病竇綜合癥安裝心臟起搏器的指征

SickSinusSyndrome:

WhomtopaceDr.DarshanJhalaCardiologist(InterventionsandEP)JaslokHospitalLilavatiHospitalNanavatiHospitalWhatisSickSinusSyndromeDefinitions:ClinicalInappropriateSinusNodefunctionforagivenphysiologicalstateSicksinussyndromeSinusbradycardiaSAarrestSAexitblockChronotropicincompetenceCombinationofSA/AVnodalconductionParoxysmalAtrialtachyarrhythmiasAtrialrateinappropriateforphysiologicalrequirementsImpulseformationImpulseconductionLossofadapatbilityOtherformsNeurogenicreflexformsCarotidsinussysndromeVasovagalsyncopeSickSinusSyndrome:Whatissoconfusingaboutit?SlowanderraticcourseNonspecificsymptomsConsiderableoverlapwithNeurologicalandFunctionaldisordersSymptomsfrequentlyintermittentPoorcorrelationbetweensymptomsandSigns/testsNoconsensusonappropriatetherapyTherapydoesnotalwaysrelievesymptomsIncidenceOneofevery600cardiacpatients>65yearsofage>50%ofpacemakerimplantsinUSA~1.1millioninthetotalpopulation~165,000in150millionaffordingpopulation

~2,500pacemakers

implantedannuallyforSND

SinusNodeDisease(SND):prevalenceinIndiaEtiologyofSNDIntrinsicchangesCelldegeneration&death,AtrophiedSAnodeAmyloiddepositsCMP,CVDIschemic??IdiopathicSNDAbnormalitiesofneuralinnervation/neuralcontrolPatientAssessmentHistoryPhysicalexaminationLifestyleassessmentUseofdrugsBB,CCB,DigoxinThyroid,RaisedICP,Jaundice,HypothermiaClinicalpresentationSyncopePre-syncopeLethargyFatigue,ExerciseintoleranceUnexplainedfallsMemorylossPalpitationsSOBAngina,HFAsymptomaticNaturalhistoryofSSSECGdiagnosisinlate1960’sSlowprogressionSinusbradycardiatoexitblockstoAFSpontaneousremissionDidnotseemtoaffectsurvivalJAMA1968Lien1977,Shaw1980,Alpert1983NaturalhistoryofSSSPatientswithrate<50and/orintermittentSAblockAge>45yearsFUx4yearsSyncopein23%CHFin17%ChronicAFin11%Paroxysmaltachyarrhythmiasin6%AmJCardiol1998Source:Menozzi,C,Brignole,M-ThenaturalcourseofuntreatedSickSinusSyndromeandidentificationofthevariablespredictiveofunfavourableoutcomeAmJCardiol82:1205-12091998ChronicAF11%HeartFailure17%ParoxysmalTachyarrhythmias6%NoCVEvent43%Syncope23%Syncope,heartfailure,AF&strokeFOURYEARSTUDYFOLLOW-UPPERIOD57%Age>65EDD>52mmEF<55%H/osyncope,cSNRT>800msRiskofdevelopingAVBRiskofAVBis0.6-1%/yearPatientswithBBB,bifascicularblocksAtimplant,1:1conduction@Apace@100PQduration>220ms(18–70years)>260ms(>70years)Wenckebachpoint≥120bpmDiagnosticexaminationsUsefulECGHolterExrecisetestingLooprecordersCarotidsinusmassageTilttestingEchocardiogramElectrophysiologicaltestLessoftenneededEEGNeuro-imagingCoronaryangiographyPulmonaryscintigraphyEHJ.2001;22:1256-1306.DiagnosisDocumentationofSNdysfunction +++CorrelationwithsymptomsBrignoleM,etal.Europace,2004;6:467-537.CorrelationofsymptomswithRhythm:thegold-standardinthediagnosisofSNDHolterSinuspauses>2seconds0.5-25%ofnormalWaking/sleepingLengthofpausehaspoorcorrelationwithSxDoesnotpredictdeathDonotrequirePPMesp.ifasymptomaticAmJCardiol1983,1985,EurJCardiol1997Subsequenttesting…2ormoreHoltersunrewardingSxsevere,suggestiveConsiderILRSelf-containedElectrodes38.5mmapartImplantablelooprecordersLeadless(twoself-containedelectrodes)Upto14-monthsofcontinuousmonitoringUpto42minutesofstorageVolume:8ccMass:17g

chronotropicincompetence

ExercisetestingHeart

RateSlowStart

ActivityTimeUnstableMaxRestStop

ActivityQuickExercisetestingInabilitytoachieve85%APMHR(220–age)70yearold,APMHR=150Exercises2min,SOB,PeakHR130Achieved85%APMHR!!Heartratereserve%HeartratereservePeakHR–RestingHRAPMHR–RestingHRValues<80%abnormal70yearold(RHR90/min)APMHR(220-70)=150bpmPeakHRatexercise=130bpm

HRR=130-90=0.67

150-90AbnormalHRdeclineReductioninHRfrompeakto1min3min5min8minAJC2001DiagnosticexaminationsUsefulECGExrecisetestingHolterLooprecordersCarotidsinusmassageTilttestingEchocardiogramElectrophysiologicaltestEHJ.2001;22:1256-1306.CarotidSinusMassageSite:CarotidarterialpulsejustbelowthyroidcartilageMethod:Rightfollowedbyleft,pausebetweenMassage,NOTocclusionDuration:5-10secContraindicationsCarotidbruit,significantcarotidarterialdisease,previousCVAinlast3monthsCarotidSinusMassageOutcome:

3secasystoleand/or50mmHgfallinSBPwithreproduction

ofsymptomsRisks1in5000massagescomplicatedbyTIAElderly:false+SymptomcorrelationisimportantTilttesting(HUT)BasalPharmacologicalprovocationRepsonsesCardioinhibitoryVR<40/minfor>10secs,noasystole>3secAsystole>3secsVasodepressorFallinSBPHRdoesnotfallby>10%MixedEPSstudiesSNRTSACTSinusnoderecoverytimeAtrialpacing@700,600,500…x30-secsSensitivity55-60%,specificity80-88%>1500mseccSNRT=SNRT–SCL>525msecAdenosinetest0.15mg/kgIVbolusLengtheningofSCLnoted(Ado-SCL)Pause/AVblock>6secsAdo-SCL–BSCL=Ado-cSNRT+vePPV 70% -vePPV 95% 80% 97%ESCGuidelinesEPSAdenAutonomictonePostatropine,Isoproterenol,HRincreasesAtropine(0.04mg/kg)+Propranolol(0.2mg/kg)IHR=117.2–(0.57xage)bpmOnlyAtropineFailuretoincreasebeyondpredictedIHRDiagnosticYieldsTest/ProcedureYield*ECG2-11%1HolterMonitoring2-20%2ExternalLoopRecorder20%2ILR43-80%6,7,8TiltTable11-87%3,4EPStudywithoutSHD10-20%5EPStudywithSHD30-70%3*Basedonmeandiagnosistimeof5.1mos.2**StructuralHeartDisease1Kapoor,AmJMed,1991. 5Linzer,AnnInternMed,1997.2Krahn,CardiolClinics,1997. 6Krahn,AmJCardiol,1998.3Kapoor,Medicine,1990. 7Krahn,Circ,1999.4Kapoor,JAMA,1992. 8Krahn,JACC,2003.ConclusionsVariableandintermittentnatureofSxVarietyofdiagnostictestsProperselectionimportantClinicalcorrelationisvitalSickSinusSyndrome:

GoalsofTherapyRelievesymptomsIsit=IncreasingHR?PreventStrokesPreventAtrialArrhythmiasPreventCHFDevelopmentofChronicAFinStudiesofPacemakerTherapyforSNDStudyPacingModeMeanFollow-UpTimeIncidenceofAFAnnualizedIncidenceAndersen1997AAI5years8.8%1.8%Sutton1986AAI3years4.5%1.5%Brandt1992AAI5years7.0%1.4%PASE1998DDDRonly18months19.0%12.7%CTOPP2000DDDR/VVIR3years16.6%5.5%(DDDR)TheMOSTSub-Study–RateofHeartFailureHospitalization1339NormalQRSdurationpatientsfromMOSTAssociationbetweenCumVpandriskforHFSweeneyMO,etal.Circulation2003,inpressDanishStudy

OverviewHypothesis:InpatientswithSND,atrialpacing(AAI)willresultinlessatrialfibrillation,thromboembolism,heartfailureandoverallmortalitythanventricularpacing(VVI)n=225,singlecentreMeanfollow-up–upto5.5yearsDanishStudy

Overallsurvivalbypacingmodep=0.045AtrialpacingVentricularpacingTime(years)024681000-20-40-60-81-0DanishStudy

CardiovasculardeathbypacingmodeTime(years)p=0.0065AtrialpacingVentricularpacing024681000-20-40-60-81-0CumulativesurvivalDanishStudy

CumulativeriskofPAFbypacingmode00-20-40-60-81-0p=0.012AtrialpacingVentricularpacingTime(years)0246810ProportionwithoutAFDanishStudyConclusionsOverlongtermfollow-up,AAIpacingisbetterthanVVIpacinginSSSpatients:ReducedoverallmortalityReducedcardiovascularmortalityReducedheartfailureReducedatrialfibrillationReducedthromboembolismAAIvsVVIinSND:theDanishStudy225Patients-upto5.5yearfollow-upPotentialProblemswithAAIPacingDevelopmentofAVBlockrequiringventricularpacingDevelopmentofatrialfibrillationwithbradycardiarequiringventricularpacingAtrialleaddislodgementRiskofdevelopingAVBRiskofAVBis0.6-1%/yearPatientswithBBB,bifascicularblocksAtimplant,1:1conduction@Apace@100PQduration>220ms(18–70years)>260ms(>70years)Wenckebachpoint≥120bpmDevelopmentofPersistent(Complete)AVBlockinSNDStudyMeanFollow-UpTimeIncidenceofCHBAnnualizedIncidenceRosenqvist1989(literaturereview)3yearsMedian2.1%Range:0-11.9%Median:0.6%Range:0-4.5%Andersen19978years3.6%0.6%Brandt19925years8.5%1.8%Sutton19863years8.4%2.8%Rosenqvist19862years4.0%2.0%Rosenqvist19855years3.3%0.7%Hayes19843years3.4%1.1%IsDualChamberPacing(asitispractisedtoday)reallyPhysiological?AVSynchronyReducedAFReducedCHFsymptomsBetterQOLMajorclinicaltrialsinvolving>10,000patients(UK-PASEC-TOPP,MOST)havebeenunabletodemonstrateaclearbenefitofDDDRpacingoverVVIRfortheclinicalendpointsoftotalmortality,cardiovascularmortalityandstroke.WhydoesDualChamberpacingnotconfertheexpectedbenefits?DualChamberPacing–DDD/DDDRAVSynchronizationVentricularDesynchronizationFunctionalAsynchronouselectricalactivation1Perfusiondefects2IncreasedatrialfillingpressuresMitralregurgitation3dP/dt,strokework4Pumpingfunction,EF4-6StructuralAlteredproteinexpression7Myofibrillardisarray8Asymmetrichypertrophy9Endsystolicanddiastolicvolumes4NegativeEffectsofVentricularDesynchronization1VassaloJAmCollCardiol1986;7:1228-1233. 6NielsenJAmCollCardiol2000;6:1453-146132TenCateTJFHeartRhythm2005;2:1058-1063 7SpraggCirculation2003;108:929-9323

KanzakietalJAmCollCardiol2004;44:1619-1625 8KarpawhichAmHeartJ1990;119:1077-10835

4PrinzenPacingClinElectrophysiol2002;25:484-498

9VanOosterhoutMFM.Circulation1998;98:588-595 5NahlawiJAmCollCardiol2004;44:1883-1888

.

NegativeEffectsofVentricularDesynchronizationClinicalConsequencesAtrialfibrillation1-2Heartfailureworsening/hospitalization2-6Ventriculararrhythmias6Mortality5-61NielsenJAmCollCardiol2000;6:1453-14612SweeneyCirculation2003;23:2932-29373ShuklaHeartRhythm2005;2:245-2514SweeneyCirculation2006;inpress5DAVIDTrialInvestigatorsJAMA2002;288(24):3115-31236SteinbergJCardiovascElectrophysiol2005;16(4):359-365.DualChamberPacing:topreventcomplicationsoffutureCHBinSNDpatientsConventionaldualchamberpacemakersaredesignedtopacetheventriclemaycauseharmfuleffectsofventriculardyssynchronybyunnecessarilypacingtheventriclesinSNDpatientswhentheyhaveintactAVconductionConventionaldualchamberpacemakersarenotoptimalforthetreatmentofSNDDualchamberpacemakerscanresultinUNECESSARYRVAPICALPACINGItispossiblethatthehigherlevelofventricularpacingassociatedwithconventionalDDDRpacingsystemshasadverselong-termeffectsonventricularperformancethatmitigatethebenefitofAVsynchrony?WhydoesunnecessaryRVpacingoccurinSNDpatientstreatedwithDualChamberPacemakers?AVInterval=120msPRInterval>120msAVintervalof120ms,SNDpatientsareUNNECESSARILYpacedintheRVmorethan80%ofthetimeMOSTSub-study:DDDRpacingwithahighpercentageofventricularpacingincreasesAFRandomizedtoDDDRmode,baselineQRSd<120msSweeneyMO,etal.Circulation2003;23:2932-2937RiskforHFhospitalizationsbeginstoreduceonlywhenRVpacingfallsbelow40%Every10%reductioninRVpacingbelow40%,54%reductioninHFriskMinimizationofRVpacing(<5%)minimizesriskforHFMOSTSub-study:DDDRpacingwithahighpercentageofventricularpacingincreasesHFAVHysteresisSearchAV+NominalSettings

DanishIIStudy177patientsAAIRvsDDDR–shortAVvsDDDRwithLongAV3yearfollow-upDDDR–shortAV&LongAVcauseincreasedLAdiameterDDDR–shortcausesincreasedLVFSAAIcausesnochangeinLA,LVdiametersorLVFSDanishStudyII:FreedomfromAFbyPacingMode7%18%23%TheMOSTSub-Study–RateofHeartFailureHospitalization1339NormalQRSdurationpatientsfromMOSTAssociationbetweenCumVpandriskforHFSweeneyMO,etal.Circulation2003,inpressSweeneyMO,etal.Circulation2003;23:2932-2937V-pacingis>40%-HFHriskisconstantV-pacingis<40% -Foreach10%reductioninV-pacingthereisa54%relativereductioninriskforHFH -2%whenpacingwasminimizedto<10%MOSTSub-study:RVPacingandHeartFailureHospitalization(HFH)RiskofHFH5Cumulative%VentricularPacingWithin95%confidenceRiskofAFRelativeto

DDDRPatientwithCum%VP=0Cumulative%VentricularPacingIncreasedRiskofHospitalizationAHAEndorsementPhysiciansCallforChange“Forpatientswhoneedadualchamberpacemaker,effortsshouldbemadetoprogramthedevicetominimizetheamountofventricularpacingwhenatrioventricularconductionisintact.〞AHAScienceAdvisory

Circulation,January18,2005StrategiesforReducing/MinimizingUnecessaryRVPacinginDDD/DDDRProgrammingLongAVDelaysSearchAVHysteresisUniversalPacingModeAdvancedDualChamberPacemakers:minimizeventricularpacinginSNDpatientsOptimalAAI/RpacingwheneverAVconductionisintactDualchamberventricularsupportduringtransientorpersistentlossofconductionMinimizesunnecessaryventricularpacing&itslongtermharmfuleffectsofincreasedAFandHFUniversalPacingMode-MVP(ManagedVentricularPacing)MVPprovidesfunctionalAAI/RpacingwiththesafetyofdualchamberventricularsupportinthepresenceoftransientorpersistentlossofconductionMVPBasicOperationAAI(R)Mode

AtrialbasedpacingallowingintrinsicAVconductionTheSAVE-PACeTrial

SearchAV

ExtensionandManagedVentricularPacingforPromotingAtrioventricularConductionMichaelO.Sweeney,MD-Boston,MA,PrincipalInvestigatorAlanJ.Bank,MD–St.Paul,MNEmmanuelNsah,MD–Salisbury,MDMariaKoullick,PhD–Medtronic,Inc.QianCathyZeng,MS–Medtronic,Inc.DouglasHettrick,PhD–Medtronic,Inc.ToddSheldon,MS–Medtronic,Inc.GervasioA.Lamas,MD–Miami,FLA,PrincipalInvestigatorOnBehalfoftheSAVEPACeTrialInvestigatorsPrimaryEndpoint:PersistentAFLogrankp=0.004NotableChangesin2021ACC/AHA/HRSGuidelinesICDrecommendationsarecombinedintoasinglelistbecauseofoverlapbetweenprimaryandsecondaryindications.PrimarypreventionICDindicationsinnonischemiccardiomyopathyareclarifiedusingdatafromSCD-HeFT(i.e.,ischemicandnonischemiccardiomyopathiesandLVEF≤35%,NYHAII-III)forsupport.IndicationsforICDtherapyininheritedarrhythmiasyndromesandselectednonischemiccardiomyopathiesarelisted.MADITIIindication(i.e.,ischemiccardiomypathyandLVEF≤30%,NYHAI)isnowClassI,elevatedfromClassIIa.EFcriteriaforprimarypreventionICDindicationsarebasedonentrycriteriafortrialsonwhichtherecommendationsarebased.EmphasizedprimarySCDpreventionICDrecommendationsapplyonlytopatients

receivingoptimalmedicaltherapyandreasonableexpectationofsurvivalwithgoodfunctionalcapacityfor>1year.IndependentriskassessmentprecedingICDimplantationisemphasized,includingconsiderationofpatientpreference.OptimizationofpacemakerprogrammingtominimizeunneededRVpacingisencouraged.Pacemakerinsertionisdiscouragedforasymptomaticbradycardia,particularlyatnight.AsectionhasbeenaddedthataddressesICDandpacemakerprogrammingatendoflife.SND:ACC-AHA2002guidelinesforpacemakerimplantationClassIIndicationsSNdysfunctionwithdocumentedsymptomaticbradycardia,includingfrequentsinuspausesthatproducesymptomsMaybeaconsequenceofessentiallong-termdrugtherapyforwhichthereisnoalternativeSymptomaticchronotropicincompetenceSickSinusSyndrome–ACC/AHA/NASPEPracticeGuidelines2002forPacemakerImplantationClassIIndicationsSinusnodedysfunctionwithdocumented

symptomaticsinusbradycardiaSymptomaticchronotropicincompetenceJACCVol.31,no.5April1998,1175-1209SickSinusSyndromeNoevidenceofimpairedAVconductionWenckebachpoint≥120bpmPossibilityoffutureAVBlockPQduration>220ms(18–70years)>260ms(>70years)QRSduration>120ms(RBBBorLBBB)Wenckebachpoint<120bpmSND:pacemakertherapyoptionsSinglechamberventricularfixedrateandrateresponsivepacemakers–VVI/VVIRSinglechamberatrialfixedrateandrateresponsivepacemakers–AAI/AAIRConventionaldualchamberpacemakers–DDD/DDDRDualchamberpacemakersthatminimizeventricularpacing–AAI/AAIRDDD/DDDRSinglechamberventricularpacing(VVI):couldbeharmfulforSNDpatientsSingleChamberRightVentricular(Apical)PacingVVIVentricularDyssynchronyAVDyssynchronyValvularRegurgitationMyocardialDysfunctionCongestiveHeartFailureAtrialDilatationAtrialFibrillationDeathStrokeSingleChamberAtrialPacing:AAI/AAIRAVSynchronyVentricularSynchronyAAI/AAIRpacing:thebestoptionforSNDpatientswithnosignsofAVconductionabnormalitySingleChamberAtrialPacingAAI/AAIRVentricularSynchronyNormalventricularactivationthroughintactAVNodeAVSynchronyNormalsequentialactivationofatriafollowedbyventriclesImprovedHemodynamicsReducedLong-termAF/StrokeReducedLong-termHFriskReducedMortality comparedtoVVIpacingSND:summaryoftreatmentoptionsDDD/DDDRwithminimizationofventricularpacingpatientswherethesafetyofventricularsupportispreferredpatientslikelytodevelopheartblockAAI/AAIRpatientswithnosignsofAVconductionabnormalityWenckebachpoint≥120bpmDDD/DDDRpatientslikelytodevelopheartblockwithoutaccesstoadvancedDDD/DDDRwithminimizationofventricularpacingVVI/VVIRpatientswithseveresymptomslikelytodevelopheartblockwithoutaccesstoDDD/DDDRpacingProposalsforPacinginSSSProvideAtrialPacingMinimizeVentricularPacingProvideDualChamberPacingifAVBlockorBradycardiaduetoAFdevelopsProposalsforthemanagementofSSSDDD/DDDRwithMVPto:minimize

ventricularpacingprovidefullatrialsupportprovidefullsafetyofDDD/DDRDDD/DDDRprogrammedtoAAI/AAIRwithregularmonitoringforAVconductionproblems:minimizeventricularpacingprovidefullatrialsupport

ProposalsforthemanagementofSSSAAIRwithregularmonitoringforAVconductionproblems:minimizeventricularpacingprovidefullatrialsupportProposalsforthemanagementofSSSDDD/DDDRwithSearchAV+orRVPto:reduceventricularpacingprovidefullatrialsupportprovidefullsafetyofDDD/DDR

ProposalsforthemanagementofSSSDDD/DDDRwithlongprogrammedAVdelaysreduceventricularpacingprovidefullatrialsupportprovidefullsafetyofDDD/DDR

ProposalsforthemanagementofSSSVVIwithlowprogrammedratetoreduceventricularpacingProposalsforthemanagementofSSSSummaryofProposalsforPacinginSSS–nolikelihoodofAVblockDDD/DDRwithMVPDDD/DDRprogrammedtoAAIAAIRDDD/DDRwithSearchAVHysteresisDDD/DDRwithLongAVDelaysVVISSSwithindicatorsoffutureAVBlockpossibilityPQduration>220ms(18–70years)>260ms(>70years)QRSduration>120ms(RBBBorLBBB)Wenckebachpoint<120bpm

17%ofSNDpatientshavesomeformofAVBlockatdiagnosisSND:summaryoftreatmentoptionsforpatientswithfuturepotentialforAVblockDDD/DDDRwithminimizationofventricularpacingDDD/DDDRVVI/VVIRConsequencesLvdysfunctionAFDanishStudy

OverviewHypothesis:InpatientswithSND,atrialpacing(AAI)willresultinlessatrialfibrillation,thromboembolism,heartfailureandoverallmortalitythanventricularpacing(VVI).Meanfollow-up–upto8yearsDanishStudy

Overallsurvivalbypacingmodep=0.045AtrialpacingVentricularpacingTime(years)024681000-20-40-60-81-0DanishStudy

CardiovasculardeathbypacingmodeTime(years)p=0.0065AtrialpacingVentricularpacing024681000-20-40-60-81-0CumulativesurvivalDanishStudy

CumulativeriskofPAFbypacingmode00-20-40-60-81-0p=0.012AtrialpacingVentricularpacingTime(years)0246810ProportionwithoutAFDanishStudy

CumulativeriskofchronicAFbypacingmodeAndersenH,etal.Lancet1997;350:1210-16.p=0.004AtrialpacingVentricularpacingTime(years)0246810ProportionwithoutchronicAF00-20-40-60-81-0DanishStudyConclusionsOverlongtermfollow-upAAIpacingisbetterthanVVIpacinginSSSpatients:ReducedoverallmortalityReducedcardiovascularmortalityReducedheartfailureReducedatrialfibrillationReducedthromboembolismDevelopmentofPersistent(Complete)AVBlockinStudiesofPacemakerTherapyforSNDStudyMeanFollow-UpTimeIncidenceofCHBAnnualizedIncidenceRosenqvist1989(literaturereview)3yearsMedian2.1%Range:0-11.9%Median:0.6%Range:0-4.5%Andersen19978years3.6%0.6%Brandt19925years8.5%1.8%Sutton19863years8.4%2.8%Rosenqvist19862years4.0%2.0%Rosenqvist19855years3.3%0.7%Hayes19843years3.4%1.1%DualchamberpacemakerscanresultinUNECESSARYRVAPICALPACINGSickSinusSyndromeIntermittentHeartBlockPatientsItispossiblethatthehigherlevelofventricularpacingassociatedwithconventionalDDDRpacingsystemshasadverselong-termeffectsonventricularperformancethatmitigatethebenefitofAVsynchrony?SweeneyMO,etal.Circulation2003;23:2932-2937Cumulative%V-paceandRiskofFirstHFHospitalization(HFH)RiskofHFHincreasedbetween0%and40%CumVP,butrelativeriskwaslevelabove40%V-pacingRiskofHFHisreducedtoabout2%ifventricularpacingisminimizedto<10%.MOSTSub-study:DDDR

MOST

DDDR+Higher%VP=MoreAFRandomizedtoDDDRmode,baselineQRSd<120msSweeneyMO,etal.Circulation2003;23:2932-2937DanishIIStudy177patientsAAIRvsDDDR–shortAVvsDDDRwithLongAV3yearfollow-upDDDR–shortAV&LongAVcauseincreasedLAdiameterDDDR–shortcausesincreasedLVFSAAIcausesnochangeinLA,LVdiametersorLVFSDanishStudyII:FreedomfromAFbyPacingMode7%18%23%HypothesisTheSAVEPACeTrialtestedthehypothesisthatdualchamberpacingincorporatingastrategytominimizerightventricularstimulationwouldleadtoalowerriskofdevelopingpersistentatrialfibrillationcomparedwithconventionaldualchamberpacinginpatientswithsinusnodedisease

ConclusionsUtilizationofalgorithmstolengthenoruncouplethepacemakerAVdelayledtoareductionofventricularpacingby>90%.Dualchamberminimalventricularpacingconferreda40%reductionintherelativeriskofdevelopingpersistentatrialfibrillationcomparedtoconventionaldualchamberpacing.ThisreductioninpersistentatrialfibrillationwasdirectlyassociatedwithfewerinvasiveablationproceduresandheartfailurehospitalizationsinposthocanalysesYesNoSinusNodeDysfunction

NoAtrialpacemakerRate-responsiveatrialpacemakerRate-responsivedual-chamberpacemakerDual-chamberpacemakerVentricularpacemakerRate-responsiveventricularpacemakerYesNoYesNoYesNoYesSelectionofPacemakerSystemsforPatientsWithSinusNodeDysfunctionEpsteinA,etal.ACC/AHA/HRS2021GuidelinesforDevice-BasedTherapyofCardiacRhythmAbnormalities.JAmCollCardiol2021;51:e1–62.Figure2.EvidenceforimpairedAVconductionorconcernoverfuturedevelopmentofAVblockDesireforrateresponseDesireforAVsynchronyDesireforrateresponseDesireforrateresponseDanishIITrial1AAI(R)

vs

DDD(R)w/shortAV

vs

DDD(R)w/longAVCTOPPTrial4DDD(R)orAAI(R)

vs

VVI(R)DAVIDTrial5DDD(R)

vs

VVIICDsMOSTSubstudy6DDDR

vs

VVIRHFHospitalizationNotspecificallymeasured;studyindicatesthathighproportionofRVpacingreducesLVfunctionNotmeasured1yrevent-freerateofcompositeendpoint(deathorHFH)wasworseinDDDRgroupwhen

%V-pacing>40%2.6-fold

increasedriskwhen

%V-pacing>40%

(forDDDRgroup)HemodynamicPerformanceLong-termDDDRpacinginducesLAdilationandahighproportionofRVpacingdecreasesLVfunctionPatientswithpreservedLVfunction,nohistoryofMIorCADderivedmostbenefitfromphysiologicpacingNotmeasuredSupportsconclusionthatventriculardysynchronyimposedbyRV-pacingmaybemostdramaticinpatientswithfailingleftventriclesIncidenceofAFFreedomfromAFduringfollow-upissignificantlybetterwithAAIRpacing

(p=0.03);

17%RV-pacinginDDDR-lgroupPhysiologicpacingreducesannualrateofdevelopmentofchronicAFNotmeasuredRiskincreasedlinearlyby1%foreach1%increaseinV-pacing

(upto~85%)ClinicalEvidenceforReducing%RV-pacingTheClinicalEvidenceexists…DAVIDTrialJAMA2002;288:3115-23RVpacingmoredeleteriousinpatientswithadvancedLVdysfunction(ICDcandidates);DDDR-70worsethanVVI-40;morepacing(60%)seeninDDDR-70DanishPacemakerStudyAndersenHR,etal.Lancet1997;350:1210-16AAIvs.VVIforSSSAAIhadbettersurvivalandassociatedwithloweroccurrenceofCHF(nativeAVconductionisbetter)DANISHIIStudyNielsenJ,etal.JAmCollCardiol2003;42:614-23.AAI