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