Arrhythmias 1 and 2 Flashcards Preview

1st Year - Cardiology > Arrhythmias 1 and 2 > Flashcards

Flashcards in Arrhythmias 1 and 2 Deck (125)
Loading flashcards...
1
Q

What is an arrhythmia?

A

Abnormality of heart rate or rhythm

2
Q

What are the 2 broad anatomical types of arrhythmias?

A

SupraventricularVentricular

3
Q

What are the names of the 3 internal tracts that connect the SA node and AV node?

A

Anterior, middle and posterior internodal tracts

4
Q

What are ectopic beats?Name when you have several of these in a row?

A

Beats or rhythms that originate in places other than the SA node (when the latent pacemaker fires at a rate faster than the SA node)Ectopic rhythm - ectopic focus dictates the entire rhythm

5
Q

Are ectopic beats/ rhythms dangerous?

A

Depends how the affect the cardiac output

6
Q

How can arrhythmias be categorised based on rate?

A

TachyarrhymiasBradyarrhytmias

7
Q

What are the 4 types of atrial tachycardia? (SVT)

A

Atrial fibrillationAtrial flutterEctopic atrial tachycardiaSinus tachycardia

8
Q

What are the 2 types of atrial bradycardia?

A

Sinus bradycardiaSinus pauses

9
Q

What are the 3 types of atrioventricular node arrhythmias?

A

AV node re-entryAccessory pathwaysAV block

10
Q

What are the 4 types of ventricular arrhythmias??

A

Premature ventricular complexVentricular tachycardiaVentricular fibrillationAsystole

11
Q

What are the clinical causes of arrhythmias? (5)

A

Abnormal anatomy e.g. left ventricular hypertrophy, accessory pathwaysAutonomic e.g. sympathetic stimulation (nervousness, hyperthyroidism), increased vagal toneMetabolic e.g. hypoxic myocardium, ischaemic myocardium, electrolyte imbalancesInflammation e.g. viral myocarditis]DrugsGenetics (mutations of cardiac ion channels) e.g. congenital long QT syndrome

12
Q

What are the 5 mechanisms of arrhythmias?

A

Defects in impulse formation (altered automaticity, triggered activity)Defects in impulse conduction (re-entry, accessory tracts, conduction block)

13
Q

What is altered automaticity?

A

When a latent pacemaker takes over the SA nodes function as the normal pacemaker of the heart (causes escape or ectopic beats) - can occur physiologically when the ANS modulates the SA nods activity e.g. caused by drugs, ischaemia

14
Q

What is triggered activity?

A

When abnormal action potentials are triggered by a preceding action potential resulting in the heart cells beating twice e.g. tornadoes de points

15
Q

What is re-entry?

A

Self-sustaining electrical circuit stimulates an area of the myocardium to be stimulated repeatedly

16
Q

What is conduction block?

A

Any disease that disrupts electrical conduction may reduce conduction or cause heart block

17
Q

What are accessory pathways?

A

Additional electrical conduction pathway between 2 areas of the heart e.g. WPW

18
Q

What effect does hypothermia have on phase 4 of AP slope?

A

Decreases it (altered automaticity)

19
Q

What effect does hyperthermia have on phase 4 of action potential slope?

A

Increases it (altered automaticity)

20
Q

What effect do hypoxia and hypercapnia have on phase 4 of AP slope?

A

increase it (altered automaticity)

21
Q

What effect does hypokalaemia have on phase 4 of AP slope?

A

Increases it (also prolongs repolarisation and increases ectopics)

22
Q

Symptoms of arrhythmias?

A

Palpitations (a noticeably rapid, strong or irregular heart beat)SOBDizinessSyncopeSudden cardiac deathWorsen pre-exisiting conditiosn e.g. angina

23
Q

Investigations of arrhythmias? (&)

A

12 lead ECGCXREchocardiogramStress ECG24 hours ECG hotter monitoringEvent recorderElectrophysiological (EP) study

24
Q

Why is an ECG done for arrhythmias?

A

To assess rhythmSigns of previous MI, pre-excitation (WPW)

25
Q

What sign on an ECG suggests a previous MI?

A

Pathological Q waves

26
Q

Why perform an exercise ECG in a patient with suspected arrhythmia?

A

To assess for ischaemiaExercise induced arrhythmia

27
Q

Why perform a 24 hour hotter ECG in a patient with suspected arrhythmia?

A

To assess for paroxysmal arrhythmiaTo link symptoms to underlying heart rhythm

28
Q

Why perform an echo in a patient with suspected arrhythmia?

A

To assess for structural heart disease

29
Q

Why perform an electrophysiological study in a patient with a suspected arrhythmia?

A

To trigger the arrhythmia and study its mechanismOpportunity to treat by ablation at the same time

30
Q

What are the symptoms of atrial ectopic beats?

A

Asymptomaticpalpitations

31
Q

Treatment of atrial ectopic beats?

A

Generally no treatment but patients may find B blockers helps (avoid stimulants e.g. caffeine)

32
Q

When is sinus bradycardia physiological?

A

Athlete

33
Q

What is sick sinus syndrome?

A

Sinus node dysfunction causing bradycardia +/- rest, senatorial block, or SVT alternating with bradycardia/ asystole

34
Q

What are causes of sinus bradycardia?

A

Drugs e.g. beta blockersIschaemiaLots more

35
Q

Treatment of sinus bradycardia?

A

Atropine (if acute, e.g. MI)Pacing if haemodynamic compromise e.g. hypotension, CHF, angina, collapse

36
Q

Causes of sinus tachycardia?

A

Physiological in anxiety, fever, hypotension, anaemiaInappropriate due to drugs, etc.

37
Q

Treatment of sinus tachycardia?

A

Treat underlying causeB-adrenergic blockers

38
Q

What is an example of a paediatric vagal manoeuvre (used to treat SVT)?

A

ice water to face for infantsBlow through straw (valsalva) for child or adolescents

39
Q

What is the most common cause of SVT?

A

Atriventricular re-entry

40
Q

What causes atrioventricular re-entry anatomically?

A

A small re-entry circuit involving the atrioventricular node and surrounding atrial tissue

41
Q

What is wolf-parkinson-white?

A

Presence of an accessory pathway between the atria na ventricles causing ventricular pre-excitation

42
Q

What type of abnormality does WPW cause on an ECG?

A

Delta waves

43
Q

Acute management of SVT?

A

Vagal manoeuvresIV adenosine (extremely short half life so have to push it in as fast as you can)IV verapamil

44
Q

Chronic management of SVT?

A

Avoid stimulantsRadifrequency ablationAnti-arrhythmic drugs (Class II or IV)

45
Q

What is cardiac ablation?

A

Selective cauterisation of cardiac tissue to prevent tachycardia, targeting either an automatic focus or part of a re-entry circuit

46
Q

What does cardiac ablation involve?

A

Placement of catheters in heart via femoral veinsIntracardiac ECG recorded during sinus rhythm, tachycardia and during pain manoeuvresCatheter placed over focus/ pathway and tip heated

47
Q

What causes AV node conduction disease?

A

Ageing processAcute MIMyocarditisInfiltrative disease e.g. amyloidDrugs e.g. B blcokers, Calcium channel blockersCalcific aortic valve diseasePost-aortic valve diseasesGenetic e.g. Lenore’s disease, myotonic dystroph

48
Q

1st degree heart block?

A

PR interval prolonged (greater than 0.2 seconds)

49
Q

Treatment of 1st degree heart block?

A

None - long term follow up recommended as more advanced block may develop

50
Q

What are the 2 types of 2nd degree heart block?

A

Mobitz IMobitz II

51
Q

What is Mobitz I?

A

Prolong PR interval cumulating in a droped ventricular beat (QRS complex)

52
Q

what is Mobitz II?

A

Regularly more than one P wave to each QRS complex in a 2:1, 3:1 or 4:1 ratio

53
Q

Treatment of mobitz II?

A

Permanent pacemaker

54
Q

Treatment of mobitz I?

A

Ventricular pacing

55
Q

What is third degree heart block?

A

Complete atrioventricular dissociation: regular P waves, regular QRS complexes but no association between the 2

56
Q

Treatment of 3rd degree heart block?

A

Ventricular pacing

57
Q

What is trancutaneous pacing?

A

Using a defibrillator to pace the heart during an emergency (other type is transvenous)

58
Q

What are the 2 types of pacemakers available?

A

Single chamber (paces the right atria or right ventricle only)Dual chamber (paces the RA and RV)

59
Q

What is a single chamber pacemaker used for?

A

Atrial = isolated SA node disease but normal AV nodeVentricular = AF with slow ventricular rate

60
Q

What is a dual chamber pacemaker used for?

A

Maintains AV synchrony - AVN disease

61
Q

What are premature ventricular complexes?

A

ectopic impulses originating from an area distal to the His Purkinje system. VPCs are the most common ventricular arrhythmia

62
Q

What causes premature ventricular complexes?

A

May not have structural heart diseaseIschaemic heart diseaseHypertension with left ventricular hypertrophyHeart failureMay be marker for inherited arrhythmia syndrome

63
Q

Symptoms of premature ventricular complexes?

A

Usually asymptomatic

64
Q

Treatment of premature ventricular ectopics?

A

Beta blockers

65
Q

What is a broad complex tachycardia in a patient with no history of cardiac disease?

A

VT

66
Q

What is ventricular tachycardia?

A

Tachycardia originating from a ventricular focus

67
Q

Is VT life threatening?

A

Yes

68
Q

What type of patients does VT occur in?

A

Usually those with significant heart disease e.g. coronary artery disease Rarely, cardiomyopathyInherited syndrome e.g. long QT, Brugada syndrome(look for cause of VT .e.g electrolytes (hypokalaemia, hypomagnesaemia, ischaemia, hypoxia, medications)

69
Q

what is long QT syndrome?

A

a rare inherited or acquired heart condition in which delayed repolarization of the heart following a heartbeat increases the risk of episodes of torsades de pointes

70
Q

What is Brugada syndrome?

A

a genetic disease that is characterised by abnormal electrocardiogram (ECG) findings and an increased risk of sudden cardiac death.

71
Q

Difference between monomorphic and polymorphic VT?

A

in mono. QRS = symetricalIn poly. QRS = unsymetrical

72
Q

What is ventricular fibrillation?

A

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

73
Q

Treatment of VF?

A

Defibrillation and cardiopulmonary resuscitation

74
Q

Treatment of VT?

A

DC cardioversion if unstableIf stable consider pharmacologic cardioversion with AADIf unsure if VT or something else, consider adenosine to make a diagnosis

75
Q

what long term treatments are available for VT?

A

Implantable cardiovertor defibralltorsCHF therapies

76
Q

What is normally the cause of ventricular arrhythmias?

A

Structural problems

77
Q

What causes atrial flutter?

A

rapid heart rate causes by re-entry circuits in the atrium

78
Q

Appearance of atrial flutter on ECG?

A

Saw tooth appearance

79
Q

What is atrial fibrillation caused by physiologically?

A

Rapid, unsynchronised and chaotic electrical activity which causes conduction of irregular signals to the ventricles due to multiple weavlets of re-entry and ectopic focus around the pulmonary veins

80
Q

What results in increased R wave amplitude in the left-sided ECG leads (I, aVL and V4-6) and increased S wave depth in the right-sided leads (III, aVR, V1-3)?

A

Left ventricular hypertrophy

81
Q

Type of heart beat in A Fib?

A

Irregular

82
Q

What are the 3 different types of AFib?

A

ParoxysmalPersistentPermanent (chronic)

83
Q

What is paroxysmal AFib?

A

Reverts to sinus rhythm spontaneously - often recurrent

84
Q

What is persistent AFib?

A

AF that is not self terminating/ has lasted longer than 7 days but can be terminated through treatment

85
Q

What is permanent AFib?

A

Continuos AF that cannot be successfully terminated

86
Q

What does incidence of AFib increase with?

A

Age

87
Q

Associated diseases/ causes of AFib?

A

HypertensionCongestive heart failureSick sinus syndrome - “tachy brady syndrome”Coronary heart diseaseThyroid diseaseFamilialValvular heart diseaseAlcohol abuseCongenital heart diseaseCardiac surgeryOther rarer causes e.g. COPDEither classified into cardiac or non-cardiac cause

88
Q

What is lone (idiopathic) AFib?

A

Absence of any underlying cause for AF (diagnosis of exclusion)

89
Q

Symptoms of AFib?

A

PalpitationsPre-syncope (dizziness)SyncopeChest painDyspnoeaSweatinessFatigueCan be asymptomaticSymptoms often worse at the onset of AF

90
Q

Termination of atrial fib?

A

pharmacological cardioversion with anti-arrhythmic drugs (30% effective)Electrical cardioversion (90% effective)Spontaneous reversion to sinus rhythm

91
Q

What are the anti-arrhythmic drug examples that can be used to terminate and prevent atrial fib?

A

FlecainideSotalolAmiodarone

92
Q

ECG of atrial fib?

A

Atrial rate greater than 300 bpm

93
Q

Rhythm in Atrial Fib?

A

Irregularly irregular

94
Q

Ventricular rate in atrial fib?

A

Variable (dependent upon AV node conduction properties, sympathetic and parasympathetic tone, presence of drugs which act on the AV node)

95
Q

Recognition of atrial fib on ECG?

A

Absence of P waves, presence of f waves - ventricular rate is irregular

96
Q

What pharmacological agents are useful in controlling ventricular rate in AF by decreasing conduction in the AV node?

A

Beta blcokersCalcium channel blcokers

97
Q

Ventricular rate in A fib?

A

IrregularCan be slow, normal or fast (and ranging between these) - depends on AV node conduction properties, sympathetic and parasympathetic tone, presence of drugs which act on the aV node (e.g. flecanide, sotolol, amiodarone)

98
Q

What is it called when AF goes so fast that it looks regular but it actually its?

A

Pseudoregularisation

99
Q

How does AF cause a reduced cardiac output?

A

Lost atrial kick and decreased killing time

100
Q

If the patient has hypertrophic cardiomyopathy, what can AFib result in?

A

Congestive heart failure

101
Q

What does ventricular rates less than 60bpm in AF suggest?

A

AV conduction disease

102
Q

Management of AF?

A

Rhythm control (maintain SR predominantly)ORRate control: Accept AF but control ventricular rateAnti-coagulation for both approaches if high risk for thromboembolism

103
Q

Rate control during AFib?

A

Pharmacological therapy to slow down AVN conduction:DigoxinBetablcokersVerapamil, diltizamGive the above alone or in combinationIf the above doesnt work, the aV node can be completely ablated and a pacemaker fitted

104
Q

Rhythm control of Afib?

A

Restoration of NSR:Pharmacological cardioversion (anti-arrhythmic drugs e.g. amiodarone)Direct current cardioversionMaintenance of NSR:Anti-Arrhythmic drugsCatheter ablation of atrial focus/ pulmonary veinsSurgery (Maze procedure)

105
Q

Treatment of paroxysmal AF?

A

Rhythm control:Cardiovert (pharma/ DC)Anti-Arrhythmic drugs to preventAnti-coag

106
Q

Treatment of persistent or permanent AF?

A

Rate control (digoxin, beta blocker, verapamil or diltiazem)Anti-coagulation if high riskDC cardioversion if structurally normal heart

107
Q

what is tornadoes de pointes?

A

a specific form of polymorphic VT in patients with a long QT interval. It is characterized by rapid, irregular QRS complexes, which appear to be twisting around the ECG baseline - it can be acquired or congenital (very deadly form of vt)

108
Q

Heart rate in torsades de points?

A

200-250 bpm

109
Q

Rhythm in torsades de pointes?

A

Irregular (In comparison to normal VT)

110
Q

Recognition of tornadoes de pointes?

A

Long QT intervalWide QRSContinuously changing QRS morphology

111
Q

Events leading to Torsdaes de points?

A

hypokalaemiaProlongation of AP duration (drug induced)Renal impairment (increased drug levels)

112
Q

What is the scoring system used to assess risk of thromboembolism in atrial fib?

A

CHADVASC score

113
Q

What is the CHADSVASC score

A

C Congestive heart failure (or Left ventricular systolic dysfunction) 1 H Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication) 1 A2 Age ≥75 years 2 D Diabetes Mellitus 1 S2 Prior Stroke or TIA or thromboembolism 2 V Vascular disease (e.g. peripheral artery disease, myocardial infarction, aortic plaque) 1 A Age 65–74 years 1 Sc Sex category (i.e. female sex) 1 Score is 1 maybe antii-cogaulantIf 2 or greater then you should be on anti-coagulants

114
Q

What puts patients at a high risk of thromboembolism?

A

Valvular heart diseaseAge greater than 75 especially femaleHypertensionHeart failurePrevious TE/strokeCoronary artery disease or diabetes and greater than 60yoThyrotoxicosis

115
Q

Indications for anti-coag in AF?

A

Valvular AF (mitral valve disease)Non valvular AF if:Age greater than 75HypertensionHeart failurePrevious stroke/ thromboembolismCAD/ DMDaibetes

116
Q

Bleeding risk assessment for AF?

A

HAS BLEDHypertension 1Abnormal renal or liver function 1 or 2Stroke 1Bleeding 1Labile INRs 1Elderly (age greater than 65) 1Drugs or alcohol 1 or 2(if score is greater than 3 = high risk)

117
Q

Why type of ablation is done in AF to maintain sinus rhythm?

A

Ablating AF focus

118
Q

What type of ablation is done in AF to control rate?

A

Ablation of AVN to stop fast conduction to the ventricles

119
Q

Is Atrial flutter regular or irregular?

A

Regular - usually paroxysmal and is rapid

120
Q

Where is the re-entry circuit in atrial flutter?

A

Right atrium

121
Q

How long can episodes of Atrial flutter last?

A

Seconds to years

122
Q

What does chronic atrial flutter usually progress to?

A

Atrial fibrillation

123
Q

Risk of atrial flutter?

A

May result in thrombi-embolism

124
Q

Characteristic feature of Atrial flutter on eCG?

A

Regular rapid rate with saw root F wave

125
Q

Treatment of Atrial flutter?

A

RF ablationPharmacological therapy to slow the ventricular rate = restores sinus rhythm, and maintains sinus rhythm once convertedCardioversionWarfarin for prevention of thromboembolism