14 Feline myocardial diseases

Innocent (no cardiac disease), functional (high output states like anemia, fever, hyperthyroid), and pathologic cardiomyopathies/endocarditis

What are the 3 types of murmurs in cats?

FALSE = MUST DO echocardiogram

TRUE OR FALSE: In cats, absence of a murmur rules out significant cardiomyopathy

Dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, nonspecific cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy

What are the different types of cardiomyopathies?

Cardiomyopathy (HCM)

What is the most common cause of heart disease in cats?

CHF, arterial thromboembolism, sudden death, and unexpected anesthesia death

What other abnormalities is HCM the cause of in cats (what disease manifestations does it have?):

Diastolic

HCM is a *systolic/diastolic* problem

Concentric left ventricular hypertrophy = wall gets thick so the inside gets smaller. There is also left atrial enlargement

Briefly describe HCM:

Genetic (most common), idiopathic, and secondary myocardial mimickers (systemic hypertension, hyperthyroid, aortic stenosis)

Name the causes of feline HCM

Myosin binding protein C mutation

Genetic HCM is the most common cause in cats. What causes it in maincoons and ragdolls?

TRUE (for example, a cat may be completely subclinical,--asymptomatic and no murmurs--go under anesthesia, and suddenly theyre in severe respiratory distress)

TRUE OR FALSE: The first clinical manifestations of cardiac disease in cats is usually a "crisis" event.

Male

Which sex of cat is more commonly affected by HCM?

Jugular vein distention from pleural effusion or hepatomegaly

What is one of the most distinctive signs of HCM in cats?

Genetic testing (esp. maine coon and ragdoll), NT-proBNP, mild cardiomegaly on rads, T4 to make sure they arent hyperthyroid

How do you diagnose HCM?

Normal feline heart

Normal or abnormal?

Abnormal = feline heart with HCM

Normal or abnormal?

Normal feline heart

Normal or abnormal?

Abnormal "valentine heart" of feline HCM

Normal or abnormal?

Left ventricular hypertrophy and left atrial enlargement

What will HCM look like in cats on echocardiography?

Abnormal HCM = marked left atrial enlargement

Normal or abnormal?

Abnormal = HCM cat with left ventricular hypertrophy

Normal or abnormal?

Abnormal = HCM cat with left ventricular hypertrophy

Normal or abnormal?

Systolic anterior motion (SAM) of mitral valves = a form of dynamic obstruction where the mitral valve moves towards the interventricular septum

What will the mitral valve do in cats with HCM that you will be able to see on echocardiography?

If STABLE = drugs to slow HR (beta blockers) and antithrombotics

If CHF = furosemide, pimobendan, ACEi, Spironolactone

If SAM with VLOT obstruction = beta blockers

How do you treat cats with hypertrophic cardiomyopathy?

Felycin CA1

What is the only medication so far that can halt or modestly reverse hypertrophy from HCM in asympatomatic cats?

Feline Aortic thromboembolism (FATE)

What is the specific type of thromboembolism that can occur as a complication to HCM and left atrial thrombus in cats?

Occurs in 10-40% of cats with cardiomyopathy

How common is feline aortic thromboembolism (or saddle thrombus)?

When there is increase left atrial size

When does feline aortic thromboembolism happen?

*Rear limbs*

Where does feline aortic thromboembolism normally happen?

Pain, paleness (pallor), pulselessness, polar (cold), paresis/paralysis

*Name the 5 clinical signs associated with feline aortic thromboembolism*

Clinical signs and echocardiography

How do you diagnose feline aortic thromboembolism?

Clot (can lead to feline aortic thromboembolism)

What is this?

"Smoke" or spontaneous contrast in the left atrium indicative of turbulent blood flow and a pending clot (feline aortic thromboembolism)

What is this?

Analgesics, antithrombotics (heparin), supportive care

How do you treat feline aortic thromboembolism?

They help to prevent it

How are aspirin, clopidogrel, and rivaroxaban related to feline aortic thromboembolism?

Clopidogrel

Of the feline aortic thromboembolism prevention mechanisms, which is the CORNERSTONE?

AntiCOAGULANT: heparin, Rivaroxaban

AntiPLATELET: aspirin, clopidogrel (plavix)

Of the feline aortic thromboembolism correction and treatment drugs, which are anticoagulant drugs and which are antiplatelet drugs?

Clopidogrel

Which feline aortic thromboembolism drug inhibits ADP receptor on platelet surfaces, reducing platelet aggregation?

Aspirin

Which feline aortic thromboembolism drug is an irreversible COX inhibitor?

Rivaroxaban

Which feline aortic thromboembolism drug is a direct acting Factor Xa inhibitor to reduce thrombin generation?

Heparin (regular unfractionated heparin)

Which feline aortic thromboembolism drug binds to antithrombin which inactivates thrombin, factor Xa and other proteases?

NO

Should you treat an asymptomatic HCM cat?

Treat when the cat has left atrial enlargement, SAM or LVOT obstruction, or arrhythmia

If a cat is asymptomatic for HCM, *when should you consider treating*?

true

TRUE OR FALSE: most asymptomatic cats do not need meds for HCM

FALSE: monitor every 6-12 months

TRUE OR FALSE: monitor asymptomatic HCM cats every month with echocardiograph and NT-proBNP

HCM after feline aortic thromboembolism: 30-50% survival with a HIGH recurrence rate

How do cats' prognosis change with HCM on top of feline aortic thromboembolism?

Systolic

DCM is characterized by impaired *systolic/diastolic* function

Dilation

DCM is characterized by ventricular *dilation/constriction*

Taurine

Deficiency of what was commonly linked to DCM in cats?

DCM

On echo, a cat shows dilated left ventricle with poor contractility, and low fractional shortening. What is this?

If STABLE: taurine supplements (DCM only), antithrombotics

If CHF: PIMOBENDAN, furosemide

What is the treatment for DCM and RCM like in cats?

Restrictive cardiomyopathy

What is this?

Restrictive cardiomyopathy

This is characterized by impaired diastolic ventricular filling due to myocardial stiffness with preserved systolic function

Diastolic

Restrictive cardiomyopathy is a *systolic/diastolic* problem

Idiopathic fibrosis of the endocardium and myocardium

What causes restrictive cardiomyopathy?

FALSE

TRUE OR FALSE: restrictive cardiomyopathy is associated with taurine deficiency

Restrictive cardiomyopathy

On echocardiography, this abnormality will present as biatrial enlargement, normal left ventricular systolic function and endocardial bands

Restrictive cardiomyopathy (these are endocardial bands)

What are the fibrous structures in the left ventricle as a result of chronic myocardial injury from diastolic dysfunction characteristic of?