12. Peri-operative arrhythmias Flashcards Preview

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Flashcards in 12. Peri-operative arrhythmias Deck (28):
1

causes of sinus bradycardia

- vagal reflex (associated with hypotension) tx: atropine
- opioids/alpha 2s
- sudden onset hypertension
- Cushing's response (BP high, compensatory mechanism for brain PP) tx:mannitol

(hypoglycemia, hypoxemia
hypothyroidism
hyperkalemia)

2

causes of sinus tachycardia

- inc. adrenergic tone
- hypovolemia
- pheochromocytoma

3

sequela of sinus tach

hypertension, hypotension
myocardial ischemia triggered arrhythmias

4

sinus means?

one QRS for every P wave

5

sinus arrhythmia in cats usually means vs. dogs?

upper respiratory obstruction

more common in normal dogs

6

APCs common with?
hemodynamic consequences?

L atrial enlargement
- usually none, may have smaller pulse associate with the APC

7

irregularly irregular rate associated with what arrhythmia?
breeds?

atrial fibrillation (no P wave)
giant dog breeds, horses

8

causes of atrial fibrillation

increased parasympathetic tone - triggered by opioids, GI/resp/neuro disease

9

hemodynamic consequences of A fib

decreased CO

10

second degree AV block

- prolonged or normal PQ followed by non conducted p wave

11

all brady arrhythmias may be _______ response

Cushing

12

mobitz type I vs. II

Second Degree AV block:

I - prolonged interval before nonconducted P wave
II - PQ constant before nonconducted P
II Hight grade - 2 consecutive nonconducted p waves

13

treatment second degree av block

- anticholinergic may help
-pacemaker if chronic high grade
- dobutamine acts on beta adrenergic which increases HR

14

before giving anticholinergic need to check what?

- blood pressure
only treat if abnormal
- low dose ace, inc. inhalant to cause vasodilation if super low HR with normal BP

15

Third degree AV block

complete dissociation between atria and ventricles - two independent rates
- junctional escape (40-60 bpm)
- ventricular escape (20-40 bpm)

16

causes of third degree AV block?

very rarely vagally mediated
- idiopathic, neoplastic, hyperkalemia

17

treatment third degree AV block

pacemaker
may respond to anticholinergic (if not a myocardial issue)
fix hyperkalemia..
(isoproterenol)

18

sick sinus syndrome

why is it dangerous?
treatment?

idiopathic disease of sinus node
- WHWT, schnauzers, cockers
- periods of tachy, brady, long pauses in sinus (arrest) followed by escape rhythm
- may sound normal

**when anesthetized pauses may become severely prolonged
- pacemaker!!

19

Which drugs should you avoid in patients with life-threatening bradyarrhythmias?

opioids
alpha twos

20

bundle branch block

ECG?
L vs. R?

impulse takes longer to get to ventricles
- p wave always associated with qrs.
- L block:severe disease vs. R block: may be incidental
- R BBB: deep s wave
- L BBB: wide, regular s

21

treatment for VPCs

rarely necessary
lidocaine

if frequent, multifocal, frequent runs or impacts CO

22

causes of VPCs

primary cardiac disease
trauma, shock, hypoxemia
electrolyte/AB imbalance
GDV
hemangiosarcoma

23

ventricular escape rhythm

treatment?

ventricle beats because nothing else is, happens after a pause
- atropine not lidocaine!

24

Idioventricular rhythm

causes?
tx?

Accelerated IR if rate >100
- FB, sepsis, GDV, hemoabdomen
- treat underlying cause
NOT LIDOCAINE may cause asystole; atropine if necessary

25

VTach

two types?
treatment?

polymorphic - needs defibrillator, call for help
monomorphic - can not need

treatment - lidocaine in dogs

26

ventricular fibrillation or PVT

time phases?

shockable

- electrical phase <2 min: shock first
- circulatory (4-6 min): 2 min chest compressions then defibrillate
- metabolic (>6min): irreversible damage

27

treatment for asystole or PEA

low dose epi (.01 mg/kg) every other cycle (2 minute cycles, 120/min)
+/- atropine e/o cycle

28

Causes of all the different AV blocks?

type 1 - vagal
type 2I: vagal/ opioids, alpha 2/ Cushing
type 2II: pathologic (not vagal)
type 3: idiopathic/pathologic