DCM

Question 1

what is the 2nd most common acquired heart disease in dogs?

Answer 1

DCM (most common is DVD)

Question 2

T/F: DVD is more common in LBD

Answer 2

FALSE, DCM

except: cocker spaniel, portuguese water dog, toy manchester terrier

Question 3

what is DCM primarily characterized by?

Answer 3

primary ventricular SYSTOLIC dysfunction (dilation is secondary to)

Question 4

what breed is DCM more prevalent in?

Answer 4

dobermans

Question 5

what are the two genetic mutations for dobermans with DCM?

Answer 5

PDK4 and NCSU DCM 2

Question 6

what cardiac dz is familial in the great dane, irish wolfhound, newfoundland, portuguese water dog, and toy manchester terrier?

Answer 6

DCM

Question 7

what do you see on histo of a dog with DCM?

Answer 7

attenuated wavy myofibers, myocytolysis, vacuolization of myocytes, necrosis, fibrosis, +/- fatty infiltration

Question 8

why does the systolic dysfunction in DCM cause secondary dilation?

Answer 8

decreased contractility > decreased SV > decreased CO > RAAS activation > increased preload > volume overload (CHF causes increased diastolic pressure and mitral regurg) > hypertrophy

Question 9

what type of hypertrophy do you see in DCM?

Answer 9

eccentric (volume overload)

Question 10

what arrhythmias are common in DCM?

Answer 10

atrial fibrillation and VPCs/ventricular tachycardia

Question 11

what are the two stages of DCM?

Answer 11

occult (asymptomatic) and overt (symptomatic)

Question 12

T/F: most dogs are asymptomatic (in the occult stage) for their lifetime, if they do develop signs it can take years

Answer 12

FALSE, most dogs progress to SYMPTOMATIC stage (overt) though it can take years

Question 13

what is a common end stage occurrence in dobermans with DCM?

Answer 13

sudden death due to ventricular arrhythmia

Question 14

T/F: sudden death is not a first sign in DCM

Answer 14

FALSE, sudden death can be a first sign

Question 15

what type of murmur may be present in patients with DCM?

Answer 15

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

Question 16

T/F: a doberman negative for PDK4 and NCSU DCM 2 mutations will not develop DCM

Answer 16

FALSE, may still develop

Question 17

what is the most common arrhythmia in dogs with DCM?

Answer 17

atrial fibrillation

Question 18

what would you see in an echocardiogram that would indicate DCM in a dog?

Answer 18

systolic fractional shortening in M-mode (almost the same length as diastole)

Question 19

why are thoracic radiographs not used as the primary diagnostic tool for DCM?

Answer 19

doesn’t look at function like echo does

Question 20

when would you want to use the diagnostic tool FAST in a dog with DCM?

Answer 20

if you suspect biventricular CHF (look for peritoneal/pleural effusion)

Question 21

what nutrient can be a factor in causing DCM?

Answer 21

taurine which is important in myocardial function and can cause systolic dysfunction (check blood levels in atypical breeds or non-AAFCO or new diets)

Question 22

what drugs might you consider in treating a dog with DCM in the occult stage?

Answer 22

• benazepril & pimobendan (delay progression to CHF esp. in dobermans)
• beta blocker therapy +/- ACEi (but can be dangerous because beta blockers decrease HR and contractility)

Question 23

what drugs might you consider in treating a dog with DCM in the overt stage?

Answer 23

• diuretic, pimobendan, ACEi, spironolactone (for CHF)
• diltiazem +/- digoxin (AF)
• mexiletine or sotalol (ventricular arrhythmias)
• amiodarone (refractory VT)

Question 24

tachycardia, taurine-deficiency, doxorubicin (chemo agent), inflammatory/infectious dz, and hypothyroidism are all differential diagnoses of DCM for what type of dysfunction?

Answer 24

systolic dysfunction

Question 25

hyperthyroidism, systemic hypertension, acromegaly, infiltrative dz, hyperadrenocorticism, and DM are all differential diagnoses of DCM for what type of dysfunction?

Answer 25

concentric hypertrophy and diastolic dysfunction

Question 26

T/F: DCM is more common in cats than dogs

Answer 26

FALSE, dogs more common

Question 27

T/F: symptoms tend to occur early on in cats with DCM

Answer 27

FALSE, don’t usually occur until HF or ATE develops

Question 28

are murmurs common in cats with DCM?

Answer 28

NO, gallop sounds are common