Cardiomyopathies Flashcards
What are the important cardiomyopathies
DCM (dilated cardiomyopathy)
HCM (hypertrophic cardiomyopathy
Restrictive/unclassified/ moderator band cardiomyopathies
Boxer cardiomyopathy
DCM main problem
heart lacks contractility→ incomplete emptying→volume overload (incr afterload)→eccentric hypertropy
Causes of DCM
idiopathic
familial (genetic): Dobes, IW, Boxers
3 stages in Dobes:
Arrythmogenic (@2-5y), Occult (@3-6y), Classic(@6-9y)
Signalment for DCM
Lg-Giant breed dogs
4-10 years
CS DCM
Sudden Death (30%)
LCHF (classic stage)
RCHF (classic stage, develops after LCHF)
Seen on PE w/ DCM
Thin
L/R CHF
lung wheezes (inflammation) & ventral crackles (edema)
Afib/VPDs/V tach
soft systolic murmur
S3 gallop (slow filling, Lub Dubdub)
Lab findings DCM
prerenal azotemia
incr liver enz d/t congestion
low taurine/carnitine is some dogs
Occult phase: elev. BNP/ANP
Radiograph DCM
enlarged heart
lung edema
U/S: wobbly heart in later stages M mode can determine fractional shortening
EKG: IW Afib, Dobes VPDs
Tx for DCM arrythmogenic stage
AFib otherwise ok (no other arrythmias, fract short norm(contractility)) & norm HR → No tx
incr HR → pick one: ß-blocker(?), diltiazem, digoxin (but not 1st choice)
incr HR w/decr contractility (fract short)→ pick diltiazem + digoxin or digoxin + ß-blocker at same time
if ventricular arrhythmias? tx if CS
runs of VPDs, R-on-T, rate, frequency
sotalol (if contractility ok) / mexiletine (oral lidocaine)
Tx for DCM Occult
ACE inhibitors
pimobendan
ß-blockers (metoprolol/ carvedilol)
Tx arrhythmias
TX Classic DCM
mild cases
tx at home preferred
furosemide
pimobendan
ACE inhibitor
Tx Severe DCM
Tx in hospital 25% survival - px poor
FONS
pleural effusions/ascites drained
pimobendan
Na nitroprusside CRI
po ACE inhibitor
How to tx arrhythmias in DCM
Afib - digoxin =/- diltiazem or ß-blocker
VPDs - lidocaine then soltalol or mexiletine
HCM in cats
murmur
ventricular heave
HCM Tx CATS
if normal happy cat w/ only murmur & ventricular heave:
no tx
?
if comes in with heart Failure:
FONS - sedation, oxygen, tx pleural effusion/shock - dobutamine, furosemide, nitroglycerine?
Addt’l tx:
ß-blocker (atenolol) in obstructed animal
decr Na+ diet, avoid stress
Main complication with HCM in cats and Tx?
Thromboembolism
usually euthanize!
analgesia-condition very painful!
fluids (?CHF)- chest rads first to ck for pleural edema! helps open up collateral circulation
acepromazine- maybe for vasodilation effect but watch with ACE inhibitor d/t profound hypotension
streptokinase & TPA ? $$$
unfractionated hep
aspirin? Plavix - ADP antagonist?
warfarin?
Prevention of HCM in cats
Px HCM
Ddx:
Don’t breed
genetic testing in Maine Coons & ragdolls?
Asymptomatic : guarded to good
focal: benign, diffuse & severe: bad!
CHF: 3 mos
Thromboembolism - grave
Primary from secondary HCM
Boxer cardiomyopathy aka….
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Fibrous/fatty replacement of cardiomyocytes
contractility normal but normal die from arrythmias
striatin gene (controller)
What are the forms of Boxer CM?
Concealed form - no CS but VPDs apparent on Holter
Overt form - CS apparent (syncope etc)
Myocardial dysfunction form - RHF
Signalment of Boxer CM
CS?
Findings on PE?
mostly 6-10y
Asymptomatic, sudden death, weakness & syncope, R or LHF
VPDs, R/LHF
Dx Boxer CM
Definitive Dx is postmortem histological changes
Antemortem - family hx, CS, Holter ⇒>50-100 VPDs
Tx of Boxer CM
Stops signs but not sudden death (decr VPDs)
Sotalol or mexilitene
monitor w/ Holter
Tx ones w/ CS: >1000 VPDs, VT, R-on-T
Carnitine? Omega-3 - 2g/day decr VPDs
Px of Boxer CM
Prevention
Other things boxers get
Cautious! Sudden death always possible!
Striatin gene test
DCM, Aortic stenosis, Atrial Septal Defects
