LBBBCardiomyopathyandHis-BundlePacing

RajeevSinghGeneralCardiologyFellow

October2018

Disclosures•  Norelevantdisclosures

GoalsofthisPresentaIon•  I.Background:IntroducetheaudiencetotheconceptofLBBBCardiomyopathy

•  II.IUExperiencewithHisBundlePacingandLeQBundleBranchCardiomyopathy

•  III.NovelConceptsandFutureWork

Background:HisBundlePacing

Carlson, Joe. “Making pacemakers easier on the heart may come down to connections.” Star Tribune. May 27, 2017.

Background:LBBBCardiomyopathy•  Firstproposedin2013;basedon

JACCarIclewhichretrospecIvelyanalyzed375paIentsform2007-2010

•  SixPaIentswereidenIfiedthatfitpre-exisIngcriteriawhichincluded

1)HistoryoftypicalLBBB>5years2)LVEF>50%3)DecreaseLVEF<40%anddevelopmentofHFtoNYHAII-IV4)Majormechanicaldyssychrony4)IdiopathiceIologyofcardiomyopathy

Vaillant, Caroline, et al. "Resolution of left bundle branch block–induced cardiomyopathy by cardiac resynchronization therapy." Journal of the American College of Cardiology 61.10 (2013): 1089-1095.

Background:LBBBHFREFDoesNotRespondtoConvenIonalTreatment

•  January2018Dukestudy;QRSduraIon,EF,andOMTstudiedon659paIents

•  HighestHFhospitalizaIon,mortalityforLBBB,worstresponsetoOMT(3.5%improvementinEFvs10%)

Sze, Edward, et al. "Impaired recovery of left ventricular function in patients with cardiomyopathy and left bundle branch block." Journal of the American College of Cardiology71.3 (2018): 306-317.

5paIentswhounderwentCRTwithLBBB*

5paIentswhometcriteriaforLBBBCardiomyopathy

7PaIentswhounderwentBi-VPacing

72PaIentswhounderwentHisBundlePacingorBi-VenIcular

Pacingfrom08/1/2015–08/2017

65PaIentswhounderwentHis-BundlePacing

7paIentswhounderwentCRTwithLBBB

2paIentswithischemic

cardiomyopathy

QRSDuraIonDecrease

0

20

40

60

80

100

120

140

160

180

Pt1 Pt2 Pt3 Pt4 Pt5

QRSduraI

on(m

s)

PaIent#

LBBB,duraIonofQRS(ms) HispacingQRSduraIon(ms)

•  28% decrease in QRS duration from 153 ms à 110 ms

EFImprovement

19 20

3430

21

52 5451 50 51

0

10

20

30

40

50

60

Pt1 Pt2 Pt3 Pt4 Pt5

EEjecIon

FracIon

(%)

PaIent(#)

LVEFatbaseline(%) LVEFatfollowup(%)

•  Average improvement in EF by 52% from 24% à 52%

•  100% patients were hyper-responders (EF> 50%)

PaIentCharacterisIcs Pt 1 Pt 2 Pt 3 Pt 4 Pt 5

Age/Gender 59/F 51/F 71/F 61/F 50/M

LBBB, duration (months) 16 36 6 72 24

LVEDD at baseline (mm) 52 53 59 58 64

LVEDD at follow up (mm) 40 45 42 50 54

Hyper-response noted on follow up duration (months)

13 3 5 5 3

Nature of His bundle pacing S S NS NS S

ElectricalRemodelingviaHBP?•  OnepaIentwithresoluIonofLBBBonfollow-up

BaselineECGwithLBBB

HisbundlepacingwithrecruitmentofLBBfibers

SinusrhythmwithLBBreverseremodelingaQer3months

AtrialpacingwithfasterventricularratesandnoevidenceofLBBB

LBBBCardiomyopathy:ANewParadigm?

Wang, Norman C., et al. "Left Bundle Branch Block–Associated Cardiomyopathies and Early Cardiac Resynchronization Therapy: Conceptualizing a Tailored Approach." Journal of the American College of Cardiology71.17 (2018): 1943-1944.

•  Markov Model: Cost Effectiveness/Value Based Care

•  Improved response with HBP vs BiV CRT

•  No PIM with HBP vs RVP

•  Higher thresholds lead to decreased generator longevity

Conclusions•  LBBBNICMdoesnotrespondtoGDMTinsamemanner

asothercardiomyopathies.Whyshoulditbetreatedassuch?

•  PHBPappearstobeaviablestrategyintreaIngLBBB-inducedcardiomyopathy,addressingtheunderlyingphysiologyratherthanmechanicalmanifestaIonsofLBBB

•  OurcasedemonstrateselectricalreverseremodelingofchronicandpersistentLBBBwithHBP.

FutureWork•  Futurerandomizedtrials:HIS-SYNCII:8000ptrandomizingCRTtoHBP

•  LBBBCardiomyopathygroupundergoingstrainanddysynchronyanalysisforamorecompleteLVsystolicfuncIonassessmentratherthanjustEjecIonFracIon

QuesIonsandThanks•  Specialthanks:Dr.Dandamudi;Dr.Devahaktuni,Dr.Simon,Dr.Ezzedine

LBBBRecruitmentbyHBP•  1)LongitudinaldisassociaIonofHisBundle(somefibersinHisbundlearepre-desInedtogointoleQbundleorrightbundle)

•  2)VEP:VirtualElectrodePolarizaIon:ElectricalsImulaIoncandecreasethreshold

•  3)Source-sink:OvercomingdiseasedIssuethroughhigheroutput

•  4)Bypassingblockthroughdistalpacing

Recruitment