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ECG Flashcards

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1
Q

describe the passage of blood through the heart

A

deoxygenated blood from the body arrives from cranial vena cava
right atrium
tricuspid valve
right ventricle
pulmonary valve
pulmonary artery to the lungs
pulmonary vein from the lungs
left atrium
mitral valve
left ventricle
aortic valve
aorta to systemic circulation

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2
Q

what is the purpose of the heart beating?

A

pump blood around the body and lungs

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3
Q

what is myocardium made up of?

A

cardiac muscle

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4
Q

is heart contraction governed by nerve impulse?

A

no - contracts automatically

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5
Q

what is the process of heart contraction controlled by?

A

electrical impulses

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6
Q

what relating to the heart is controlled by the autonomic nervous system?

A

heart rate

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7
Q

what part of the nervous system controlls heart rate?

A

autonomic

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8
Q

what are the 2 branches of the autonomic nervous system?

A

sympathetic
parasympathetic

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9
Q

what effect does the sympathetic nervous system have on heart rate?

A

increases HR

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10
Q

what effect does the parasympathetic nervous system have on heart rate?

A

slows

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11
Q

how does the parasympathetic nervous system slow heart rate?

A

release of acytylcholine

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12
Q

how does the sympathetic nervous system increase heart rate?

A

releases catecholamines to accelerate HR

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13
Q

what catecholamines increase HR?

A

adrenaline
noradrenaline

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14
Q

what are the 2 types of cardiac cells?

A

electrical cells
myocardial cells

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15
Q

what is the role of electrical cells within the heart?

A

conduction system of the heart
spontaneously generate and respond to electrical impulses
transmit electrical impulses

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16
Q

how are electrical cells distributed throughout the heart?

A

orderly fashion throughout the heart

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17
Q

where are myocardial cells found?

A

within the walls of the atrium and ventricles

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18
Q

what is the role of myocardial cells?

A

responsible for contraction and stretch of the heart

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19
Q

what is required for the heart to function properly?

A

coordinated contraction of both atria and ventricles

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20
Q

what is coordinated atrioventricular contraction?

A

coordinated contraction of both atria and ventricles to expel blood into aorta and pulmonary artery

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21
Q

what do cardiac muscle cells require to contract?

A

electrical stimulus

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22
Q

what state are cardiac cells in when relaxed?

A

polarised

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23
Q

what happens to cardiac cells when stimulated by an electrical impulse?

A

cells start to depolarise

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24
Q

what area of the heart must be depolarised first in order to allow the heart to function properly?

A

two atria

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25
Q

what part of the heart is depolarised after the atria?

A

ventricles

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26
Q

what must the heart do between beats?

A

repolarise (relax) and return to resting potential

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27
Q

why must the heart repolarise (relax) and return to resting potential between beats?

A

to allow appropriate filling during dyastole ready for the next contraction

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28
Q

what is the sinoatrial (SA) node?

A

small area of cardiac muscle cells that are specialised found in the wall of the right atrium

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29
Q

where is the SA node located?

A

wall of the right atrium

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30
Q

what is the role of the SA node?

A

initiation of heart beat

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31
Q

why is the SA node the initiator of the heart beat?

A

fastest area to generate electrical activity

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32
Q

what is the role of the SA node?

A

pacemaker of the heart
controls HR

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33
Q

what is the SA node influenced by?

A

autonomic tone

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34
Q

what effect will increased sympathetic tone have on the SA node?

A

increase HR

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35
Q

what effect will increased parasympathetic tone have on the SA node?

A

decrease HR

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36
Q

how does the SA node lead to atrial systole?

A

SA node fires electrical impulse which causes depolarisation to spread through atrial muscle cells
impulse spreads over atria causing both to contract

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37
Q

what is caused by creation of electrical impulse by SA node?

A

atrial systole

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38
Q

where is the atrioventricular (AV) node located?

A

top of the interventricular septum

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39
Q

what happens to the nerve impulse after it moves across the atria?

A

passes through AV node

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40
Q

how rapidly does the electrical impulse from the SA node spread through the AV node?

A

more slowly

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41
Q

what is the purpose of the slow conduction through the AV node?

A

slows electrical impulse before it reaches the ventricles to ensure that ventricular contraction is correctly coordinated following atrial contraction
atria can fully contract before ventricles

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42
Q

is the myocardium of atrial walls in continuity with myocardium of ventricular walls?

A

no

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43
Q

how does electrical impulse pass from atria to ventricles?

A

through AV ring to bundle of His

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44
Q

what is the bundle of His?

A

specialised nerve tissue fibres

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45
Q

where is the bundle of His located?

A

interventricular septum

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46
Q

what does the bundle of His divide into?

A

right and left bundle branches

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47
Q

where are bundle branches found?

A

right and left ventricles

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48
Q

what does the left bundle branch divide into?

A

anterior and posterior fascicles

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49
Q

what does the bundle of His connect to?

A

Purkinje fibres

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50
Q

what are Purkinje fibres?

A

network of specialised neurons organised into fine branches

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51
Q

where are Purkinje fibres found?

A

spread out through the myocardium of the ventricles

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52
Q

where does the wave of depolarisation begin in the ventricles?

A

apex of the heart (the bottom)

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53
Q

where does the contraction of the ventricles move once initiated at the apex of the heart?

A

upwards through muscle of the ventricles

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54
Q

what is contraction of the ventricles known as?

A

ventricular systole

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55
Q

what happens once the heart cells repolarise?

A

SA node fires another impulse and the cycle begins again

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56
Q

what is measured by an ECG?

A

changing electrical activity of the heart

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57
Q

what is used to measure electrical activity of the heart?

A

ECG using positive and negative electrodes

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58
Q

what is electrocardiography?

A

process of recording changing potential differences within the heart

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59
Q

what is the most common method of electrocardiography?

A

leads placed on limbs or chest

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60
Q

what is ECG essential for the diagnosis of?

A

cardiac rhythm disturbance

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61
Q

what is detected by an ECG machine?

A

depolarisation wave travelling across the heart from the SA node across the atria in the direction of the ventricles

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62
Q

what charge of electrodes does the electrical impulse of the heart travel between?

A

negative to positive

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63
Q

what does the ECG machine record the electrical wave as?

A

deflections

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64
Q

what are negative ECG deflections displayed as on an ECG machine?

A

downward strokes

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65
Q

what are positive ECG deflections displayed as on an ECG machine?

A

upward strokes

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66
Q

what is created when parts of the atria nearest the SA node are depolarised?

A

electrical potential difference

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67
Q

what is the electrical potential difference detected by ECG between?

A

depolarised atria and parts still in a resting state

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68
Q

when are ECGs used?

A

diagnosis of arrhythmia
triage
anaesthesia
patient monitoring
pulse deficits
CPR
metabolic or electrolyte abnormalities
pericardiocentesis / central line placement to detect and arrhythmias caused
hands off monitoring during blood transfusion

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69
Q

where are ECG leads placed?

A

red - right fore
yellow - left fore
green - left hind
(black - right hind, if used)

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70
Q

what are the 2 common types of ECG electrode?

A

crocodile clips
ECG pads

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71
Q

what position should an ECG be obtained in ideally?

A

right lateral

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72
Q

what needs to be removed from the area where an ECG is being performed to ensure accurate ECG reading?

A

anything that may create interference (e.g. mobile)

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73
Q

what are the main types of ECG equipment?

A

multiparameter
paper-trace recording
Holter monitor
telemetry

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74
Q

what are papertrace ECGs used for?

A

diagnosis of arrhythmia

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75
Q

what are Holter monitors used for?

A

longer term monitoring so patient can go home

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76
Q

what should be checked if the ECG is not working?

A

settings
battery
are leads attached
are leads on correct legs
minimal patient movement
ideally right lateral
is patient panting / purring
check contact and apply spirit
change if not sticking
clip more fur

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77
Q

what are the phases of an ECG complex?

A

P
QRS
T

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78
Q

what does the P wave represent?

A

atrial electrical activity

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79
Q

why are P waves small?

A

muscle mass of atria relatively small so associated electrical changes are also small

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80
Q

when are P waves seen?

A

atrial depolarisation

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81
Q

what type of deflection is atrial depolarisation wave?

A

+

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82
Q

what else is depolarised along with the atria?

A

AV node

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83
Q

what does the P-R interval represent?

A

time between atrial depolarisation and ventricular depolarisation

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84
Q

how is the P-R interval measured?

A

distance between onset of the P wave and onset of the R wave

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85
Q

what does a normal P-R interval mean?

A

electrical impulse is travelling at the correct speed between the atria and the ventricles

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86
Q

what happens to the depolarisation wave once it has passed through the AV node?

A

travels through bundle of His and Purkinjie fibres

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87
Q

what is the first part of the ventricles to depolarise?

A

ventricular septum

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88
Q

what is the Q wave?

A

small depolarisation wave seen when the ventricular septum depolarises

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89
Q

what shape is the Q wave?

A

downward wave (negative deflection) on the ECG trace

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90
Q

what sort of deflection is the Q wave?

A

negative

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91
Q

what direction does the Q wave travel?

A

away from the positive electrode

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92
Q

when does the R wave occur?

A

when the majority of the ventricles are depolarised

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93
Q

what direction does the depolarisation of the R wave travel?

A

towards the positive electrode creating a positive deflection

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94
Q

what is the largest wave on the EGC trace?

A

R wave

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95
Q

what makes the R wave the largest wave on the ECG?

A

large mass of tissue in the ventricles creating the largest positive deflection

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96
Q

when does the S wave occur?

A

following depolarisation of the majority of the ventricles

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97
Q

where does the final depolarisation of the ventricles occur?

A

base of the heart

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98
Q

what direction does the wave of depolarisation that forms the S wave travel in?

A

away from the positive electrode creating a negative deflection

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99
Q

why is the S wave small?

A

small tissue mass so small electrical deflection

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100
Q

what is represented by the QRS complex?

A

depolarisation of the ventricles followed by ventricular muscle contraction

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101
Q

what happens to the electrical potential difference once the atria are depolarised?

A

no longer an electrical potential difference

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102
Q

what is the PR segment?

A

area of the ECG between the P wave and the Q wave

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103
Q

what is occurring during the PR segment?

A

slow impulse conduction through the AV node

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104
Q

when does the ST segment occur?

A

once the ventricles are depolarised

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105
Q

what does the ST segment represent?

A

interval between ventricular depolarisation and repolarisation

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106
Q

what is represented by the T wave?

A

repolarisation of the ventricles following depolarisation and contraction

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107
Q

what does the T wave mark the beginning of?

A

ventricular relaxation and repolarisation

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108
Q

what is created during the T wave phase?

A

potential difference across the ventricular myocardium until the ventricles are completely repolarised

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109
Q

how may the T wave appear on ECG?

A

positive deflection
negative deflection
mixed deflection

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110
Q

what are the main areas to look at when interpreting an ECG?

A

rate
all expected waves present (P, QRS,T)
any arrhythmias

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111
Q

what can be assessed about the rate of ECG?

A

tachycardia
bradycardia

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112
Q

what can be assessed about the presence of all ECG complexes?

A

are they all present
are all complexes identical
is there a P wave for every QRS and vice versa

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113
Q

what can be assessed about the presence arrhythmia on ECG?

A

regularly irregular
regularly regular
irregularly irregular
intermittent or continuous
sinus, ventricular or supraventricular

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114
Q

what is included within arrhythmias?

A

abnormailities in:
rate
electrical impulse conduction
ectopia

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115
Q

what can cause arrhythmias to occur?

A

when other areas of the heart begin to generate their own electrical activity which overrides pacing of the SA node

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116
Q

what are the main sinus rhythms?

A

normal sinus
sinus arrhythmia

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117
Q

what are the main bradyarrhythmias?

A

sinus bradycardia
sick sinus syndrome
atrioventricular beats
escape beats
hyperkalaemia

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118
Q

what are the main tachyarrhythmias?

A

sinus tachycardia
supraventricular tachycardia
atrial fibrillation
ectopic beats
accelerated idioventricular rhythm
ventricular tachycardia
R-on-T phenomenon

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119
Q

what are they main cardiac arrest rhythms?

A

ventricular fibrillation
pulseless ventricular tachycardia
pulseless electrical activity
asystole

120
Q

describe sinus rhythm on an ECG

A

P, QRS, T all present
P for every QRS
all complexes identical

121
Q

what is heard on auscultation of a patient with sinus rhythm?

A

regular heart sounds
HR normal for age, breed and species

122
Q

are pulse deficits seen with sinus rhythm?

A

no

123
Q

what does the ECG trace look like with sinus arrhythmia?

A

normal P for every QRS-T

124
Q

describe sinus arrhythmia

A

impulse originates from SA node
a regular variation in HR which coincides with respiration

125
Q

what is sinus arrhythmia also known as?

A

respiratory sinus arrhythmia

126
Q

what is sinus arrhythmia thought to be caused by?

A

increase in parasympathetic activity (vagal tone) on the SA node

127
Q

when is sinus arrhythmia seen?

A

normal and common in dogs as long as HR in normal range
rare in cats

128
Q

what is occurring when sinus bradycardia is seen?

A

SA node impulse and corresponding depolarisation occurs more slowly than normal

129
Q

describe sinus bradycardia

A

normal sinus rhythm
P wave for every QRS-T
HR inappropriately slow for age breed and species
pulse for every beat
regularly regular rhythm

130
Q

what are the main causes of sinus bradycardia?

A

normal in some breeds (e.g. giant breeds or very fit animals)
issue with SA node
secondary to other disease process which increases vagal tone

131
Q

what diseases which increase vagal tone may cause sinus bradycardia?

A

hypoadrenocorticism
BOAS
raised ICP
vaso-vagal reaction
hypocalcaemia
hyperkalaemia
hypothermia
hypoglycaemia
hypothyroidism

132
Q

how is sinus bradycardia treated?

A

underlying cause treated
anticholinergic to increase HR

133
Q

what may be used to temporarily treat sinus bradycardia?

A

anticholinergic
atropine or glyco

134
Q

what may be used to treat sinus bradycardia if anticholinergic is unsuccessful?

A

positive inotrope

135
Q

what are examples of positive inotropes that may be used to treat sinus bradycardia?

A

dopamine
dobutamine

136
Q

what is sick sinus syndrome caused by?

A

problem with SA node function which means there is an issue with discharge of the electrical impulse

137
Q

what are the signs of sick sinus syndrome?

A

severe bradycardia (<30 bpm)
may see periods of asystole for several seconds without escape beats
SA node will restart but sinus arrest common

138
Q

what is sinus arrest?

A

periods of asystole

139
Q

in what animals is sick sinus syndrome seen?

A

older (6-10 years)
common in WHWT, spaniels and schnauzers
rare in cats

140
Q

how is sick sinus syndrome treated?

A

pacemaker
rarely responds to medical management well

141
Q

how long do most pacemakers last for?

A

5-10 years

142
Q

what are the risks associated with pacemakers?

A

infection
lead dislodgement
failure to place correctly
venous thrombosis

143
Q

what are the nursing considerations for patients with pacemakers?

A

no walking for 48 hours post surgery
harness only
care with neck restraint
no jugular samples

144
Q

what are pacemakers used to treat?

A

bradyarrhythmias

145
Q

what is heart block?

A

problem with the electrical conduction system of the heart

146
Q

what happens during heart block?

A

electrical impulses from the SA node are delayed or completely blocked from going through the AV node

147
Q

what is the effect of delayed or blocked electrical impulses from the AV node?

A

electrical impulse may not reach the ventricles

148
Q

what can AV block be caused by?

A

disease process
drug effect at AV node

149
Q

what are the main blocks which affect the AV node?

A

atrioventricular block (AV block)
AV nodal block

150
Q

what are the blocks which affect the left or right bundle branches?

A

bundle branch blocks

151
Q

what happens during first degree AV block?

A

delayed conduction through AV node

152
Q

what is seen on ECG with first degree AV block?

A

normal P and QRS complex
longer interval between P and corresponding QRS complex (prolonged P-R)

153
Q

what happens during second degree AV block?

A

longer conduction delay through the AV node - some impulses not transferred at all

154
Q

how may second degree AV block appear on an ECG trace?

A

some P waves will not have corresponding QRS complexes
QRS complexes normal in morphology

155
Q

why are QRS complexes normal in morphology during 2nd degree AV block?

A

as there has been conduction through the AV node

156
Q

what are the 2 types of 2nd degree AV block?

A

Mobitz type 1 (Wenckebach)
Mobitz type 2

157
Q

what does the ECG look like in Mobitz type 1 (Wenckebach) AV block?

A

P-R interval increases in size
then a P wave will be seen without QRS
following missing QRS the rhythm returns to normal

158
Q

what does the ECG look like in Mobitz type 2 AV block?

A

P-R interval the same each time
occasional P wave seen with no corresponding QRS complex

159
Q

what happens during 3rd degree AV block?

A

complete lack of conduction through the AV node
ventricular escape beats (ectopics) seen to prevent death

160
Q

how does 3rd degree AV block appear on ECG?

A

multiple P waves with no QRS
P waves occur faster
wide and bizarre escape beats seen - have no P wave attached

161
Q

why are ventricular escape beats seen with 3rd degree AV block?

A

rescue for the heart as no conduction through the AV node and so animal would otherwise die

162
Q

how are ventricular escape beats in 3rd degree AV block caused?

A

radondomly generated by cardiac cells

163
Q

what HR is seen with 3rd degree AV block?

A

20-40 bpm

164
Q

what are the clinical signs of AV block?

A

if severe (3rd degree) there will be signs of decreased CO

165
Q

what are the signs of decreased CO?

A

syncope
lethargy
collapse

166
Q

how is AV block treated?

A

management of any underlying conditions
vagolytic drugs
pacemaker for severe second degree and third degree

167
Q

what vagolytic/anticholinergic drugs may be used in AV block?

A

atropine
glycopyrrolate

168
Q

what arrhythmia is seen with hyperkalaemia?

A

bradycardia

169
Q

what may be seen on an EGC of a patient with hyperkalaemia?

A

bradycardia
reduced or absent P waves
spiked T waves
shortened QT
prolonged QRS

170
Q

what can hyperkalaemia progress to?

A

atrial standstill
sine wave pattern
v fib
asystole

171
Q

what is the normal range for potassium?

A

3.5-5 mmol/l

172
Q

what are the causes of hyperkalaemia?

A

urethral obstruction
AKI
hypoadrenocorticism

173
Q

how can hyperkalaemia be managed?

A

calcium gluconate bolus
neutral insulin infusion
dextrose infusion

174
Q

what is the role of calcium gluconate in the management of hyperkalaemia?

A

reduction of risk of v fib and protection of cardiac myocytes from elevated K+

175
Q

what is the role of neutral insulin in the management of hyperkalaemia?

A

causes movement of K+ into cells

176
Q

what is the role of dextrose infusion in the management of hyperkalaemia?

A

causes cells to increase uptake of glucose which leads to an intracellular shift of K+
prevents hypoglycaemia due to insulin admin

177
Q

what causes sinus tachycardia?

A

SA node generates an impulse and depolarisation at a rate faster than normal

178
Q

what is seen on an ECG of a patient with sinus tachycardia?

A

normal sinus rhythm
P-QRS-T normal
regularly regular

179
Q

what may happen to pulses with extreme sinus tachycardia?

A

should be synchronous
may become weaker with very fast pulse rates

180
Q

what can sinus tachycardia be caused by?

A

normal process (e.g. exercise)
pain
hypovolaemia
anaemia

181
Q

what are the 2 categories of arrhythmia?

A

supraventricular
ventricular

182
Q

where do supraventricular arrhythmias originate from?

A

atria

183
Q

where within the atria do supraventricular arrhythmias come from?

A

point other than the SA node

184
Q

how do supraventricular arrhythmias appear on ECG?

A

QRS relatively normal
may be taller and more narrow

185
Q

where do ventricular arrhythmias originate from?

A

ventricles

186
Q

do ventricular arrhythmias follow the normal conduction pathway?

A

no

187
Q

how does the ECG of a patient with ventricular arrhythmias appear?

A

QRS complexes are wide and bizarre

188
Q

what has happened if the P-QRS-T complex looks different to normal?

A

impulse has arisen from an ectopic location

189
Q

what does ectopic mean?

A

out of place (i.e. not the SA node)

190
Q

what is occurring during ectopic beats?

A

beats originate from cells other than those in the SA node

191
Q

when do ectopic beats occur in the cardiac cycle?

A

prematurely - interrupt normal rhythm

192
Q

where can ectopic beats originate from?

A

atria or ventricles

193
Q

what are ectopic beats classified by?

A

point of origin

194
Q

what are atrial ectopic beats known as?

A

atrial premature complex

195
Q

what are junctional ectopic beats known as?

A

junctional premature complex

196
Q

what are ventricular ectopic beats called?

A

ventricular premature complex

197
Q

what are other forms of ectopic beats?

A

supraventricular tachycardia
escape beats seen with 3rd degree AV block

198
Q

why are supraventricular ectopic beats called that?

A

originate above the SA node

199
Q

what is caused by supraventricular ectopic beats?

A

heartbeat occurs earlier than expected after the last complex before the next SA node impulse

200
Q

how would supraventricular arrhythmias appear on ECG?

A

abnormal P wave as not initiated by SA node
QRS complex after

201
Q

what is the rhythm like in supraventricular arrhythmia?

A

irregularly irregular

202
Q

what are supraventricular arrhythmias known as?

A

atrial premature complex
premature atrial contraction
atrial premature beat

203
Q

what is indicated by 3 or more atrial premature complexes in a row?

A

supraventricular tachycardia

204
Q

what HR may be seen with supraventricular tachycardia?

A

170-350 bpm

205
Q

how may supraventricular tachycardia appear on ECG?

A

QRS complexes narrower and more upright than normal
may or may not see an associated P wave

206
Q

what are the clinical signs of slow SVT?

A

often none

207
Q

what are the clinical signs of fast SVT?

A

weakness
collapse
poor PQ
poor peripheral perfusion
pale MM
prolonged CRT

208
Q

why do clinical signs of SVT occur?

A

inadequate diastolic filling due to sort period of diastole

209
Q

what are the causes of SVT?

A

often associated with underlying cardiac disease (DCM)
can be associated with systemic disease such as hypovolaemia, toxicity, ischemia and electrolyte imbalances

210
Q

how can SVT be treated?

A

decrease HR
treat underlying cause

211
Q

what drugs may be used for SVT?

A

beta blockers (Solatol / Atenolol)
calcium channel blockers (Diltiazem)

212
Q

what sort of arrhythmia is atrial fibrillation?

A

supraventricular tachycardia

213
Q

what happens when the heart is in atrial fibrillation?

A

rapid and irregular contraction of the atria

214
Q

in what animals is atrial fibrillation seen?

A

common in dogs
rare in cats

215
Q

what is the pulse like in a patient with AF?

A

pulse deficits
irregular pulse

216
Q

what is the HR like of a patient with AF?

A

rapid often >200
irregular beat with no pattern

217
Q

what does AF appear like on ECG?

A

supraventricular QRS complex (taller and narrower)
no visible P waves as impulse not from SA node

218
Q

what does a heart with atrial fibrillation sound like?

A

trainers in a tumble dryer!

219
Q

how is AF treated?

A

decrease HR
increase CO
calcium channel blockers
beta blockers
digoxin
amiodarone

220
Q

what are junctional premature complexes?

A

ectopic beats that arise from an area within the atrioventricular junction

221
Q

what is the effect of junctional premature complexes arising from the region of the AV node?

A

ventricles usually activated normally

222
Q

how common are JPCs?

A

less common than APCs or VPCs

223
Q

how do JPCs appear on ECG?

A

QRS complex premature with morphology similar to sinus complexes but narrower
usually without preceding P wave but this can be hidden, abnormal or premature

224
Q

what controls ventricular contractions when ventricular arrhythmia seen?

A

ectopic site below the AV node
an area of the ventricles becomes the pacemaker

225
Q

why are ventricular complexes wide and bizarre on ECG?

A

normal electrical pathway not followed and conduction is slower

226
Q

what are the causes of ventricular arrhythmias?

A

underlying primary cardiac disease (e.g. DCM)
complication due to another condition (e.g. GDV, pyo, pancreatitis)

227
Q

when do VPCs occur in the cardiac cycle?

A

prior to normal SA node depolarisation

228
Q

how do VPCs appear on ECG?

A

no preceding P wave except by coincidence
wide and bizarre QRS

229
Q

describe pulse quality with VPCs

A

weak on certain beats

230
Q

are pulse deficits seen with VPCs?

A

yes

231
Q

what are VPCs also known as?

A

premature ventricular contractions (PVCs)

232
Q

what is accelerated idioventricular rhythm?

A

3 or more VPCs together

233
Q

what is the heart rate like with accelerated idioventricular rhythm?

A

not very elevated 140-180 bpm

234
Q

how should accelerated idioventricular rhythm be managed?

A

generally considered benign at this rate
unlikely to affect CO
treatment not usually needed
monitor for V tach

235
Q

when may accelerated idioventricular rhythm be seen?

A

patients recovering from extensive abdominal surgery

236
Q

what may accelerated idioventricular rhythm progress to?

A

VT

237
Q

what is ventricular tachycardia?

A

3 or more VPCs in a row
with HR of >180 bpm

238
Q

how does VT appear on ECG?

A

QRS wide and bizarre
absent P waves
T waves large

239
Q

what are the clinical findings in a patient with VT?

A

decreased CO
signs of haemodynamic compromise

240
Q

what is the pulse of a patient with VT like?

A

weak
rapid and irregular

241
Q

what indicates decreased CO?

A

hypotension
collapse

242
Q

what are signs of haemodynamic compromise?

A

altered mentation
signs of hypoperfusion (pale MM, >CRT, hypothermia, poor PQ)

243
Q

what are the causes of VT?

A

primary cardiac disease
significant abdominal pathology
inflammation
severe anaemia
abnormal autonomic activity (high sympathetic tone)
electrolyte disturbances
drug toxicities
neoplasia

244
Q

what can cause abnormal autonomic activity (high sympathetic tone)?

A

pain

245
Q

what are the consequences of sustained VT?

A

cardiogenic shock
decreased systemic tissue perfusion
decreased cardiac perfusion
myocardial failure
malignant arrhythmia (VF)
sudden death

246
Q

what is the aim of treatment of VT?

A

convert to sinus rhythm and slow HR down to allow better CO and peripheral perfusion

247
Q

what does treatment of VT depend on?

A

degree of haemodynamic compromise
underlying cause

248
Q

what are patients with underlying heart disease more likely to need if in VT?

A

immediate drug intervention as risk of CPA

249
Q

what is PVT?

A

ventricular tachycardia with no associated pulse

250
Q

what should be done if PVT identified?

A

CPR commenced immediately

251
Q

what drugs are used to treat VT?

A

lidocaine
beta blockers
amiodarone
procainamide
magnesium

252
Q

what is the most common drug used for VT?

A

lidocaine

253
Q

how does lidocaine work?

A

sodium channel blocker

254
Q

what is R on T phenomenon?

A

VPC is so premature it is superimposed on the T wave of the preceding complex
can be sinus or ectopic beat

255
Q

what happens in the ventricles during R on T phenomenon?

A

have not had time to completely repolarise from previous contraction before they are depolarised again

256
Q

what makes R on T phenomenon so serious?

A

end of T wave is a vulnerable period
anything abnormal in this time can preclude VT or VF

257
Q

what may R on T phenomenon preclude?

A

VT
VF

258
Q

what is the aim of defibrillation?

A

high energy electric shock to the heart to reset the electrical state of the heart and convert from shockable rhythm to normal sinus

259
Q

what is the effect of defibrillation of a non-shockable rhythm?

A

may be detrimental to survival

260
Q

what are the shockable rhythms?

A

PVT
VF

261
Q

what are the non-shockable rhythms?

A

PEA
asystole

262
Q

what can VF result in?

A

patient death unless instantly recognised and treated

263
Q

what occurs during VF?

A

no effective ventricular contraction
no cardiac output so no pulse
patient will be collapsed

264
Q

how does VF appear on ECG?

A

rapid, irregular wavy baseline with no recognisiable normal complexes

265
Q

what are the 2 types of VF?

A

course
fine

266
Q

how is VF treated?

A

CPR
defibrillation

267
Q

what is occurring during PEA?

A

electrical impulses within the heart but no corresponding contractions

268
Q

how does PEA appear on ECG?

A

slow, normal or fast HR
normal P-QRS-T which may become increasingly wide and bizarre

269
Q

what is found on exam of a patient in PEA?

A

no audible heart beats
no palpable pulses
no CO

270
Q

how is PEA treated?

A

CPR
adrenaline and atropine
check pulse concurrently
only shock if converts to shockable rhythm

271
Q

what is the most common arrest rhythm in dogs and cats?

A

asystole

272
Q

how does asystole appear on ECG?

A

flat line
no complexes

273
Q

how is asystole treated?

A

CPR
non-shockable rhythm

274
Q

what disease processes is asystole associated with?

A

end stage disease
can be caused by very high vagal tone

275
Q

identify this ECG trace

HR regularly irregular
normal range for species

A

sinus arrhythmia

276
Q

identify this ECG trace

HR of 40

A

sinus bradycardia

277
Q

identify this ECG trace

A

sick sinus syndrome

278
Q

identify this ECG trace

A

first degree AV block

279
Q

identify this ECG trace

A

second degree AV block - Mobitz type 1 / Wenckebach

280
Q

identify this ECG trace

A

sinus rhythm

281
Q

identify this ECG trace

A

second degree AV block (Mobitz (2))

282
Q

identify this ECG trace

A

3rd degree AV block
P waves
Escape beats seen

283
Q

identify this ECG trace (rhythm is faster than normal for age, breed, species)

A

sinus tachycardia

284
Q

identify this ECG trace

A

supraventricular tachycardia

285
Q

identify this ECG trace

A

Atrial fibrillation

286
Q

identify this ECG trace

A

junctional premature complex

287
Q

identify this ECG trace

A

ventricular premature complex

288
Q

identify this ECG trace (rate is not very elevated - 140-180 bpm)

A

accelerated idioventricular rhythm

289
Q

identify this ECG trace (HR >180 bpm)

A

VT

290
Q

identify this ECG trace

A

R on T phenomenon

291
Q

identify this ECG trace (no pulse palpable)

A

pulseless ventricular tachycardia

292
Q

identify this ECG trace

A

fine VF

293
Q

identify this ECG trace

A

course VF

294
Q

identify this ECG trace (no pulse)

A

PEA

295
Q

identify this ECG trace

A

asystole

Advanced Clinical Nursing Theory (36 decks)

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