EKG

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Rapid Interpretation of ECGsRapid Interpretation of ECGsThe Dale Dubin MethodThe Dale Dubin Method

David Myers, MS,RN,ANPDavid Myers, MS,RN,ANP--BCBC

Richard J. Nadan, MBA,MS,RN,ACNPRichard J. Nadan, MBA,MS,RN,ACNP--BCBC

With Sections from:With Sections from: IntroductionIntroduction

Why the Dale Dubin method?Why the Dale Dubin method? Classic, most popular, & most referencedClassic, most popular, & most referenced

ECG text bookECG text book

First published in April, 1970First published in April, 1970

Printed in 46 languagesPrinted in 46 languages

Uses a systematic & logical approachUses a systematic & logical approach

Quick & easy learningQuick & easy learning

Used by all healthcare professionalsUsed by all healthcare professionalsaround the worldaround the world

Myth or Fact?Myth or Fact?

Who is Dale Dubin, MD?Who is Dale Dubin, MD? Born in 1940Born in 1940

A famous, millionaire, plastic surgeon &A famous, millionaire, plastic surgeon &medical school professormedical school professor

Arrested in Florida in 1986 & charged withArrested in Florida in 1986 & charged withsending & receiving child pornography bysending & receiving child pornography byUS mailUS mail

Sentenced to 5 years in jail on 22 counts ofSentenced to 5 years in jail on 22 counts ofchild pornography & cocaine usechild pornography & cocaine use

He was released in 1989He was released in 1989

Myth or Fact?Myth or Fact?

Although Dr. Dubin lost his medicalAlthough Dr. Dubin lost his medicallicense he continues to publish highlicense he continues to publish high

quality texts on topics in cardiology &quality texts on topics in cardiology &electrophysiologyelectrophysiology

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And now, to the reallyAnd now, to the reallyimportant stuffimportant stuff

Cardiovascular AnatomyCardiovascular Anatomy

Tissue LayersTissue Layers

EndocardiumEndocardium

MyocardiumMyocardium

PericardiumPericardium


Coronary CirculationCoronary Circulation


Cardiovascular AnatomyCardiovascular Anatomy Cardiovascular AnatomyCardiovascular Anatomy

RCARCA:: SA Node 50% of population, AV Node 90%, RtSA Node 50% of population, AV Node 90%, Rtatrium, Rt ventricleatrium, Rt ventricle

Inferior wall of LV, Posterior wall 90%Inferior wall of LV, Posterior wall 90%

LCALCA:: Left anterior descendingLeft anterior descending

Anterior wall, septum, His bundle, rt bundle,Anterior wall, septum, His bundle, rt bundle,Anterior fascicle of left bundleAnterior fascicle of left bundleCircumflexCircumflexSA node 50%, AV node 10%, Left atrium, LateralSA node 50%, AV node 10%, Left atrium, Lateralwall of left ventricle, Posterior wall 10%,wall of left ventricle, Posterior wall 10%,Posterior fascicle of left branchPosterior fascicle of left branch

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Cardiac PhysiologyCardiac PhysiologyThe Cardiac CycleThe Cardiac Cycle

DiastoleDiastole

SystoleSystole

Ejection FractionEjection Fraction

Stroke VolumeStroke Volume

PreloadPreload

Cardiac ContractilityCardiac Contractility

AfterloadAfterload

Cardiac PhysiologyCardiac Physiology

Nervous Control ofNervous Control of

the Heartthe Heart SympatheticSympathetic

ParasympatheticParasympathetic

AutonomicAutonomicControl of theControl of theHeartHeart

Role ofRole ofElectrolytesElectrolytes


ElectrophysiologyElectrophysiology

Cardiac MuscleCardiac Muscle

AtrialAtrial

VentricularVentricular

Excitatory &Excitatory &Conductive FibersConductive Fibers

AtrioventricularAtrioventricularBundleBundle


Cardiac Conduction System: PropertiesCardiac Conduction System: Properties

ExcitabilityExcitability

ConductivityConductivity

AutomaticityAutomaticity

ContractilityContractility


ComponentsComponents Sinoatrial NodeSinoatrial Node

InternodalInternodalAtrial PathwaysAtrial Pathways

AtrioventricularAtrioventricularNodeNode

AtrioventricularAtrioventricularJunctionJunction

Bundle of HisBundle of His

Left & RightLeft & RightBundle BranchesBundle Branches

Purkinje FibersPurkinje Fibers

A Brief History of EKGsA Brief History of EKGs

In 1790, LuigiIn 1790, LuigiGalvani made aGalvani made adead frogdead frogs legss legsdance by electricaldance by electricalstimulationstimulation

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In 1855, Kollicker &In 1855, Kollicker &

Mueller found thatMueller found thatwhen a motor nervewhen a motor nerveto a frogto a frogs leg wass leg waslaid over its isolatedlaid over its isolatedbeating heart, thebeating heart, theleg kicked with eachleg kicked with eachheartbeatheartbeat


This made an association between theThis made an association between the

rhythmic pumping of the heart & anrhythmic pumping of the heart & anelectrical phenomenaelectrical phenomena

Very basic & very importantVery basic & very important


In the mid 1880sIn the mid 1880sLudwig & WallerLudwig & Wallerused aused a capillarycapillaryelectrometerelectrometer totomonitor the heartsmonitor the heartselectric stimuli fromelectric stimuli froma persona persons skins skin


Dr. WillemDr. WillemEinthoven placedEinthoven placedskin sensors on askin sensors on aperson & suspendedperson & suspendeda silver wirea silver wirebetween the poles ofbetween the poles ofa magnet. The wirea magnet. The wiretwitched with eachtwitched with eachheart beat.heart beat.


This was a great idea, but Dr. EinthovenThis was a great idea, but Dr. Einthovenwanted a timed tracingwanted a timed tracing

He drilled two holes in the poles of theHe drilled two holes in the poles of themagnet & projected a light beammagnet & projected a light beamthough the holes onto photographicthough the holes onto photographicpaperpaper

He named the waves P, QRS, & THe named the waves P, QRS, & T

He named his 1901 invention theHe named his 1901 invention theEElectrolectroKKardioardioGGramram


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Since 1901 the medical profession hasSince 1901 the medical profession has

usedused EKGEKG to represent theto represent theelectrocardiogram. Some say thatelectrocardiogram. Some say thatECGECG is more correct. Medicine tendsis more correct. Medicine tendsto honor tradition & has used EKG forto honor tradition & has used EKG forover a century.over a century.

Basic PrinciplesBasic Principles

The EKG records the electrical activityThe EKG records the electrical activity

of contraction of the myocardiumof contraction of the myocardium

The EKG provides a record of cardiacThe EKG provides a record of cardiacelectrical activityelectrical activity

The EKG provides information aboutThe EKG provides information aboutthe heartthe hearts function & structures function & structure

Basic PrinciplesBasic Principles Basic PrinciplesBasic Principles

Myocytes (myocardial cells) areMyocytes (myocardial cells) arepolarized (negative) at restpolarized (negative) at rest

When depolarized (positive) theyWhen depolarized (positive) theycontractcontract

Technically, however, in the strictestTechnically, however, in the strictestsense, a resting polarized cell has asense, a resting polarized cell has anegatively charged interior & anegatively charged interior & apositively charged outside surface. Butpositively charged outside surface. But

we will keep this simple & onlywe will keep this simple & onlyconsider the interior.consider the interior.


Depolarization can be considered aDepolarization can be considered awave traveling through the heartwave traveling through the heart

The cellThe cell--toto--cell conduction ofcell conduction ofdepolarization through thedepolarization through themyocardium is carried by fastmyocardium is carried by fast--movingmovingNaNa++ ionsions


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Cardiac DepolarizationCardiac Depolarization


Repolarization is an electrical phenomenonRepolarization is an electrical phenomenonthat begins immediately after depolarization.that begins immediately after depolarization.The broad hump that we see on an EKG waveThe broad hump that we see on an EKG waveis the most active phase of repolarizationis the most active phase of repolarization

Basic PrinciplesBasic Principles Sensors calledSensors called

electrodes are put onelectrodes are put onthe skinthe skin

As the positive wave ofAs the positive wave ofdepolarization withindepolarization withinthe myocytes flowsthe myocytes flowstowards a positivetowards a positiveelectrode, there is anelectrode, there is anupward deflection onupward deflection onthe EKGthe EKG


The heartThe hearts dominant pacemaker is thes dominant pacemaker is theSA Node (sinoatrial node)SA Node (sinoatrial node)

Its pacing activity is known as SinusIts pacing activity is known as SinusRhythmRhythm

Generation of pacemaking stimuli isGeneration of pacemaking stimuli isautomaticityautomaticity

Other focal areas of the heart that haveOther focal areas of the heart that haveautomaticity are calledautomaticity are called automaticityautomaticity

focifoci


The SA Node is located in the upperThe SA Node is located in the upper--posterior wall of the right atriumposterior wall of the right atrium

The depolarization wave flows awayThe depolarization wave flows awayfrom the SA Node in all directionsfrom the SA Node in all directions

Imagine the atria as a pool of water, aImagine the atria as a pool of water, apebble dropped in at the SA Nodepebble dropped in at the SA Nodeproduces an enlarging, circular waveproduces an enlarging, circular wave(depolarization) that spreads outward.(depolarization) that spreads outward.


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Basic PrinciplesBasic Principles Each depolarization wave emitted by the SA NodeEach depolarization wave emitted by the SA Node

spreads through both atria producing aspreads through both atria producing a P waveP wave ononthe EKGthe EKG

Note the positive wave of atrial depolarizationNote the positive wave of atrial depolarizationadvancing toward a positive electrode producing anadvancing toward a positive electrode producing anupward P waveupward P wave


The P waveThe P wave

represents therepresents thedepolarization ofdepolarization ofboth atria & theboth atria & thevirtuallyvirtuallysimultaneoussimultaneouscontraction of thecontraction of theatria.atria.


AtrioAtrio--Ventricular (AV) valves preventVentricular (AV) valves preventventricleventricle--toto--atrium blood backflowatrium blood backflow

AV valves electrically insulate theAV valves electrically insulate theventricles from the atriaventricles from the atria EXCEPT forEXCEPT forthethe AV NodeAV Node, the only conducting path, the only conducting pathbetween the atria & ventriclesbetween the atria & ventricles


The AV Node is just above, butThe AV Node is just above, butcontinuous with, a specializedcontinuous with, a specializedconduction system that distributesconduction system that distributesdepolarization to the ventricles verydepolarization to the ventricles veryefficiently.efficiently.


Blood flowBlood flow

OO22 depleted blood enters the RA via thedepleted blood enters the RA via the

IVC, SVC, & coronary sinusIVC, SVC, & coronary sinus Atrial contraction forces blood through theAtrial contraction forces blood through the

tricuspid valve into the RVtricuspid valve into the RV

Ventricular contraction will force bloodVentricular contraction will force bloodthrough the pulmonic valve into thethrough the pulmonic valve into thepulmonary arterypulmonary artery

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RememberRemember

TTriricuspid valve is on thecuspid valve is on the rirightght

Both atria contract simultaneously, bothBoth atria contract simultaneously, bothventricles contract simultaneouslyventricles contract simultaneously

Right & left sides of the heart have veryRight & left sides of the heart have verydifferent responsibilitiesdifferent responsibilities



Blood flowBlood flow

Blood enters the LA through theBlood enters the LA through thepulmonary veinspulmonary veins

The LA contracts & forces blood throughThe LA contracts & forces blood throughthe mitral valve into the LVthe mitral valve into the LV

The LV contracts & forces blood throughThe LV contracts & forces blood throughthe aortic valve in to the Ao (aorta) intothe aortic valve in to the Ao (aorta) intosystemic circulationsystemic circulation

RememberRemember MitraMitrall valve in on thevalve in on the llefteft



Back to the AV NodeBack to the AV Node

When the wave of atrial depolarizationWhen the wave of atrial depolarization

enters the AV Node, depolarization slowsenters the AV Node, depolarization slowsdown, producing a brief pausedown, producing a brief pause

This allows time for blood in the atria toThis allows time for blood in the atria toenter the ventriclesenter the ventricles

Slow conduction through the AV Node isSlow conduction through the AV Node iscarried by Cacarried by Ca++++ ionsions


RememberRemember

The AV Node is the only electricalThe AV Node is the only electricalconduction pathway between the atria &conduction pathway between the atria &

ventriclesventricles We are correlating electrical activity withWe are correlating electrical activity with

mechanical physiologymechanical physiology

Atria contract forcing blood through theAtria contract forcing blood through theAV valvesAV valves

It takes time for blood to flow though theIt takes time for blood to flow though thevalves into the ventriclesvalves into the ventricles

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Time for blood flow means a necessary pauseTime for blood flow means a necessary pause

It takes time for blood to flow though theIt takes time for blood to flow though thevalves into the ventriclesvalves into the ventricles

A necessary pause that produces a short flatA necessary pause that produces a short flatbaseline after each P wave on the EKGbaseline after each P wave on the EKG

Remember this pause!!! You will need it laterRemember this pause!!! You will need it later


Note the pauseNote the pause


Just a thoughtJust a thought

So far we have talked about NaSo far we have talked about Na++ & Ca& Ca++++

What medications do you know about thatWhat medications do you know about thatmight affect these channels?might affect these channels?


Depolarization conducts slowlyDepolarization conducts slowlythrough the AV Nodethrough the AV Node

Upon reaching the ventricularUpon reaching the ventricularconduction system, depolarizationconduction system, depolarizationrapidly shoots through therapidly shoots through the His BundleHis Bundle& the& the LeftLeft && Right Bundle BranchesRight Bundle Branches


The ventricular conduction system originatesThe ventricular conduction system originatesat the His Bundle, which penetrates the AVat the His Bundle, which penetrates the AVvalves, then immediately bifurcates in thevalves, then immediately bifurcates in theinterventricular septum into the Right & Leftinterventricular septum into the Right & LeftBundle BranchesBundle Branches

The His bundle & both Bundle Branches areThe His bundle & both Bundle Branches arebundlesbundles of rapidly conductingof rapidly conducting PurkinjePurkinjeFibersFibers


Like theLike themyocardium,myocardium,Purkinje Fibers usePurkinje Fibers usefastfast--moving Namoving Na++

ions for theions for theconduction ofconduction ofdepolarizationdepolarization

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The ventricular conduction system isThe ventricular conduction system is

composed of bundles of rapidlycomposed of bundles of rapidly--conducting Purkinje Fibers that carryconducting Purkinje Fibers that carrydepolarization away from the AV Nodedepolarization away from the AV Nodeat high speedat high speed


The Purkinje Fibers terminate in tinyThe Purkinje Fibers terminate in tiny

filaments that directly depolarize thefilaments that directly depolarize theventricular myocytesventricular myocytes

The rapid passage of depolarizationThe rapid passage of depolarizationdown the ventricular conductiondown the ventricular conductionsystem is too weak to record on thesystem is too weak to record on theEKGEKG


Depolarization of the ventricularDepolarization of the ventricularmyocardium records as a QRS complexmyocardium records as a QRS complex


The terminalThe terminalfilaments of thefilaments of thePurkinje FibersPurkinje Fibers

Producing a QRSProducing a QRScomplexcomplex


The terminal filaments of the PurkinjeThe terminal filaments of the PurkinjeFibers spread out just beneath theFibers spread out just beneath the

endocardium that lines both ventricularendocardium that lines both ventricularcavitiescavities

Ventricular depolarization begins at heVentricular depolarization begins at helining & proceeds outward to thelining & proceeds outward to theoutside surface (epicardium) of theoutside surface (epicardium) of theventriclesventricles


Purkinje Fibers branch & subdivide justPurkinje Fibers branch & subdivide justbeneath the endocardial lining, but dobeneath the endocardial lining, but do

not penetrate the myocardium.not penetrate the myocardium.

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The QRS complex actually represents theThe QRS complex actually represents thebeginning of ventricular contractionbeginning of ventricular contraction

The physical event of ventricular contractionThe physical event of ventricular contractionactually last longer than the QRS complexactually last longer than the QRS complex


The Q wave is the first downward waveThe Q wave is the first downward wave

of the QRS complex. It is followed by anof the QRS complex. It is followed by anupward R wave. The Q wave is oftenupward R wave. The Q wave is oftenabsent on the EKGabsent on the EKG


The Q wave, whenThe Q wave, whenpresent ALWAYSpresent ALWAYSoccurs at theoccurs at thebeginning of thebeginning of theQRS complex & isQRS complex & isthe first downwardthe first downwarddeflection of thedeflection of thecomplexcomplex


If there is anIf there is an upupward deflection in a QRSward deflection in a QRScomplex that appears before a Q wave, it iscomplex that appears before a Q wave, it isNOT a Q wave.NOT a Q wave.

When present, the Q wave is ALWAYS theWhen present, the Q wave is ALWAYS thefirst wave in the complexfirst wave in the complex

It is now popular to use small letter toIt is now popular to use small letter todesignate small waves in the QRS complex; adesignate small waves in the QRS complex; aqq wave is a small wave, awave is a small wave, a QQ wave is a bigwave is a bigwavewave


The first upward wave of the QRS is theThe first upward wave of the QRS is theR waveR wave

Any downward wave PRECEDED byAny downward wave PRECEDED byan upward wave is an S wavean upward wave is an S wave


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Basic PrinciplesBasic Principles An upward wave is always called an RAn upward wave is always called an R

wavewave

Distinguishing between the downwardDistinguishing between the downwardQ & downward S waves really dependsQ & downward S waves really dependson whether the downward wave occurson whether the downward wave occursbefore or after the R wavebefore or after the R wave

The Q is before the R, & the S is afterThe Q is before the R, & the S is afterthe Rthe R

Just remember the alphabet!Just remember the alphabet!

Lets Play Name That WaveLets Play Name That Wave

1:1: Q waveQ wave

2:2: R waveR wave

3:3: S waveS wave

4:4: QS waveQS wave

Name That WaveName That Wave

Yes, # 4 is a little unfair. There is no upward wave,Yes, # 4 is a little unfair. There is no upward wave,hence we cannot determine whether it is a Q wave orhence we cannot determine whether it is a Q wave oran S wave. Therefore it is called a QS wave, & isan S wave. Therefore it is called a QS wave, & isconsidered to be a Q wave when we look for Qsconsidered to be a Q wave when we look for Qs


Following the QRS complex, there is aFollowing the QRS complex, there is asegment of horizontal baseline known as thesegment of horizontal baseline known as theST segment, & then a broad T wave appearsST segment, & then a broad T wave appears


The St segment is aThe St segment is ahorizontal, flat, & mosthorizontal, flat, & mostimportantly, it isimportantly, it isnormally level withnormally level withother areas of theother areas of thebaselinebaseline

If it is elevated orIf it is elevated ordepressed beyond thedepressed beyond thenormal baseline level, itnormal baseline level, itis usually a seriousis usually a seriouspathologypathology


The ST segment represents the plateauThe ST segment represents the plateau(initial) phase of ventricular(initial) phase of ventricular

repolarization.repolarization. Ventricular repolarization is ratherVentricular repolarization is rather

minimal during the ST segmentminimal during the ST segment

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The T waveThe T wave

represents the final,represents the final,rapidrapid phase ofphase ofventricularventricularrepolarizationrepolarization


Both phases ofBoth phases of

repolarization isrepolarization isaccomplished by Kaccomplished by K++

ions leaving theions leaving themyocytesmyocytes

Ventricular systoleVentricular systolebegins with the QRSbegins with the QRS& persists until the& persists until theend of the T waveend of the T wave


Ventricular contraction (systole) spansVentricular contraction (systole) spansdepolarization & repolarization of thedepolarization & repolarization of theventriclesventricles

This a major & convenient physiologicalThis a major & convenient physiologicalmarkermarker


Since ventricular systole lasts from theSince ventricular systole lasts from thebeginning of the QRS until the end ofbeginning of the QRS until the end ofthe T wave, thethe T wave, the QT intervalQT interval has clinicalhas clinicalsignificancesignificance


The QT interval is a good indicator ofThe QT interval is a good indicator ofrepolarization, since repolarizationrepolarization, since repolarization

comprises most of the QT intervalcomprises most of the QT interval Patients with Long QT interval (LQT)Patients with Long QT interval (LQT)

syndromes are vulnerable to deadlysyndromes are vulnerable to deadlyrapid ventricular rhythmsrapid ventricular rhythms

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With rapid heart rates both depolarization &With rapid heart rates both depolarization &

repolarization occur faster for greaterrepolarization occur faster for greaterefficiency, therefore the QT interval variesefficiency, therefore the QT interval varieswith heart ratewith heart rate

Precise QT interval measurements arePrecise QT interval measurements arecorrected for rate, we call this the QTccorrected for rate, we call this the QTc

In general, the QT interval is normal if it isIn general, the QT interval is normal if it isless than half the Rless than half the R--toto--R interval at normalR interval at normalratesrates


Physiologically, a cardiac cyclePhysiologically, a cardiac cycle

represents atrial systole followed byrepresents atrial systole followed byventricular systole, & the resting stageventricular systole, & the resting stagethat follows until another cardiac cyclethat follows until another cardiac cyclebeginsbegins


So far you have seen the P, QRS, & TSo far you have seen the P, QRS, & Twaveswaves

There is one other wave that you mayThere is one other wave that you maysee on occasionsee on occasion

The U waveThe U wave


The U waveThe U wave

A small deflection that may occasionally followA small deflection that may occasionally follow

the T wavethe T wave Neither presence nor absence is abnormalNeither presence nor absence is abnormal

Part of ventricular repolarizationPart of ventricular repolarization

Generally small, rounded ( < 2 mm), sameGenerally small, rounded ( < 2 mm), samedirection as T wavedirection as T wave

Larger with at slow heart rate, smaller at fast heartLarger with at slow heart rate, smaller at fast heartraterate


U waveU wave

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The movement of three types of ions determinesThe movement of three types of ions determines

all aspects of cardiac conduction, contractions, &all aspects of cardiac conduction, contractions, &repolarizationrepolarization

Basic PrinciplesBasic Principles -- ReviewReview

Relationship of theRelationship of the

ECG to electrical eventsECG to electrical events

in the heartin the heart

ECG componentsECG components

P waveP wave

QRS complexQRS complex

T waveT wave

Basic PrinciplesBasic Principles -- ReviewReview

Basic PrinciplesBasic Principles -- ReviewReview Basic PrinciplesBasic Principles -- ReviewReview

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Recording the EKGRecording the EKG

EKG paper is graph paperEKG paper is graph paper

The smallest divisions are 1 mmThe smallest divisions are 1 mm

squaressquares 1 mm high x 1 mm long1 mm high x 1 mm long

Time axis (x) is horizontal & moves leftTime axis (x) is horizontal & moves leftto right, like we readto right, like we read

Amplitude axis (y) is verticalAmplitude axis (y) is vertical


Between heavy black lines there are 5 small squaresBetween heavy black lines there are 5 small squares

Each large square is formed by heavy black lines onEach large square is formed by heavy black lines oneach side & is 5 mm long x 5 mm higheach side & is 5 mm long x 5 mm high

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Deflection is the direction of a waveDeflection is the direction of a wave Upward or downwardUpward or downward

Amplitude is the magnitude of voltage of electrical activityAmplitude is the magnitude of voltage of electrical activity

Amplitude is measured from the baseline (isoelectric line)Amplitude is measured from the baseline (isoelectric line)


When a wave of depolarizationWhen a wave of depolarization

advances toward a positive skinadvances toward a positive skinelectrode it produces a positiveelectrode it produces a positivedeflectiondeflection

Be positive. This will make more sense in aBe positive. This will make more sense in alittle while.little while.


Upward deflectionsUpward deflectionsare called positiveare called positivedeflectionsdeflections

DownwardDownwarddeflections aredeflections arecalled negativecalled negativedeflectionsdeflections


As we said earlier, the horizontal axis is timeAs we said earlier, the horizontal axis is time

Each small box is 0.04 of a secondEach small box is 0.04 of a second

Each big box (or 5 small boxes) is 0.2 of aEach big box (or 5 small boxes) is 0.2 of asecondsecond


With this information it is now possible toWith this information it is now possible todetermine the time of any part of the cardiacdetermine the time of any part of the cardiaccyclecycle


EKG paper passes out of the EKG machine atEKG paper passes out of the EKG machine ata set & constant speeda set & constant speed

In 0.12 second, 3 small squaresIn 0.12 second, 3 small squares

In general, the paper travels at 25 mm / secondIn general, the paper travels at 25 mm / second

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A standard EKG is composed of 12A standard EKG is composed of 12

separate leadsseparate leads 6 limb leads6 limb leads

6 chest leads (also called precordial leads6 chest leads (also called precordial leadsor vector leads)or vector leads)



Limb leads are placed on the right &Limb leads are placed on the right &left arms & left legleft arms & left leg

Two electrodes are used to record aTwo electrodes are used to record aleadlead

A different pair for each leadA different pair for each lead



Remember the positive & negativeRemember the positive & negativedeflections that an EKG tracing candeflections that an EKG tracing can

make? This is where it all comesmake? This is where it all comestogethertogether


Bipolar limb leadsBipolar limb leadsare recorded using 2are recorded using 2electrodeselectrodes

Selecting differentSelecting differentelectrodes will yieldelectrodes will yielddifferent leadsdifferent leads

One electrode isOne electrode ispositive & one ispositive & one isnegativenegative

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Bipolar simply means one pole isBipolar simply means one pole is

positive & one pole is negativepositive & one pole is negative

The poles are the electrodesThe poles are the electrodes


Lead I is horizontalLead I is horizontal

Left arm positive, right arm negativeLeft arm positive, right arm negative

Lead II is diagonalLead II is diagonal

Left foot is positive, right arm is negativeLeft foot is positive, right arm is negative

Lead III is verticalLead III is vertical

Left foot is positive, but now the left arm isLeft foot is positive, but now the left arm isnegativenegative


The EKG machine will switch theThe EKG machine will switch thepolarity of the electrodes automaticallypolarity of the electrodes automatically

i.e.: the left arm switched from positive toi.e.: the left arm switched from positive tonegative depending which lead we werenegative depending which lead we werelooking atlooking at

This bipolar limb configuration is callThis bipolar limb configuration is callEinthovenEinthovens Triangle (remember him?)s Triangle (remember him?)


With your pen drawWith your pen draw

Negative sign (Negative sign (--) on) onyour right handyour right hand

Positive sign (+) onPositive sign (+) onyour left legyour left leg

Both signs (+/Both signs (+/--) on) onyour left handyour left hand

Lets play Twister!!!Lets play Twister!!!


Creating three intersecting lines produces aCreating three intersecting lines produces apoint of referencepoint of reference


So far we have discussed 3 of the 6 limbSo far we have discussed 3 of the 6 limbleadsleads

Lead ILead I

Lead IILead II

Lead IILead II

Now for the other 3Now for the other 3 AVRAVR

AVLAVL

AVFAVF

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Another standard lead is the AVF leadAnother standard lead is the AVF lead

AVF uses the left foot as positive & bothAVF uses the left foot as positive & botharms as a common negative groundarms as a common negative ground

TheThe AA in AVF meansin AVF means augmentedaugmented


Dr. Emanuel Goldberg designed theDr. Emanuel Goldberg designed the

augmented limb leadsaugmented limb leads He discovered that he had to amplifyHe discovered that he had to amplify

(augment) the voltage in the EKG(augment) the voltage in the EKGmachine to match the magnitude ofmachine to match the magnitude ofLeads I, II, & IIILeads I, II, & III

He named it A (augmented) V (voltage)He named it A (augmented) V (voltage)F (Foot)F (Foot)


AVF is a combination of Leads II & IIIAVF is a combination of Leads II & III

Recording the EKGRecording the EKG AVR & AVL are obtained in the same mannerAVR & AVL are obtained in the same manner

Augmented limb leads are unipolar becauseAugmented limb leads are unipolar becausethey stress the importance of the positivethey stress the importance of the positiveelectrodeelectrode


RememberRemember

AVAVRR RRight arm positiveight arm positive

AVAVLL LLeft arm positiveeft arm positive AVAVFF LeftLeft ffoot positiveoot positive


The augmented (unipolar) limb leads,The augmented (unipolar) limb leads,AVR, AVL, & AVF intersect at differentAVR, AVL, & AVF intersect at different

angles than the bipolar limb leads, I, II,angles than the bipolar limb leads, I, II,& III& III

They produce three other intersectingThey produce three other intersectinglines of referencelines of reference

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Recording the EKGRecording the EKG Recording the EKGRecording the EKG

The 6 limb leads combinedThe 6 limb leads combined


Deep breathDeep breath DonDont panic by thet panic by thekaleidoscope of limb leads. It will makekaleidoscope of limb leads. It will makemore sense in a little while.more sense in a little while.


Think of each leadThink of each leadas a camera lookingas a camera lookingat the heart from aat the heart from adifferent angledifferent angle

In the ICU orIn the ICU ortelemetry floor,telemetry floor,think of the camerathink of the cameraas a video cameraas a video camera


Points to rememberPoints to remember

The heartThe hearts electrical activity remains electrical activity remain

constantconstant The positive electrode position changesThe positive electrode position changes

from lead to leadfrom lead to lead

The tracing will look slightly different inThe tracing will look slightly different ineach leadeach lead



The angle from which we record theThe angle from which we record the

electrical activity changes with each leadelectrical activity changes with each lead A wave of depolarization is a progressiveA wave of depolarization is a progressive

wave of POSITIVE charges passingwave of POSITIVE charges passingthrough myocardial cellsthrough myocardial cells

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When a depolarization wave movesWhen a depolarization wave movestoward a POSITIVE electrode, a POSITIVEtoward a POSITIVE electrode, a POSITIVEdeflection is produceddeflection is produced

When a POSITIVE current moves toward aWhen a POSITIVE current moves toward aPOSTIVE electrode it produces a POSITVEPOSTIVE electrode it produces a POSITVEdeflectiondeflection

Repetitious, but vitally important!!!Repetitious, but vitally important!!!


Lets go car shoppingLets go car shopping

Based only on the photo below, would you buyBased only on the photo below, would you buythis car?this car?


Now would you buy this car?Now would you buy this car?

Recording the EKGRecording the EKG A bit of triviaA bit of trivia In 2001, Jeffrey Seiden, a thirdIn 2001, Jeffrey Seiden, a third--yearyear

medical student at Yale University, was studyingmedical student at Yale University, was studyinghis electrocardiography textbook when hehis electrocardiography textbook when hehappened upon the following message tucked awayhappened upon the following message tucked awayin the book's copyright notice:in the book's copyright notice: Congratulations forCongratulations foryour perseverance. You may win the car on page 46 byyour perseverance. You may win the car on page 46 bywriting down your name & address & submitting it towriting down your name & address & submitting it tothe publisher.the publisher.

Trivia ContinuedTrivia Continued

Dr. Dale Dubin had inserted the note into his 50thDr. Dale Dubin had inserted the note into his 50thprinting of his "Rapid Interpretation of EKGs,"printing of his "Rapid Interpretation of EKGs,"putting his classic Thunderbird up for grabs. Of theputting his classic Thunderbird up for grabs. Of the

60,000 who bought the book containing the offer,60,000 who bought the book containing the offer,only five spotted the hidden message & contacted theonly five spotted the hidden message & contacted thepublisher with news of their find. The five namespublisher with news of their find. The five nameswere placed in a hat, & Jeffrey Seiden's was chosen atwere placed in a hat, & Jeffrey Seiden's was chosen atrandom. The 1965 Thunderbird convertible wasrandom. The 1965 Thunderbird convertible wasdelivered to him on 4 December 2001 by Dubin'sdelivered to him on 4 December 2001 by Dubin'sdaughter, who drove it to Seiden's school.daughter, who drove it to Seiden's school.


The point of the car is that observationThe point of the car is that observationfrom six angles is clearly better than onefrom six angles is clearly better than one

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A positive left arm electrode is used to recordA positive left arm electrode is used to recordLATERAL leads (I & AVL)LATERAL leads (I & AVL)

A positive left foot electrode is used to recordA positive left foot electrode is used to recordINFERIOR leads (II, III, & AVF)INFERIOR leads (II, III, & AVF)


Lateral & inferior will play a role laterLateral & inferior will play a role later

when referring to myocardial ischemia,when referring to myocardial ischemia,injury, or infarctioninjury, or infarction


Now for the six chest leads (also calledNow for the six chest leads (also calledprecordial leads or vector leads)precordial leads or vector leads)


The chest leads are VThe chest leads are V11, V, V22, V, V33, V, V44, V, V55, &, &VV66

The chest lead is always positiveThe chest lead is always positive

The leads are positioned on the chestThe leads are positioned on the chestfrom right to left covering the heart infrom right to left covering the heart inits normal anatomical positionits normal anatomical position

Again, the lead is positive, the patientAgain, the lead is positive, the patientss

back is negativeback is negative


Each of the vectorEach of the vectorleads is orientedleads is orientedthrough the AVthrough the AV

Node & projectsNode & projectsthrough thethrough thepatientpatients back whichs back whichis negativeis negative

Dr. Frank WilsonDr. Frank Wilsonintroduced the Vintroduced the Vleadsleads

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One more timeOne more time

A positive depolarization wave movingA positive depolarization wave movingtowards a positive electrode produces atowards a positive electrode produces apositive deflectionpositive deflection

Get it?Get it?

Got it.Got it.

Good!Good!


When observing the chest leads from VWhen observing the chest leads from V11to Vto V66 you should note gradual changesyou should note gradual changesin all the waves as the position of thein all the waves as the position of thepositive electrode changes for eachpositive electrode changes for eachsuccessive leadsuccessive lead


Leads VLeads V11 & V& V22 are oriented over theare oriented over theright side of the heart while Vright side of the heart while V55 & V& V66 areareoriented over the left side of the heart.oriented over the left side of the heart.

Therefore they are often called the rightTherefore they are often called the right& left chest leads& left chest leads


Leads VLeads V33 & V& V44 are oriented over theare oriented over theinterventricular septum with Vinterventricular septum with V33 beingbeing

closer to the right ventricle & Vcloser to the right ventricle & V44 closercloserto the left ventricleto the left ventricle

The right & left bundle branches courseThe right & left bundle branches coursethrough the interventricular septumthrough the interventricular septum

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Quick reviewQuick review

The six limb leads all lie in the frontalThe six limb leads all lie in the frontalplaneplane

The six precordial leads lie in theThe six precordial leads lie in thehorizontal planehorizontal plane

6 + 6 = 12, therefore a 126 + 6 = 12, therefore a 12--Lead EKGLead EKG



We rarely place theWe rarely place theelectrodes on aelectrodes on apatientpatients wrists ors wrists orankles, so we haveankles, so we havemodified themodified thelocationslocations

Recording the EKGRecording the EKG -- ReviewReview

ECG LeadsECG Leads

Bipolar (Limb)Bipolar (Limb)

EinthovenEinthovenss

TriangleTriangle

Leads I, II, IIILeads I, II, III

Precordial (unipolar)Precordial (unipolar)

VV11 VV66


Lead ILead I

Left arm +Left arm +

Right armRight arm

Shoulder toShoulder toshouldershoulder

Always uprightAlways upright


Lead IILead II

Left leg +Left leg +

Right armRight arm

Right shoulder toRight shoulder toapexapex

Always uprightAlways upright

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Lead IIILead III Left leg +Left leg +

Left armLeft arm

Left Shoulder toLeft Shoulder toapexapex

UprightUpright


Leads I, II, IIILeads I, II, III


Enlargement ofEnlargement ofwaveformwaveform

aVR, aVL, aVFaVR, aVL, aVF


aVRaVR

UnipolarUnipolar

Right arm +Right arm +

Neutral referenceNeutral reference

Orphan leadOrphan lead

Negative deflectionNegative deflection

If positive, 98% ofIf positive, 98% ofthe time itthe time its VTs VT


aVLaVL

UnipolarUnipolar

Left arm +Left arm +


Upright deflectionUpright deflection


aVFaVF

UnipolarUnipolar

Foot +Foot +


PositivePositive

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Vector leadsVector leads

UnipolarUnipolar Encircle theEncircle the

pericardiumpericardium

V1: Right ventricleV1: Right ventricle

VV22 & V& V33::intraventricularintraventricularseptumseptum

VV4:4: cardiac apexcardiac apex

VV55 & V& V66: Left lateral: Left lateralwallwall

Recording the EKGRecording the EKG -- ReviewReview VV11: 4: 4

thth ICS @ rightICS @ rightsternal bordersternal border

VV22: 4: 4thth ICS @ leftICS @ left

sternal bordersternal border

VV44: 5: 5thth ICS @ MCLICS @ MCL

VV33: 5: 5thth ICS between VICS between V22

& V& V44 VV66: 5: 5

thth ICS @ MALICS @ MAL

VV55: 5: 5thth ICS between VICS between V44

& V& V66

Recording the EKGRecording the EKG -- ReviewReviewAutonomic Nervous SystemAutonomic Nervous System

Autonomic Nervous SystemAutonomic Nervous System

Regulates all vitalRegulates all vitalfunctions by reflexfunctions by reflex& CNS control& CNS control

Not consciousNot consciouscontrolcontrol


InhibitsInhibits

SympatheticSympathetic

StimulatesStimulates


Both the sympatheticBoth the sympathetic& parasympathetic& parasympatheticsystems secrete theirsystems secrete their

own neurotransmitterown neurotransmitter ParasympatheticParasympathetic

AcetylAcetylcholinecholine (Ach)(Ach)((cholinecholinergic)rgic)

SympatheticSympathetic Norepinephrine (NNorepinephrine (N--

epi or NE)epi or NE)((adrenadrenalinealine--like =like =adrenadrenergic)ergic)

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SympatheticSympathetic

NorepinephrineNorepinephrine

Activates cardiacActivates cardiac 11 adrenergic receptorsadrenergic receptors

Rate of SA Node pacingRate of SA Node pacing

Rate of conductionRate of conduction

Force of contractionForce of contraction

Irritability of fociIrritability of foci


Norepinephrine is a close relative ofNorepinephrine is a close relative of

epinephrine (epinephrine (adrenalineadrenaline))

Epinephrine is more potentEpinephrine is more potent

Both are emergency drugs as well asBoth are emergency drugs as well asnaturally occurring chemicalsnaturally occurring chemicals

Norepinephrine is also called LevophedNorepinephrine is also called Levophed

Autonomic Nervous SystemAutonomic Nervous System Autonomic Nervous SystemAutonomic Nervous System

Quick reviewQuick review WeWeve discussed norepinephrine,ve discussed norepinephrine,

epinephrine, &epinephrine, & receptorsreceptors

WeWeve discussed Nave discussed Na++, K, K++, Ca, Ca++++

Continue to think about all the differentContinue to think about all the differentcardiac & emergency medications we cancardiac & emergency medications we cangive our patients. Which ones might affectgive our patients. Which ones might affectall the receptors & electrolytes weall the receptors & electrolytes wevevediscusseddiscussed



InhibitoryInhibitory

Rate of SA Node pacingRate of SA Node pacing Rate of conductionRate of conduction

Force of contractionForce of contraction

Irritability of atrial & junctional fociIrritability of atrial & junctional foci


The vagus nerves are the bodyThe vagus nerves are the bodys mains mainparasympathetic pathwayparasympathetic pathway

Vagal stimulation = inhibitsVagal stimulation = inhibits Vagal stimulation also greatly affectsVagal stimulation also greatly affects

the gastrointestinal systemthe gastrointestinal system

Recalling the agony of a sever episode ofRecalling the agony of a sever episode ofvomiting or painful, crampy diarrhea willvomiting or painful, crampy diarrhea willhelp you to remember the parasympathetichelp you to remember the parasympatheticsystemsystem

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Controls blood flow & pressureControls blood flow & pressure

ConstrictionConstriction

DilationDilation

Alpha adrenergic = constrictsAlpha adrenergic = constricts

RememberRemember constricts ( see the nextconstricts ( see the nextphoto)photo)


Blood flow is very dependent on heartBlood flow is very dependent on heartraterate

Sympathetic stimulation increases the SASympathetic stimulation increases the SANode pacing rateNode pacing rate

Parasympathetic decreases itParasympathetic decreases it


Sever pain, seeing oneSever pain, seeing ones own blood,s own blood,severe loss of blood may induce asevere loss of blood may induce a

parasympathetic reflex causing syncopeparasympathetic reflex causing syncope This is known asThis is known as merciful syncopemerciful syncope butbut

better known in health care asbetter known in health care as vasovaso--vagalvagalsyncopesyncope

Be compassionate to the patient thatBe compassionate to the patient thatpassespasses--out when you draw their blood.out when you draw their blood.They cannot help it!They cannot help it!


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Vagal maneuversVagal maneuvers

Can be inducedCan be induced GaggingGagging

CoughingCoughing

Carotid sinusCarotid sinusmassage (DONmassage (DONT DOT DOTHIS UNLESS YOUTHIS UNLESS YOUREALLY KNOWREALLY KNOWWHAT YOU AREWHAT YOU AREDOING!!!)DOING!!!)


Pressure receptorsPressure receptors

BaroreceptorsBaroreceptors Especially sensitive when standingEspecially sensitive when standing

Normally sympathetic reflexes constrictNormally sympathetic reflexes constrictperipheral arteries & increase heart rateperipheral arteries & increase heart rateslightlyslightly

Orthostatic hypotension (postural hypotension)Orthostatic hypotension (postural hypotension)

Near syncopal or syncopal when standingNear syncopal or syncopal when standing

Autonomic Nervous SystemAutonomic Nervous System Autonomic Nervous SystemAutonomic Nervous System NeuroNeuro--cardiogenic syncopecardiogenic syncope

Pooling of blood in lower extremities fromPooling of blood in lower extremities fromprolonged standingprolonged standing

Sinus pacing accelerates, but peripheralSinus pacing accelerates, but peripheralvasoconstriction is inadequatevasoconstriction is inadequate

Partially filled ventricles contract rigorouslyPartially filled ventricles contract rigorouslywhich stimulates parasympatheticwhich stimulates parasympatheticmechanoreseptors in the LVmechanoreseptors in the LV

Parasympathetic reflex slows the SA NodeParasympathetic reflex slows the SA Node

BP fallsBP falls

Patient becomes syncopalPatient becomes syncopal

Autonomic Nervous SystemAutonomic Nervous System RateRate

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RateRate

RememberRemember

RateRate

When examining an EKG you shouldWhen examining an EKG you should

determine the regularity firstdetermine the regularity first RegularRegular

IrregularIrregular

Regularly irregular (has a pattern)Regularly irregular (has a pattern)

Irregularly irregular (no pattern)Irregularly irregular (no pattern)

Then examine the rateThen examine the rate Rate is read as cycles (beats) per minuteRate is read as cycles (beats) per minute

(bpm)(bpm)

RateRate The SA Node (Sinus Node) isThe SA Node (Sinus Node) is

the heartthe hearts dominant centers dominant centerof automaticityof automaticity

It is the heartIt is the hearts pacemakers pacemakerunder normal circumstancesunder normal circumstances

It paces the heart in theIt paces the heart in thenormalnormal range of 60range of 60 9999(100) bpm(100) bpm

The regular rhythm itThe regular rhythm itgenerates is called sinusgenerates is called sinusrhythm (SR)rhythm (SR)

RateRate

If the SA nodesIf the SA nodespaces at a rate lesspaces at a rate lessthan 60 bpm it isthan 60 bpm it iscalled sinuscalled sinusbradycardia (SB)bradycardia (SB)

Brady = slow; cardiaBrady = slow; cardia= heart= heart

RateRate

SB most often results fromSB most often results fromparasympathetic excess, as in aparasympathetic excess, as in a

conditioned athletes at restconditioned athletes at rest SB can be a sideSB can be a side--effect of medicationeffect of medication

RateRate If the SA Node paces faster than 100 (99) it is calledIf the SA Node paces faster than 100 (99) it is called

sinus tachycardia (ST)sinus tachycardia (ST) Tachy = fastTachy = fast

Exercise produces sympathetic stimulation, aExercise produces sympathetic stimulation, acommon cause of STcommon cause of ST

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RateRate

There are focal areas of automaticity in the heartThere are focal areas of automaticity in the heartknown as automaticity foci (ectopic foci)known as automaticity foci (ectopic foci)

They are potential pacemakersThey are potential pacemakers

Under normal circumstances they are electricallyUnder normal circumstances they are electricallysilent, hence potentialsilent, hence potential

RateRate

The proximal end of the AV Node hasThe proximal end of the AV Node has

no automaticity focino automaticity foci

The middle & distil regions do, this isThe middle & distil regions do, this iscalled the AV junctioncalled the AV junction

Junctional automaticity fociJunctional automaticity foci

The the AV junction paces at a rate of 40The the AV junction paces at a rate of 40-- 6060

RateRateNot the SA Node

RateRate

SA Node overdrive suppresses all other fociSA Node overdrive suppresses all other foci

All automaticity centers will overdriveAll automaticity centers will overdrive

suppress all others that have a slowersuppress all others that have a slowerpacemaker ratepacemaker rate

RateRate Overdrive suppression also provides an emergencyOverdrive suppression also provides an emergency

backupbackup RateRate

DonDont let the 80 vs. 100 conf use yout let the 80 vs. 100 confuse you

SA node is inherently 60SA node is inherently 60 99 (100)99 (100)

Atrial automaticity foci is 60Atrial automaticity foci is 60 80 !!!80 !!!

RateRate

So, without SA Node pacing & atrialSo, without SA Node pacing & atrialautomaticity foci can take over, if thatautomaticity foci can take over, if that

fails, the AV junction can take over, iffails, the AV junction can take over, ifthat fails, the ventricular automaticitythat fails, the ventricular automaticitycenter takes overcenter takes over

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RateRate

The AV junction has automaticity fociThe AV junction has automaticity foci

Its inherent rate is 40Its inherent rate is 40 60 bpm60 bpm

The proximal end of the AV Node has no fociThe proximal end of the AV Node has no foci

The middle & distil end of the AV Node doesThe middle & distil end of the AV Node doeshave focihave foci

If the junctional foci is the active pacemaker itIf the junctional foci is the active pacemaker itproduces a junctional rhythmproduces a junctional rhythm

RateRate

RateRate

Remember that the AV Node is the onlyRemember that the AV Node is the onlyconduction link between the atria &conduction link between the atria &ventricular conduction systemventricular conduction system

If there is a complete conduction blockIf there is a complete conduction blockin the AV Node then the AV junctionin the AV Node then the AV junctionwill not receive stimulus from above &will not receive stimulus from above &will take over pacingwill take over pacing

RateRate

RateRate

Ventricular automaticityVentricular automaticity

Inherent rate 20Inherent rate 20 --40 bpm40 bpm

Specialized Purkinje fibersSpecialized Purkinje fibers Produces an idioventricular rhythmProduces an idioventricular rhythm

Idio = Greek, meaningIdio = Greek, meaning oneones owns own

RateRate

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RateRate

A note one ventricular automactictyA note one ventricular automacticty

In a physiological or pathologicalIn a physiological or pathologicalemergency, an irritable automaticity focusemergency, an irritable automaticity focusmay suddenly discharge at a rapid rate.may suddenly discharge at a rapid rate.

Frequently this rate is around 150Frequently this rate is around 150 200200bpmbpm

This is a life threatening emergency calledThis is a life threatening emergency calledventricular tachycardia (VT)ventricular tachycardia (VT)

More about this laterMore about this later

RateRate

Easy rate determinationEasy rate determination

In an emergency you will not have timeIn an emergency you will not have timeto find or use a calculator, or theto find or use a calculator, or thepresence of mind to spend a long timepresence of mind to spend a long timeanalyzing an EKG strip.analyzing an EKG strip.

So here is a real quick & simpleSo here is a real quick & simplemethodmethod

RateRate

MemorizeMemorize

RateRate

First find an R wave that peaks on a heavyFirst find an R wave that peaks on a heavyblack line, this is STARTblack line, this is START

RateRate

Now, count off: 300, 150, 100Now, count off: 300, 150, 100

The line the R wave peaks on is START, then theThe line the R wave peaks on is START, then theheavy black lines that follow get countedheavy black lines that follow get counted

RateRate

One more timeOne more time

START, 300, 150, 100, 75, 60, 50,START, 300, 150, 100, 75, 60, 50,

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RateRate

What you are doing is called the tripletWhat you are doing is called the triplet

methodmethod

It works best for regular rhythmsIt works best for regular rhythms

RateRate

What is the rate?What is the rate?

RateRate

PracticePractice

RateRate

What is the rate?What is the rate?

RateRate

A = 100A = 100

B = about 150B = about 150

C = 60C = 60

D = 75D = 75

RateRate

Triplet methodTriplet method

Why does it make sense?Why does it make sense?

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RateRate RateRate

The small lines have values as wellThe small lines have values as well

In the back of your Jane Huff workbookIn the back of your Jane Huff workbookthere is a card forthere is a card for counting the boxescounting the boxes

This is the triplet methodThis is the triplet method

RateRate RateRate

Stop counting!!!Your patient is dead!!!

RateRate

Another method for rate determinationAnother method for rate determination

On the top of all EKG strips are 3On the top of all EKG strips are 3--secondsecond

interval hash marksinterval hash marks They could be noted as dots, lines,They could be noted as dots, lines,

triangles, circles, etctriangles, circles, etc

RateRate

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RateRate

We like to use a 6We like to use a 6--second strip to determinesecond strip to determine

raterate

RateRate Count the number of R to R cycles in a 6Count the number of R to R cycles in a 6--

second stripsecond strip

RateRate RateRate

RateRate

1 = 201 = 20

2 = about 452 = about 45

3 = 503 = 50

Rhythm InterpretationRhythm Interpretation

Now that you have all the basics lets getNow that you have all the basics lets getready to identify rhythmsready to identify rhythms

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At this point we will only be looking at 1 lead atAt this point we will only be looking at 1 lead at

a timea time It is important to remember that using only 1It is important to remember that using only 1

lead cannotlead cannot

Identify/locate an infarctIdentify/locate an infarct

Identify axis deviation or chamber enlargementIdentify axis deviation or chamber enlargement

Identify rightIdentify right--toto--left differences in conductionleft differences in conduction

Provide feedback about the quality or presence ofProvide feedback about the quality or presence ofpumping actionpumping action


Time IntervalsTime Intervals

PPR Interval:R Interval:

0.120.120.200.20

secsec

QRS Interval:QRS Interval:

0.080.080.12 sec0.12 sec

SSTT

Segment:Segment:

0.330.330.42 sec0.42 sec

Rhythm InterpretationRhythm Interpretation Rhythm InterpretationRhythm Interpretation

Absolute refractory periodAbsolute refractory period

Onset of the QRS to the peak of the TOnset of the QRS to the peak of the T

Cardiac cells are depolarized & are in theCardiac cells are depolarized & are in theprocess of repolarizingprocess of repolarizing

At this time the cells cannot be stimulated,At this time the cells cannot be stimulated,conduct, or contractconduct, or contract

Rhythm InterpretationRhythm Interpretation Rhythm InterpretationRhythm Interpretation

Relative refractory periodRelative refractory period

Peak of the T to end of the TPeak of the T to end of the T

Cells are repolarizedCells are repolarized This is a vulnerable periodThis is a vulnerable period

A strong stimulus can potentially take overA strong stimulus can potentially take overthe primary pacemaker of the heartthe primary pacemaker of the heart

This is calledThis is called R on T phenomenaR on T phenomena

Potential for sudden cardiac deathPotential for sudden cardiac death

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Arrhythmia literally means withoutArrhythmia literally means without

rhythmrhythm

Dysrhythmia means bad rhythm & isDysrhythmia means bad rhythm & isthe correct terminologythe correct terminology


Always be consistent & analyticalAlways be consistent & analytical

Always use the 5Always use the 5--step methodstep method Learn the rules for each dysrhythmiaLearn the rules for each dysrhythmia

Analyze a given rhythm strip according toAnalyze a given rhythm strip according toa specific formata specific format

Compare your analysis to the rules for eachCompare your analysis to the rules for eachdysrhythmiadysrhythmia

Identify the dysrhythmia by its similarityIdentify the dysrhythmia by its similarityto established rulesto established rules


The 5 step methodThe 5 step method

Determine the regularity (rhythm) of the RDetermine the regularity (rhythm) of the Rwaveswaves

Calculate the heart rateCalculate the heart rate

Identify & examine the P wavesIdentify & examine the P waves

Measure the PRI (PMeasure the PRI (P--R interval)R interval)

Measure the QRS complexMeasure the QRS complex


Step 1: Determine the regularityStep 1: Determine the regularity

RegularRegular

IrregularIrregular

Regularly IrregularRegularly Irregular

Irregularly IrregularIrregularly Irregular


Step 2: Calculate the rateStep 2: Calculate the rate

66--second stripsecond strip

Triplet methodTriplet method Heart rate calculator (counting the boxes)Heart rate calculator (counting the boxes)


Step 3: Identify & examine the P wavesStep 3: Identify & examine the P waves

Are P waves present?Are P waves present?

Are the P waves upright or inverted?Are the P waves upright or inverted? Do all the P waves look alike?Do all the P waves look alike?

Are the P waves regular (PAre the P waves regular (P--P interval)?P interval)?

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Step 4: The PRIStep 4: The PRI

Is there one P wave for each QRS complex?Is there one P wave for each QRS complex?

Analyzing the PAnalyzing the PR IntervalR Interval

Within normal limitsWithin normal limits

LongLong

ShortShort

ChangingChanging


Step 5:Step 5: The QRS complexThe QRS complex

Do all the QRS complexes look alike?Do all the QRS complexes look alike?

What is the QRS duration?What is the QRS duration?

R to R intervalR to R interval


In addition you can also look atIn addition you can also look at

T wave configurationT wave configuration

Check to see if there is a P wave hiddenCheck to see if there is a P wave hidden

Review of SA Node & AtrialReview of SA Node & AtrialRhythmsRhythms



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