TRANSTHORACIC ECHOCARDIOGRAPHY (TTE) - …ECHOCARDIOGRA… · TRANSTHORACIC ECHOCARDIOGRAPHY (TTE)...

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TRANSTHORACIC ECHOCARDIOGRAPHY (TTE) An overview for Perioperative Care Dr Andrew Cluer, Sydney, Australia 2015 This piece of work is not meant to teach students echo interpretation, but instead offers an insight into interpretation and gives the reader a broad understanding of the uses and limitations of this powerful technology. It is important to recognise from the outset that echo data should be considered in clinical context and as such is useful when it corroborates clinical suspicions and often misleading when used in isolation. This is particularly so when a doctor says “I know, lets get an echo”! Both images and clips are included for student interest. By way of introduction and for those students who have never been introduced to the technical aspects of ultrasound, Wikipedia is on hand to help! This link acts as a good introduction, but it is not considered essential reading for this echo review. Rather the piece adds value where students would like to read more widely. https://en.wikipedia.org/wiki/Medical_ultrasound Indications for resting preoperative transthoracic echocardiogram (TTE) have been published by the European Society of Cardiology (ESC)/European Society of Anaesthesiology (ESA), British Society of Echocardiography (BSE) and American Heart Association (AHA)/American College of Cardiology (ACC) (see links at the end of the document). For ease of reading the documents have been summarised in Table 1. These guidelines are extremely useful but it is worth noting they do not adequately address some important issues such as suspected or known pulmonary hypertension (PHT). Where deficient supplemental links are provided. In general terms the advantages of resting preoperative Trans Thoracic Echocardiography (TTE) in non-cardiac surgical patients are not entirely clear. Wijeysundera et al. (2011) retrospectively looked at over 260,000 patients who had undergone medium or high risk non-cardiac surgery and found that preoperative resting TTE was not associated with either a decreased hospital stay or an improved survival. Although retrospective this very large study suggests that much more research needs to be done to define which patients benefit from an increasingly common preoperative investigation. A relatively recent editorial in Anaesthesia (Heyburn & McBrien 2012) has actually advocated resting preoperative TTE for all patients with hip fractures though these recommendations are not reflected in any current international guidelines. Despite the above it is generally accepted that for specific individuals TTE can have a major impact on their perioperative clinical management. TTE enables rapid assessment of cardiac structure and function. It has certain advantages over Transoesophageal Echocardiography (TOE) including superior assessment of aortic valve areas and gradients, better imaging of the left ventricular apex and more accurate assessment of ejection fraction (EF%). It is also non-invasive, quicker and involves minimal risk to the patient. Indications for TOE include imaging of the mitral valve prior to cardiac surgery, detailed assessment of atrial structures,

Transcript of TRANSTHORACIC ECHOCARDIOGRAPHY (TTE) - …ECHOCARDIOGRA… · TRANSTHORACIC ECHOCARDIOGRAPHY (TTE)...

TRANSTHORACICECHOCARDIOGRAPHY(TTE)AnoverviewforPerioperativeCare

DrAndrewCluer,Sydney,Australia2015Thispieceofworkisnotmeanttoteachstudentsechointerpretation,butinsteadoffersaninsightintointerpretationandgivesthereaderabroadunderstandingoftheusesandlimitationsofthispowerfultechnology.Itisimportanttorecognisefromtheoutsetthatechodatashouldbeconsideredinclinicalcontextandassuchisusefulwhenitcorroboratesclinicalsuspicionsandoftenmisleadingwhenusedinisolation.Thisisparticularlysowhenadoctorsays“Iknow,letsgetanecho”!Bothimagesandclipsareincludedforstudentinterest.Bywayofintroductionandforthosestudentswhohaveneverbeenintroducedtothetechnicalaspectsofultrasound,Wikipediaisonhandtohelp!Thislinkactsasagoodintroduction,butitisnotconsideredessentialreadingforthisechoreview.Ratherthepieceaddsvaluewherestudentswouldliketoreadmorewidely.https://en.wikipedia.org/wiki/Medical_ultrasoundIndicationsforrestingpreoperativetransthoracicechocardiogram(TTE)havebeenpublishedbytheEuropeanSocietyofCardiology(ESC)/EuropeanSocietyofAnaesthesiology(ESA),BritishSocietyofEchocardiography(BSE)andAmericanHeartAssociation(AHA)/AmericanCollegeofCardiology(ACC)(seelinksattheendofthedocument).ForeaseofreadingthedocumentshavebeensummarisedinTable1.Theseguidelinesareextremelyusefulbutitisworthnotingtheydonotadequatelyaddresssomeimportantissuessuchassuspectedorknownpulmonaryhypertension(PHT).Wheredeficientsupplementallinksareprovided.IngeneraltermstheadvantagesofrestingpreoperativeTransThoracicEchocardiography(TTE)innon-cardiacsurgicalpatientsarenotentirelyclear.Wijeysunderaetal.(2011)retrospectivelylookedatover260,000patientswhohadundergonemediumorhighrisknon-cardiacsurgeryandfoundthatpreoperativerestingTTEwasnotassociatedwitheitheradecreasedhospitalstayoranimprovedsurvival.Althoughretrospectivethisverylargestudysuggeststhatmuchmoreresearchneedstobedonetodefinewhichpatientsbenefitfromanincreasinglycommonpreoperativeinvestigation.ArelativelyrecenteditorialinAnaesthesia(Heyburn&McBrien2012)hasactuallyadvocatedrestingpreoperativeTTEforallpatientswithhipfracturesthoughtheserecommendationsarenotreflectedinanycurrentinternationalguidelines.DespitetheaboveitisgenerallyacceptedthatforspecificindividualsTTEcanhaveamajorimpactontheirperioperativeclinicalmanagement.TTEenablesrapidassessmentofcardiacstructureandfunction.IthascertainadvantagesoverTransoesophagealEchocardiography(TOE)includingsuperiorassessmentofaorticvalveareasandgradients,betterimagingoftheleftventricularapexandmoreaccurateassessmentofejectionfraction(EF%).Itisalsonon-invasive,quickerandinvolvesminimalrisktothepatient.IndicationsforTOEincludeimagingofthemitralvalvepriortocardiacsurgery,detailedassessmentofatrialstructures,

suspectedaorticdissectionandinvestigationofendocarditisandisrarelyindicatedintheperioperativeperiod.ItisimportanttounderstandthatTTEisa‘snapshot’atoneparticularpointintime.Thisisnotanissueineuvolaemic,hemodynamicallystablepatientsbutcanbeofrelevanceatothertimesintheperioperativeperiod.IntheunstablepatientmeasurementsmadeusingTTEcanchangerapidlyandaredependentonmanyfactorsincludingvolumeloading,inotropeuseandlungventilatorysettings.Itmaythereforebeappropriatetocarryoutserialexaminationsintheperioperativeperiod,echobeingusedasamonitorratherthanadiagnostictool.ItisalsoimportanttounderstandthatTTEisa‘snapshot’atrestandthereforehasaverylimitedroleinthepreoperativeassessmentofischaemicheartdisease.RecommendationsonpreoperativeimagingstresstestingareincludedintheESC/ESAandAHA/ACCdocumentsmentionedabove.Askilledechocardiographerwillalwaysacquireasetofstandardviewsandmeasurementshowever,theywillseektoobtainextrainformationdependentonthepatientinformationprovided.ItisthereforeessentialthatTTEreferralsstatetheclinicalquestiontobeanswered.Acomprehensiveechocardiographicassessmentofpulmonaryhypertensionisverydifferenttoanassessmentofaorticstenosis.AcasestudyinheartfailureMrsPisa60yearsoldladyreviewedinthesurgicalpre-assessmentclinicpriortoplannedOesophagectomyforcancer.Thepatientspastmedicalhistoryincludes:-

ParoxysmalAtrialFibrillation(anticoagulated)Non-InsulinDependentDiabetesMellitusNewonsetparoxysmalnocturnaldyspnoeaandorthopnoeaExercisetoleranceiscurrently50metresontheflatAsystolicmurmurisheardonauscultation

TheTTErequeststates–‘Pleaseassessbiventricularfunction,pulmonarypressuresandcheckforanyvalvularpathology’.MrsP’sTTEreportprovidesanoverallpictureofhercardiacstructureandfunction.Likeallreportsitshouldmakesenseclinicallyandtheindividualcomponentsmustfittogether.Forexample,severelyimpairedleftventricular(LV)systolicfunctionwillgenerallybeassociatedwithsomediastolicdysfunction,severemitralregurgitation(MR)willgenerallybeassociatedwithsignificantlyraisedpulmonarypressuresandsignificantdiastolicdysfunctionwillgenerallybeaccompaniedbyalargeleftatrium.AspectsofaTTEreportthatdonotmakeclinicalsenseimplysomeerrorsinmeasurementmayhavebeenmadeandshouldbeviewedwithsuspicion.UnderstandingtheoverallmessageanechocardiographerorcardiologististryingtoconveywithaTTEreportismoreimportantthansimplyfocusingonisolatednumberssuchasejectionfraction(EF%).ThereferencerangesofmostTTE

measurementsareaffectedbyageandsex.ManymeasurementsshouldalsobeindexedtoBodySurfaceArea(BSA)soapatient’sheightandweightshouldideallyberecorded(whenwasthelasttimeyouincludedthisdatainyourrequestforinvestigation?).ForexampleaLeftVentricularEndDiastolicDiameter(LVEDD)of6.0cmcanbenormalforalargemanbutveryabnormalforasmallwoman.TheBritishSocietyofEchocardiographysmartphoneapp.isfreetodownloadandisausefulreferencefornormalandabnormalvalues.

MedicalpractitionersoftenviewaTTEreportasabewilderingarrayofdataandfocusonlyontheshortwrittenconclusionwhichcanoccasionallybefalselyreassuring.ItisimportanttounderstandthatanechocardiographerandclinicianmayregarddifferentaspectsofaTTEreportasbeingsignificant.Togetthemostoutofareportitisbettertotryandseparatethemeaningfuldatafromthelesshelpfulmeasurementsandgainadeeperunderstandingofalltheinformationprovided.ForexampleEF%(measuredbySimpsonsBiplanetechnique)isavalidatedandreproduciblemeasurement,whereasEF%(measuredbyTeichholztechnique)isnot.AsummaryofthemostusefulmeasurementsonaTTEreportisprovidedinTable2andthefollowingdiscussionaimstoprovidesomeguidanceonhowtointerpretthedata.

Understandingthedetail:Aguidetoechointerpretation

Thedetailbelowisnotmeanttobememorised,ratherthestudentshouldbegintounderstandwhatelementsoftheinvestigationaregloballyassessed(oftenwiththeexperiencedeyeball)andwhicharemeasured.Forbothelementsofassessmentitisimportanttoappreciatethescopeforerror.

1. LEFTVENTRICLE:Assessmentoftheleftventricleshouldbedividedintostructureandfunction(systolicanddiastolic).

Structure-ThemostimportantaspectsofLVstructurearesizeandwallthickness.BotharemeasuredatenddiastoleonaParasternalLong-AxisView(PLAX)(Video1-PLAX)Thethicknessoftheinterventricularseptum(IVS)andposteriorwall(PW)isroutinelyreportedalongwithanyotherabnormalitiessuchasasymmetrichypertrophyorscarredmyocardium.StructureoftheLValsoincludesotherpathologysuchasthrombusorseptaldefects.Simple2-Dmeasurements(seewikilinktounderstandthesemodesofimaging)aregenerallymoreaccuratethanM-Mode,whichcanoverestimatetheLVdiameterifnotcareful.Itisimportanttonotethatisolatedbasalseptalhypertrophycanbeanormalfindingintheelderlyandshouldnotbeconfusedwithhypertrophiccardiomyopathy.

MrsP:LVDiastolicDiameter=5.6cm,IVS=0.9cm,PW=1.0cm.Conclusion=mildlydilatedLVwithnormalwallthickness.(Image1–LVSize&WallThickness)

Image1

SystolicFunction-LVsystolicfunctioncanbegloballyorregionallyimpaired.QuantificationofsystolicfunctionisbestachievedbycalculatinganEF%usingSimpson’sBiplanemethod.ViewsrequiredaretheApical4Chamber(Video2–A4C)andApical2Chamber(Video3-A2C).OnoccasionsanexperiencedechocardiographerwillvisuallyestimatetheEF%orsimplyquantifysystolicfunctionasgoodoverallfunctionormild,moderateorsevereimpairment.ItisaninterestingandimportantfactthatvisualestimatesbyexperiencedpractitionersareasusefulasacalculatedEF%.Regionalwallmotionabnormalities(RWMA)usuallyimplyischaemicheartdiseaseandtheirdistributionoftenassistsindeterminingthespecificcoronaryarteryaffected.Forexample,anakineticLVapexandanteriorseptumislikelysecondarytodiseaseoftheleftanteriordescendingcoronaryartery.RWMAcanbesubtleanddifficulttoidentifyandthereareoftenvariationsinreportingbetweenechocardiographers.Segmentalbasalinferiorandinferoseptalhypokinesisiscommonlyreportedandoflittlesignificance.Apicalakinesisshouldalwaysraisethesuspicionofathrombusandsomedepartmentswillroutinelyinvestigatewithacontraststudy.MrsP:LVEjectionFraction=20.2%.Conclusion=Global,severeimpairmentofsystolicfunction.(Image2,3,4&5)

Image2

Image3

Image4

Image5

DiastolicFunction(dysfunction-alternativelyknownasheartfailurewithpreservedejectionfraction).LVDiastolicfunctionassessmentiscomplexandinterestedreadersaredirectedtoESCguidelinesonthistopic(Linkprovidedattheendofthedocument).AnimportantdistinctiontomakeiswhetherthereisisolatedLVdiastolicdysfunctionordoesitaccompanyLVsystolicdysfunction.Traditionallydiastolicdysfunctionisgraded(1-4)usingDopplerpatternsfrommitralinflow(MitralEandAwaves)andtissueDopplerfromLVSeptal(E’SeptalVelocity)andLVLateralWalls(E’LateralVelocity).Grade1dysfunctionisdefinedasimpairedrelaxationwhereasGrade4dysfunctionisdefinedasirreversiblerestrictivedisease.Inthepresenceofnormalsystolicfunctionitisappropriatetogradediastolicdysfunctioninthismanner.Importantlytype1diastolicdysfunctionintheelderlyisanormalfinding.E/E’ratioisthemostusefulmeasurementandanE/E’Septal>15orE/E’Lateral>12isabnormal.DiastolicdysfunctionisgenerallyalwayspresentinpatientswithsignificantlyimpairedLVsystolicfunctionandinthissituationitmakesmoresensetotryandquantifyelevationsinleftatrialpressure.E/E’isusefulandwillincreaseasleftatrialpressure(LAP)increases.E/E’isthereforeadynamicmeasurementandchangeswithfluidloading.MrsP:MitralEtoLVE’SeptalRatio=39.4.Conclusion=SeverelyelevatedLAP(Image6–MitralE&AWaves,Image7-E’SeptalVelocity)

Image6

Image7

2.RIGHTVENTRICLE:Therightventricle(RV)isbestassessedqualitativelyforsize,structureandfunction.Fewquantitativemeasurementsareuseful.IftheRVisenlargedandhasnormalsystolicfunctionthenitislikelytobevolumeoverloaded(TricuspidRegurgitation(TR),PulmonaryRegurgitationorAtrialSeptalDefect).IftheRVisenlargedandhassignificantlyimpairedsystolicfunctionthenpossiblepathologyincludesRVpressureoverload,cardiomyopathyorinfarction.TricuspidAnnularPlaneSystolicExcursion(TAPSE)isoftenquotedasaquantitativemeasureofRVsystolicfunctionbutinrealityonlyreflectsbasalRVfunctionandprovidesnoinformationabouttheRVfreewall.MrsP:Qualitativecomment‘NormalRVsizeandmildlyimpairedsystolicfunction’(Video4-RV).TAPSE=1.5cm(Image8)CalculationofRightVentricularSystolicPressure(RVSP)orPulmonaryArterySystolicPressure(PASP)isrelativelyeasyandanextremelyusefulmeasurementintheassessmentofPHT.RVSP=4x(PeakTRVelocity)2+RightAtrialPressure(RAP).RAPisestimatedfromthesizeoftheInferiorVenaCava(IVC)anditscollapsibilityondeepinspiration(Video5–IVC).Itisimportanttonotethatpulmonaryhypertensionisdefinedbymeanpulmonaryarterypressure(linkprovided)andnotPASP(orRVSP)whichisquotedonaTTEreport.ComprehensiveechocardiographicassessmentofPHThasbeenoutlinedinanexcellentdocumentwrittenbyHammersmithHospitalCardiologyDepartment(linkprovided).MrsP:TRPeakVelocity=3.95m/sec,RAP=10mmHg.PASP=72.4mmHg.Conclusion=moderate/severeelevationinpulmonarypressures.(Video6–TRColourDoppler,Image9–PeakTRVelocity)

Image8

Image9

3.ATRIA:Atriaareconsideredasthe‘window’totheventricles.ForexamplethefirstsignofsignificantLVdiastolicdysfunctionisanenlargedleftatrium.Qualitativecommentsabouttheshapeoftheinteratrialseptumcanalsohelpwiththeassessmentofleftandrightatrialpressure.Volumetricmeasurementsaremostaccurate.MrsP:LAVolume=66.5mls.Conclusion=EnlargedLeftAtrium.(Image10–LAVolume)Image10

4.VALVES:Assessmentofeachvalveshouldbebystructureandfunction.Structureisusuallyassessedbyzoomed2DimageswhereasassessmentofvalvularfunctionrequiresDopplerinterrogationofbloodflowthroughthevalve.Dopplerinterrogationrequiresexcellenttechnicalskillsandoffaxismeasurements(misalignedDopplercursor)cansignificantlyunderestimatetrans-valvulargradients.ReferencerangesforallmeasurementscanbefoundontheBSEsmartphoneapp.Tricuspid&PulmonaryValves-TRandPRareusuallyassessedby‘eyeballing’thecolourDopplerregurgitantjet.MildTRandPRisofnoclinicalsignificance.SevereTRcausesflowreversalinthehepaticveins.Bothtricuspidandpulmonarystenosisisrarebuttrans-valvulargradientscanbemeasured.Ingeneralqualitativecommentsaboutthetricuspidandpulmonaryvalvesaresufficient.MrsP:Structurallynormaltricuspidvalvewithmoderateregurgitation.Structurallynormalpulmonaryvalvewithnoregurgitation.

AorticValve(AV)-SignificantaorticstenosisisusuallydiagnosedbytheappearanceofcalcifiedandrestrictedleafletsonPara-sternallongaxis(PLAX)andParasternalShortAxis(PSAX)views(Video7–PLAXAorticStenosis&Video8–PSAXAorticStenosis.BothvideosareprovidedasexamplesbutarenotrelevanttothecaseofMrsP).Thecontinuityequationisthemostaccuratemethodofestimatingaorticvalveareaandisgivenbytheequationbelow.ExtremelyaccuratemeasurementsfromtheLeftVentricularOutflowTract(LVOT)arerequired.ItisassumedthattheLVOTisacircleandthereforeLVOTareaissimplycalculatedusingtheformulaπr2.ImportantlysmallerrorsmeasuringtheLVOTdiameterorradiusaremagnifiedbecausethevalueisthensubsequentlysquaredinthecalculation.VelocityTimeIntegrals(VTI)areusuallycalculatedautomaticallybystandardsoftwareinstalledonmostultrasoundmachines.AorticValveArea=(LVOTVTIxLVOTArea)/AorticValveVTI(Images11–LVOTDiameter,Image12–LVOTVTI,Image13–AVVTI.TheseimagesareprovidedasexamplesbutarenotrelevanttothecaseofMrsP).PressuregradientsacrossastenoticvalvearealsousedtogradeseveritybuttheyaremorepronetoerrorandcanbeaffectedbyotherfactorssuchasLVsystolicfunction.InterestedstudentsaredirectedtotheESCguidelines(linkprovided).AorticregurgitationisassessedbyacombinationofmethodsincludingcolourandspectralDoppler.MrsP:Nomeasurementsneededasvalvenormal.Onlyaqualitativecomment‘Structurallynormaltrileafletvalvewithnosignificantregurgitation’Image11

Image12

MitralValve-Mitralstenosisis99%rheumaticinaetiologyandthevalvehasacharacteristic‘hockeystick’appearanceonPLAXview.MitralvalveareaisbestcalculatedbytracingaroundtheopenvalveleafletsinaPSAXview(planimetry)butinformationderivedfromDopplerinterrogationisalsouseful.Mitralregurgitation(Video9-MR)isthemostdifficultofvalvularlesionstoaccuratelyassessandinterrogationfromallparasternalandapicalviewsinrequired.ThemostaccuratewaytoquantifyMRisbycalculatingregurgitantvolumefrommeasurementofProximalIsovelocitySurfaceArea(PISA)oncolourDoppler(Image13-PISA).TheaetiologyofMRshouldalwaysbestatedandcanbedividedintoorganicorfunctionalcauses.MildMRisofnoclinicalsignificance.InterestedstudentsareagaindirectedtotheESCguidelines(linkprovided)MrsP:MRRegurgitantVolumePISA=43.9mls.Conclusion=ModeratefunctionalMRAORTA,PERICARDIUM&OTHERFINDINGS:Theaortacanbeassessedatmanypoints(ascending,arch,descending)usingTTE.Standardmeasurementsincludethewidthatthelevelofaorticsinuses.Pericardialeffusionsaremeasuredatenddiastoleandquantifiedassmall,moderateorlargehowever,sizeislessimportantthanwhetherthereareanyechocardiographicsignsofhemodynamiccompromiseasaresultofthepericardialeffusion.https://www.youtube.com/watch?v=eCZQig--5oQ

Image13

ManyadditionalfindingscanbeidentifiedonTTEincludingnon-cardiacpathologysuchaspleuraleffusionsandabdominalaorticaneurysms.SIGNIFICANTFINDINGSONPERIOPERATIVETTEInpatientsscheduledfornon-cardiacsurgeryitisalsohelpfultoconsiderthequestionofwhatconstitutesasignificantfindingonpreoperativerestingTTE.Significantfindingscanbeconsideredasthosewhichaffectperioperativeriskstratification,alterclinical(medical,anaestheticorsurgical)managementandattheextremeendofthescalethosefindingswhichleadtocardiacsurgicalinterventionpriortoundergoingnon-cardiacsurgery.Leftventricular(LV)systolicheartfailureisconsideredariskfactorforadverseperioperativecardiaceventsandisacomponentofseveralclinicalriskindices.Kazmersetal.(1988)foundanLVejectionfraction(EF)oflessthan35%tobethemostaccuratepredictorofadverseperioperativeeventsandthiswasconfirmedbyHammilletal.(2008).Matyaletal.(2009)showedthatdiastolicdysfunctionwasanindependentriskfactorforperioperativecongestiveheartfailureinastudyof313highriskpatientsundergoingvascularsurgery.However,moreresearchiscertainlyneededinthisparticulararea.Diastolicdysfunctionisoftennotassessedpreoperativelyanddoesnotfeatureonanycommonlyutilizedclinicalriskindicesandmaybeanevolvingpathologythatwewillbegintounderstandbetterinthefuture.

Withregardstovalvularfunctionitishelpfultoconsiderstenoticandregurgitantpathologyseparatelywithstenoticpathologybeingmorepoorlytoleratedbypatientsundergoingnon-cardiacsurgery.TheACC/AHAconsidersseverestenoticvalvulardisease(ASwithavalveareaof<1sqcmandsymptomaticmitralstenosis(MS))asoneoffouractivecardiacconditionsthatrequireevaluationandtreatmentpriortonon-cardiacsurgery.Theissuewithregardstovalvularregurgitationinpatientsundergoingnon-cardiacsurgeryismorecomplex.TheESC/ESAguidelines(DalbyKristensenetal.2014)advisethatasymptomaticpatientswithpreservedLVsystolicfunctionandseveremitralregurgitation(MR)oraorticregurgitation(AR)arenotatincreasedperioperativerisk.The2014ACC/AHAValvularHeartDiseaseGuidelines(Nishimuraetal.2014)statethatitisreasonabletoperformmoderaterisknon-cardiacsurgery,withappropriatehaemodymanicmonitoring,onpatientswithasymptomaticsevereMRandasymptomaticsevereARifEF%ispreserved.Althoughitmaybereasonabletoproceedwithsurgeryinthesecasespriordiagnosisandaccuratequantificationofvalvularregurgitationisclearlyessentialforperioperativeplanning.Inadditiontherewillbemanyotherfactorsthatdeterminehowanindividualpatientismanaged.Pulmonaryhypertension(PHT)isanotherareaofuncertaintywithmostevidencecomingfromobservationaldataofpatientswithpulmonaryarterialhypertension(Type1PHT).However,complicationratesareextremelyhighinthisgroupwithsignificantperioperativemorbidityandmortality.BoththeESC/ESAandACC/AHAmakeanumberofrecommendationsregardingtheperioperativemanagementofpatientswithPHTincludingthoroughevaluationandoptimisationbyaPHTspecialistpriortosurgery.Itisknownthatelevationsinrightatrialpressure(RAP)andreducedcardiacoutputaremoreimportantthanisolatedelevationsinrightventricularsystolicpressure(RVSP)astheformerarerepresentativeofrightventricular(RV)failure.AnRVSP>70mmHghas,neverthelessbeenidentifiedasariskfactorforadverseperioperativeevents(Minaietal.2014).Itisextremelyunlikelytherewilleverbeanystudieslookingatmajorincidentalfindingssuchasintra-cardiacmassorpericardialeffusiononpreoperativerestingTTEhowever,itwouldseemlogicaltoconsiderthesefindingssignificant.ThechallengeofinterpretingapreoperativerestingTTEisseparatingthe‘woodfromthetrees’.TheclinicianneedstoextractalltherelevantfindingswhilstnotattachingsignificancetominorandirrelevantabnormalitiessuchasPASPof40mmHginanobesepatientorType1diastolicdysfunctioninanelderlyman.CorrectinterpretationcomeswithexperienceandbystudyingalargenumberofTTEreports,seekingadvicewhennecessaryfromexpertsinthefield.AnoteregardingthelinksbelowLinks1and2areincludedtogivethereaderanideaofthecomplexnatureofadiagnosticTTE.Link3givesreferencerangesforallTTEdata(itisnotexpectedthisinformationiscommittedtomemory).SomeofthearticlesreferencedinthediscussionarealsooutsidethescopeofMScPerioperativeMedicineandprovidedforinterestonly.

Keylinks:1-https://www.youtube.com/watch?v=NUVF-RxEZbE,2-http://www.bsecho.org/tte-minimum-dataset/3-http://www.bsecho.org/bse-app/

Appendices:

Table1:IndicationsforPreoperativeRestingTTEasperAHA/ACC,ESC/ESA&BSE

Indication ClassofRecommendation

LevelofEvidence

Organisationrecommending

Patientswithshortnessofbreath(SOB)ofunknownorigin

ClassIIa LevelC AHA/ACC

HeartfailurewithworseningSOBorotherchangeinclinicalstate

ClassIIa LevelC AHA/ACC

Patientswithclinicallysuspectedmoderateorgreaterdegreesofvalvularstenosisorregurgitationifa/nopriorTTEin1yearorb/significantclinicalchangesincelaststudy.

ClassI LevelC AHA/ACC

‘SystolicmurmursuggestiveofAS’

‘Appropriate’ AHA/ACC

‘Clinicalhistoryorphysicalexaminationsuggestsvalvulardisease’

‘Helpful’ AHA/ACC

‘Estimatepulmonaryarterysystolicpressure(PASP)’

‘Usefulinperioperativeplanning’

AHA/ACC

Patientsundergoinghighrisksurgery

ClassIIb LevelC ESC/ESA

AllpatientswithknownorsuspectedValvularHeartDisease,whoarescheduledforelectiveintermediateorhighrisk,non-cardiacsurgery.

ClassI LevelC ESC/ESA

Ischaemicheartdisease&Exercisetolerance<4metabolicequivalents(METS)

BSE

SOBinabsenceofclinicalsignsofheartfailure.Electrocardiogram(ECG)+/-ChestX-Ray(CXR)abnormal)

BSE

Heartmurmur&cardiacorrespiratorysymptoms

BSE

Presenceofheartmurmurinasymptomaticpatientwhohasclinicallysuspectedseverestructuralheartdisease.

BSE

Table2:MostUsefulMeasurementsonaTTEReportStructure MeasurementLeftVentricleSize LeftVentricularEndDiastolicDiameter(PLAX)LeftVentricleWallThickness LVInterventricularSeptum(PLAX)

LVPosteriorWall(PLAX)LeftVentricleSystolicFunction LVEjectionFractionMODBPLeftVentricleDiastolicFunction E/E’,LAVolumeRightVentricleSystolicFunction TAPSE

RVS’LeftAtrium LAVolumeRightAtrium RAVolumeAorta AortaatSinuses(+otherlocations) Pericardium SizeofPericardialEffusionIVC SizeandCollapsibility(toestimateRAP) Valves AorticStenosis AVPeakVelocity&Gradient

AVMeanGradientAVAreaContEqn(VTI)

AorticRegurgitation AIPressureHalfTimeAIVenaContracta

MitralStenosis MitralValveArea(Planimetry)PressureHalfTimeMVMeanGradient

MitralRegurgitation RegurgitantVolume(PISA)TricuspidRegurgitation TRPeakVelocity(toestimateRVSP/PASP)PulmonaryStenosis PVPeakvelocity

References:

Hammill, B.G. et al., 2008. Impact of heart failure on patients undergoingmajornoncardiacsurgery.Anesthesiology,108(4),pp.559–567.Heyburn, G. &McBrien,M.E., 2012. Pre-operative echocardiography for hipfractures: time tomake it a standardof care.Anaesthesia, 67(11), pp.1189–1193.Kazmers,A.etal.,1988.Perioperativeandlateoutcomeinpatientswithleftventricularejectionfractionof35%orlesswhorequiremajorvascularsurgery.JVascSurg.1988Sep;8(3):307-15Matyal, R. et al., 2009. Perioperative diastolic dysfunction during vascularsurgery and its association with postoperative outcome. Journal of vascularsurgery,50(1),pp.70–76. Minai,O.A.etal., 2013.Perioperative riskandmanagement inpatientswithpulmonaryhypertension.Chest,144(1),pp.329–340.

Nishimura et al., 2014. 2014 AHA/ACC Guideline for the Management ofPatientsWithValvularHeartDisease.JAC,63(22),pp.e57–e185.Wijeysundera,D.N.etal.,2011.Associationofechocardiographybeforemajorelectivenon-cardiacsurgerywithpostoperativesurvivalandlengthofhospitalstay:populationbasedcohortstudy.BMJ,342(jun301),pp.d3695–d3695.