DCM Flashcards
what is the 2nd most common acquired heart disease in dogs?
DCM (most common is DVD)
T/F: DVD is more common in LBD
FALSE, DCM
except: cocker spaniel, portuguese water dog, toy manchester terrier
what is DCM primarily characterized by?
primary ventricular SYSTOLIC dysfunction (dilation is secondary to)
what breed is DCM more prevalent in?
dobermans
what are the two genetic mutations for dobermans with DCM?
PDK4 and NCSU DCM 2
what cardiac dz is familial in the great dane, irish wolfhound, newfoundland, portuguese water dog, and toy manchester terrier?
DCM
what do you see on histo of a dog with DCM?
attenuated wavy myofibers, myocytolysis, vacuolization of myocytes, necrosis, fibrosis, +/- fatty infiltration
why does the systolic dysfunction in DCM cause secondary dilation?
decreased contractility > decreased SV > decreased CO > RAAS activation > increased preload > volume overload (CHF causes increased diastolic pressure and mitral regurg) > hypertrophy
what type of hypertrophy do you see in DCM?
eccentric (volume overload)
what arrhythmias are common in DCM?
atrial fibrillation and VPCs/ventricular tachycardia
what are the two stages of DCM?
occult (asymptomatic) and overt (symptomatic)
T/F: most dogs are asymptomatic (in the occult stage) for their lifetime, if they do develop signs it can take years
FALSE, most dogs progress to SYMPTOMATIC stage (overt) though it can take years
what is a common end stage occurrence in dobermans with DCM?
sudden death due to ventricular arrhythmia
T/F: sudden death is not a first sign in DCM
FALSE, sudden death can be a first sign
what type of murmur may be present in patients with DCM?
low grade left apical systolic murmur
as ventricle dilates, papillary muscles move away from each other and can cause functional mitral regurg as the leaflets don’t reach each other
T/F: a doberman negative for PDK4 and NCSU DCM 2 mutations will not develop DCM
FALSE, may still develop
what is the most common arrhythmia in dogs with DCM?
atrial fibrillation
what would you see in an echocardiogram that would indicate DCM in a dog?
systolic fractional shortening in M-mode (almost the same length as diastole)
why are thoracic radiographs not used as the primary diagnostic tool for DCM?
doesn’t look at function like echo does
when would you want to use the diagnostic tool FAST in a dog with DCM?
if you suspect biventricular CHF (look for peritoneal/pleural effusion)
what nutrient can be a factor in causing DCM?
taurine which is important in myocardial function and can cause systolic dysfunction (check blood levels in atypical breeds or non-AAFCO or new diets)
what drugs might you consider in treating a dog with DCM in the occult stage?
- benazepril & pimobendan (delay progression to CHF esp. in dobermans)
- beta blocker therapy +/- ACEi (but can be dangerous because beta blockers decrease HR and contractility)
what drugs might you consider in treating a dog with DCM in the overt stage?
- diuretic, pimobendan, ACEi, spironolactone (for CHF)
- diltiazem +/- digoxin (AF)
- mexiletine or sotalol (ventricular arrhythmias)
- amiodarone (refractory VT)
tachycardia, taurine-deficiency, doxorubicin (chemo agent), inflammatory/infectious dz, and hypothyroidism are all differential diagnoses of DCM for what type of dysfunction?
systolic dysfunction
hyperthyroidism, systemic hypertension, acromegaly, infiltrative dz, hyperadrenocorticism, and DM are all differential diagnoses of DCM for what type of dysfunction?
concentric hypertrophy and diastolic dysfunction
T/F: DCM is more common in cats than dogs
FALSE, dogs more common
T/F: symptoms tend to occur early on in cats with DCM
FALSE, don’t usually occur until HF or ATE develops
are murmurs common in cats with DCM?
NO, gallop sounds are common