dog with respiratory distress case

Question 1

Left apical systolic murmurs are nearly always secondary to

Answer 1

mitral regurgitation (MR)

Question 2

You note a left apical systolic murmur. What might cause mitral regurgitation **

Answer 2

VALVE PROBLEMS
1) Myxomatous (degenerative) mitral valve disease - acquired, very common
2) Infective endocarditis of MV (acquired, rare)
3) Mitral valve dysplasia/malformation (congenital; rare)

CHAMBER REMODELING (FUNCTIONAL MR)
1) Dilated cardiomyopathy (acquired, common)
2) Other causes of LV dilation

Question 3

Left apical systolic murmurs secondary to DCM tend to be

Answer 3

quieter, usually grade 1 or 2
occasionally 3, rarely 4
never 5 or 6

Question 4

T/F: dogs tend to get high grade murmurs with DCM

Answer 4

False

Question 5

You have a 7yo dog with dyspnea, tachypnea, coughing/retching, increased lung sounds, reduced energy, hyporexia, tachycardia, irregular/chaotic cardiac rhythm, variable femoral pulses and a Grade II/VI left apical systolic murmur
What do you do first

Answer 5

ORDER
1) Flow by oxygen and sedation
2) Electrocardiogram (ECG)
3) Place IV (while setting up ECG) - POC blood work
4) Airway exam, thoracic imaging (POCUS)
5) Blood pressure ideal (QAR, hypotensive?)

Question 6

What are the ECG hallmarks of atrial fibrillation

Answer 6

1) No discernable p waves
2) Chaotic (irregularly irregular) rhythm (R to R intervals differ)
3) Narrow complex/ supraventricular tachycardia

Question 7

How do you differentiate atrial fibrillation from Ventricular tachycardia

Answer 7

ventricular tachycardia is usually a regular rhythm with a wide complex QRS
both sound similar on ausciltation

Question 8

Is urgent therapy required for atrial fibrillation or ventricular tachycardia

Answer 8

Ventricular tachycardia - IV lidocaine

Question 9

T/F: urgent therapy is required for atrial fibrillation

Answer 9

False- it is not urgent but you need to figure out the cause of Afib
Goal is to slow/delay AV node conduction

Question 10

What two arrhythmias are usually associated with severe cardiac disease when together

Answer 10

Atrial fibrillation + tachycardia
1) Severe atrial enlargement
2) Heart failure in dogs and cats

Question 11

What is the treatment goal of atrial fibrillation

Answer 11

slow / delay AV node conduction

Question 12

You notice a grade II/VI left apical systolic murmur. What should you do for diagnostics

Answer 12

-Brief echo/cardiac POCUS
-Thoracic radiogrpahs
-NT-proBNP

Question 13

What are the echo hallmarks of DCM

Answer 13

LV and LA chamber dilation secondary to overt systolic dysfunction

Question 14

What will you see on thoracic radiographs that tells you DCM

Answer 14

1) LA enlargement (backpack on lateral, VD- bowlegged cowboy)
2) Left auricular buldge (2-3oclock on VD)
3) Tall heart
+/- pulmonary venous distension
+/- pulmonary edema -> perihilar and caudodorsal interstitial (+/- alveolar) pattern; diffuse distribution

Question 15

Left sided CHF, edema typically occurs where on radiographs

Answer 15

Perihilar and caudodorsal interstitial +/- alveolar pattern
diffuse distribution when severe

Question 16

How do you treat acute (in-hospital) congestive heart failure

Answer 16

Goal: alleviate suffering and decrease preload and increase O2 delivery -SPOF
1) Sedation (butorphanol)
2) Pimobendan (increase contractility and vasodilator)
3) Oxygen
4) Furosemide (diuretic to decrease preload / venous pressure)

Question 17

What two ways does Pimobendan help in CHF tx

Answer 17

1) Increases contractility
2) Vasodilator

Question 18

What is the purpose of giving furosemide in CHF tx

Answer 18

(diuretic to decrease preload / venous pressure)

Question 19

Once a patient is stabilized, you begin to treat Atrial fibrillation. How do you treat

Answer 19

You need to slow AV node conduction
Diltiazem +/- digoxin

Question 20

How does Diltiazem slow AV node conduction in case of atrial fib

Answer 20

Ca2+ channel blocker
AV node is reliable on calcium

Question 21

How does Digoxin slow AV node conduction in cases of atrial fib

Answer 21

It does increase contractility but it mainly increases parasympathetic toe, which slows the AV node conduction

Question 22

When should you transition from acute CHF tx to chronic CHF tx

Answer 22

once no longer oxygen dependent

Question 23

primary myocardial disease is characterized by

Answer 23

Functional impairment and/or electrical abnormalities (tachyarrhthmias) in the absence of any other cardiovascular disease to cause the myocardial abnormality

ex: primary DCM- the pump doesnt work

Question 24

At what time does DCM usually present

Answer 24

adult onset

Question 25

How can you clinically recognize DCM in dogs

Answer 25

1) Cardiac auscultation -> usually low grade/soft, gallop sounds, arrhythmia 2) Clinical signs: exercise intolerance, syncope, breathing difficulty, abdominal distension 3) Breed screenings with echo

Question 26

What are the clinical signs of DCM

Answer 26

Exercise intolerance Syncope Breathing difficulty abdominal distension

Question 27

Causes of Secondary DCM (DCM phenotype) *

Answer 27

1) Nutritionally mediated (low taurine or L-carnitine) 2) Tachycardia-induced CM (TICM) 3) Myocarditis (infectious, inflammatory, immune-mediated, idiopathic) 4) Cardiotoxicities (Doxorubicin) 5) Ischemic cardiomyopathy (humans) 6) Endocrinopathies (HypoT4 or Addisons) - very unlikely

Question 28

How can you diagnose primary DCM

Answer 28

1) DCM phenotype 2) Diagnosis of exclusion -ECG and Holter (TICM) -CBC, CHEM, troponin, infectious disease testing -Drug hx -Diet history (boutique, exotic, grain-free, pulses - lentils, peas, beans) as the main ingredient 3) ECHO ** 4) 24h holter monitor

Question 29

How should you manage preclinical DCM *

Answer 29

Pimobendan * +/- ACEi, spironolactone, betablockers? Antiarrhthmics as needed (lidocaine, sotalol) treat underlying cause, if possible change the diet if high pulse / nontraditional and supplement taurine if low

Question 30

What is the long-term prognosis of primary/idiopathic DCM

Answer 30

6-12 months, worse if atrial fib

Question 31

How do you treat atrial fibrillation

Answer 31

Slow AV node conduction (decrease ventricular rate) -Diltiazem -+/- digoxin or beta blocker

Question 32

How do you treat ventricular tachycardia

Answer 32

Acute: lidocaine IV bolus or CRI Chronic (oral): sotalol or atenolol

Question 33

How do you treat atrial standstill

Answer 33

temporary: NaHCO3, Ca2++ permanent: pacemaker

Question 34

What is the number one cause of mitral regurgitation in old small dogs

Answer 34

Myxomatous (degenerative) mitral valve disease

Question 35

Loud left apical systolic murmur (grade 5 or 6) in old small dogs often correlate with

Answer 35

clinically significant MMVD

Question 36

What is your top priority of ruling out when you have a loud left apical systolic murmur in old small dogs with breathing difficulty

Answer 36

Cardiogenic pulmonary edema Sets: 1) Flow by oxygen +sedation 2) Consider empircial furosemide 3) Place IVC (point of care bloodwork) 4) Airway exam, thoracic imaing (POCUS) 5) Brief echo if possible 6) Thoracic radiographs ** 7) Blood pressure ideal but not urgent

Question 37

What is a normal vertebral heart score in a dog

Answer 37

<10.7

Question 38

What is a normal vertebral left atrial (VLAS) size in dog

Answer 38

<2.3

Question 39

Why is getting a systolic arterial pressure important to get in cases of mitral regurgitation

Answer 39

if there is systemic hypertension then it will increase the backflow into the left atrium

Question 40

Radiographic signs of CHF should be paired with ________ to make a clinical diagnosis of CHF

Answer 40

clincal signs

Question 41

Dogs with suspected CHF should have moderate to severe radiographic signs of cardiomegaly. How can you make this less subjective

Answer 41

VHS and/or VLAS

Question 42

T/F: cough is a reliable clinical sign of CHF

Answer 42

false tachypnea /dyspnea is

Question 43

What is the most important thing in the treatment plan of dogs with chronic CHF

Answer 43

Furosemide *most important Pimobendan

Question 44

Once the patient with CHF is no longer O2 dependent you can discharge and transition to chronic CHF meds. What do you prescribe

Answer 44

DOGS ARE FOR SPECIAL PEOPLE 1) Diet: Low in sodium 2) Angiotensin converting enzyme (ACE) inhibitor 3) Furosemide * 4) Spironolactone 5) Pimobendan *

Question 45

T/F: spironolactone has a weak diuretic effect

Answer 45

T- it is mainly important for treating chronic CHF because it blocks Aldosterone and RAS

Question 46

Why is an ACE inhibitor paired with spironolactone when treating chronic CHF

Answer 46

need to block ACE and Aldosterone RAS= sodium retention, vasoconstriction, and increasing blood volume also blocks growth factors that promote adverse remodeling (such as scar tissue which can further cause arrhythmias)

Question 47

______ % of small breed dogs have MMVD by 13 years of age

Answer 47

85% slowly progressive in asymptomatic small breed dogs

Question 48

T/F: most dogs with MMVD dont require therapy

Answer 48

True

Question 49

T/F: large breed dogs also get MMVD

Answer 49

True- has a faster progression, overt myocardial dysfunction, Afib

Question 50

T/F: tricuspid valve is commonly affected by degernation but it is unimportant

Answer 50

True

Question 51

How do you predict clinically significant MMVD

Answer 51

Heart size (and rate of change of heart size) = tried and true progression of the progression 1) LA and LV size 2) Echocardiography vs radiography

Question 52

subclinical MMVD where there is MMVD without cardiac remodeling needs no treatment, just watchful waiting

Answer 52

Stage B1

Question 53

sublinical MMVD where there is at risk breed with no current disease -no treatment, just breed screening

Answer 53

Stage A

Question 54

clinical MMVD where there is heart failure -requires treatment for CHF (dogs are for special people) -up titrate drugs (furosemide) as needed

Answer 54

Stage C

Question 55

clinical MMVD where there is heart failure and end stage/ refractory to treatment -requires treatment for CHF (dogs are for special people) -up titrate drugs (furosemide) as needed

Answer 55

Stage D

Question 56

subclinical MMVD where there is MMVD with significant cardiac remodeling (specific crtieria defined) without CHF -Start Pimobendan 0.3mg/kg PO q12h to delay onset of CHF and prolong the survival

Answer 56

Stage B2

Question 57

approved ace inhibitors for CHF

Answer 57

Benazepril, enalapril, imidapril and ramipril