CS: Problem arrhythmia Flashcards Preview

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Flashcards in CS: Problem arrhythmia Deck (35)
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1
Q

Name 3 features of a physiological aortic flow murmu

A

heard during systole
noticed at rest on left heart base
quiet

2
Q

What is the top diagnostic test for arrhythmia investigation?

A

ECG

3
Q

What do you want to rule out with arrhythmias?

A

any underlying metabolic abnormalities (e.g. liver metabolism, low Ca, high K)

4
Q

Why perform blood work on a horse with an arrhythmia?

A

to determine any unlying metabolic issue s- electrolyte imbalances, hypoxia, other metabolic abnormalities

5
Q

What is the first sign of cardiac compensation?

A

tachycardia

6
Q

List ECG signs of AF

A

F waves
normal QRS
no P waves
RR variable

7
Q

What is the main treatment option for AF?

A

Quinidine sulphate

8
Q

Other than quinidine sulphate, name 2 tx options for AF.

A

ANTI-ARRHYTHMIC DRUGS (as for small animals but high dose needed and can cost a lot, rarely used)
BIPHASIC ELECTRICAL CARDIOVERSION - only 2 centres in Europe offer this treatment

9
Q

What dose of quinidine sulphate should be given?

A

10g/450kg of horse

10
Q

Side effects - quinidine sulphate

A

CARDIOVASCULAR - tachycardia (atrial tachycardia), QRS widening, hypotension
GIT - diarrhoea, colic

11
Q

Where does ventricular tachycardia (VT) originate?

A

this rhythm originates in the ventricles

12
Q

Long-term prognosis - AF treated with quinidine sulphate

A

Conversion to sinus rhythm, no other heart disease- GOOD
If CHF occurs - POOR
Diagnosis <3 months = do better than older cases of AF.

13
Q

When can full training be resumed in horses treated with quinidine sulphate for AF?

A

7-10 days after treatment

14
Q

How should you treat a horse with CHF AND AF?

A

NOT with quinidine sulphate. Treat for CHF with positive inotropic agents, diuretics and other medications needed for stabilisation.

15
Q

How does quindine sulphate work?

A

class 1 anti-arrhythmic - vagolytic action
increases the fibrillation threshold of atrial myocardium
ALPHA-ADRENERGIC ANTAGONIST - decreases vascular tone and MAP.
Negative inotrope
Positive chronotrope (can lead to supraventricular tachycardia).

16
Q

Why does quinidine sulphate have to be given via a nasogastric tube?

A

cases significant oral ulceration. (IV forms also availabe)

17
Q

How does Digoxin work?

A

Negative chronotrope
Positive inotrope
Decreases AVN conduction and ventricular response rate.
Increased vagal tone

18
Q

What happens to plasma levels of digoxin when concurrently administered with quinidine sulphate?

A

Plasma levels increase because of competitive protein binding between the 2 drugs.

19
Q

What should you do before initiating quinidine sulphate treatment?

A

place an IV catheter in case rapid venous access is required for treatiing severe arrhythmia or hypotension.

20
Q

What do crackles in the CdV lung fields suggest?

A

pulmonary oedema - suggestive of left sided HF.

21
Q

What is the top differential for a large dog with biventricular compensated HF?

A

Cardiomyopathy due to DCM

22
Q

What can you measure using echocardiography? 4

A
  • contractility
  • FS%
  • diameter of chambers
  • wall thickness (free and septal walls)
23
Q

What do increased left atrial to aortic ration, enlarged LV diameter and reduced FS% suggest?

A

global mycoardial dysfunction

24
Q

Outline evidence-based treatment for HF - 4

A
  • Furosemide (diuretic to reduce circulating load)
  • Pimobendan (calcium sensitiser increases cardiac contractility)
  • ACEI (Benazepril) - blocks Ang2 to relieve hypertension
  • Digoxin (anti-arrhythmic and positve inotrope)
25
Q

What should you treat AF with if there is presence of underlying heart failure ?

A

Digoxin first

26
Q

What should you treat AF with if there is NOT presence of underlying heart failure ?

A

beta-blocker first (this area is less well researched)

27
Q

What is Holter monitoring?

A

allows continuous ECG for 24-48 hours. 2 electrodes are contained in a vest worn by the dog on either side of the thorax.

28
Q

Prognosis - DCM with acute onset CHF

A

very guarded

29
Q

What are dobermans prone to?

A

sudden death due to arrhythmias

30
Q

Are CHF maladapted hearts predisposed to AF?

A

Yes - therefore if it is converted to normal sinus rhythm, it is likely to revert.

31
Q

Will NTproBNP levels be altered in AF?

A

No but they will be altered in DCM and MVD.

32
Q

Name drugs that can be used for pharmacological conversion of AF to normal sinus rhythm

A

Amiodarone

Sotalol

33
Q

If a dog has no signs of cardiac disease is electrical or pharmacological cardioversion preferred?

A

Electrical conversion is preferrable.

34
Q

What is atenolol?

A

Beta-blocker to lower HR

35
Q

What type of dogs is relapse to AF most common?

A

giant breed dogs.