MODULEMODULE 11

RhythmRhythm BasicsBasics ModuleModule 1:1: RhythmRhythm BBaasicssics OverviewOverview •• TheThe ConductionConduction SystemSystem –– ImpulseImpulse FormationFormation –– ImpulseImpulse ConductionConduction –– PropertiesProperties ofof CardiacCardiac FunctionFunction –– 55 PhasesPhases ofof ActionAction PotentialPotential •• RhythmRhythm DisordersDisorders –– MechanisMechanismsms –– ArrhythmArrhythmiaia RecognitionRecognition •• CausesCauses ofof RhythmRhythm DisordersDisorders ModuleModule 1:1: RhythmRhythm BBaasicssics

ObjectivesObjectives •• IdentifyIdentify thethe componentscomponents thatthat makemake upup thethe electricalelectrical pathwaypathway knownknown asas thethe conductionconduction systemsystem •• StateState thethe 55 phasesphases ofof actionaction potentialpotential •• DescribeDescribe thethe mechanismsmechanisms causingcausing rhythmrhythm disordersdisorders •• IdIdentifyentify rhythmrhythm ddiisorderssorders onon anan EKGEKG THETHE CONDUCTIONCONDUCTION SYSTEMSYSTEM HeartHeart BeBeatat AnatomyAnatomy

SINUS NODE • The Heart’s ‘Natural Pacemaker’ Sinus Node (SA Node) - 60-100 BPM at rest HeartHeart BeBeatat AnatomyAnatomy

AV NODE • Receives impulse from Sinus Node SA Node (SA Node) • Delivers impulse to the His- Purkinje System Atrioventricular Node (AV Node) • 40-60 BPM if SA Node fails to deliver an impulse HeartHeart BeBeatat AnatomyAnatomy

BUNDLE OF HIS •Begins conduction to Sinus Node the Ventricles (SA Node) • AV Junctional Tissue: 40-60 BPM Atrioventricular Node (AV Node)

Bundle of His HeartHeart BeBeatat AnatomyAnatomy

THE PURKINJE NETWORK • Bundle Branches Sinus Node (SA Node) • Purkinje Fibers • Moves the impulse through the ventricles for contraction Atrioventricular Node (AV Node) • Provides ‘Escape Rhythm’: 20-40 BPM

Bundle of His

Bundle Branches

Purkinje Fibers NormalNormal SinusSinus RhythmRhythm *Animation

Click heart to view animation ImpulseImpulse FormationFormation InIn SASA NodeNode AtrialAtrial DepolarizationDepolarization DelayDelay AtAt AVAV NodeNode ConductConductiionon ThroughThrough BundleBundle BranchesBranches ConductConductiionon ThroughThrough PurkinjePurkinje FiberFiberss VentricularVentricular DepDepoolarizationlarization PlateauPlateau PhasePhase ofof RepolarizationRepolarization FinalFinal RapidRapid (Phase(Phase 3)3) RepolarizationRepolarization NormalNormal EKGEKG ActivationActivation ReadingReading EKGsEKGs

IntervalsIntervals andand TimingTiming NormalNormal RRaannggeses inin MiMillisecolliseconds:nds:

•• PRPR IntervalInterval 120120 –– 220000 mmss •• QRSQRS ComplexComplex 6060 –– 110000 msms •• QTQT IntervalInterval 363600 –– 444040 mmss QuesQuestion?tion?

WherWheree doesdoes thethe SASA NodeNode getget itsits energy?energy? AutomaticAutomaticiityty

CardiacCardiac CCeellslls havehave AUTOMAUTOMATICIATICITTY!Y! AutomaticAutomaticiityty CaCardiacrdiac CellsCells

•• SpontaneouslySpontaneously depolarizedepolarize •• GenerallyGenerally presentpresent inin::

•• UpperUpper (SA(SA Node)Node) -- 660-0-101000 BPMBPM

•• MiddleMiddle (AV(AV JJuunction)nction) -- 440-0-6060 BPMBPM

•• LowerLower (Pur(Purkinjekinje Network)Network) -- 220–0–4040 BPMBPM AutomaticAutomaticiityty

OnceOnce aa papacemakercemaker cellcell initiainitiatestes anan impulse,impulse, itsits neighbneighboringoring cellscells followfollow suitsuit –– llikeike dominos!dominos! QuesQuestion?tion?

WhatWhat TriggersTriggers thethe FirstFirst Cell?Cell? ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

55 PhasesPhases ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

55 PhasesPhases •• PhasePhase 00 –R–Raappiidd oorr uuppssttrrookkee depodepolarizatlarizatiioonn witwithh anan infinflluxux ofof sodiumsodium ionsions intointo thethe cellcell ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

55 PhasesPhases •• PhasePhase 00 –R–Raappiidd uuppssttrrookkee depodepolarizatlarizatiioonn witwithh anan infinflluxux ofof sodiumsodium ionsions intointo thethe cellcell •• PhasePhase 11 –– EEarlyarly rapidrapid repolarizationrepolarization wwiithth transtransiientent outwoutwardard movemmovemeentnt ofof potassiumpotassium ionsions ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

55 PhasesPhases •• PhasePhase 00 –R–Raappiidd uuppssttrrookkee depodepolarizatlarizatiioonn witwithh anan infinflluxux ofof sodiumsodium ionsions intointo thethe cellcell •• PhasePhase 11 –– EEarlyarly rapidrapid repolarizationrepolarization withwith transienttransient onwardonward movemmovemeentnt ofof potassiumpotassium ionsions •• PhasePhase 22 –– PPlateaulateau Phase:Phase: ContinuedContinued InfluxInflux ofof SodiumSodium && slowslow InfluxInflux ofof CalciumCalcium ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

55 PhasesPhases •• PhasePhase 00 –R–Raappiidd uuppssttrrookkee depodepolarizatlarizatiioonn witwithh anan infinflluxux ofof sodiumsodium ionsions intointo thethe cellcell •• PhasePhase 11 –– EEarlyarly rapidrapid repolarizationrepolarization withwith transienttransient onwardonward movemmovemeentnt ofof potassiumpotassium ionsions •• PhasePhase 22 –– PPlateaulateau Phase:Phase: ContinuedContinued InfluxInflux ofof SodiumSodium && slowslow InfluxInflux ofof CalciumCalcium •• PhasePhase 33 –– RRepolarizationepolarization:: PPootastasssiiumum outflowoutflow ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

55 PhasesPhases •• PhasePhase 00 –R–Raappiidd uuppssttrrookkee depodepolarizatlarizatiioonn witwithh anan infinflluxux ofof sodiumsodium ionsions intointo thethe cellcell •• PhasePhase 11 –– EEarlyarly rapidrapid repolarizationrepolarization withwith transienttransient onwardonward movemmovemeentnt ofof potassiumpotassium ionsions •• PhasePhase 22 –– PPlateaulateau Phase:Phase: ContinuedContinued InfluxInflux ofof SodiumSodium && slowslow InfluxInflux ofof CalciumCalcium •• PhasePhase 33 –– RRepolarizationepolarization:: PPootastasssiiumum outflowoutflow •• PhasePhase 44 –– RRestingesting PhasePhase ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

RefractoryRefractory PeriodsPeriods

•• ERPERP -- EEffectffectiveive RefraRefracctorytory PeriodPeriod –Phases–Phases 0,0, 1,1, 22 andand earlyearly PhasePhase 33 –A–A depolarizationdepolarization cannotcannot bebe initiainitiatedted byby anan impulseimpulse ofof anyany strengthstrength ActionAction PotentialPotential ofof aa CardiacCardiac CellCell

RefractoryRefractory PeriodsPeriods •• RRPRRP -- RRelelatiativvee RefraRefracctorytory PeriodPeriod ––LLateate PhasePhase 33 andand earlyearly PhasePhase 44 ––AA strongstrong impulseimpulse cancan causecause dedepolapolarization,rization, possiblpossiblyy wiwithth ababerrancyerrancy ActionAction PotentialPotential ofof aa CardiacCardiac CellCell EffectiveEffective && RelativRelativee RefractoryRefractory PeriodsPeriods QuesQuestion?tion?

NowNow thatthat wewe understandunderstand impulseimpulse formationformation andand normalnormal heartheart function,function, let’slet’s thinthink…k… WhatWhat cancan possiblypossibly gogo wrongwrong?? RHYTHMRHYTHM DISORDERSDISORDERS RhythmRhythm DisordersDisorders 22 CaCategoritegorieses ofof RhytRhythmhm DisordersDisorders

ImpulseImpulse FormationFormation DisordersDisorders ofof ImpulseImpulse ConductioConductionn RhythmRhythm DisordersDisorders UnderlyingUnderlying MechanismsMechanisms

ImpulseImpulse FormationFormation •• AbAbnornormmalal AutomaticityAutomaticity

ImpulseImpulse ConductioConductionn MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders AbnormalAbnormal AutomaticiAutomaticityty

AbnormallyAbnormally SlowSlow == BradycardiaBradycardia •• FFailureailure duedue toto disdiseaseease

ExcessivelyExcessively RapidRapid == TachycardiaTachycardia •• DDueue toto sympatheticsympathetic nervousnervous systemsystem MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders

ImpulseImpulse FormationFormation •• AbAbnornormmalal AutomaticityAutomaticity •• TriggeredTriggered ActivitActivityy

ImpulseImpulse ConductioConductionn MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders TriggeredTriggered ActivityActivity

•• AAfterpotentialsfterpotentials occurrioccurringng inin PhasePhase 33 (early)(early) oror 44 (late)(late) ofof actionaction potentialpotential

•• CCanan triggertrigger arrhythmiasarrhythmias MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders TriggeredTriggered ActivityActivity

EarlyEarly AfteAfterdepolarizationrdepolarization LateLate AfterAfterddepolariepolarizzationation •• PotentiPotentiaall CaCauses:uses: •• PotentiPotentiaall CaCauses:uses: -- LLooww ppotassiumotassium bloodblood levelslevels –– PrematurePremature beatsbeats -- SSloloww heartheart raratete –– IncreasedIncreased calciumcalcium bloodblood -- DDrugrug toxictoxicityity (ex.(ex. QuiQuinnidineidine levelslevels – Increased adrenaline causingcausing ToTorsadesrsades dede Pointes)Pointes) – Increased adrenaline levelslevels –– DigitalisDigitalis toxitoxicitycity MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders UnderlyingUnderlying MechanismsMechanisms

ImpulseImpulse FormationFormation •• AbAbnornormmalal AutomaticityAutomaticity •• TriggeredTriggered ActivitActivityy

ImpulseImpulse ConductioConductionn •• SSllowow oror BBllocockkeedd ConductionConduction MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders *Animation SlowedSlowed oror BlBlockedocked ConductionConduction

•• ImpulseImpulse generatedgenerated normallynormally •• IImmpulsepulse slowsloweded oror blocblockkeedd asas itit mmaakkeess itsits wwaayy throughthrough thethe conductionconduction systemsystem MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders UnderlyingUnderlying MechanismsMechanisms

ImpulseImpulse FormationFormation •• AbAbnornormmalal AutomaticityAutomaticity •• TriggeredTriggered ActivitActivityy

ImpulseImpulse ConductioConductionn •• SSllowow oror BBllocockkeedd ConductionConduction •• ReentryReentry MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders ReentryReentry ConditionsConditions ooff ReentrReentryy MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders ReentryReentry

SubsSubstrtrateate ++ TrTriggeiggerr == ReeReenntrtryy MechanismsMechanisms ofof RhyRhytthmhm DisordersDisorders ReentryReentry ReentryReentry IdentifyingIdentifying ReentryReentry

•• PPaceace thethe heartheart atat aa rraatete fasterfaster thanthan thethe knownknown intrintrinsicinsic tachycardiatachycardia raterate •S•Sttoopp tthhee ppaacciinngg •• IIff thethe iinntritrinnsicsic rraatete rreesumessumes tactachhycardicycardic,, thenthen reentryreentry isis identiidentifiedfied RHYTHMRHYTHM DISORDERSDISORDERS

BradyarrhythmiasBradyarrhythmias BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation DisordersDisorders BradycardiasBradycardias ImpulseImpulse ConductioConductionn DisordersDisorders BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest DisordersDisorders

ImpulseImpulse ConductioConductionn DisordersDisorders SinusSinus ArrestArrest *Animation

•• FaiFaillureure ofof sisinusnus nodenode didischargescharge •• AbsenceAbsence ooff atatririalal depodepollaarizrizaattiioonn •• PeriodsPeriods ofof asystoleasystole BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest DisordersDisorders •• SinusSinus BrBradycadycardiaardia

ImpulseImpulse ConductioConductionn DisordersDisorders SinusSinus BradycardiaBradycardia

•• SinusSinus NodeNode emitsemits energyenergy veryvery slslowlyowly BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest DisordersDisorders •• SinusSinus BrBradycadycardiaardia •• BBrradyady//TacTachhyy SSyyndrndromeome

ImpulseImpulse ConductioConductionn DisordersDisorders Brady/TacBrady/Tachhyy SyndromeSyndrome

•• IntermittentIntermittent episodesepisodes ofof slowslow andand fafastst raratestes fromfrom thethe SASA nodenode oror aattririaa •• BradyBrady <6<600 BPMBPM •• TaTachchyy >>110000 BPBPMM BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest Disorders Disorders •• SinusSinus BrBradycadycardiaardia •• BBrradyady//TacTachhyy SSyyndrndromeome

ImpulseImpulse ConductioConductionn •• ExitExit BlockBlock DisordersDisorders ExitExit BlockBlock

•• TransientTransient blockblock ofof impulsesimpulses frfromom thethe SASA nodenode •• IdentifiedIdentified byby P-PP-P intervalinterval rreelationshiplationship BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest Disorders Disorders •• SinusSinus BrBradycadycardiaardia •• BBrradyady//TacTachhyy SSyyndrndromeome

ImpulseImpulse ConductioConductionn •• ExitExit BlockBlock Disorders Disorders •• 11stst DegreeDegree AVAV BlockBlock First-DegreeFirst-Degree AVAV BlockBlock

•• PRPR intervalinterval >> 200200 msms •• DelaDelayedyed conductionconduction throughthrough thethe AVAV NodeNode -- EExamplexample showsshows PRPR IntervalInterval == 320320 msms BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest Disorders Disorders •• SinusSinus BrBradycadycardiaardia •• BBrradyady//TacTachhyy SSyyndrndromeome

ImpulseImpulse ConductioConductionn •• ExitExit BlockBlock Disorders Disorders •• 11stst DegreeDegree AVAV BlockBlock •• 22ndnd DeDegreegree AVAV BlockBlock Second-DegreeSecond-Degree AVAV BlockBlock -- MMobitzobitz II *Animation KnownKnown asas WenckebachWenckebach BlockBlock

•• ProgressiveProgressive prolongaprolongatitionon ofof thethe PRPR intervintervaall untiluntil therethere isis fafaiillureure toto conductconduct aanndd aa vveentriculantricularr beabeatt isis dropdroppedped Second-DegreeSecond-Degree AVAV BlockBlock –– MMobitzobitz IIII

•• RegulRegulaarlyrly ddrroppedopped venventtricularricular bebeatsats –– Ex:Ex: 2:12:1 blockblock (2(2 P-wavesP-waves toto 11 QRSQRS complex)complex) –– AtrialAtrial raterate == 7575 BPMBPM –– VentricularVentricular raterate == 4242 BPBPMM BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest Disorders Disorders •• SinusSinus BrBradycadycardiaardia •• BBrradyady//TacTachhyy SSyyndrndromeome

ImpulseImpulse ConductioConductionn •• ExitExit BlockBlock Disorders Disorders •• 11stst DegreeDegree AVAV BlockBlock •• 22ndnd DeDegreegree AVAV BlockBlock •• 33rdrd DegrDegreeee AVAV BlockBlock Third-DegreeThird-Degree AVAV BlockBlock *Animation

•• NoNo impulseimpulse conductionconduction fromfrom thethe aattriaria ttoo thethe ventriclesventricles –– VentricularVentricular raterate == 3737 BPBPMM –– AtrialAtrial raterate == 130130 BPMBPM –– PRPR intervalinterval == variablevariable BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation •• SinusSinus ArrestArrest Disorders Disorders •• SinusSinus BrBradycadycardiaardia •• BBrradyady//TacTachhyy SSyyndrndromeome

ImpulseImpulse ConductioConductionn •• ExitExit BlockBlock Disorders Disorders •• 11stst DegreeDegree AVAV BlockBlock •• 22ndnd DeDegreegree AVAV BlockBlock •• 33rdrd DegrDegreeee AVAV BlockBlock •• Bi/TrifascicularBi/Trifascicular BloBlocckk BifascBifasciculicularar BlockBlock

•• AA completecomplete oror incompleteincomplete blockblock iinn aatt lealeasstt twotwo conductionconduction systemsystem ppaatthhwawaysys belobeloww thethe AVAV NodeNode •• MarkMarkeded byby aa widwideenedned QRSQRS BifascBifasciculicularar BlockBlock

Right bundle Complete left Right bundle RighRightt bbundundlele Complete left branch block bundle branch branch block branchbranch bbllockock anandd bundle branch and left anterior block and left anterior lefleftt posposteriterioror block hemiblock hemiblock hemihemiblockblock TrifascicularTrifascicular BlockBlock

•• CompleteComplete blockblock inin thethe rightright bundlebundle brabrannch,ch, andand •• ComplCompleetete oorr incompincompletletee blocblockk inin bothboth divisionsdivisions ofof thethe leftleft bundlebundle branchbranch •• IdentifiedIdentified byby EPEP StudyStudy BradyarrhythmiaBradyarrhythmia ClassificClassificaationstions SummarySummary

ImpulseImpulse FormationFormation ImpulseImpulse ConductionConduction DisorderDisorderss DisordersDisorders

•• SinusSinus ArrestArrest •• ExitExit BlockBlock •• SinusSinus BrBradycadycardiaardia •• 11stst DegreeDegree AVAV BlockBlock nd •• BBrradyady//TacTachhyy SSyyndrndromeome •• 22nd DeDegreegree AVAV BlockBlock --MobitzMobitz II (Wenckeb(Wenckebachach Block)Block) -Mobitz-Mobitz IIII •• 33rdrd DegrDegreeee AVAV BlockBlock •• Bi/TrifascicularBi/Trifascicular BloBlocckk RHYTHMRHYTHM DISORDERSDISORDERS

TachyarrhythmiasTachyarrhythmias TermsTerms DescribingDescribing TachycardiasTachycardias

•• ParoxysmalParoxysmal –– EctopicEctopic focus,focus, suddensudden onset,onset, abruptabrupt cesscessatioationn •• SustainedSustained –– DuratioDurationn ofof >> 3030 seconseconddss –– RequiresRequires iinnterventiontervention toto terminaterminattee •• NonNon--SustainedSustained –– AtAt leastleast 66 beatsbeats oror << 3030 secondsseconds –– SpontaneouslySpontaneously termiterminnatesates •• RecurrentRecurrent –– OccursOccurs periperiodicalodicallyly –– PeriodsPeriods ofof nono ttaachycachycarrdiadia areare lolongernger thathann periodsperiods ofof ttaachycachycarrdidiaa TermsTerms DescribingDescribing TachycardiasTachycardias

•• IncessantIncessant –– LongLong perioperioddss ofof tatachy,chy, shortshort perioperioddss ofof NSRNSR •• MonomorphicMonomorphic –– SingleSingle focusfocus –– CCoommpplelexxeess aarree simsimiilarlar wwiithth eeqquauall ininteterrvvalalss •• PoPolymorphiclymorphic –– MultipMultiplele focfocii –– ComplexesComplexes aappppeeaarr differentdifferent withwith vavariedried intervaintervallss •• SVTSVT (Supraventricular(Supraventricular Tachycardia)Tachycardia) –– OriginatingOriginating fromfrom aboveabove thethe ventriclesventricles TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder

ImpulseImpulse FormationFormation DisordersDisorders TachycardiasTachycardias ImpulseImpulse ConductioConductionn DisordersDisorders TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation DisordersDisorders

ImpulseImpulse ConductioConductionn DisordersDisorders SinusSinus TachycardiaTachycardia

• Origin: Sinus Node • Rate: 100-180 BPM • Mechanism: Abnormal (Hyper) Automaticity TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa DisordersDisorders

ImpulseImpulse ConductioConductionn DisordersDisorders AtrialAtrial TachycardiaTachycardia

• Origin: Atrium - Ectopic Focus • Rate: >100 BPM • Mechanism: Abnormal Automaticity TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa • Premature Contractions DisordersDisorders • Premature Contractions

ImpulseImpulse ConductioConductionn DisordersDisorders PrematurePremature BeatsBeats PrematurePremature AtrialAtrial ContractionContraction (PAC)(PAC)

•• Origin:Origin: AAtriumtrium (out(outsideside thethe SinusSinus Node)Node) •• MechMechanisanism:m: AbnoAbnormrmalal AAuuttoommataticiticityy •• ChChararactacteerisristtics:ics: AnAn ababnonormrmalal P-P-wwaavvee ooccurringccurring earlearlierier thanthan expected,expected, followefollowedd byby compensacompensatorytory pausepause PrematurePremature BeatsBeats PrematurePremature JunctionalJunctional ContractionContraction

•• Origin:Origin: AAVV NodeNode JunctionJunction •• MechMechanisanism:m: AbnoAbnormrmalal AAuuttoommataticiticityy •• ChChararactacteerisristtics:ics: AA nonormrmallyally conductedconducted complexcomplex wiwithth aann ababsesentnt p-p-wawave,ve, followfolloweedd bbyy aa compenscompensaattooryry ppaauseuse PrematurePremature BeatsBeats PrematurePremature VentricularVentricular ContractionsContractions (PVCs)(PVCs)

•• Origin:Origin: VVentriclesentricles •• MechMechanisanism:m: AbnoAbnormrmalal AAuuttoommataticiticityy •• CharCharacterisacteristtics:ics: AA broadbroad cocomplexmplex occuoccurringrring eeaarlierlierr thanthan expecexpectted,ed, follfollowedowed byby aa compenscompensaattooryry ppaauseuse PVCPVC PattePatternsrns

••BigeminyBigeminy --EveryEvery otherother bebeatat

••TrigeminyTrigeminy --EveryEvery thirdthird beatbeat

••QuadrigeQuadrigeminyminy --EveryEvery fourtfourthh bebeatat MultifocalMultifocal PVCPVC

••Origin:Origin: VVariesaries witwithhiinn thethe VentricleVentricle ••MechMechanisanism:m: AbnoAbnormrmalal AAuuttoommataticiticityy ••ChChararactacteerisristtics:ics: EachEach prempremaattureure bebeatat cchhaanngesges axisaxis;; impliesimplies aa didifferentfferent focusfocus originorigin forfor eacheach bebeatat TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm

ImpulseImpulse ConductioConductionn DisordersDisorders AcceleratAccelerateedd Idio-JunctionaIdio-Junctionall RhythmRhythm

••Origin:Origin: AAVV NodeNode oror JJuunctionanctionall TissueTissue ••MechMechanisanism:m: AbnoAbnormrmalal AAuuttoommataticiticityy ••CharacterisCharacteristtics:ics: OccursOccurs whenwhen cellscells depdepoolarizelarize atat aa raratete fafasterster thathann thethe SiSinusnus NodeNode TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm •• AccelerateAcceleratedd IdioveIdioventrintricularcular RhytRhythmhm (AIVR)(AIVR) ImpulseImpulse ConductioConductionn DisordersDisorders AcceleratedAccelerated IdioventricularIdioventricular RhythmRhythm

••Origin:Origin: VentricVentricllee ••MechanisMechanism:m: AbnorAbnormmalal AutomaticityAutomaticity ••RaRattee:: VentricularVentricular raratete >sinus>sinus rarate,te, butbut

SinusSinus RhyRhytthhmm beibeinngg taktakeenn oovverer bbyy aann IdioventricularIdioventricular RhythmRhythm TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm •• AccelerateAcceleratedd IdioveIdioventrintricularcular RhytRhythmhm (AIVR)(AIVR) ImpulseImpulse ConductioConductionn •• AtrialAtrial FluttFlutteerr DisordersDisorders AtrialAtrial FlutterFlutter *Animation

••Origin:Origin: RRightight && LefLeftt AtriumAtrium ••MechanisMechanism:m: ReentryReentry ••ChChararactacteerisristtics:ics: RaRapid,pid, regularregular p-wavesp-waves TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm •• AccelerateAcceleratedd IdioveIdioventrintricularcular RhytRhythmhm (AIVR)(AIVR) ImpulseImpulse ConductioConductionn •• AtrialAtrial FluttFlutteerr • Atrial Fibrillation DisordersDisorders • Atrial Fibrillation AtriaAtriall FibrFibrillaillationtion (AF)(AF) *Animation

•• Origin:Origin: RRightight and/oand/orr leftleft atriumatrium •• MechanisMechanism:m: MultipMultiplele waveletswavelets ofof reentryreentry •• RatRatee 400400 BBPPMM •• ChaCharraaccteristics:teristics: Random,Random, chachaoticotic rhythm;rhythm; atatririaa quivquiverer;; assoassociciatateedd witwithh irreirreggulularar veventriculntriculaarr rrhhyythmthm AtriaAtriall FibrFibrillaillationtion (AF)(AF) AFAF MechanismMechanism

WhyWhy AFAF begetsbegets AFAF

•• FreqFrequenuentt oror lolongng AFAF episoepisoddeses mmaayy causecause chrochronniicc oorr pepermrmananentent AFAF bbyy:: –– ProducingProducing pprrogressivelyogressively shshorterorter refrarefracctorytory periodsperiods aallollowiwingng reentryreentry wawavesves toto self-propaself-propagagatete && spreaspreadd OtherOther AFAF MechanismsMechanisms MultifocalMultifocal FiringFiring

••MechMechanisanism:m: AbnoAbnormrmalal AAuutomaticitytomaticity (multi(multi-sites)-sites) ••ChChararactacteerisristtics:ics: MaManyny dedepopollaarizrizaattiioonn wwaavveess;; aacctivtivaationtion ooccursccurs aassynchronously;ynchronously; notnot inin rhytrhythmhm withwith sinussinus nodenode OtherOther AFAF MechanismsMechanisms SingleSingle FocusFocus FirFiriingng

••MechMechanisanism:m: AbnoAbnormrmalal AAuuttoommataticiticityy (si(sinngle-gle- focufocus,s, usuallyusually inin thethe PostePosterriorior LeftLeft Atrium)Atrium) ••CharacterisCharacteristtics:ics: RRaapipidd discharge;discharge; singlesingle ectoectopicpic sitesite AtrialAtrial FlutterFlutter vs.vs. AtrialAtrial FibrillationFibrillation SummarySummary ofof DiseasDiseasee CharacteristicsCharacteristics AtrialAtrial FFlluttutteerr AtrialAtrial FFiibrillatiobrillationn

AtrialAtrial RateRate •• 252500 toto 404000 BBPPMM •• 404000 BPMBPM

VentVentricularricular •• VariVarieses w/conductionw/conduction •• VariVarieses w/conductionw/conduction RatRatee •• UsuallyUsually regulregulaarr •• GrosslyGrossly IrreguIrregularlar RhytRhythmhm • Saw tooth baseline • Wavy baseline PattePatterrnn • Saw tooth baseline • Wavy baseline

•• MultipleMultiple waveletwavelet rereentrentryy UnderlyingUnderlying •• ReentryReentry viavia macromacro MechanismMechanism reentrantreentrant circirccuituit •• Multiple/singMultiple/singllee focusfocus firinfiringg TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm •• AccelerateAcceleratedd IdioveIdioventrintricularcular RhytRhythmhm (AIVR)(AIVR) ImpulseImpulse ConductioConductionn •• AtrialAtrial FluttFlutteerr Disorders •• AtriaAtriall FibriFibrillallatitionon Disorders •• AVRTAVRT AVRTAVRT

•• AnAn SVTSVT causedcaused byby thethe existencexistencee ofof anan extraextra pathwaypathway frfromom thethe atriaatria toto thethe ventriclesventricles •• ExtraExtra pathwaypathway ++ AVAV NodeNode == rereentryentry •• 22 TypesTypes –– OrthodroOrthodromimicc •• AA toto VV throughthrough node,node, thenthen entersenters accessaccessoryory pathwaypathway toto looploop •• PrProducesoduces narnarrrowow comcompplleexx SVTSVT –– AntidromicAntidromic •• AA toto VV throughthrough acceaccessoryssory ppaathway,thway, thenthen entersenters nonodede ttoo looloopp •• PrProducesoduces wide-comwide-complplexex SVSVTT AVRTAVRT *Animation OrthodromicOrthodromic

••MechanisMechanism:m: ReentryReentry ••RatRatee:: 180180 -- 226060 BBPPM,M, sometsometiimesmes fasterfaster ••ChaCharraaccteristics:teristics: ExtraExtra electricaelectricall papatthhwayway toto ventriclesventricles Wolf-PWolf-Pararkkiinson-Whnson-Whiitete (WP(WPWW)) SyndromeSyndrome iiss mostmost commoncommon AVRTAVRT *Animation AntidromicAntidromic

••MechanisMechanism:m: ReentryReentry ••RatRatee:: 180180 -- 226060 BBPPM,M, sometsometiimesmes fasterfaster ••ChaCharraaccteristics:teristics: ExtraExtra electricaelectricall papatthhwayway toto ventriclesventricles producesproduces widewide compcomplexlex tatachycachycarrdiadia Wolff-ParWolff-Parkinson-Whitekinson-White

•• AccessoryAccessory PaPathwathwayy == BundleBundle ofof KentKent •• OrthodroOrthodromimicc -- 990%0% -- AAVV nodenode –– aantntegradeegrade conduconduccttiion;on; -E-Exxttrraa ppaatthhwwaayy –r–reettrrooggrraaddee ccoonndduuccttiioonn •• AntidromicAntidromic –– 10%10% -- EExtraxtra ppaatthhwayway –– aantntegradeegrade conductconductiionon -A-AVV nnooddee –r–reettrrooggrraaddee ccoonndduuccttiioonn Wolff-ParWolff-Parkinson-Whitekinson-White

••Origin:Origin: OutsideOutside tthhee AVAV NodeNode ••MechanisMechanism:m: ReentryReentry ••RatRatee:: 180180-260-260 BPMBPM –– ccanan bebe ffaasterster ••ChaCharraaccteristics:teristics: ShortShort PRPR IntInteervarvall (<(< 121200 msms),),wiwidede QRSQRS (>(> 111100 ms)ms),, obvobviiououss deltdeltaa wavwavee TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm •• AccelerateAcceleratedd IdioveIdioventrintricularcular RhytRhythmhm (AIVR)(AIVR) ImpulseImpulse ConductioConductionn •• AtrialAtrial FluttFlutteerr Disorders •• AtriaAtriall FibriFibrillallatitionon Disorders •• AVRTAVRT •• AVNRTAVNRT AVNRTAVNRT

••Origin:Origin: AVAV NodeNode ••MechanisMechanism:m: ReentryReentry ••RatRatee:: 150150 -- 223030 BBPPM,M, fastfasterer iinn teenteenagersagers ••ChChararactacteerisristtics:ics: NoNormarmall QRSQRS witwithh absenabsentt P-P-wwaavveess;; mostmost commoncommon SVTSVT inin adultsadults AVRTAVRT vs.vs. AVNRTAVNRT

AVRTAVRT AVNRTAVNRT •• 180180 –– 260260 BPMBPM •• 150150 –– 230230 BPMBPM •• NarrowNarrow QRSQRS ifif orthodromicorthodromic •• NarrowNarrow QRSQRS • Short RP interval •• WideWide QRSQRS ifif antidromicantidromic • Short RP interval •• NoNo deltadelta waveswaves •• DeltaDelta wavewave ++ inin SRSR •• InitiaInitiatingting PRPR longlong •• PRPR << 120120 msms •• P-wavesP-waves burburiieded inin QRSQRS • 1:1 Conduction • 1:1 Conduction •• ConductionConduction 1:1,1:1, oror 2:2:11 whenwhen distaldistal blockblock presentpresent TachyarrhythmiaTachyarrhythmia ClassificClassificaationstions ClassificationClassification BasedBased onon DisorderDisorder •• SinusSinus TaTachycachycarrdidiaa ImpulseImpulse FormationFormation •• AtAtrialrial TTaachchycardiycardiaa Disorders •• PrematurPrematuree ContrContraactionctionss Disorders •• AcceleratedAccelerated IdioIdio-- JunctionaJunctionall RhythmRhythm •• AccelerateAcceleratedd IdioveIdioventrintricularcular RhytRhythmhm (AIVR)(AIVR) ImpulseImpulse ConductioConductionn •• AtrialAtrial FluttFlutteerr Disorders •• AtriaAtriall FibriFibrillallatitionon Disorders •• AVRTAVRT •• AVNRTAVNRT •• VentricularVentricular TachycardiTachycardiaa VentricularVentricular ArrhythmiasArrhythmias ClassificationClassification BasedBased onon MorphologyMorphology

VentricularVentricular TachycardiaTachycardia •• MonomorphicMonomorphic (VT)(VT) •• PolymorphicPolymorphic MonomorphicMonomorphic VTVT *Animation EKGEKG CharaCharaccterteriisticsstics

•• Origin:Origin: VentriclesVentricles (Single(Single Focus)Focus) •• Mechanism:Mechanism: ReentryReentry InitInitiatediated byby abnormalabnormal AutomaAutomatticiticityy oror TriggeredTriggered aacctivittivityy •• ChChararactacteerisristtics:ics: RaRapidpid,, widewide,, andand regulregulaarr QQRRSS PolymorphicPolymorphic VTVT *Animation

•• OrOrigin:igin: VeVentrntriiclecless (Wand(Wandeeringring SingleSingle Focus)Focus) •• MechanisMechanism:m: ReentryReentry witwithh movemmovemeenntt inin thethe circucircui InitiInitiaatedted byby AbnormalAbnormal AutomaticitAutomaticityy oo TriggeredTriggered activityactivity •• ChChararactacteerisristtics:ics: WideWide aanndd irregularirregular QRSQRS CompComplexlex tthhaat chanchanggeses inin axisaxis TorsadesTorsades dede PointePointess

••Origin:Origin: VVentricleentricle ••MechanisMechanism:m: ReentryReentry (movement(movement iinn focus)focus) ••RatRatee:: 200200 –– 225050 BBPPMM ••ChChararactacteerisristtics:ics: AssoAssociatciateded witwithh LLoongng QTQT intinteervrvaall;; QRSQRS chchangeangess axaxisis && momorphorpholologygy witwithh altalteernrnatatinging popositsitiivvee/neg/negatativivee complexescomplexes VentricularVentricular FibrillationFibrillation (VF)(VF) *Animation

••Origin:Origin: VVentricleentricle ••MechanisMechanism:m: MultipMultiplele WWaaveletsvelets ofof reentryreentry ••CharCharacterisacteristtics:ics: IrregulIrregulaarr wiwithth nono ddiiscrescretete QRSQRS RHYTHMRHYTHM DISORDERSDISORDERS

CommonCommon CauCausseses CausesCauses ofof RhythmRhythm DisordersDisorders

CongenitaCongenitall ••PresentPresent atat birthbirth duedue ttoo geneticsgenetics,, environenvironmmeenntt

HeartHeart DiseDiseasease ••MyoMyoccarardidialal InfarctInfarctiion,on, CardiomyopCardiomyopaatthy,hy, HighHigh BlooBloodd PressurePressure

ChemiChemiccaalllyly InducedInduced •• DietDiet PillsPills,, CCooldld MedicinMedicinee,, IllIlleegalgal Drugs,Drugs, CaffeiCaffeinne,e, TobaccoTobacco,, AlcoholAlcohol CausesCauses ofof RhythmRhythm DisordersDisorders

SecondarySecondary toto otherother conditionsconditions •• Hyper-ThyroidHyper-Thyroid •• NeurocaNeurocarrdidiogenicogenic SyncopeSyncope -- HHypersensitiveypersensitive CaCarotirotidd SinusSinus SyndromeSyndrome (CSS(CSS)) -- VVasovaasovaggaall SyncopeSyncope (VS)(VS)