1 basic arrhythmias © 2011 american heart association. do not edit

1

Basic ArrhythmiasBasic Arrhythmias

© 2011 American Heart Association. Do not edit.

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ECG MeasurementsECG Measurements

• PR intervalPR interval0.12 0.12 0.20 s 0.20 s

• QRS complexQRS complex<0.12 s<0.12 s

• QT intervalQT intervalCorrected for Corrected for Heart RateHeart Rate

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Heart Rate EstimationHeart Rate Estimation

1.1. Pick a complex that falls on a heavy linePick a complex that falls on a heavy line

2.2. Then estimate the rate by counting heavy boxesThen estimate the rate by counting heavy boxes

3.3. Using 300, 150, 100, 75, 60, 50, 40, 30Using 300, 150, 100, 75, 60, 50, 40, 30

So about 75So about 75

150 100 75 60 50 40 30150 100 75 60 50 40 30300300

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Standard Monitoring Leads Standard Monitoring Leads Lead 1Lead 1

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6


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Rhythm Strip InterpretationRhythm Strip Interpretation

Normal Sinus RhythmNormal Sinus Rhythm

Sinus BradycardiaSinus Bradycardia

Sinus TachycardiaSinus Tachycardia

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Initial Approach—AnalysisInitial Approach—Analysis4 Questions4 Questions

• Rate?Rate?– NormalNormal– Bradycardia, TachycardiaBradycardia, Tachycardia

• Rhythm?Rhythm?– Regular or IrregularRegular or Irregular

• Are there P waves?Are there P waves?– Is each P wave related to a QRS Is each P wave related to a QRS

with 1:1 impulse conduction?with 1:1 impulse conduction?

• QRS normal or wide?QRS normal or wide?

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Arrhythmias—EtiologyArrhythmias—Etiology

• Disturbance in AutomaticityDisturbance in Automaticity– Pacemaker speeds upPacemaker speeds up– New pacemaker takes overNew pacemaker takes over

• Disturbance in ConductionDisturbance in Conduction− Slowing or block in conductionSlowing or block in conduction

of electrical impulseof electrical impulse

• Combination of BothCombination of Both− Reentry arrhythmiasReentry arrhythmias

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Normal Sinus RhythmNormal Sinus Rhythm

• RateRate• RhythmRhythm• P wavesP waves• P P → QRS→ QRS• TherapyTherapy

60-100/min60-100/min

RegularRegular

PresentPresent

1:1 conduction1:1 conduction

NoneNone

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Sinus BradycardiaSinus Bradycardia


<60/min<60/min

RegularRegular

PresentPresent


Treat underlying causeTreat underlying cause

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Sinus TachycardiaSinus Tachycardia


>100/min>100/min

RegularRegular

PresentPresent



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Self-AssessmentSelf-AssessmentWhat are the rate and rhythm?What are the rate and rhythm?

B

A

C

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Self-AssessmentSelf-Assessment

What is this rhythm?What is this rhythm?

A

B

If there is no pulse, what is this rhythm?If there is no pulse, what is this rhythm?

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Supraventricular ArrhythmiasSupraventricular Arrhythmias

Premature Atrial Contraction (PAC) Premature Atrial Contraction (PAC) Premature Atrial Beat (PAB) Premature Atrial Beat (PAB) Atrial Premature Beat (APB)Atrial Premature Beat (APB)Premature Atrial ComplexPremature Atrial Complex

Atrial FibrillationAtrial FibrillationAtrial FlutterAtrial Flutter

Reentry TachycardiaReentry Tachycardia

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Premature Atrial Contraction (PAC)Premature Atrial Contraction (PAC)

Sinus rateSinus rate

IrregularIrregular—i—interrupted by PACnterrupted by PAC

Incomplete compensatory pauseIncomplete compensatory pause

Different morphologyDifferent morphology

Usually conducted with normal QRSUsually conducted with normal QRS


• RateRate• RhythmRhythm

• P wavesP waves• P P → QRS→ QRS• TherapyTherapy

QRS Normal

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Premature Atrial Contraction (PAC)Premature Atrial Contraction (PAC)

QRS Normal

Sinus Node

Atrium

AV Node

Ventricle

PAC

Premature Beat Present

Pause (Incomplete) Sinus Node Reset

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Atrial FibrillationAtrial Fibrillation

Atrial rate cannot be measuredAtrial rate cannot be measured

Ventricular rateVentricular rate——variablevariable

Irregular (irregularly irregular)Irregular (irregularly irregular)

Absent (fibrillation waves)Absent (fibrillation waves)

Conduction irregularConduction irregular

Slow ventricular rateSlow ventricular rate



• P wavesP waves• F F → QRS→ QRS• TherapyTherapy

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Atrial FlutterAtrial Flutter

Atrial rate 250-400/min (often 300)Atrial rate 250-400/min (often 300)

Ventricular rateVentricular rate—v—variableariable

Regular (2:1 AV block common)Regular (2:1 AV block common)

Absent (flutter waves)Absent (flutter waves)

Conduction regular (unless variable block)Conduction regular (unless variable block)

Slow ventricular rate: terminate arrhythmiaSlow ventricular rate: terminate arrhythmia



• P wavesP waves• F F → QRS→ QRS• TherapyTherapy

QRS Normal

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Supraventricular Tachycardia (SVT)Supraventricular Tachycardia (SVT)

AV AV NodalNodal Reentry Tachycardia Reentry TachycardiaAV Reentry TachycardiaAV Reentry Tachycardia Atrial TachycardiaAtrial Tachycardia

Connection betweenConnection betweenatria and ventricleatria and ventricle

Uses dual pathwayUses dual pathwaywithin AV nodewithin AV node

Ectopic atrial focusEctopic atrial focus

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Supraventricular Tachycardia (SVT)Supraventricular Tachycardia (SVT)

AV Reentry Tachycardia

Connection betweenatria and ventricle

Connection betweenatria and ventricle

What is differentbetween these2 examples?(Look carefully atthe arrow directions)

Is the QRS complexnormal or wide for each?

Why?

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Reentry (Paroxysmal) SVTReentry (Paroxysmal) SVT

Atrial rate 150-250/minAtrial rate 150-250/min

Onset tachycardiaOnset tachycardia abruptabrupt

RegularRegular

PresentPresent——inverted in leads 2, 3, and aVFinverted in leads 2, 3, and aVF

Conduction regularConduction regular

Vagal maneuvers, adenosine, Vagal maneuvers, adenosine, synchronized cardioversionsynchronized cardioversion



Usually onsets with PAC

QRS Normal

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Self-AssessmentSelf-AssessmentWhat are the rate and rhythm?What are the rate and rhythm?

B

A

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Clinical CorrelationClinical Correlation

This patient is unresponsive and This patient is unresponsive and BP is 70/50 mm Hg.BP is 70/50 mm Hg.

What is the rhythm?What is the rhythm?

What is your next action?What is your next action?

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Basic ArrhythmiasBasic ArrhythmiasVentricular ArrhythmiasVentricular Arrhythmias

Premature Ventricular Contraction (PVC)Premature Ventricular Contraction (PVC)Ventricular Premature Contraction (VPC)Ventricular Premature Contraction (VPC)

Premature Ventricular Beat (PVB) Premature Ventricular Beat (PVB)Premature Ventricular ComplexPremature Ventricular Complex

Ventricular TachycardiaVentricular TachycardiaVentricular FibrillationVentricular Fibrillation

AsystoleAsystolePulseless Electrical Activity (PEA)Pulseless Electrical Activity (PEA)

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Premature Ventricular Premature Ventricular Contraction (PVC)Contraction (PVC)

Compensatory pauseSinus node continues to discharge

2 HR

P wave obscured

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Mechanism PVCsMechanism PVCs

Unidirectional Unidirectional BlockBlock

ReentryReentry

Purkinje FiberPurkinje Fiber

Muscle Fiber

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PVC Morphology—Match the NamePVC Morphology—Match the Name

• Unifocal PVCs

• Multifocal PVCs

• Bigeminy

• Ventricular Tachycardia

• Torsades

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Ventricular TachycardiaVentricular TachycardiaMonomorphic*Monomorphic*

Atrial rate normal Atrial rate normal

Onset tachycardia abruptOnset tachycardia abrupt

RegularRegular

PresentPresent——obscuredobscured

BlockedBlocked——fusion complexes possiblefusion complexes possible

Antiarrhythmic agent, cardioversion, Antiarrhythmic agent, cardioversion,

high-energy (defibrillation dose) shock high-energy (defibrillation dose) shock



*Sustained—requires intervention for >30 seconds*Sustained—requires intervention for >30 seconds

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Polymorphic VT*Polymorphic VT*

Atrial rate normal (obscured)Atrial rate normal (obscured)

Onset tachycardia abruptOnset tachycardia abrupt

IrregularIrregular

PresentPresent——obscuredobscured

BlockedBlocked——fusion complexes possiblefusion complexes possible

Unsynchronized high-energy shock,Unsynchronized high-energy shock,magnesium (beneficial with baseline QTmagnesium (beneficial with baseline QTCC

prolongation)prolongation)



*Torsades de pointes*Torsades de pointes——QT prolongedQT prolonged

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Ventricular FibrillationVentricular Fibrillation

Chaotic, uncountable Chaotic, uncountable

Onset abruptOnset abrupt

IrregularIrregular

Absent; no normal QRS complexesAbsent; no normal QRS complexes

Not applicableNot applicable

Immediate shock(s) Immediate shock(s)



Coarse VF

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Ventricular FibrillationVentricular Fibrillation

Chaotic, uncountable Chaotic, uncountable

Onset abruptOnset abrupt

IrregularIrregular

Absent; no normal QRS complexesAbsent; no normal QRS complexes


Immediate shock(s) Immediate shock(s)



Fine VF

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AsystoleAsystole

Absent Absent

NoneNone——“flatline”“flatline”

AbsentAbsent


CPR, vasopressor, atropine CPR, vasopressor, atropine


Agonal ComplexesPulseless Electrical

Activity

ASYSTOLE

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Pulseless Electrical Activity (PEA)Pulseless Electrical Activity (PEA)

VariableVariable——depends on baseline rhythm depends on baseline rhythm

PEA is not a single rhythm but anyPEA is not a single rhythm but any

organized rhythm without a pulseorganized rhythm without a pulse

Identify and treat underlying causeIdentify and treat underlying cause

CPR, vasopressor, atropine CPR, vasopressor, atropine


• TherapyTherapy

ARTERIAL PRESSURE

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A

B

A B

C

Self-AssessmentSelf-Assessment

What are the rate and rhythm?What are the rate and rhythm?

36


You see this rhythm on the monitor while You see this rhythm on the monitor while standing next to the patient.standing next to the patient.

How many rhythms do you see?How many rhythms do you see?

What is your first action?What is your first action?

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Atrioventricular BlocksAtrioventricular Blocks

First-Degree AV BlockFirst-Degree AV Block

Second-Degree AV BlockSecond-Degree AV Block

Third-Degree AV blockThird-Degree AV block

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Atrioventricular BlocksAtrioventricular Blocks

ClassificationClassification

• Complete AV BlockComplete AV Block

Third-Degree AV BlockThird-Degree AV Block

• Incomplete AV BlockIncomplete AV Block

First-Degree AV BlockFirst-Degree AV Block

Second-Degree AV BlockSecond-Degree AV Block

Type IType I——WenckebachWenckebach Mobitz I Mobitz I

Type IIType II——Mobitz IIMobitz II

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Atrioventricular Block Atrioventricular Block Normal AV ConductionNormal AV Conduction

• Underlying sinus Underlying sinus rhythmrhythm

• One P waveOne P wave

• PR interval 0.12 to PR interval 0.12 to 0.20 second0.20 second

• One P wave for each One P wave for each QRSQRS

AV NodalAV NodalTissueTissue

AV NodeAV Node

His-Purkinje SystemHis-Purkinje System

PP

QRS <0.12QRS <0.12

0.12-0.20 seconds0.12-0.20 seconds

Sinus NodeSinus Node

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First-Degree AV Block First-Degree AV Block

• Underlying sinus rhythmUnderlying sinus rhythm

• One P wave One P wave

• PR interval >0.20PR interval >0.20secondsecond




PP

QRS <0.12QRS <0.12

>0.20 seconds>0.20 seconds


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AV NodeAV Node


PP

QRS <0.12QRS <0.12





• PR interval >0.20PR interval >0.20secondsecond


First-Degree AV Block First-Degree AV Block

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• P wave fails to P wave fails to periodicallyperiodicallyconduct conduct

• PR interval prolongedPR interval prolonged

• One P wave for each One P wave for each QRS until blockQRS until block

PR intervalPR interval





QRSQRS

XX

PP

Second-Degree AV Block—Mobitz ISecond-Degree AV Block—Mobitz IWenckebach PhenomenonWenckebach Phenomenon

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• PR interval usually PR interval usually normal, no prolongationnormal, no prolongation

• One P wave for each QRS One P wave for each QRS until sudden block and until sudden block and dropped QRSdropped QRS

Second-Degree AV BlockSecond-Degree AV Block——Mobitz IIMobitz II

PR intervals unchanged


AV NodeAV Node


PP

Often normal Often normal QRS complexQRS complex

Often NormalOften Normal


BlockBlock

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• Underlying sinus rhythm Underlying sinus rhythm (usual)(usual)

• Escape junctional rate 40-60 Escape junctional rate 40-60

• PR interval variablePR interval variable

• P waves unrelated to QRSP waves unrelated to QRS

• Narrow QRS = block above Narrow QRS = block above His junctionHis junction

AV NodeAV Node

His Purkinje SystemHis Purkinje System

PP

QRS <0.12QRS <0.12


QRS fromQRS fromAV-HisAV-His

escapeescape

Third-Degree AV Block—Junctional EscapeThird-Degree AV Block—Junctional EscapeP waves unrelated to QRS

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• Underlying sinus rhythm Underlying sinus rhythm (usual)(usual)

• Escape ventricular rate Escape ventricular rate 30-40 30-40

• PR interval variablePR interval variable

• P waves unrelated to QRSP waves unrelated to QRS

• Wide QRS = block below Wide QRS = block below His junctionHis junction

AV NodeAV Node

PP



QRS >0.12QRS >0.12QRS fromQRS fromHis-PurkinjeHis-Purkinje escapeescape

P waves unrelated to QRS

Third-Degree AV Block—Third-Degree AV Block—Ventricular EscapeVentricular Escape

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AV Block—Which Type?AV Block—Which Type?

47


What treatment is indicated?What treatment is indicated?

An athlete in the ED with a sprained ankle

A diabetic woman in the ED with chest tightness

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What treatment is indicated?What treatment is indicated?

A 78-year-old woman with altered consciousness, BP 80/60 mm HgA 78-year-old woman with altered consciousness, BP 80/60 mm Hg

External pacer not immediately available


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PacingPacingTranscutaneous—TransvenousTranscutaneous—Transvenous

Ventricular,Ventricular,

Atrial, and Dual ChamberAtrial, and Dual Chamber

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• TranscutaneousTranscutaneous

• Transvenous Transvenous

− VentricularVentricular

− AtrialAtrial

− Dual ChamberDual Chamber

PacemakersPacemakers

–

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–• TranscutaneousTranscutaneous


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• Transvenous Transvenous

— VentricularVentricular


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Sinus Node

Pacemaker MalfunctionPacemaker Malfunction

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Transvenous Transvenous

— AtrialAtrial

— Dual ChamberDual Chamber

A V

“PR”


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CardioversionCardioversion

• SynchronizedSynchronized

• TranscutaneousTranscutaneous

–

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CardioversionCardioversionEnergy RecommendationsEnergy Recommendations

Biphasic WaveformBiphasic Waveform

• Atrial FibrillationAtrial Fibrillation 120-200 J Initial 120-200 J Initial

• Atrial Flutter & SVT 50-100 J InitialAtrial Flutter & SVT 50-100 J Initial

• Monomorphic VTMonomorphic VT 100 J Initial 100 J Initial

• Increase the energy dose in a stepwise Increase the energy dose in a stepwise fashion for any subsequent fashion for any subsequent cardioversion attemptscardioversion attempts

• Use manufacturer-recommended dosesUse manufacturer-recommended doses

–

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CardioversionCardioversionEnergy RecommendationsEnergy Recommendations

Monophasic WaveformMonophasic Waveform

• Atrial FibrillationAtrial Fibrillation 200 J200 J

• Atrial Flutter & SVTAtrial Flutter & SVT 200 J200 J

• Monomorphic, UnstableMonomorphic, UnstableWith Pulse 100 JWith Pulse 100 J

• Polymorphic or Pulseless VT—Treat as Polymorphic or Pulseless VT—Treat as VF with high-energy unsynchronized VF with high-energy unsynchronized defibrillation dosesdefibrillation doses

(Do not use low energy—high likelihood of causing (Do not use low energy—high likelihood of causing VF in unsynchronized mode)VF in unsynchronized mode)

–

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BasicBasic Arrhythmias Arrhythmias

QUESTIONS?QUESTIONS?

1 basic arrhythmias © 2011 american heart association. do not edit

Documents

atrial fibrillationatrial

atrial flutteratrial

heart rate estimationpick

pacqrs normal

standard monitoring

sqrs complex

qrs complexnormal

impulse conduction