Acquired Valvular Diseases Flashcards
what is the most common canine heart disease?
myxomatous mitral valve disease
what is the main cause of acquired valvular disease?
myxomatous degeneration
what dogs are most commonly affected by myxomatous mitral valve disease?
small to medium-size breeds
cavalier king charles spaniels
middle-aged or older
male>female
what makes up the mitral valve apparatus?
mitral leaflets
chordae tendinae
papillary muscles
mitral annulus
left ventricular wall
left atrial wall
what are the four layers of a valve?
atrialis
spongiosa
fibrosa
ventricularis
what can the chordae tendinae look like in myxomatous mitral valve disease?
thickened or ruptured
what is arteriosclerosis?
small vessel narrowing
what enlarges with myxomatous mitral valve disease?
left atrium
left ventricle
what parts of the valve are affected by myxomatous mitral valve disease?
mitral and tricuspid leaflets
how many dogs with myxomatous mitral valve disease progress to CHF?
20-30%
most severely affected ones do
what are some signs of myxomatous mitral valve disease?
history of murmur or click
cough, dyspnea, syncope with advanced disease
what type of click is associated with myxomatous mitral valve disease?
mid-systolic click
where is the murmur with myxomatous mitral valve disease?
left sided, systolic
apical location
what vertebral left atrial size has a high likelihood of left atrial enlargement?
> =3.0v
what can you see with myxomatous mitral valve disease on electrocardiography?
P mitrale
QRS prolongation
LV enlargement pattern
ST segment slurring, depressiom
arrhythmias possible
what can be found on echocardiography with myxomatous mitral valve disease?
thickened mitral leaflets
mitral valve prolapse
mitral +/- tricuspid regurgitation
LV volume overload: LV, LA dilation
pulmonary artery dilation +/- right heart dilation
what laboratory testing do you want to do for myxomatous mitral valve disease?
minimum database
urinalysis before furosemide
NT-proBNP or c-BNP
what is stage B2 of heart disease?
cardiac enlargement sufficient to benefit from treatment
what is the progression of myxomatous mitral valve disease?
no clinical signs
left mainstem bronchus compression by left atrium that causes cough
left sided congestive heart failure
ruptured chordae tendinae
syncope
endocardial split/left atrial tear: hemopericardium
should you treat dogs with cardiac enlargement, but no CHF, with pimobendan?
yes: live longer, no increase in adverse effects
should you start ACE inhibitors in dogs with myxomatous mitral valve disease?
probably does not help a lot, if at all
when should you start pimobendan in a dog with asymptomatic myxomatous mitral valve disease (owner with unlimited funds)?
murmur >=III/VI
VHS =>10.5
echo criteria LA/Ao >1.6
echo criteria LV enlargement
what is the surgery for myxomatous mitral valve disease?
Japan experience
annuloplasty and chordal repair
what does transcatheter edge-to-edge repair do?
limits mitral regurgitation using a clip
what do candidates for transcatheter edge-to-edge repair have to have?
severe mitral regurgitation
advanced stage B2, C, +/- D
leaflets must not be “flail”
A2-P2 prolapse
who gets acquired mitral stenosis?
uncommon in veterinary medicine
bull terriers
cats
what is the median survival after murmur detection in myxomatous mitral valve disease?
25 months of CHF
what valves are affected by myxomatous mitral valve disease?
mitral valve usually
tricuspid 30%
aortic rarely- old dogs
is there an inherited component to myxomatous mitral valve disease?
identified in some breeds
what are the predominant cell types in valves?
valvular interstitial cells: extracellular matrix
valvular endothelial cells
what can be seen grossly with myxomatous mitral valve disease with the valve?
thickened, curled, nodular margins
non-inflammatory, myxomatous degeneration
valvular fibrosis, hemorrhage, calcification
chordae tendinae thickened or ruptured
atrial jet lesions
what is often the first auscultation finding with myxomatous mitral valve disease?
mid-systolic click
what is the mid-systolic click in myxomatous mitral valve disease associated with?
mitral and/or tricuspid valve prolapse
what are some signs of left atrial enlargement on thoracic radiographs?
LAA bulge 2-3 o’clock
bow-legged cowboy: separation mainstem bronchi
lateral: tracheal elevation, left atrial bulge
what are the clinical syndromes of myxomatous mitral valve disease?
no clinical signs
left mainstem bronchus compression by left atrium
left sided congestive heart failure
ruptured chordae tendinae
syncope
endocardial split/left atrial tear: hemopericardium
what are some causes of mitral regurgitation and stenosis?
myxomatous mitral valve disease
DCM/HCM/RCM
mitral valve endocarditis
congenital mitral dysplasia
mitral stenosis
traumatic mitral injury
neoplasia
