Test 1: lecture 17 feline Flashcards
primary myocardial disease of cats
hypertrophic (HCM)
Restrictive (RCM)
dilated (DCM)
secondary myocardial diseases in cats
systemic hypertension
hyperthyroid
transient myocardial thickening
nutritional (taurine)
myocardial disease in cats can lead to — cardiac dysfuction, — and atrial dilation leading to —
diastolic
arrhythmias, sudden death
thromboembolic event
diastolic dysfunction is caused by
- impaired relaxation
- increase LV stiffness, decreased LV compliance
- fibrosis
diastolic dysfunction will lead to increased — pressure and increased — size
↑LV diastolic pressure
↑LA pressure
↑LA size
HCM causes — hypertrophy and — dysfunction
concentric LV
diastolic
what cause HCM
we dont know
but it is inherited
histo of cat with HCM
disarray
increased size of cell
increased cells in interstitial space
prevalence of HCM in cats
15% of cats
29% of older cats
most subclinical
what kind of cats get HCM
middle aged males
maine coon, ragdoll, sphinx
genetics of HCM in cats
Autosomal dominant
Genetic mutations
Myosin binding protein C (MYBPC) – sarcomeric protein
* Maine Coon: Missense mutation (A31P)
* Ragdoll: Missense mutation (R820W)
ALMS1 – Protein involved in cell cycle control
* Sphinx: Glycine to arginine variant in exon 12
PE of cat with HCM
systolic murmur
gallop heart sound (S4)
arrhythmias
dyspnea, tachpnea
abnormal lung sounds
clots
what valves close at S1
AV valves
what valves close at S2
semilunar valves (end of sytolic- aorta and pulmonary)
what happens at S4
atria contract, fill noncompliant LV
happens with HCM in cats
EKG of HCM in cats
LV and/or LA enlargement pattern
Ventricular arrhythmia
Conduction disturbance
* Left anterior fascicular block (partial LBBB)
Supraventricular arrhythmia
* Atrial fibrillation rare
left anterior fascicular block will have mean toward
-30
will have negative QRS in lead 2, 3, aVF
xray of cat with HCM
heart could be normal: does not rule it out
cardiomegaly
CHF: pulmonary venous distension
pulmonary edema
echo of HCM in cats
LV hypertrophy
* Symmetric
* Asymmetric
* Focal/regional
+/- LA dilation
+/- Spontaneous echocontrast (“smoke”)
+/- Intracardiac thrombi
+/- Dynamic LV outflow tract obstruction (HOCM)
what causes HOCM in cats
HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HOCM)
Dynamic left ventricular outflow tract obstruction
* Systolic anterior motion (SAM) of the mitral valve
mitral valve gets in the way during systolic (ventricle contracting)
what can worsen HOCM
Decreased diastolic filling (increased HR, diuretics)
Increased myocardial contractility (increased SNS, positive inotropes)
Reduced afterload (exercise, vasodilators)
differential diagnosis for thick LV in cat
HCM
hyperthyroid
systemic hypertension
treatment of HCM in cats
no drugs can prevent LV thickening
minimize LV outflow tract obstruction (atenolol)
control CHF
treat arrhythmias
prevent/treat clots
how to treat severe LV outflow tract obstuction in cats with HCM
give atenolol- slow HR= decrease LV pressure
only for severe or LVOTO with clinical signs
cats with Left sided CHF can form
pleural effusions and pulmonary edema
what anti-arrhythmic for ventricular and/or supraventricular arrhythmias caused by HCM
atenolol
sotalol
— is an AA to stop supreventricular arrhythmias
diltiazem
used for treatment in HCM in cats
what is ATE
aterial thromboemoblism
what causes ATE
aterial thromboembolism
virchow’s triangle: hypercoagulability, vessel wall injury, stasis
LA dilation cause clot to form, can travel to hindlimbs (saddle), forelimbs, kidney or brain
what is smoke in echo
micro thrombi
clinical signs of ATE
acute paralysis
pain
weakness
pale pink/cyanotic paw pads
cold
+/- dyspnea
5 Ps of ATE
pain
paresis/paralysis
pallor
pulselessness
poikilothermy (cold limbs)
what are bad signs for cat with ATE
hypothermia
bradycardia
absent motor functions
more than one limb affected
arterial thromboembolism
how to diagnose ATE
echo and xrays
low glucose in affected limbs
high lactase in affected limbs
serial bloodwork
* kidney function
* reperfusion injury = ↑K
how to treat ATE
prophylaxis
platelet inhibitor: clopidogrel(plavix), ASA
anti-coagulants: heparin
Thrombolysis (rare)
urokinase, TPA
Thromboectomy (surgery)
clopidogrel
plavix
platelet inhibitor: prevents platelet aggregation and fibrin cross linking
effect after 3 days, and lasts 7 days
can cause GI upset
bitter taste
how does rivarozaban work
xarelto
inhibits factor Xa: prevents clot formation
super cat study still ongoing
how does TPA work
tissue plasminogen activator
activated plasminogen which will break up clots
cat at risk for ATE is treated with
clopidogrel
cat with current ATE is treated with
clopidogrel +/- other prophylaxis
pain meds
supportive care
+/-CHF therapy
heart with restrictive cardiomyopathy will look
normal LV thickness
with diastolic dysfunction
unknown origin
Physical of cat with RCM
gallop heart sound
murmur
arrhythmia
Dyspnea, tachypnea
Abnormal lung sounds
Thromboembolism
what type of cats get RCM
older, male cats
no specific breeds
echo of RCM with show
- Normal LV thickness
- Left atrial dilation +/- right atrial dilation
- +/- Systolic dysfunction
- +/- Spontaneous echocontrast (“smoke”)
- +/- Intracardiac thrombi
cats with systolic dysfunction can be treated with
pimobendan
DCM in cats will have — dilation and — dysfunction
cardiac chamber
systolic
can be idiopathic or secondary to taurine deficiency
— is an amino acid important for cardiovascular function. Cats cannot synthesize this
taurine
deficiency can lead to DCM in cats
taurine deficiency in cats can lead to
central retinal degeneration
DCM
how to treat DCM in cats
treat for CHF:
furosemide
ACE inhibtor: enalapril or benazepril
spironolactone
treat arrhythmias:
atenolol and sotalol (ventricular and/or supraventricular)
diltiazem (supraventricular)
treat poor pumping (positive inotropes)
dobutamine (seizures)
pimobendan
Taurine supplements
how to treat HCM in cats
treat for CHF:
furosemide
ACE inhibtor: enalapril or benazepril
spironolactone
treat arrhythmias:
atenolol and sotalol (ventricular and/or supraventricular)
diltiazem (supraventricular)
what is TMT
TRANSIENT MYOCARDIAL THICKENING
- Form of secondary cardiomyopathy
- Can mimic HCM
- Occurs more commonly in younger cats
- Antecedent events (general anesthesia, stress, other illness)
- Increased cardiac troponin I (CTnI) may strengthen suspicion
- Hypertrophy resolves over time
- Good prognosis
cats with — have a higher likely of having TMT
previous stressful event (general anesthesia, stress, other illness)
increased troponin
younger cats
TMT will look like —
HCM
but hypertrophy will resolve over time
transient myocardial thickening (TMT)
