Acquired Cardiovascular Disease in Cats

Question 1

What are the common heart diseases in cats?

Answer 1

1. Cardiomyopathies
2. Congenital
3. Arrhythmias

Question 2

What are the traditional classifications of cardiomyopathy in cats?

Answer 2

Hypertrophic (walls too thick)
Dilated (systolic function)
Restrictive (increased atrial pressures)
Arrhythmogenic right ventricular (muscle replaced by scar tissue)

Question 3

What is the most common form of cardiomyopathy in cats?

Answer 3

Hypertrophic cardiomyopathy

Question 4

Why are the left ventricles thick in hypertrophic cardiomyopathy?

Answer 4

Genetic mutation in sarcomere contractile proteins

Question 5

What are the effects of left ventricle hypertrophy in cats?

Answer 5

Diastolic dysfunction
+ Left ventricle doesn’t relax
+ Stiff ventricle

Poor myocardial perfusion

Question 6

What are the clinical effects of cardiomyopathy in cats?

Answer 6

Pulmonary oedema (due to increased LA pressure)
Intra-cardiac thrombus
Arrhythmias (due to ischaemic myocardium)
Sudden death

Question 7

Describe aortic thromboembolisms in cats…

Answer 7

Due to HCM
Get blood stasis
Thrombus lodges in terminal aorta occluding blood flow to hindlimbs
Get sudden onset paralysis

Question 8

What is dynamic left ventricular outflow tract obstruction?

Answer 8

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)

Question 9

What is dynamic LVOT obstruction made worse by?

Answer 9

High sympathetic tone (stress)

It increases work of left ventricle.

Question 10

What is the signalment for HCM?

Answer 10

From <6m to >12yo
Main coon, persian, ragdoll, bengal etc
Most cats are moggies

Question 11

What percentage of all cats does HCM effect?

Answer 11

15%

Question 12

What are the findings on CE of HCM?

Answer 12

Variable intensity murmur
Prominent apical impulse
Gallop, arrhythmias (rare)
Tachypneoa, crackles
May appear normal

Question 13

What are the findings of HCM on echo?

Answer 13

Enlarged left atrium

Question 14

What are you looking for on radiography of HCM?

Answer 14

LV hypertrophy - long cardiac silhouette

Pulmonary oedema/pleural effusion

Question 15

What biomarkers are available for HCM?

Answer 15

Cardiac Troponin-I

NT-proBNP

Question 16

What factors indicate poor prognosis for HCM in cats?

Answer 16

Aortic thromboembolism
CHF
Gallop
Arrhythmia
NT-proBNP >250mol/l
High cardiac troponin-I

Question 17

What do treatment options of HCM depend on?

Answer 17

Stage of disease

Question 18

Describe staging of heart disease in cats…

Answer 18

1. At risk
2. Heart disease, no CHF
3. Previous CHF/mild-mod CHF/life-threatening CHF
4. Refractory CHF

Question 19

How can you screen for HCM in at risk animals?

Answer 19

Genetic testing
Echo
NT-proBNP

Question 20

What is the treatment for HC in asymptomatic cats?

Answer 20

No treatment

Question 21

Which cats are considered ‘low risk’ cats in terms of HCM, and therefore do not qualify for treatment?

Answer 21

No clinical signs
No gallop
No arrhythmia
Normal LA size
Low biomarkers

Question 22

What treatments are available for cats with dynamic LF outflow tract obstruction?

Answer 22

Angina control = atenolol

reduces myocardial work which reduces pain

Question 23

What treatments are available for cats with HCM, are asymptomatic but have LA enlargement?

Answer 23

Reduce the risk of thromboembolism by using Clopidogrel (anti-platelet drug)

Question 24

What treatments are available to cats with HCM and signs of heart failure?

Answer 24

Furosemide
Clopidogrel
ACEi
Consider spironolactone

Question 25

What treatments are available to cats with HCM and refractory CHF?

Answer 25

Increase furosemide
Spironolactone
Replace furosemide with torasemide
Pimodenban (NOT in cats with outflow tract obstruction!)