Andersons pediatric cardiology 1465

CardiacMagneticResonanceImagingin
RheumaticHeartDisease
ThepotentialstrengthsofcardiacMRIintheassessmentofpatientswithRHD
areincreasedaccuracyinassessmentofventricularvolumesincomparisonto
echocardiography,theabilitytomeasurethevolumeofregurgitantflow,andto
characterizethetissuepropertiesofthemyocardiumwhenthediagnosisofRHD
isindoubt.Thefirsttwoapplicationsmaybeofuseindeterminingthetimingof
surgerywithgreaterprecision.39Theabilitytodetectandquantifythedegreeof
carditisusingtechniquessuchasT1/T2sequencesandT1mappingmaybeof
useindeterminingthediagnosisormonitoringtherapyoverandaboveblood
markersofsystemicinflammation.40
Clearlypooraccesstohighlyspecializedequipmentandtechnologysuchas
cardiacMRIinthepopulationofpatientsmostaffectedbyRHDisitsgreatest
limitation.Thereforeechocardiographyislikelytoremainthemainimaging
techniqueusedtodiagnoseandmonitorcardiacchangesinthemajorityof
patientsaffected.


ComplicationsofRheumaticHeart
Disease
Onceestablished,RHDisassociatedwithsubstantialmorbidityandmortality.
Heartfailure,infectiveendocarditis,atrialfibrillation(AF),pregnancy-related
complications,andstrokearekeycomplicationsofRHD.2,15,41Thereislittlein
thecontemporaryliteraturerelatingtomorbidityassociatedwithRHD.The
REMEDYstudy15reportedthat33%patientshadheartfailure,22%hadAF,7%
hadpreviouslyhadastroke,and4%hadinfectiveendocarditis.Inresource-poor
settings,themanagementofpregnantwomenwithRHDischallenging.Maternal
morbidityinthesettingofsevereRHDhasbeenreportedtobe3.3%inSouth
Africa42and33%inSenegal.43

AtrialFibrillation

AFisarelativelyrarecomplicationofRHDinthepediatricpopulation;itis
mostcommonlyseeninthesettingofMS.Ageandleftatrialdimensionarethe
mostimportantriskfactorsforthedevelopmentofAFinthesettingofMS.44
Otherriskfactorsincludeleftatrialstrainaswellaselevatedrightatrialpressure
andejectionfraction.44InitiallyAFmaybeparoxysmal,butasMSandleftatrial
dilatationprogresses,iteventuallybecomeschronic.45AFhasveryserious
complications,includingsystemicembolismorstroke.TheriskofAFandits
complicationspersistsevenafterthespecificstructuraldiseasehasbeentreated
withuseofeitherpercutaneousorsurgicaltechniques.46Evenepisodesof
transientAFshorterthan30secondsdetectedbyHoltermonitoringpredictthe
primarycompositeendpointofstroke,transientischemicattack,ornon–central
nervoussystemsystemicembolization.47

Stroke
Inpediatricpopulations,theincidenceofcerebrovascularaccidentsinthesetting
ofRHDisnotwelldefined.Itmaybeischemicorhemorrhagicinnatureandcan
beassociatedwiththespecificnativevalvarabnormality,suchasMS,
mechanical/bioprostheticvalvereplacements,and/oratrialarrhythmiassuchas
AF/flutter.However,factorsotherthanAF—includingregional(leftatrial)


hypercoagulability,increasedprothromboticbiomarkers,andreduced
fibrinolyticactivity—maycontributetostroke.48,49Mechanicalvalve
replacementsinthepediatricpopulationposeanextremeriskofcerebrovascular
events.50Thisisespeciallysoinresource-poorsettings,wherethemajorityof
RHDpatientsreside.15

HeartFailure
Advancedvalvardysfunctioneventuallyleadstocongestivecardiacfailure.An
Australianstudyshowedthat27%ofpatientsdevelopedheartfailurewithin5

yearsfromthetimeofdiagnosisofRHD.51Thosewhodevelopheartfailure
requiresurgicalorpercutaneousinterventionortheywillsuccumb.InSouth
Africathe60-daymortalityafteradmissionwithacuteheartfailureduetoRHD
was25%and180-daymortalitywas35%.30

InfectiveEndocarditis
RHDisariskfactorforinfectiveendocarditis,52whichcanbeminimizedby
exercisingmeticulousdentalhygiene.ItisunclearwhetherRHD,comparedwith
othervalvediseases,posesanincrementallyincreasedriskduetorheumatic
valvepathologyitselfortoconfoundingfactors(suchaspoordentition,low
levelofeducation,andothersocialdeterminatesofhealth)commoninpatients
withthisdisease.WithRHD,theneedforinfectiveendocarditisprophylaxis
beforedentalandsurgicalproceduresiscontroversial;itisrecommendedbythe
Australian53andNewZealandauthorities54butnotbytheAmericanCollegeof
Cardiology(ACC)andtheAmericanHeartAssociation(AHA)2017
guidelines.55