Small Animal Cardiology

Front 1

What are some common presenting complaints w/ heart failure?

Back 1

cough (dog), dyspnea, ↓ appetite, wt. loss, lethargy, episodic weakness, abdominal distension

Front 2

What are some causes of cough resulting from heart dz & what type of cough does each produce?

Back 2

cough resulting from heart dz may manifest as a large airway cough:
-LA enlargement --> compression of bronchi
HW dz --> inflammation of airways & lung parenchyma
-should be distinguished from noncardiogenic causes such as tracheitis, bronchitis, tracheal collapse, & neoplasia

small airway cough is less frequently assoc. w/ heart dz
-may result from cardiogenic pulmonary edema
-should be distinguished from noncardiogenic causes such as pulmonary fibrosis

Front 3

What do gallop sounds indicate & when might you hear:

a. S3
b. S4

Back 3

indicate a stiff ventricle

a. early diastole (ventricular filling): hear w/ DCM
b. atrial contraction: hear w/ HCM

Front 4

What are some cardiovascular causes of syncope?

Back 4

usually brief & often occurs w/ exertion

• bradarrhythmia, ex. sick sinus syndrome, 3º AV block
• tachyarrhythmia, ex. paroxysms of atrial or ventricular tachycardia
• inadequate CO relative to demand caused by cardiomyopathy, acquired valvular dz, HW dz, or severe congenital stenosis of a great vessel (aortic or pulmonic stenosis)

Front 5

What are some causes of:

a. pulse deficits
b. hypokinetic (weak) pulses
c. hyperkinetic (bounding) pulses

Back 5

a. usually indicate arrhythmia
b. volume contraction or shock, HF, aortic stenosis
c. aortic regurg, PDA, high sympathetic tone, hyperthyroidism, fever, anemia

Front 6

How can you differentiate b'twn syncope & seizure?

Back 6

syncope: often assoc. w/ excitement or exertion, can have rear limb weakness or sudden collapse, lateral recumbency, stiffening of forelimbs & opisthotonos, micturition, vocalization

do NOT have tonic/clonic motion, facial fits, postictal dementia, neuro deficits or defecation w/ syncope

Front 7

What are some common PE abnormalities assoc. w/ left heart failure?

Back 7

pulmonary edema --> cough, tachypnea, dyspnea, orthopnea, pulmonary crackles, tiring, hemoptysis, cyanosis; secondary RHF, arrhythmias

Front 8

What are some common PE abnormalities assoc. w/ R heart failure?

Back 8

ascites, pleural effusion --> dyspnea, orthopnea, cyanosis, systemic venous congestion --> high CVP, jugular venous distension, hepatojugular reflex, heaptic +/- splenic congestion, small pericardial effusion, SQ edema, arrhythmias

Front 9

What are some general PE findings in HF?

Back 9

hypothermia (esp. cats)
tachycardia: bradycardia in ~20% of cats
+/- arrhythmia
murmur or gallop: 1/2 of cats don't have either
+/- weak or irregular pulses
tachypnea
breath sounds: loud +/- crackles w/ edema, soft w/ effusion
pale mm

Front 10

What are some ways to distinguish b'twn cardiac dz & respiratory dz?

Back 10

cardiac dz: previous heart dz, signalment, dec. appetite, wt. loss, new cough (dog), sinus tachycardia (dog), concurrent tachypnea, lethargy

resp. dz: chronic cough, cough (cat), no wt. loss, vomiting, sinus arrhythmia (dog), eupnea, normal activity

Front 11

What is the highest yield test in dyspneic or coughing animals?

Back 11

thoracic rads

Front 12

What are 3 thoracic rad findings consistent w/ congestive heart failure?

Back 12

venous distension: pulmonary vv. are ventral & central
cardiomegaly: vertebral heart score > 10.7
consistent pulmonary patterns
•dog: progressive pattern is typical in both distribution & nature of infiltrates; perihilar to caudal dorsal to diffuse, interstitial to alveolar
•cat: variable pattern that is usally multifocal patchy interstitial; variable amts. of pleural effusion may be present

Front 13

What clinically relevant info can be derived from echo?

Back 13

o anatomy: ID each chamber, valve anatomy, & cause of murmur
o cardiac function
o pulmonary arterial pressure: pulmonary venous inflow patterns, tissue Doppler (mitral valve motion)
o measurements may be helpful in differentiating cardiac vs. non-cardiac causes of dyspnea

Front 14

What clinically relevant info can be derived from ECG?

Back 14

o can be helpful to detect chamber enlargement but NOT as sensitive or specific as rads or echo
o can detect conduction, electrolyte, & ischemic abnormalities
- presence of atrial fib or L BBB in animal w/ consistent clinical signs is VERY suggestive of HF

Front 15

What are the ECG findings w/ atrial fibrillation?

Back 15

loss of P waves
chaotic rhythm
fast rate
normal QRS complexes

Front 16

What are the 4 basic determinants of cardiac output, & define each.

Back 16

preload: amt. of stretch on ventricle just prior to contraction
afterload: sum of forces that resist ejection of blood from ventricle
contractility: pumping ability of ventricle, independent of how stretched the myocardium is
heart rate/rhythm

Front 17

What is the definition of heart failure?

Back 17

diminished CO assoc. w/ normal or high ventricular filling pressures

Front 18

What are some neurohumoral abnormalities that contribute to heart failure?

Back 18

o short term good: ↑ water, sodium resorption, vasoconstriction, baroreceptor dysfunction (epi, norepi), ↑ HR/inotropy
o long term bad --> ↑ preload, edema, effusion, ↑ afterload, ↑ workload, ↑ myocardial O2 consumption, death


o ↑ sympathetic tone: norepi, epi
o ↑ RAAS --> ↑ aldosterone, ADH & NE release; vasoconstriction; ↑ thirst; renal sodium & water resorption; myocardial toxic
o ↑ cortisol
o ↑ atrial & b-type natriuertic peptide (ANP, BNP): body’s attempt to antagonize vasoconstriction & salt & water retention (weak)
o ↑ ADH, ↑ endothelin, ↑ TNF-α, IL-1

Front 19

What tests are used to dx heart failure?

Back 19

no single test: hx, PE, chest rads, ECG, echo, plasma or serum NT-pro BNP, response to therapy

Front 20

What specific test findings, abnormalities, etc. are highly suggestive of heart failure?

Back 20

o diuretic response
o radiographic or physical evidence of venous distention
o consistent radiographic pulmonary pattern & cardiomegaly
o ↑ pro-NT BNP
o tachypnea & abnormal breath sounds
o murmur + arrhythmia + gallop sound
o pulses paradoxus
o A fib
o LBBB
o large atria on echo (pulmonary venous outflow abnormalities)
o CVP > 15 mm Hg

Front 21

What are the goals for tx of acute heart failure?

Back 21

o restore comfort at rest
- mechanical removal of life threatening fluid accumulations
- O2 supplementations
- ↓ anxiety
- ↓ work of breathing
o hemodynamic stabilization: assess & optimize preload, afterload, HR & rhythm, contractility
o keep them eating

Front 22

What are the goals for tx of chronic heart failure?

Back 22

o maintain acute hemodynamic gains
o improve quality of life: exercise tolerance, appetite/weight
o improve survival: blunt neurohumoral aberrations
o minimize hospitalizations
o optimize owner & patient compliance
o economic impact
o moderately low salt intake

Front 23

What is the signalment assoc. w/ PDA?

Back 23

-breeds: poodles, collies, shelties, GSDs, Pomeranians, Cockers, English springer spaniels, maltese
-F > M (3:1)

Front 24

What is the signalment assoc. w/ subaortic stenosis in dogs?

Back 24

goldens, Newfies, boxers, GSDs, rotties

Front 25

What are common historical complaints assoc. w/ PDA in dogs?

Back 25

asymptomatic or signs of CHF

Front 26

What are common historical complaints assoc. w/ subaortic stenosis in dogs?

Back 26

many asymptomatic, exercise intolerance, syncope, CHF

Front 27

What are common historical complaints assoc. w/ pulmonic stenosis in dogs?

Back 27

many asymptomatic, RHF (ascites), low CO (syncope, exercise intolerance), hypoxemia/dyspnea (L --> R shunting across AV defect)

Front 28

What PE findings are assoc. w/ PDA?

Back 28

loud continuous machinery murmur at L base, hyperdynamic arterial pulses

Front 29

What PE findings are assoc. w/ subaortic stenosis?

Back 29

-L basilar systolic ejection murmur: radiates well to R axilla
-weak, late rising pulse w/ severe dz
-rarely, concurrent soft diastolic murmur of aortic insufficiency

Front 30

What PE findings are assoc. w/ pulmonic stenosis?

Back 30

-L basilar ejection systolic murmur
-R ventricular lift: apex beat felt better on R side
-jugular venous pulsation
-R holosystolic murmur: tricuspid regurg

Front 31

What PE findings are assoc. w/ ventricular septal defect?

Back 31

holosystolic R sided murmur
• concurrent loud L basilar systolic ejection murmur may be heard d/t relative pulmonic stenosis: too much blood going thru pulmonary a.
• sometimes assoc. w/ aortic insufficiency & soft diastolic murmur

Front 32

What PE findings are assoc. w/ mitral valve dysplasia in cats?

Back 32

-similar to MR in older dogs: L apical systolic murmur, signs of L HF (cough, dyspnea, lethargy, exercise intolerance)

Front 33

What PE findings are assoc. w/ tetrology of Fallot?

Back 33

small size (stunted growth), variable cyanosis, esp. worse w/ exertion, variable, +/- soft holosystolic murumur at L base

Front 34

What PE findings are assoc. w/ reverse PDA (R --> L)?

Back 34

clinical signs, px, tx similar to tetralogy of fallot
• one important PE difference: caudal cyanosis d/t position of PDA after L subclavian a. & brachiocephalic trunk (head & neck blood supply may not be as desaturated)

Front 35

What thoracic rad patterns are typical for PDA?

Back 35

LA & LV enlargement
pulmonary overcirculation
dilation of pulmonary a. & aorta: “ductus bump”

Front 36

What thoracic rad patterns are typical for subaortic stenosis?

Back 36

LV enlargement, prominent aorta (d/t post-stenotic dilation)

Front 37

What thoracic rad patterns are typical for pulmonic stenosis?

Back 37

under perfusion of pulmonary circulation
RV enlargement
post-stenotic dilation of pulmonary a.

Front 38

What thoracic rad patterns are typical for ventricular septal defect?

Back 38

variable: large shunts cause pulmonary overcirculation & L cardiomegaly

Front 39

What is the tx & px for PDA?

Back 39

if in CHF: stabilize medically 1st

surgical ligation: excellent px if not in CHF (5% mortality rate)

transcatheter occlusion: alternative to surgical ligation
•↓ mortality & morbidity
- generally can’t do in dogs < 3 kg
•retrograde approach via femoral a.

o px w/o correction of PDA
- ~80% die of HF w/in 1-2 yrs: most common cause of CHF in young dogs (LV failure, pulmonary edema, A fib)
- if PDA is small, occ. dog will survive to be mature adult

Front 40

What is the tx & px for subaortic stenosis?

Back 40

mild to moderate SAS: no tx
• ↑ risk for endocarditis
• mild exercise restriction

severe SAS
• medical
o B-blockers (atenolol) may ↓ myocardial O2 demand, have a mild ventricular anti-arrhythmic effect, & improve survival
o if CHF: furosemide, enalapril, digoxin, pimo, low salt diet

•surgical
o transvalvular dilation: not recommended: no improvement in survival compared to no sx

•balloon valvuloplasty: rarely performed
o initial ↓ in pressure gradient: 50%
o 85% have re-stenosis w/in 1 yr

px
severe SAS: pressure gradient from aorta --> LV > 80 mm Hg (normal: < 16 mm Hg)
• median survival: 3-6 yrs
• sudden cardiac death common

mild SAS: pressure gradient < 50 mm Hg
• median survival: 10-11 yrs
• occasional sudden cardiac death, CHF, infectious endocarditis

Front 41

What is the tx & px for pulmonic stenosis?

Back 41

mild to moderate PS: no tx

severe PS (gradient > 75 mm Hg)
• if in CHF, tx medically 1st
• surgery vs. balloon valvuloplasty
o sx: many types (modified patch graft is probably best)
- ↑ morbidity & mortality
- sx may be preferred if pulmonic valve annulus is hypoplastic
o balloon valvuloplasty
- ↓ morbidity & mortality (< 5%)
- tx of choice if normal pulmonic valve annulus
- infundibular hypertrophy will regress w/ time
- re-stenosis uncommon
o caution w/ English bulldogs & boxers: may have anomalous L coronary a. encircles RV outflow tract & contributes to stenosis
- high risk of death w/ balloon valvuloplasty, patch graft sx contraindicated

Front 42

What is the signalment assoc. w/ chronic degenerative mitral valve dz in dogs?

Back 42

poodles (toys, minis), Chihuahuas, dachshunds, beagles, cocker spaniels, CKC spaniels, yorkies, malteses, shelties, mini schnauzers, whippets

age
• usually > 10 yo, but varies
• unusual in dogs < 5 yo, except CKC spaniels
o CKC spaniels usually have a more rapid progression than other dogs

Front 43

What is the common signalment assoc. w/ endocarditis in dogs?

Back 43

o most commonly affects large breed dogs: GSDs, Boxers, golden retrievers
o M > F (2:1)
o average age: 4-7 yrs

Front 44

What is the common signalment assoc. w/ DCM in dogs?

Back 44

o strong breed & family predispositions
o Dobermans, Boxers, Cockers, Labs, Goldens, GIANT breeds (Great Danes, Irish Setters, St. Bernards, Great Pyrennes)
o M > F
o usually young to middle aged

Front 45

What are the common historical complaints & PE findings assoc. w/ valvular endocardiosis?

Back 45

usually 1st noted as asymptomatic murmur
LHF: cough, dyspnea, exercise intolerance, wt. loss
less common: RHF (ascites, abdominal distension)
rare: acute onset of HF assoc. w/ acute chordae tendinae rupture

Front 46

What are the common historical complaints & PE findings assoc. w/ infectious endocarditis?

Back 46

hx
- patient is SICK
- predisposing event: ex. dentistry, sx, or prior infection
- lethargy, inappetance, weakness
- signs of HF: cough, shortness of breath, syncope
- lameness: d/t IM polyarthritis
- signs of thrombosis: hematuria, epistaxis, seizure, paresis

PE findings: variable
- NEW murmur + fever + lameness: HIGH suspicion for endocarditis
- +/- fever (> 103º)
- murmur: 50-75%
- lameness
- arrhythmia: common

Front 47

What are the common historical complaints & PE findings assoc. w/ DCM?

Back 47

hx
o usually signs of CHF
o occ. asymptomatic
o syncope more common in Boxers & Dobermans

PE findings
o depends on clinical stage of heart dz
o soft systolic murmur of AV insufficiency, gallop sound, arrhythmia/pulse deficits
o signs of CHF: thin, weak pulses, pale mm, long CRT, ascites, pleural effusion or pulmonary edema

Front 48

What thoracic rad patterns are typical of endocardiosis?

Back 48

normal to L/generalized cardiomegaly
- if CHF: perihilar pulmonary edema (interstitial to alveolar pattern in caudodorsal lungs) w/ pulmonary venous distension

Front 49

What is the tx & px for valvular endocardiosis w/ acute or chronic symptomatic CHF?

Back 49

acute symptomatic CHF
• FONSE: furosemide, enalapril, +/- nitroglycerin, +/- oxygen, +/- sedation
• +/- pimobendan
• +/- Ca channel blocker (dilitiazem) if significant concurrent SV arrhythmias

chronic symptomatic CHF
• furosemide: lowest effective dose
• enalapril
• +/- pimobendan: esp. if recurrent or refractory HF or azotemia on furosemide & enalapril
o can ↓ furosemide dose

• +/- spironolactone
• +/- digoxin: esp. if persistent tachycardia or refractory CHF
• +/- amlodipine: 2nd vasodilator if recurrent or refractory CHF or concurrent hypertension
• +/- β-blocker: once in stable CHF
• px: 6 mo. to 2 yrs w/ therapy

Front 50

What thoracic rad patterns are typical of DCM?

Back 50

- normal to left or generalized cardiomegaly
- typical CHF findings: pulmonary edema, pleural effusion or both, pulmonary venous distention

Front 51

What arrhythmias are commonly assoc. w/ DCM?

Back 51

often A fib or ventricular arrhythmias (ex. VPCs)
• A fib: SA node not firing: doesn’t cause heartbeat
• hundred of re-entrant circuits bombard AV node
normal to L atrial & ventricular enlargement
holter monitoring helpful for screening & for better assessment of arrhythmia
• don’t breed animal w > 100 VPCs in 24 hrs

Front 52

What is the tx & px for asymptomatic valvular endocardiosis?

Back 52

if asymptomatic & no cardiomegaly
• no medical tx
• feed geriatric diet: mildly salt restricted
• px: usually many yrs

if asymptomatic & cardiomegaly (implies remodeling d/t more significant regurg)
• +/- ACE inhibitor
o enalapril & early MV dz
no ↑ in adverse effects
modest benefit in delay of HF: 4 mo.
important benefit in delaying death d/t all causes: extended life 10.6 mo.
• suggests non-cardiac (perhaps renal protective) benefits

• +/- β-blocker if tachycardic
• mild to moderately low salt diet
• px: difficult to predict (1-5 yrs?)

Front 53

What is the tx for infectious endocarditis?

Back 53

o principles: kill infecting organism, tx complications (cardiac manifestations)
o long term ABs: > 3 mo.
o hard to cure: poor penetration of ABs, altered metabolic state of bacteria w/in lesion, absence of adequate host defense response

Front 54

What is the px for infectious endocarditis?

Back 54

o extremely poor
o median survival time: ~2 mo, occasionally have a long term survivor

Front 55

What is the tx & px for asymptomatic DCM?

Back 55

uncommon, but may be seen if screening breeding Boxers or Dobermans
- ACE inhibitor &/or β-blocker may delay progression of dz
- avoid high salt diets & heavy exercise
- recheck q 6-12 mo.
- px: usually years, even in giant breeds

Front 56

What is the tx & px for symptomatic DCM?

Back 56

tx CHF: furosemide, enalapril, low salt diet, cage rest, usually Pimobendan
• usually add Digoxin once stabilized if no contraindications
• once out of CHF, slowly titrate in β-blocker, if owners are committed

tx arrhythmias
• A fib: Digoxin, then add β-blocker (atenolol) or Ca channel blocker (diltiazem)
• significant V tach: chronic tx w/ β-blocker, K channel blocker (sotolol), or Na channel blocker (mexilitine: oral version of lidocaine)
if recurrent or refractory CHF, seek consult for additional therapies (additional diuretics or vasodilators)

px
• once in CHF: a few months – 1-2 yrs w/ drug therapy
o Doberman, Boxer: up to 1 yr
• most of these dogs will die from sudden death (~50%) or CHF

Front 57

What are the clinical signs & PE findings assoc. w/ canine pericardial dz?

Back 57

signs: usually sudden onset of weakness, collapse, anorexia, lethargy, dyspnea, abdominal distention, occ. cough

PE findings: basis of dx
- combo of low CO signs & RHF signs
- muffled heart sounds, weak pulses, +/- pulses paradoxus (pulses go away w/ inspiration: pathognomonic), jugular venous distension, positive hepatojugular reflex, hepatomegaly, ascites

Front 58

What are the common etiologies of canine pericardial dz?

Back 58

neoplasia: #1 cause
- HSA: common at R auricle (GSDs, goldens)
- chemodectoma: tumor of chemoreceptors of aortic body (brachycephalic breeds)
- also mesothelioma, metastatic carcinoma
o idiopathic: middle aged large breed dogs
o less common: coagulopathy (ex. rat poisoning), L atrial tear d/t chronic MR, trauma, infectious dz (ex. Coccidiomycosis)

Front 59

How is canine pericardial dz diagnosed?

Back 59

PE findings: basis of dx
o rads: greatly enlarged, spherical cardiac silhouette (basketball heart), +/- pleural effusion
o ECG: sinus tachycardia, low voltage (small) QRS, electrical alternans (alternating QRS heights d/t heart swinging back & forth w/ each beat: almost pathognomonic)
o echo: most sensitive & specific test
- ideally perform prior to pericardiocentesis: look for tumors

Front 60

What is the tx for canine pericardial dz?

Back 60

o pericardiocentesis: only effective tx for cardiac tamponade
- fluid analysis rarely helpful in dx: usually hemorrhagic
o furosemide/ACE inhibitors may be helpful

Front 61

What is the px for canine pericardial dz?

Back 61

o idiopathic
- px variable, usually years, but most will recur
- if recurs more than twice, sx (pericardectomy) or balloon pericardiotomy are options

o neoplasia
generally poor
HSA: days to weeks, occ. will tx w/ chemo w/ mixed results
chemodectoma: months to years
• slow growing tumors, slow to met
• surgical pericardectomy significantly improves survival

Front 62

What clinical signs & PE findings are assoc. w/ canine HW dz?

Back 62

usually asymptomatic, cough, exercise intolerance, lethargy, poor condition, syncope, dyspnea
o if in RHF: hepatomegaly, ascites, ↑ breath sounds, split S2, tricuspid insufficiency murmur

Front 63

What thoracic rad findings are consistent w/ clinically significant HW dz?

Back 63

abnormalities develop early in course of dz
• pulmonary a. enlargement: main pulmonary a. & caudal pulmonary aa.
• blunting of & tortuous pulmonary aa.
• R heart enlargement: “reverse D”
• pulmonary interstitial opacities suggestive of inflammation

Front 64

What are the indications & clinically relevant info available from various blood tests for HW dz?

Back 64

o serology (ELISA): tests for adult female Ag
- screening test of choice: 100% specificity & > 85% sensitivity
- allows semi-quantification of worm burden: must be interpreted w/ hx, rads

o microfilaria test: Knotts or filter test
- perform if positive Ag test
- 1% of Ag (-) dogs may be microfilaria (+)

Front 65

What is recommended tx for canine HW dz?

Back 65

o adulticide therapy: melarsomine (Immiticide)
arsenical administered IM (deep epaxial)
2 protocols
• mild infection: 2 injections 24 hrs apart
• more severe infection: 3 injections (give 1, then a month later give 2 injections 24 hours apart)
o NCSU cardio recommends 3 injections for ALL cases
(+): more efficacious, safer (1 injection kills ~50% of worms)
(-): more expensive, more cage rest required

prior to adulticide tx
• start Heartgard as microfilaricide on day of dx
• doxycycline PO BID x 2 weeks prior to adulticide tx
o killing Wolbachia prior to adulticide may ↓ post adulticide inflammation & improve efficacy of worm kill
• CAGE REST: very important before & after tx
o exercise worsens lesions
o 1 month of rest recommended for each injection: 3 injection protocol requires 3 mo. of rest
- prednisone can be given if pulmonary parenchymal complications occur (ex. lung inflammation --> coughing)
- if dog is in CHF, tx w/ diuretics & ACE inhibitors prior to adulticide tx

Front 66

What are some adverse effects of melarsomine used to tx canine HW dz?

Back 66

• pain & swelling at injection site: 30-40%
o give NSAIDs unless using prednisone, then give an opiate (ex. butorphanol, tramadol)
• neurologic signs, fever, cough, anorexia, pulmonary thromboembolism 1-2 weeks post injection

Front 67

feline HW dz

a. clinical signs
b. dx
c. tx

Back 67

a. cough, dyspnea, vomiting, neuro signs, syncope, sudden death; RHF uncommon
b.
definitive: positive Ag test or echo
if suspicious clinical signs: chest rads showing enlarged caudal pulmonary aa., positive Ag test
c.
o NO chemical adulticide
o prophylaxis
o prednisone: used to control signs until worm death in 2-3 yrs
o worm extraction if no improvement w/ medical tx

Front 68

What signalment is commonly assoc. w/ feline HCM?

Back 68

o suspected genetic etiology in some families of cats (Maine Coons, Persians, Mixed, British Shorthairs, etc.)
o point mutation of myosin binding protein C identified in Main Coons & Ragdolls: genetic testing available at Washington St. CVM
o M > F (2:1)
o mean age: 5-7 yrs

Front 69

What are the common clinical signs & PE findings asoc. w/ HCM?

Back 69

clinical signs: 3 main presentations: asymptomatic murmur or arrhythmia OR CHF signs OR thromboembolism

PE findings
o systolic murmur (intensity does NOT correlate w/ severity of dz), gallop sound, +/- arrhythmias
o sometimes no murmur or gallop
o dyspnea: cats often present w/ biventricular failure (pleural effusion more common than ascites)
- muffled heart & lung sounds: pleural effusion
- ↑ breath sounds, crackles: pulmonary edema
o weak or absent femoral pulses
o if saddle thrombus: cold, painful, weak rear legs w/ cyanotic pads & nail beds

Front 70

What thoracic rad patterns are assoc. w/ HCM?

Back 70

best test to help understand cause of dyspnea
DV is best view in dyspneic cat: DO NOT STRESS
may be normal
abnormalities: pulmonary edema, pleural effusion, classic valentine shaped heart
beware of fat cat: tend to lay fat around heart

Front 71

What is the tx & px for asymptomatic HCM?

Back 71

tx optional: no evidence to show delay of progression of dz
• case by case basis: B-blocker (atenolol) or enalapril, aspirin (or other antithrombotic) if moderate to severe LA enlargement
maintain normal diet: avoid salty snacks
- preferably keep cat indoors

px: good, avg. survival of 4-7 yrs
• progression of dz is VARIABLE

Front 72

What is the tx & px for HCM if patient is in CHF?

Back 72

furosemide, enalapril
O2 supplementation
+/- atenolol or dilitiazem if tachycardic
aspirin (or other antithrombotic)
ideally, low salt diet, but if anorexic let cat eat anything

px: 6 mo. to 2 yr
• some cats will live > 2 yrs, esp. if “pushed into” HF by stress, steroids

Front 73

What is an alternative tx for canine HW dz when melarsimone is not used?

Back 73

Heartgard Plus given for 16 mo. caused a significant (50%) reduction in adult worms & a 100% worm kill in 30 mos.

Front 74

What is the tx & px for HCM cats that present w/ saddle thrombus?

Back 74

px: 60-70% die or are euthanized during 1st episode
• partial or forelimb thrombus assoc. w/ better survival
• avg. long term survival: months to 1 yr (CHF, re-embolization)
• 2/3 of cats will be in CHF: worse px if concurrent HF

buprenorphine: analagesia
anticoagulant therapy
• acute: UF heparin IV bolus, then CRI or SQ TID
• chronic: Clodipogrel (Plavix) or low molecular wt. heparin
o clodipogrel: inhibits ADP-induced platelet aggregation

Front 75

furosemide

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 75

a. potent loop diuretic
-inhibits electrolyte reabsorption
if given IV: vasodilation --> inc. renal blood flow, dec. preload
monotherapy: activates RAAS
b. "outpatient" (chronic) HF: low dose, severe decompensated acute HF,
c. hypovolemia, hypokalemia, hyponatremia

Front 76

enalapril

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 76

a. ACE inhibitor
prevents release of angiotensin II --> dec. symp. tone, dec. aldosterone, ADH release (--> diuresis)
inhibits degradation of bradykinin (vasodilator)
balanced vasodilator --> dec. preload & afterload
b. "outpatient" (chronic) HF: max dose, severe decompensated acute HF, asymptomatic mitral valve dz w/ cardiomegaly, +/- asymptomatic HCM
c. hypotension, acute renal ischemic injury, electrolyte disturbances

Front 77

digoxin

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 77

a. Na/K ATPase inhibitor --> positive inotrope (inc. contractility)
increased PS (vagal)tone --> dec. HR, dec. conduction thru AV node
incr. baroreceptor reflex sensitivity

b. -CHF in DCM (together w/ pimobendan): might add on 1st recheck for example
- supraventricular arrhythmia (A fib, SVT) in dogs w/ HF & MR or DCM
-refractory CHF & sinus tachycardia in MR
c. narrow therapeutic window
clearance highly dependent on renal function
don't use in patients w/ sinus node dysfunction, advanced AV node dz, moderate to severe bradycardia --> heart block, arrhythmias

Front 78

dilitiazem

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 78

a. Ca channel blocker --> neg. chronotropic & inotropic effects --> dec. HR, dec. AV conduction, vasodilation
b. HCM patients in CHF if tachycardic, SV arrhythmias
c. hypotension, bradycardia, AV block, dec. contractility

Front 79

atenolol

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 79

a. beta blocker (selective for B-1) --> dec. HR, dec. AV conduction, depresses SA node
b.
• prior to onset of symptomatic HF in animals w/ evidence of remodeling in both MR & DCM
• after stabilization of HF of both MR & DCM, esp. if SV or V arrhythmias: β-blockers slow HR & AV nodal conduction
c. dec. cardiac contractility, excessive bradycardia, weakness/fatigue

Front 80

carvedilol

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 80

a. non-selective β blockade, α-1 blockade, anti-oxidant
b. prior to onset of symptomatic HF in animals w/ evidence of remodeling in both MR & DCM
• after stabilization of HF of both MR & DCM, esp. if SV or V arrhythmias: β-blockers slow HR & AV nodal conduction
c. worsening of CHF (edema), bradycardia, hypotension

expensive, variable bioavailability in dog

Front 81

lidocaine

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 81

a. Na channel blocker: shortens AP & duration of refractory period
b. rapid sustained V tach
c. vomiting, seizures, mental dullness

Front 82

spironolactone

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 82

a. K sparing diuretic: antagonizes aldosterone in distal tubule --> weak diuretic, K sparing effect
synergistic w/ furosemide
b. chronic HF management: slow onset of action
c. hyperkalemia, azotemia

Front 83

pimobendan

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 83

a. "inodilator": inhibits PDE III --> vasodilation, inc. Ca sensitivity --> inc. contractility
b. ALL 1st time HF patients 2° to DCM
refractory or recurrent HF 2° to MVD or end-stage HCM
c. tachyarrhythmias, potential for sudden death: humans, not proven in dogs
although improves survival, does not appear to blunt RAAS activation

Front 84

amlodipine

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 84

a. Ca channel blocker --> vasodilation (dec. preload & afterload)
b. use as 2nd vasodilator in hypertensive patients in HF w/ MR, tx of primary hypertension in cats & dogs

Front 85

sotolol

a. mechanism of action/effects
b. indications for use
c. adverse effects

Back 85

a. K channel blocker & beta blocker: less neg. inotropic effect than other beta blockers
b. ventricular arrhythmias in dogs
c. bradycardia, pro-arrhythmic (rare)

Front 86

What conditions can cause inc. preload?

Back 86

pericardial effusion, diastolic dysfunction, HCM

Front 87

What conditions can cause inc. afterload?

Back 87

↑ PVR, aortic or pulmonic stenosis

Front 88

What conditions can alter contractility?

Back 88

DCM, valvular insufficiency

Front 89

What conditions can alter heart rate/rhythm?

Back 89

VT, SVT/AF, sick sinus syndrome, 3rd degree AV block

Front 90

What drugs can be used to dec. preload?

Back 90

diuretics, venodilators (nitroglycerin), mixed vasodilators (enalapril, amlodipine), NaCl restriciton

Front 91

What drugs can be used to dec. afterload?

Back 91

arterial vasodilators, mixed vasodilators (enalapril, amlodipine)

Front 92

What drugs can be used to inc. cardiac contractility?

Back 92

digoxin, catecholamines (epi, dobutamine, dopamine), pimobendan, (beta blockers)

Front 93

What drugs can be used to dec. HR?

Back 93

digoxin, beta blockers, Ca channel blockers (dilitiazem)

Front 94

atrial fibrillation

a. ECG
b. tx

Back 94

a. loss of P waves, chaotic rhythm, fast rate, normal QRS
b. dilitiazem

Front 95

supraventricular premature complexes: ECG

Back 95

normal QRS, w/ or w/o abnormal P wave, that interrupts normal P-p & R-R intervals, usually pause follows SVPC

Front 96

supraventricular tachycardia: ECG

Back 96

rapid regular rhythm w/ normal QRS, P wave configuration somewhat different than sinus P waves

Front 97

ventricular premature complexes: ECG

Back 97

wide bizarre QRS w/ T in opp. direction that interrupts underlying rhythm, usually followed by a pause, P waves dissociated from QRS

Front 98

ventricular tachycardia

a. ECG
b. tx

Back 98

a. HR > 150, wide bizarre QRS, no relationship b'twn P wave & QRS ( 3 or more consecutive VPCs)
b. lidocaine IV or CRI, sotolol PO

Front 99

ventricular fibrillation: ECG

Back 99

no P waves or QRS (rapidly undulating baseline w/ no organized electrical activity)

Front 100

AV block: ECG

a. 1st deg.
b. 2nd deg.
c. 3rd deg.

Back 100

a. inc. PR interval (all else normal)
b. 1 or more P waves not followed by QRS, ventricular escape complexes may occur afterward
c. no relationship b'twn P wave & QRS, ventricular escape rhythm is slow (< 40 bpm)

Front 101

bradyarrhythmias: complete AV block, sick sinus syndrome: tx

Back 101

need pacemaker: medical tx usually doesn't work well
vagolytics: atropine, probantheline
bronchodilators: terbutaline, theophylline (also inc. HR)