Cardio - DCM Flashcards
What is the structural component of DCM?
Primary myocardial disease, defect in cytoskeleton or metabolism
How does DCM affect general heart function?
Decreased LV systolic function (decreased contractility)
LV dilation
Ventricular arrhythmias
What is the cause for primary DCM?
Genetic, idiopathic
What breed gets primary DCM?
Dobermans
What are secondary causes of DCM?
Nutritional deficiencies (taurine/carnitine), infectious/inflammatory, tachycardia-induced, sepsis-induced myocardial dysfunction, doxorubicin cardiotoxicity
What do DCM hearts look like?
Attenuated (shrinking) wavy myofibers, myocardial fibrosis and fatty replacement, myocyte atrophy/degeneration/necrosis
What is the most common arrhythmia seen with DCM? When do they occur in relation to changes seen on echo?
ventricular arrhythmias;
OFTEN precede echo changes (esp. Dobermans)
What other arrhythmia can happen with DCM? When does this happen in relation to changes seen on echo?
atrial fibrillation (due to large atrium);
OFTEN precedes echo changes (esp. in Irish Wolfhounds) and is common in advanced DCM/CHF in all breeds
What is the average age that DCM occurs?
6 years
How prevalent is DCM in Dobermans?
50% of them have it >6 years
What historically causes DCM in cats?
taurine deficiency
What sex gets DCM more often?
Males > females
What are 3 ways by which DCM can be detected?
Breeder screening, veterinarian screening, Dx following a complication
What 3 things can be used in a breeder screening to detect DCM?
Echo/holter monitor, cardiac biomarkers (NT-proBNP, cTnI), genetic testing
How is DCM diagnosed on echo?
Decreased LV systolic function (FS%, EF%), increased LV size
What is the gold standard for diagnosis of ventricular arrhythmias?
Holter (>50 VPCs/24 hours)
How can ventricular arrhythmias be diagnosed with ECG?
1+ VPCs/5 min
Severity of ventricular arrhythmias is correlated with severity of _____ _____.
myocardial dysfunction
Other than ventricular arrhythmias, what else can ECGs/Holter monitors detect when DCM is suspected?
A-Fib
What are the 2 biomarkers for DCM?
NT-proBNP and cTnI
What does increased NT-proBNP mean and what is the cutoff?
myocardial stretch; >450 pmol/L
What does increased cTnI mean and what is the cutoff?
myocardial damage; >0.22 ng/ml
How can nutritional deficiency be ruled out as a secondary cause of DCM?
consider diet history and supplement taurine if low
How can infection/inflammation be ruled out as a secondary cause of DCM?
Consider history and test for infectious diseases such as Trypanosoma, Toxo/Neospora, Bartonella, Borrelia, Ehrlichia, Lepto
How can tachycardia-induced myopathy be ruled out as a secondary cause of DCM?
Treat tacharrhythmia and recheck
How can sepsis-induced myocardial dysfunction be ruled out as a secondary cause of DCM?
treat sepsis and recheck
How can Doxorubicin cardiotoxicity be ruled out as a secondary cause of DCM?
Consider history
What are CS associated with DCM?
Signs of CHF: dyspnea/tachypnea, cough exercise intolerance/inappetence/ADR, abdominal distention
____ breed dogs hide CHF better than _____ breed dogs
large, small
Other than signs of CHF, what 2 things can happen in DCM?
Syncope, sudden cardiac death (arrhythmic)
Where does the fluid go in CHF in dogs?
L-CHF = pulmonary edema
R-CHF = ascites
Where does the fluid go in CHF in cats?
L-CHF = pulm edema, pleural eff, pericardial eff
R-CHF = pleural eff, ascites, pericardial eff
DCM can cause _____ CHF.
biventricular
How does DCM progress in Dobermans that are asymptomatic?
Avg time to CHF is 2 years
How does DCM progress in Dobermans following syncope?
Average survival 7 months
How does DCM progress in Dobermans after an episode of CHF?
average survival 6 months
What is the time to CHF in other breeds that have asymptomatic DCM?
2-5 years
What is the average survival of other breeds with DCM following an episode of CHF?
6 months-2 years
What are the 2 main causes of death in DCM?
2/3 CHF, 1/3 sudden cardiac death
What are negative prognostic indictors for DCM?
Severe ventricular arrhythmias, poosrly controlled A-Fib rate, younger age of onset, pleural eff, being a Doberman/Great Dane
What 2 medications are used in DCM to optimize HR?
Sotalol and Mexiletine
What treatments are used in asymptomatic DCM (stage B)?
Inotropy, cardioprotection, tx arrhythmias
What drugs are used for inotropy and cardioprotection in DCM?
Pimobendan, ACEi, +/- Atenolol
(Atenolol NEVER given to P with CHF)
What drugs are used to treat arrhythmias in DCM?
Ventricular arrhyth = Sotalol, Mexiletine
A-Fib = Digoxin, Diltiazem
What is more common in dogs with DCM than it is in DVMD?
cardiogenic shock - use dobutamine to treat
What is arrhythmogenic R ventricular cardiomyopathy (ARVC)?
Disease of the desmosome due to a genetic mutation in striatin, resulting in fibrofatty infiltration of the RV +/- the LV and ventricular arrhythmias (RV) +/- DCM phenotype (10%)
What is the signalment for ARVC?
middle-aged Boxers
What are 3 possible clinical presentations of ARVC?
Asymptomatic (incidental arrhythmia), symptomatic (syncope >>> CHF), sudden death (arrhythmic)
What is the preferred method for diagnosis of ARVC?
Holter/ECG
What is the preferred treatment for ARVC?
Sotalol (also mexiletine) +/- treat CHF
What is the prognosis if the dog has ARVC only?
Good
What is the prognosis if the dog has ARVC and the DCM phenotype?
same as “regular” DCM
