what does a negative BNP test indicate?
high likelihood heart disease is not present
what can a false positive test for BNP indicate?
hypertension, hyperthyroidism, & renal disease
what are the different stages of heart disease in cats?
stage a - predisposed
stage b1 - low risk, subclinical with normal or mild atrial enlargement
stage b2 - higher risk, subclinical stage, moderate to severe atrial enlargement
stage c - current/previous CHF/ATE (arterial thromboembolism)
stage d - refractory CHF
what 3 clinical signs indicate CHF in cats?
pulmonary edema, pleural effusion, & pericardial effusion
what does left or right atrial enlargement indicate for prognosis of cardiac disease in cats?
increased risk of CHF
left atrial enlargement - increased risk of arterial thromboembolism
what are some differentials for cats with pericardial effusion?
heart failure!!!!
neoplasia
infectious - FIP
what are some differentials for dogs with pericardial effusion?
neoplasia!!!
idiopathic
infectious
coagulopathy
what are some risk factors for a cat with cardiac disease developing heart failure?
stressful situations
long acting corticosteroids
anesthesia
what are some poor prognostic indicators of heart failure in a cat?
clinical signs at presentation, left atrial enlargement, HCM, arterial thromboembolism, hypothermia
what clinical signs are caused by an arterial thromboembolism in a cat?
acute paresis or paralysis of any limb - 90% embolize the distal aorta, cat will lack palpable pulses, cyanotic nail beds, & cool limbs
how can you prevent an arterial thromboembolism?
prevent with a platelet inhibitor - clopidogrel
why does renal disease complicate treating cardiac disease in cats?
need to consider the use of diuretics & ace inhibitors
what is the acute management plan for a cat presenting in acute CHF?
oxygen supplementation, furosemide IV, sedation, thoracocentesis, & +/- pimobendan
what are the 5 general categories of causes of cardiac disease in cats? which is most common?
- cardiomyopathy - most common
- valve disease
- congenital heart disease
- heartworm disease
- neoplasia
what is HCM?
left ventricular wall thickening that is focal/concentric causing diastolic dysfunction
what is obstructive hypertrophic cardiomyopathy in cats?
left ventricular basilar septal wall thickening causing obstruction to left ventricular outflow
results in mitral regurgitation & left atrial enlargement
what is dilated cardiomyopathy in cats?
chamber dilation + reduced contractility (systolic dysfunction)
either dietary (taurine deficiency) or idiopathic
what is restrictive cardiomyopathy in cats?
normal to mild left ventricular hypertrophy causing wall motion abnormalities & biatrial enlargement
fibrotic tissues in the ventricles = diastolic dysfunction
what is the pathogenesis of arrhythmogenic right ventricular cardiomyopathy?
fibrotic or fatty tissues replaces myocardial cells causing dilation of the right ventricle & atrium & systolic dysfunction & arrhythmias
