Acquired Heart Diseases: DCM and ARVC Flashcards
List the dog breeds associated with familial DCM
- Dobermans
- Great danes
- Irish wolfhound
- Newfie
- Portugese water dog
- Toy manchester terrier (practically a mini doby)
DCM is a primary myocardial disease characterized by ________ dysfunction, leading to _______ hypertrophy
systolic, eccentric
(dilation occurs secondary to systolic dysfunction)
DCM is an acquired condition seen in adult dogs. Exceptions are juvenile forms of DCM found in _________ breeds
- Portugese water dog
- Toy manchester terrier
What is true about DCM?
A. More common in females
B. More common in males
C. No sex predilection
D. Common in small breed dogs
B. More common in males
How is DCM staged?
2 stages:
- Occult (asymptomatic)
- Overt (symptomatic)
True or False: DCM is not associated with sudden death
FALSEEEE
Sudden death due to ventricular arrhythmias!!
________ is the test of choice for diagnosis of overt DCM
Thoracic radiographs
(bc overt= symptomatic)
_________ is the test of choice for diagnosis of occult DCM
Echocardiogram
(Asymptomatic, so echo > rads)
If a patient has overt DCM, what would you expect to see on thoracic radiographs?
- Atrial dilation (LA usually)
- Interstitial pulmonary infiltrates
- +/- pulmonary edema
List 3 blood tests used to differentiate DCM from non cardiac causes of myocardial dysfunction
- Taurine levels (taurine deficiency can cause myocardial dysfunction, mimics DCM)
- Thyroid testing (hypothyroidism can mimic DCM)
- NT-proBNP
What is the drug treatment protocol for a patient with occult DCM?
(AKA asymptomatic)
- Benazepril (cardioprotective)
- Pimobendan (inodilator)
shown to delay progression to CHF
What is the drug treatment protocol for a patient with acute overt DCM?
(AKA symptomatic of CHF)
- Furosemide
- Pimobendan
- O2
- Dobutamine if LOHF
What is the drug treatment protocol for a patient with chronic overt DCM?
(AKA symptomatic of CHF)
- Furosemide
- Pimobendan
- ACEi
- Spironolactone
+ antiarrhythmic drugs if a-fib or VPCs
(core 4 for CHF in dogs)
Most common arrhythmias found in patients with DCM?
- VPCs
- Atrial fibrillation
What is the prognosis for a patient with occult DCM?
(AKA asymptomatic)
- Fair to guarded (worse prognosis than an asymp patient with DMVD)
- Sudden death is possible
What is the prognosis for a patient with overt DCM?
(AKA symptomatic of CHF or LOHF)
- Poor (6-12 months)
- 50% of dobys with CHF due to DCM die suddenly :(
List the secondary causes of myocardial dysfunction that must be ruled out first before considering DCM?
- Tachycardia induced
- Taurine deficiency
- Hypothyroidism
- Doxorubicin induced
- Inflammatory/infectious processes
What is the reason for the decline in cats seen with DCM?
Better diets!!
(Used to have taurine deficient diets causing DCM in cats)
Physical exam findings on a patient with DCM?
- Low grade left apical systolic murmur
- S3 gallop
- Decreased heart sounds
- Decreased or weak femoral pulses
- CS of L-CHF or LOHF
True or False: Patients who have DCM and are asymptomatic don’t require drug therapy
FALSE
- Benazepril (cardioprotective)
- Pimobendan (inodilator)
shown to delay progression to CHF
DCM and myocarditis both can cause VPCs. What test can be done to rule in/out myocarditis?
Cardiac troponin I
_________ is the most common adult-onset heart disease in Boxers
ARVC (arrhythmogenic RV cardiomyopathy)
List the 3 forms of ARVC
I: Asymp with VPCs
II: Symptomatic with VPCs
III: Ventricular dilation, systolic dysfunction, and ventricular and supraventricular tachyarrhythmias
What dog breeds are associated with ARVC?
- Boxers (heritable)
- Bulldogs
(+ cats and horses)
What is the underlying cause of ARVC?
- Genetic mutation in the striatin gene
What is true about ARVC?
A. More common in females
B. More common in males
C. No sex predilection
D. Common in small breed dogs
C. No sex predilection
What are the most common presenting complaints in a patient with ARVC?
Syncope and exercise intolerance
True or False: ARVC is associated with sudden death
TRUE
due to lethal ventricular arrhythmias
(although many present asymp)
PE findings on a dog with ARVC?
- Many have a normal PE
- VPCs
- Murmurs are not common
What is the first choice anti-arrhythmic in dogs with ARVC and no evidence of CHF?
Sotalol (Class 3, K+ channel blocker) PO
(Mexiletine is 2nd choice)
What is the first choice anti-arrhythmic in dogs with ARVC and resulting CHF?
Amiodarone (Class 3, K+ channel blocker) (better than sotalol if systolic dysfunction/CHF)
(+ CHF drugs)
- Pimobendan
- ACEi
- Spironolactone
- Furosemide
What drugs should be prescribed to a patient with Stage III ARVC?
- Amiodarone (Class 3, K+ channel blocker) (better than sotalol if systolic dysfunction/CHF)
- Omega-3 FA
(+ CHF drugs)
- Pimobendan
- ACEi
- Spironolactone
- Furosemide
What is the prognosis for patients with Type I, II and III ARVC?
Type I and II: guarded (bc risk of sudden death), but most have normal lifespan
Type III: Poor (3-9 months)
An asymptomatic boxer with ARVC. What type and how to treat?
Type I
Treat with sotalol PO
_________ is the first line DOC for patients with ARVC
Sotalol
