Large Animal Cardiology

Question 1

what is the range of normal heart rate in a horse?

Answer 1

23-48 bpm

Question 2

what murmurs are common in horses?

Answer 2

soft (<=II/VI) systolic flow murmurs

Question 3

how many heart sounds should you hear in horses?

Answer 3

two
three
four
all normal: not pathologic

Question 4

how are cardiac murmurs described?

Answer 4

timing
intensity
point of maximum intensity
quality/pitch

Question 5

what are some causes of diastolic murmurs?

Answer 5

aortic insufficiency: common
pulmonic insufficiency

Question 6

what is accurately obtained with electrocardiography in large animals?

Answer 6

rate and rhythm only

Question 7

what are the indications for an echocardiogram?

Answer 7

pre-purchase exam
evaluation of murmurs or arrhythmia
unexplained poor performance

Question 8

in whom are radiographs most useful?

Answer 8

foals: both lateral and DV views can be taken

Question 9

when is second degree AV block more concerning?

Answer 9

high grade or not responsive to exercise or anticholinergics

Question 10

what is the most common cardiac rhythm disorder in the horse?

Answer 10

atrial fibrillation

Question 11

what are the predisposing factors for atrial fibrillation?

Answer 11

concurrent high vagal tone and high sympathetic tone (cooling down post-race)
atrial enlargement
atrial stretch

Question 12

which horses should you treat atrial fibrillation in?

Answer 12

performance horses with recent onset atrial fibrillation
no underlying cardiac disease

Question 13

what can you use to treat ventricular tachycardia?

Answer 13

lidocaine
propanolol
sotalol or amiodarone
magnesium sulfate

Question 14

what valve regurgitation is common in middle-aged or older horses?

Answer 14

mitral and aortic regurgitation

Question 15

what is the range of normal heart rate for a horse?

Answer 15

23-48

Question 16

where is the mitral valve on a horse?

Answer 16

level of elbow

Question 17

where is the aortic valve on a horse?

Answer 17

craniodorsal of mitral

Question 18

what are some causes of systolic ejection murmurs?

Answer 18

innocent
fever
anemia
VSD or ASD
aortic stenosis (rare)
pulmonic stenosis (rare)

Question 19

what does it mean for something to be a category B activation pattern?

Answer 19

depolarization of ventricles in single burst
more diffuse penetration of purkinje fibers

Question 20

when might you see a globoid heart in a horse?

Answer 20

pericardial effusion
pericarditis

Question 21

when is cardiac troponin-I documented to be elevated in horses?

Answer 21

myocardial necrosis
ruptured aortic jet lesion
piroplasmosis
endurance exercise
sepsis

Question 22

is ventricular tachycardia common in horses?

Answer 22

no

Question 23

who is third degree AV block common in?

Answer 23

jerusalem donkeys
young animals: congenital

Question 24

when is paroxysmal atrial fibrillation seen?

Answer 24

racehorses up to 24 hours post race

Question 25

is atrial fibrillation usually seen with other cardiac pathology?

Answer 25

not in large horses more in ponies

Question 26

what can be the heart rate with ventricular arrhythmias?

Answer 26

can exceed 100

Question 27

what are some lidocaine side effects in horses?

Answer 27

neurologic side-effects: seizures, ataxia, CNS depression (also cats) increased defibrillation threshold suppression of escape rhythms

Question 28

what can be found of physical exam with aortic regurgitation?

Answer 28

variable intensity, cooing, descrendo holodiastolic murmur hyperdynamic pulses

Question 29

what happens with aortic insufficiency with age?

Answer 29

acquired lesions increase with age

Question 30

is intensity of the murmur a good guide to the severity of aortic insufficiency?

Answer 30

no arterial pulse quality better indicator

Question 31

what are some clinical signs of endocarditis?

Answer 31

new murmur intermittent or persistent fever tachycardia tachypnea

Question 32

how can you diagnose endocarditis?

Answer 32

clinical signs elevated WBC, fibrinogen, globulins, +/- troponin I anemia of chronic disease positive blood culture echocardiography

Question 33

what is the prognosis of endocarditis?

Answer 33

poor to guarded for performance and long-term survival

Question 34

what is there often a history of with pericardial disease?

Answer 34

respiratory disease

Question 35

what are the etiologies of pericarditis?

Answer 35

idiopathic infectious neoplasia aseptic

Question 36

what are some infectious causes of pericarditis?

Answer 36

bacterial viral eastern tent caterpillar (mare reproductive loss syndrome)

Question 37

what is the prognosis of pericarditis?

Answer 37

good if infectious and known pathogen

Question 38

how common is primary cardiomyopathy in large animals?

Answer 38

rare

Question 39

who is predisposed to ruptured sinus of valsalva?

Answer 39

breeding stallions

Question 40

who is predisposed to aorto-pulmonary fistula?

Answer 40

friesians

Question 41

who are congenital defects more common in?

Answer 41

arabs standardbreds welsh mountain ponies some breeds of cattle

Question 42

what is the most common congenital heart defect?

Answer 42

ventricular septal defect

Question 43

where are ventricular septal defects usually located?

Answer 43

membranous portion of interventricular septum just beneath aortic valve

Question 44

where is the pulmonic PMI in a horse?

Answer 44

cranial, slightly lower than aortic

Question 45

how is the point of maximal intensity described?

Answer 45

left vs right base vs apex

Question 46

what are some regurgitant causes of systolic murmurs?

Answer 46

mitral regurgitation tricuspid regurgitation

Question 47

how do you place the base apex lead?

Answer 47

right leads right jugular furrow left leads left apex

Question 48

what can you look for with radiographs for heart failure?

Answer 48

pleural effusion pulmonary edema

Question 49

are isolated premature beats in horses treated?

Answer 49

no

Question 50

what type of atrial fibrillation is most common in horses?

Answer 50

persistent

Question 51

what does atrial fibrillation require to start and maintain it?

Answer 51

trigger to start substrate to maintain

Question 52

should all horses with atrial fibrillation be treated?

Answer 52

not necessary in those that do not have to be high level athletes do not convert those with primary cardiac disease

Question 53

how is quinidine sulfate given?

Answer 53

through NG tube

Question 54

what does quinidine sulfate do?

Answer 54

negative inotrope positive chronotrope hypotensive

Question 55

what is ventricular tachycardia associated with in horses?

Answer 55

severe electrolyte disorders drug reactions hypoxia myocarditis underlying heart disease myocardial infarction toxicity

Question 56

what signs are associated with severely affected animals with acquired valvular disease?

Answer 56

reduced athletic performance exercise intolerance respiratory distress syncope or collapse

Question 57

what can the pericarditis be?

Answer 57

effusive fibrinous constrictive

Question 58

what are the secondary causes of cardiomyopathy?

Answer 58

myocarditis ionophore toxicity vitamin E/selenium or copper deficiency cantharidin toxicity neoplasia: lymphoma

Question 59

what murmurs are normal in foals?

Answer 59

less than 3 days old: continuous murmurs 2 months: soft systolic murmurs