Cardiomyopathies Flashcards
Canine Dilated Cardiomyopathy
Disease of older male, large and giant breed dogs
What is the cause of Canine Dilated cardiomyopathy?
Unknown
Could be from other myopathies, bacteria, viruses, nutritional defects, or immune-mediated diseases
What occurs in patients with Canine Dilated cardiomyopathy?
The cardiac muscle (myocardium) becomes weak and flabby.
All chambers of the heart become dilated
Low-output circulatory failure (weakness, syncope, exercise intolerance)
What do dogs with canine dilated cardiomyopathy often develop?
atrial fibrillation
What are the clinical signs of canine dilated cardiomyopathy?
Right and left-sided heart failure
When auscultating the chest of a dog with canine dilated cardiomyopathy, what do you hear?
A murmur of mitral regurgitation heard on the left chest
+/- gallop rhythm
+/- tachyrhythm
What do the radiographs of a dog with canine dilated cardiomyopathy look like?
Left ventricular enlargement
Enlargement of both atria
What does the ECG of a dog with canine dilated cardiomyopathy look like?
Insensitive
May show widened QRS and P waves
What does an echocardiogram of a dog with canine dilated cardiomyopathy look like?
Test of choice
Left and right atrial wall thickening and left ventricular dilation
What are the laboratory tests that are run to help diagnose canine dilated cardiomyopathy?
Atrial Natriuretic Peptide (ANP)
Brain Natriuretic Peptide (BNP)
Pro-BNP
Troponin 1 (cTn1)
How do you treat canine dilated cardiomyopathy?
Diuretics ACE inhibitors Digoxin Pimobendan \+/- betablockers
What is the prognosis of dogs with canine dilated cardiomyopathy?
Progressive disease
Almost always fatal in 6 months to 2 years
What is Feline Dilated Cardiomyopathy associated with
Taurine deficiency
What are the clinical signs of feline dilated cardiomyopathy?
Older, mixed breed cats Dyspnea Inactivity Anorexia Acute lameness or paralysis of the hind limbs
What will you see on the echocardiogram of a cat with feline dilated cardiomyopathy?
Dilated heart chambers
What will the ECG of a cat with feline dilated cardiomyopathy (DCM) look like?
Increased QRS voltages
Wide P waves
Ventricular arrhythmia
What is the treatment for a cat with DCM?
Oral taurine supplementation Diuretic Oxygen Digoxin ACE inhibitor Pimobendan
What is the prognosis of cats with DCM?
If they survive the 1st 2 weeks and respond to taurine supplementation they have a good prognosis
Cats that do not respond have a poor long-term prognosis
What is the most common cardiomyopathy in cats?
Feline Hypertrophic Cardiomyopathy (HCM)
What percentage of cases does HCM make up?
50-70%
What happens to the heart of cats affected with HCM?
The left ventricle becomes thickened and stiff
Mitral regurgitation and aortic embolization frequently occur
What occurs in 16-18% of cats with HCM?
Thromboembolism
When auscultating a cat with HCM, what do you hear?
Soft, systolic murmur
Gallop rhythms or other arrhythmia
What do you see on the radiographs of a cat with HCM
Normal to slight left atrial enlargement
“Valentine” heart shape
What do you see on the ECG of a cat with HCM?
Increased P-waves
Increased QRS width
Sinus tachycardia
What do you see on an echocardiogram of a cat with HCM?
Increased left ventricular free wall thickness and dilated left atrium
What are the laboratory tests used to diagnose HCM?
BNP
pro-BNP
cTn1
What is the most accurate method of HCM diagnosis?
MRI
How do you treat HCM?
ACE inhibitors
+/- Propanolol
Diltiazem
Low-dose heparin or aspirin to prevent thromboembolism
What occurs second to heart disease in cats?
Thrombus formation
Why are cats predisposed to form thrombi?
High platelet reactivity
Endothelial damage
Sluggish blood flow
Where do thrombi frequently lodge?
The trifurcation of the aorta
What do cats with feline thromboembolism present with?
A decrease in circulation in the rear legs
What are the clinical signs of feline thromboembolism
Acute onset of rear leg pain and paresis
Clod, bluish food pads
Lack of palpable pulses in the rear limbs
What is the treatment for cats with feline thromboembolism?
Tissue plasminogen activator
Heparin
Low dose aspirin
What does tissue plasminogen activator do?
Fibrinolysin to break down clots
What does heparin do?
Inhibits the formation of stable clots
What is the prognosis for feline thromboembolism?
Guarded to poor
