Lecture 15 9/19/24

Question 1

What is the most common form of acquired heart disease in cats?

Answer 1

myocardial disease

Question 2

What are the specific causes associated with feline myocardial diseases?

Answer 2

-thyrotoxic
-hypertensive

Question 3

What are the characteristics of HCM in cats?

Answer 3

-hypertrophy of a non-dilated ventricle occurs in the absence of hyperthyroidism or systemic hypertension
-heritable in maine coon cats and ragdoll sphinx cats
-familial in other purebred cats

Question 4

What is the pathophysiology of HCM?

Answer 4

-systolic ventricular performance is usually normal or hyperdynamic
-characterized primarily by diastolic dysfunction
-increased wall thickness results in increased chamber stiffness
-hypertrophy may outstrip coronary perfusion and delay relaxation

Question 5

What is diastolic function?

Answer 5

ability of ventricles to fill in the absence of a pathologic increase in pressure

Question 6

What does diastolic function depend on?

Answer 6

-myocardial relaxation
-compliance

Question 7

What are the steps of diastolic dysfunction?

Answer 7

-prolonged relaxation leads to reduced compliance
-reduced compliance leads to an increase in the diastolic pressure/volume relationship
-abnormal relationship leads to low output and congestive signs

Question 8

What causes increased venous and LA pressure?

Answer 8

hypertrophic left ventricle does not want to accept diastolic vol.

Question 9

What is a suggestive finding of diastolic dysfunction on echo?

Answer 9

atrial dilation that is disproportionate to ventricular volume

Question 10

What are the characteristics of systolic anterior motion of the MV?

Answer 10

-mitral valve leaflets move cranially during systole
-may cause dynamic obstruction of the left ventricular outflow tract, MR, and murmur
-not a therapeutic target and not important for prognosis

Question 11

What is the signalment for feline HCM?

Answer 11

-male predisposition
-seen in virtually any age

Question 12

What is the clinical presentation of feline CMs?

Answer 12

-incidentally detected murmur/gallop
-clinical signs related to CHF and systemic thromboembolism
-possible sudden cardiac death

Question 13

What are the characteristics of murmurs in cats?

Answer 13

-normal cats sometimes have murmurs as a result of dynamic phenomena
-changes in murmur intensity is not prognostically relevant
-murmurs are more common in cats with subclinical CM that in cats with HF

Question 14

What are the findings associated with feline CM?

Answer 14

-LA dilation
-gallop sounds
-extreme LV hypertrophy
-spontaneous echo-contrast or intracardiac thrombus

Question 15

What are flow/innocent murmurs?

Answer 15

soft murmurs that vary in intensity with heart rate; common in healthy, echo-normal cats

Question 16

How is heart disease diagnosed in cats on rads?

Answer 16

-pleural effusion in the absence of ascites is a common manifestation of heart failure
-pleural effusion complicates diseases that affect the left ventricle

Question 17

How is HCM diagnosed in cats?

Answer 17

echo evidence of hypertrophy of a non-dilated ventricle in the absence of hyperthyroidism or systemic hypertension

Question 18

What are the characteristics of stage B heart disease diagnosis in cats?

Answer 18

-T4 should be measured in cats older than 6-7 years of age; hyperthyroidism can cause mild, reversible myocardial disease
-echo
-systemic BP measurement
-possible thoracic rads

Question 19

Which cats should receive a cardio. workup?

Answer 19

-those with suspicious history/physical exam findings
-older patients subjected to interventions such as anesthesia or IV fluid therapy

Question 20

What are the characteristics of treating stage B2 heart disease in cats?

Answer 20

-no agent shows efficacy in delaying clinical signs/slowing disease progression
-clopidogrel is reasonable if moderate/marked LAE present

Question 21

What are the unique aspects of feline heart failure presentation?

Answer 21

-very rarely cough
-sudden onset of clinical signs
-tachycardia is not a consistent feature
-acutely decompensated heart failure is “cold and wet”

Question 22

How can acutely decompensated heart failure be diagnosed in cats?

Answer 22

-findings of tachypnea, hypothermia, and or gallop sounds
-thoracic ultrasound and/or BNP testing if rads cannot be obtained

Question 23

What are the characteristics of acutely decompensated HF treatment?

Answer 23

-empirical therapy often indicated
-provide O2, sedation, and warming
-diuretic therapy
-thoracocentesis to relieve pleural effusion
-pimobendan for cases with low cardiac output
-IV FLUIDS CONTRAINDICATED

Question 24

What are the characteristics of stage C heart disease therapy in cats?

Answer 24

-no agent superior to placebo in studies, but enalapril appears best
-atenolol may harm cats if HF is diastolic
-spironolactone may have positive effects

Question 25

What are the characteristics of pimobendan use in cats?

Answer 25

-administration seems to be tolerated
-can be considered when systolic dysfunction is present
-SAM presence is a contraindication

Question 26

How is stage C HF treated at home in cats?

Answer 26

-furosemide
-clopidogrel
-possible ACE inhibitor

Question 27

What are the characteristics of feline arterial thromboembolism?

Answer 27

-patients with myocardial disease are predisposed to development of intra-cardiac thrombi
-thrombus often develops in left atrial auricle

Question 28

What clinical signs are seen with embolization of the caudal aorta?

Answer 28

-pain
-paresis/paralysis
-absent arterial pulse
-peripheral cyanosis

Question 29

What is the prevalence of FATE?

Answer 29

-occurs in 10% of cats with echo. identified myocardial disease
-first indication of heart disease in over 80% of affected patients

Question 30

What are the risk factors for FATE?

Answer 30

-left atrial enlargement***
-possibly systolic dysfunction
-possibly spontaneous echo. contrast

Question 31

What is the therapy for FATE upon acute presentation?

Answer 31

-narcotic analgesia
-short-term anticoagulation

Question 32

What is “primary prevention” thromboprophylaxis?

Answer 32

use of clopidogrel with the intension to prevent future thrombi events in at risk patients

Question 33

What is “secondary prevention” thromboprophylaxis?

Answer 33

use of clopidogrel with the intension to prevent reoccurrence of thrombi

Question 34

What is the prognosis of FATE?

Answer 34

generally poor, with a mortality of 30% during initial hospitalization

Question 35

What is the prognosis of feline HCM?

Answer 35

-highly variable
-cats with CHF have poor prognosis
-cats with mild disease can live for years
-atrial size is most important risk factor for poor outcome

Question 36

What are the characteristics of restrictive cardiomyopathy?

Answer 36

-atrial dilation with normal ventricular dimensions and wall thicknesses
-systolic ventricular performance is normal

Question 37

What are the characteristics of right ventricular arrhythmogenic cardiomyopathy in cats?

Answer 37

-fatty or fibrofatty replacement of right ventricular myocardium
-arrhythmias
-marked right ventricular dilation