Arrhythmias Flashcards Preview

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Flashcards in Arrhythmias Deck (106):
1

where is the origin of a supraventricular arrhythmias?

above the ventricle
ie SA, atria, AV, HIS

2

where is the origin of a ventricular arrhythmia?

ventricle

3

what should be the only point of electrical contact between the atria and the ventricles?

AV node

4

what are ectopic beats?

beats or rhythms that originate in places other than the SA node

5

what are 3 common supraventricular tachycardias?
(supraventricular arrhythmias)

AF
Atrial flutter
ectopic atrial tachycardia

6

what are 2 common supraventricular bradycardia arrhythmias?

sinus bradycardia
sinus pauses

7

what are 3 common AV node arrhythmias?

AVN re-entry
Accessory pathway
AV block

8

what are 4 common ventricular arrhythmias?

premature ventricular complex (PVC)
ventricular tachycardia
ventricular fibrillation
asystole

9

what causes premature ventricular complexes?

ectopic beats originating from the ventricles

10

how can an accessory pathway arrhythmia be acquired?

MI

11

how can sleep apnoea cause arrhythmias?

because patients get hypoxic at night- metabolic cause of arrhythmia

12

what type of arrhythmia occurs in Wolf Parkinson White syndrome (WPW)?

re-entry:
accessory pathway tachycardia

13

what does hypothermia do to the pacemaker potential slope?

decreases slope- negative chronotropic effect

14

what does hyperthermia do to the pacemaker potential slope?

increases slope- positive chronotropic effect

15

what does hypoxia do to the pacemaker potential slope?

increases slope- positive chronotropic effect

16

what does hypercapnia do to the pacemaker potential slope?

increases slope- positive chronotropic effect

17

why can ischaemia or necrosis increase ectopics?

because local areas of ischaemia or necrosis increases automaticity of neighbouring cells

18

what does hypokalaemia do to the pacemaker potential slope, automaticity and length of repolarisation?

increase pacemaker potential slope
increases automaticity (therefore increases ectopics)
prolongs repolarisation

19

what does hyperkalaemia do to the pacemaker potential slope and AV conduction?

decreases pacemaker potential slope
slows AV node conduction

20

what is an afterdepolarisation?

a small depolarisation after the repolarisation phase of an AP, if this is of sufficient magnistude this will reach threshhold and lead to a full depolarisation- triggered activity

21

what are the 5 main symptoms of an arrhythmia?

palpitations
SOB
dizziness
syncope
sudden cardiac death

22

what are the 7 investigations used for a suspected arrhythmias?

12 lead ECG
CXR
echocardiogram
stress ECG
24 hour ECG Holter monitoring
event recorder
Electrophysiological study

23

what type of heart disease do echocardiograms show?

structural heart disease

24

what is a stress ECG?

heart is provoked in a controlled way, ischamia or arrhythmias may only be present when the cardiac demand is higher

25

what is an event recorder?

a monitor which only turns the recorder on if it detects a change- if the patient feels symptoms it can manually be switched on

26

what is an electrophysiological stufy?

an invasive investigation which deliberately induces a clinical arrhythmia to study mechanism and map the pathway
opportunity to treat the arrhythmias by radiofrequency ablation

27

what is pre-excitation?

accessory pathway from atria to ventricles for AP to flow

28

what is the function of a 24 hour Holter ECG?

assesses for paroxysmal arrhythmias
(heart rhythm is rarely captured though)

29

what vein is the catheter for an electrophysiological study usually put through?

femoral vein

30

if an atrial ectopic beat is asymptomatic how do you treat?

no treatment

31

if an atrial ectopic beat has palpitations how do you treat?

beta blockers
stimulant avoidance (caffeine, cigarettes)

32

what type of STEMI is most likely to cause sinus bradycardia?

inferior MI

33

how do you treat acute sinus bradycardia?

atropine

34

how do you treat sinus bradycardia if it causes haemodynamic compromise?

pacing

35

compare SVT to VT on ECG?

SVT- narrow complex tachycardia
VT- broad complex tachycardia

36

why are SVTs generally more tolerated than VTs?

because there are narrow complexes it means the heart is still pumping in a meaningful way

37

what is the purpose of vagal manoeuvers?

to stop supra-ventricular tachycardias

38

what is the vagal manouevre for infants?

ice water to face

39

what are the vagal manouevres for children?

blow through straw (valsalva manoeuvre)
carotid sinus massage

40

what are the vagal manouevres for adults?

carotid sinus massage
breath holding
coughing
NG placement
gagreflex
anal sweep

41

what 3 things may supraventricular tachycardias be due to?

AV nodal re-entrant tachycardia
accessory pathway tachycardia (ie WFW)
ectopic atrial tachycardia

42

what are the 2 types of re-entry tachycardia?

AV nodal re-entry
accessory pathway

43

where is the accessory pathway circuit in an AV nodal re-entry arrhythmia?

AV node itself

44

what is the acute management of a SVT?

vagal maneuvres
IV adenosine
IV verapamil

45

what is the chronic management of a SVT?

avoid stimulants
radiofreq ablation
antiarrhythmic drugs (class II or IV)

46

what is radioablation of an arrhythmia?

selective cautery of cardiac tissue to prevent tachycardia, targetting either an automatic focus or part of a re-entry circuit

47

what specific valve disease/surgery is most likely to disrupt the AV node?

aortic valve
eg calcification or surgery

48

what is 1st degree AV node block?

PR interval longer than 0.2s

49

what is the treatment of 1st degree AV node block?

none but long term follow up recommended

50

what is 2nd degree AV node block- Mobitz 1?

progressive lengthening of the PR interval, eventually resulting in a dropped beat
(vagal in origin)

51

what is 2nd degree AV node block- Mobitz 2?

intermittent dropped beats without lengthening, usually 2:1 or 3:1

52

which mobitz type is more indicative of a pathological cause?

mobitz type 2

53

what is the interventional indication for 2nd degree AV block mobitz type 2?

permanent pacemaker indicated (ventricular pacing)

54

what is 3rd degree AV block?

no APs from atria get through AV node
(full block)
ventricles and atria contract with no correlation

55

in full heart block, what maintains ventricular rhythm? (and so maintains cardiac output)

escape rhythm
(ie starts from somewhere else, not in sinus rhythm)

56

what is the interventional indication for 3rd degree AV block?

pacemaker

57

describe the QRS complexes in 3rd degree heart block?

very broad

58

what are the 2 acute pacing options?

transcutaneous pacer
transvenous pacer

59

what are the 2 chamber options of a pacemaker?

single chamber (RA or RV)
dual chamber (RA and RV)

60

what are single RA chamber pacemakers (atrial pacemakers) used for?

isolated SA disease with normal AV node

61

what are single VR chamber pacemakers (ventricular pacemakers) used for?

AF with slow ventricular rate

62

what is the dual chamber pacemaker used for?

AVN disease

63

what is a bad diagnostic sign when investigating a premature ventricular ectopic?

if worse on exercise

64

what drug treatment can be used for premature ventricular ectopics?

B blockers

65

what is ventricular fibrillation?

chaotic ventricular electrical activity which causes the heart to lose the ability to function as a pump

66

what is the acute treatment of VT with unstable haemodnamics?

DC cardioversion

67

what is the acute treatment of VT with stable haemodynamics?

pharmacological cardioversion with anti-arrhythmic drugs

68

what is the long term treatment for life threatening VT?

implantable cardiovertor defibrillator

69

what type of pulse is typical of AF?

irregularly irregular pulse

70

what are the 3 types of AF patterns?

paroxysmal
persistent
permanent (chronic)

71

which pattern of AF is most associated with heart disease?

permanent AF

72

why can pseudonormalisation occur with AF?

because the AF is so fast it looks like normal rhythm

73

what is paroxysmal AF?

occur in (often recurrent) sudden attacks that last less than 48 hours

74

what is persistent AF?

an episode of AF lasting greater than 48 hours, unlikely to spontaneously revert to NSR but can be cardioverted back

75

what is permanent AF?

AF which is unable to be restored to NSR by pharmacological or non pharmacological methods

76

what is lone AF?
(idiopathic AF)

AF which occurs in the absence of any heart disease and no evidence of dysfunction
(a diagnosis of exclusion)

77

what are the 7 main symptoms of AF?

palpitations
pre-syncope (dizziness)
syncope
chest pain
dyspnoea
sweatiness
fatigue

78

what are the 2 most common mechanisms of AF?

multiple wavelets of re-entry
ectopic focus around pulmonary veins

79

what are 3 ways of reverting AF back to NSR?

spontaneous
pharmacological cardioversion (anti-arrhythmic drugs)
electrical cardioversion

80

how do you recognise AF on an ECG?
(ie what extra or missing waves are there)

absence of P waves
presence of f waves

81

what does pre-excitation of the ventricles do the QRS complex?

broadens it

82

what are the 2 management options for controlling AF?

rhythm control
rate control

83

what is the purpose of rhythm control management?

to maintain sinus rhythm

84

what is the purpose of rate control management?

accept AF but control ventricular rate

85

what do you use in high risk AF to prevent thromboembolism?

anti-coagulation
(warfarin)

86

what are 3 rate controlling anti-arrhytmic drugs?

digoxin
beta blockers
calcium antagonists (verapamil, diltiazem)

87

what procedures can be done to restore AF to NSR?

direct current cardioversion
catheter ablation of atrial focus/pulmonary veins
surgery

88

what are class 1 anti-arrhythmic drugs?

Na+ channel inhibitors

89

what are class 1 anti-arrhythmic drugs used for?

rhythm contol

90

what are class 2 anti-arrhythmic drugs?

b-blockers

91

what are class 2 anti-arrhythmic drugs used for?

rate control

92

what are class 3 anti-arrhythmic drugs used for?

K+ chanel inhibitors

93

what are class 3 anti-arrhythmic drugs used for?

rhythm control

94

what are class 4 anti-arrhythmic drugs?

Calicium inhibitiors

95

what are class 4 anti-arrhythmic drugs used for?

rate conrol

96

what type of drugs are flecainide and propafenone?

class 1 anti-arrhythmic drugs
Na+ channel inhibitors
(rhythm controllers)

97

what type of drugs are amiodarone and sotalol?

class 3 anti-arrhythmic drugs
K+ channel inhibitors
(rhythm controllers)

98

how do you recognise torsades de pointes on an ECG?

heart rate of 200-250bpm
irregular rhythm
long QT interval
wide QRS
continously changing QRS morphology

99

what are the 3 mechanisms leading to torsades de pointes?

hypokalemia
drug induced- prolongation of the AP duration
renal impairment (causing increased drug levels)

100

what are the indications for anti-coagulation in AF?

1. valvular disease
2. age >75
3. hypertension
4. heart failure
5. prev stroke/thromboembolism
6. diabetes

101

what is the role of radiofrequence ablation in AF?

either to maintain SR by ablating AF focus
or
for rate control by ablation of AVN

102

in AF where are the ectopic foci usually found?

in muscle sleeves in the ostia of the pulmonary veins

103

what is atrial flutter?

rapid and regular form of atrial tachycardia (AV only conducts every 2/3 impulse so ventricle rhythm can appear more normal)

104

in atrial flutter what replaces the p wave?

saw tooth F wave

105

what is the mechanism behind atrial flutter?

macro-reentry

106

what is the treatment option with the best success in atrial flutter?

radiofrequency ablation