Acquired Cardiovascular Disease in Cats Flashcards
What are the common heart diseases in cats?
- Cardiomyopathies
- Congenital
- Arrhythmias
What are the traditional classifications of cardiomyopathy in cats?
Hypertrophic (walls too thick)
Dilated (systolic function)
Restrictive (increased atrial pressures)
Arrhythmogenic right ventricular (muscle replaced by scar tissue)
What is the most common form of cardiomyopathy in cats?
Hypertrophic cardiomyopathy
Why are the left ventricles thick in hypertrophic cardiomyopathy?
Genetic mutation in sarcomere contractile proteins
What are the effects of left ventricle hypertrophy in cats?
Diastolic dysfunction
+ Left ventricle doesn’t relax
+ Stiff ventricle
Poor myocardial perfusion
What are the clinical effects of cardiomyopathy in cats?
Pulmonary oedema (due to increased LA pressure)
Intra-cardiac thrombus
Arrhythmias (due to ischaemic myocardium)
Sudden death
Describe aortic thromboembolisms in cats…
Due to HCM
Get blood stasis
Thrombus lodges in terminal aorta occluding blood flow to hindlimbs
Get sudden onset paralysis
What is dynamic left ventricular outflow tract obstruction?
Anterior mitral valve leaflet moves towards the septum and blocks normal ejection into left ventricular outflow tract
Also get mitral regurg (due to high ventricular pressure compared to atrium)
What is dynamic LVOT obstruction made worse by?
High sympathetic tone (stress)
It increases work of left ventricle.
What is the signalment for HCM?
From <6m to >12yo
Main coon, persian, ragdoll, bengal etc
Most cats are moggies
What percentage of all cats does HCM effect?
15%
What are the findings on CE of HCM?
Variable intensity murmur Prominent apical impulse Gallop, arrhythmias (rare) Tachypneoa, crackles May appear normal
What are the findings of HCM on echo?
Enlarged left atrium
What are you looking for on radiography of HCM?
LV hypertrophy - long cardiac silhouette
Pulmonary oedema/pleural effusion
What biomarkers are available for HCM?
Cardiac Troponin-I
NT-proBNP
What factors indicate poor prognosis for HCM in cats?
Aortic thromboembolism CHF Gallop Arrhythmia NT-proBNP >250mol/l High cardiac troponin-I
What do treatment options of HCM depend on?
Stage of disease
Describe staging of heart disease in cats…
- At risk
- Heart disease, no CHF
- Previous CHF/mild-mod CHF/life-threatening CHF
- Refractory CHF
How can you screen for HCM in at risk animals?
Genetic testing
Echo
NT-proBNP
What is the treatment for HC in asymptomatic cats?
No treatment
Which cats are considered ‘low risk’ cats in terms of HCM, and therefore do not qualify for treatment?
No clinical signs No gallop No arrhythmia Normal LA size Low biomarkers
What treatments are available for cats with dynamic LF outflow tract obstruction?
Angina control = atenolol
reduces myocardial work which reduces pain
What treatments are available for cats with HCM, are asymptomatic but have LA enlargement?
Reduce the risk of thromboembolism by using Clopidogrel (anti-platelet drug)
What treatments are available to cats with HCM and signs of heart failure?
Furosemide
Clopidogrel
ACEi
Consider spironolactone
What treatments are available to cats with HCM and refractory CHF?
Increase furosemide
Spironolactone
Replace furosemide with torasemide
Pimodenban (NOT in cats with outflow tract obstruction!)
