CWEI dysrhythmias

Question 1

list 7 primary causes of dysrhythmias

Answer 1

structural heart disease
metabolic disease
electrolyte disorder
trauma
drugs/ toxins
sepsis
neoplasia

Question 2

define dysrhythmia

Answer 2

an abnormal heart rhythm caused by a disturbance in the hearts electrical conduction system

Question 3

why do we need to be careful with antidysrhythmic medication

Answer 3

it can be proarrhythmic and cause worsening of the problems

Question 4

List 4 treatment options for dysrhythmias - which are most common

Answer 4

Most common:
Anti-dysrhythmic drugs
Pacemaker

ablation with catheters
implantable cardiovertors

Question 5

when should we consider treating dysrhythmias with antidysrhythmia medication

Answer 5

if the heart rate or frequency are high enough to cause a drop in CO or if there are life threatening rhythms

Question 6

Describe how to interpret the ECG

Answer 6

what is the heart rate
is the rhythm regular or irregular
do the ECG waves appear normal
Is each P wave followed by a QRS?
Is there a P wave before each QRS?
ECG measurements

Question 7

why are supraventricular rhythms often seen in structural heart disease

Answer 7

the atria stretches and causes the cardiomyocytes to become unstable

Question 8

why are ventricular rhythms often seen in systemically sick patients

Answer 8

cytokines damage cardiomyocytes and generate rhythm abnormalities

Question 9

List the different types of dysrhythmias

Answer 9

Bradyarrhythmia
Tachyarrhythmia- supraventricular and ventricular

Question 10

define bradydysrhythmias

Answer 10

abnormally slow rhythms

Question 11

What is Supraventricular tachycardia

Answer 11

high rate arising in or above the AVN - narrow and upright complexes

Question 12

what is ventricular tachycardia

Answer 12

high rate arising from the ventricles - usually wide and bizarre complexes

Question 13

what happens in sinus arrest

Answer 13

is a bradyarrhythmia
SAN stops firing
pause noted on ECG with no P-QRS-T complex

Question 14

define sick sinus syndrome

Answer 14

arrhythmia in which bradycardia alternates with tachycardia

Question 15

what is atrial standstill

Answer 15

Atrial depolarization does not occur when SA node discharges
complete absence of p-waves

Question 16

list the clinical signs of bradydysrhythmias

Answer 16

weakness
lethargy
syncope
sudden death

Question 17

describe atrioventricular block type 2

Answer 17

occasional block; p-wave not conducted- can happen in high vagal tone, is common under GA - rarely causes clinical issue

Question 18

how can we test if a bradycardia is vagally mediated

Answer 18

run them around and see if the heart rate increases or give them atropine and monitor - both should get rid of the bradycardia if it is vagally mediated

Question 19

Describe sinus arrythmia

Answer 19

is a normal sign in a dog
when heart rate speeds up on inspiration and slows down on expiration
occurs when parasympathetic is in control

Question 20

describe how we can treat bradydysrhythmias

Answer 20

treat the primary cause
pacemaker implantation
parasympathetic drugs

Question 21

List the 2 main types of tachyarrythmias

Answer 21

Supraventricular Tachycardia (SVT)
Ventricular Tachycardia (VT)

Question 22

describe Supraventricular Tachycardia (SVT)

Answer 22

ventricular impulse conduction normal and QRS normal in appearance – tall and narrow
Problem with atria AV node

Question 23

describe Ventricular Tachycardia

Answer 23

All rhythm disturbances originating from within the ventricles
Ventricular conduction abnormal leading to wide and bizarre QRS complexes

Question 24

when do we treat supraventrciular tachycardias

Answer 24

if the output is poor and clinical signs are seen

Question 25

describe premature beats

Answer 25

any beat that occurs before it is expected- can be supraventricular or ventricular

Question 26

what drug do we give if ventricular dysrhythmia is critical

Answer 26

IV lidocaine

Question 27

what drug do we give if the ventricular dysrhythmia has stable/ episodic sign

Answer 27

solatol

Question 28

describe what you see second degree AV block on ECG

Answer 28

P wave occasionally not conducted throguh the AV node

Question 29

describe what you see with third degree AV block on ECG

Answer 29

persistent failure of conduction through the AV node

Question 30

what is atrial fibrilation

Answer 30

rapid random ineffective contractions of the atrium type of supraventricular tachycardia

Question 31

desribe how you treat atrial fibrilation

Answer 31

Diltiazem and digoxin often effective

Question 32

describe ventricular tachycardia

Answer 32

sequence of or >4 ventricular beats with a rate > 160bpm – often a fast and unstable rhythm

Question 33

describe ventricular flutter

Answer 33

a very rapid VTAC in which T waves and QRS are no longer distinguishable; DANGER – often precedes death- can see under GA, animal about to crash

Question 34

which Antiarrhythmic drugs act by altering ion flow

Answer 34

class 1, 3 and 4

Question 35

which Antiarrhythmic drugs act by impavting the sympathetic innervation to the SA and AV nodes

Answer 35

class 2 drugs + sotalol slows the heart rate