Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

8- EQ- Cardiorespiratory Disease > Equine dysrhythmias > Flashcards

Equine dysrhythmias Flashcards

(53 cards)

Start Studying
1
Q

Myocardial disease in horses causes

A

Dysrhythmias due to disruption of action potential propagation and abnormalities in contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Endocardial disease in horses causes

A

Murmurs, due to valvular regurgitation and jet lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List 4 ways that myocardial disease manifest

A

No clinical signs

poor performance- atrial fibrilation and ventricular premature depolarisation

Collapse- multiple ventricular premature depolarisations and Ventricular tachycardia

Death - Ventricular tachycardia progressing to Ventricular fibrillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe how to diagnose cardiac dysrhythmias

A

ECG
evaluation of underlying cause using echocardiogram, blood tests ect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

List the 4 conditions that may lead to myocardial dysfunction

A

Electrolyte abnormalities
Increased myocardial muscle mass
Increased chamber size
Myocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the Use of clinical pathology to evaluate the large animal myocardium

A

Sensitivity and specificity of these tests is questionable
-Proteins
- Enzymes
- Creatine kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List the bacteria that can cause myocarditis

A

Staph aureus
Strep equi
Clostridium chauvoei
Myocobacterium spp.
Secondary to sepsis, pericarditis, endocardititis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the viral causes of mocarditis

A

FMD, EIA, EVA, EIV, AHS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Other than bacterial and viral what else can cause myocarditis in horses

A

Borrelia burgdorferi (Lyme disease)
Parasites- large strongyles, Toxoplasma, Sarcocystis
Thromboembolic disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List the cardiomyopathies of large animals

A

Only DCM reported to be important (subacute to chronic, see a dilated ventricle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe how we evaluate the myocardium using echocardiography

A
  • Assessment of myocardial appearance (long/short axis views),
  • Fractional shortening (at rest and following exercise to evaluate contractility),
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe dobutamine atropine stress echocardiography

A

Causes a progressive increase in HR,
Allows function to be assessed as HR increases and how function is maintained,
Simulates exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe how myocardial biopsies can be performed

A

Can be done standing,
Ultrasound guided,
Biopsy instrument into heart via jugular vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe a Standard equine ECG at rest

A

Complexes uniform, identical and at regular intervals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe how to assess an exercising equine ECG

A

Harder to assess, P and T waves are hard to see,
Assess the regularity of the R waves (downward projections)
Check intervals are regular and they look similar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the most common physiological dysrhythmia in horses

A

2nd degree AV block
considered normal in horses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what causes 2nd degree AV block

A

due to high vagal tone in autonomic control of the equine heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe what a 2nd degree AV block looks like on ECG

A

P wave not followed by a QRS complex (blocked by the AV node),

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Are 2nd degree AV blocks of clinical concern

A

NO
will disappear when horse is stimulate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the most important cardiac dysrhythmia in the horse

A

Atrial fibrillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why does Atrial fibrillation occur

A
  • Lack of coordinated atrial electrical activity
  • Can be triggered by electrolyte/acid-based imbalances, anaesthetic and drug administration (that causes bradycardia, exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

List some horses which are more susceptible to atrial fibrilation

Study These Flashcards
A

TBs, SBs, Draught horses- large horses
due to large atrial mass

23
Q

List the clinical signs of atrial fibrillation

Study These Flashcards
A

None- most
Exercise intolerance/poor performance
Epistaxis

RARE presentations:
Weakness/syncope
Myopathy
Colic
CHF

24
Q

What are the 2 forms of atrial fibrillation

Study These Flashcards
A

Paroxysmal
Sustained

25
What is the difference between paroxysmal and sustained atrial fibrillation
Paroxysmal - Lasts less than 24-48hrs and spontaneously converts back to sinus rhythm, Sustained (lasts longer than 24-48hrs)
26
What can Paroxysmal atrial fibrillation be associated with
Potassium depletion (furosemide) and administration of bicarbonate
27
List the things seen on clincal exam in horses with atrial fibrillation
Irregularly irregular rhythm (less irregular with chronicity), HR and pulse quality varies on intensity (booming S1 and no S4), Usually a normal or decreased HR, occasionally increased if associated with heart failure, Abnormally high heart rates at exercise (can be associated with VPDs, should perform an exercising ECG)
28
Describe how to diagnose atrial fibrillation
ausculatation and physical exam resting ECG - confirms diagnosis Further diagnostics PRIOR to attempting treatment
29
what is seen on ECG with atrial fibrillation
No P wave normal QRS complexes F (fibrillation) waves
30
How does the cause of atrial fibrillation being chamber enlargement affect diagnosis
Worse prognosis for return to sinus rhythm
31
Describe the pharmacological treatment of atrial fibrillation
Quinidine sulphate Is a Negative inotrope
32
List the side effects of quinidine sulphate
Fatal dysrhythmias, Colitis (drug irritant to mucosa), Laminitis/nasal oedema/ataxia Because of this need to be cautious when using
33
Describe the Cautious use of quinidine sulphate
Need repeated physical exam Auscultation Continuous ECG at the time and 24hrs after Check acid base and electrolytes prior to treatment
34
Describe how to assess quinidine sulphate toxicity
by assessing prolongation of QRS complex (>25% of pretreatment value makes untoward effects more likely)
35
What is DC cardioversion
Wires into the heart of an anaesthetised horse, Positioned using ultrasound and radiography, Increase current to try and stop heart and convert to sinus rhythm
36
what does DC cardioversion treat
atrial fibrillation
37
Where are the two wires places in electrocardioversion
One wire in left pulmonary artery, Other wire in right atrium
38
What is the Prognosis of paroxysmal atrial fibrillation
Excellent to good unless keeps recurring
39
what is the Prognosis of sustained atrial fibrillation with no cardiac disease
<3 months - good either technique (quinidine or DC cardioversion) >3 months better with DC cardioversion, Risk of re-fibrillation
40
what is the Prognosis of sustained atrial fibrillation with underlying cardiac disease
Average with DC conversion More likely to re-fibrillate
41
what is the Prognosis of sustained atrial fibrillation with heart failure
Poor to grave, no treatment
42
What other dysrhythmias are seen in horses other than 2nd degree AV block and atrial fibrillation?
Atrial premature depolarisation Ventricular premature depolarisation Ventricular tachycardia Third degree AV block Asystole Ventricular fibrillation
43
List the Dysrhythmias which are not compatible with life
Asystole = lack of electrical activity, Ventricular fibrillation = unusual in horses, leads to sudden death
44
How can be treat ventricular dysrhythmias in horses
Lidocaine, Magnesium, Procainamide, Amiodarone
45
When is pharmacological management of acute tachyarrythmias in the horse warranted
Evidence of poor cardiac function (clinical signs) Poor perfusion/ evidence of this Malignant arrythmia = HR over 100bpm, multiform or polymorphic complexes, R-on-T
46
What is the first line treatment for ventricular tachycardia
Lidocaine
47
List the CNS adverse events associated with lidocaine to treat ventricular dysrhythmias
Nystagmus, muscle twitching, disorientation, excitement, convulsions
48
when is magnesium used to treat ventricular dysrhythmias
if lidocaine treatment has failed
49
When when can lidocaine treatment of ventricular dysrhythmias not be as effective
in hypokalaemia
50
Describe what is seen on ECG with Torsades de pointes
Undulating baseline with no beginning or end to the complexes basically looks wavy
51
what is the prognosis for a horse with Torsades de pointes on ECG
BAD this rhythm is not associated with life
52
List 4 causes of bradyarrhythmias in the horse
Drugs, Electrolyte derangements, Intestinal disease, Primary myocardial disease
53
Describe how we can manage bradyarrhythmia's in horses
Relevance of 2nd degree AV block is unknown, likely require further investigation if persistent at exercise, Anticholinergics = Glycopyrrolate, atropine, hyoscine (buscopan), Ventricular pacemaker

8- EQ- Cardiorespiratory Disease (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions