Andersons pediatric cardiology 1485

Imaging
Echocardiography
Transthoracicechocardiography(TTE)hasmuchhighersensitivityinchildren
(>85%)thaninadults.Two-dimensional(2D)imageshavehighspatial
resolutionandhighqualityanddiagnosticyield.Theinterplaybetween2Dand
colorDoppler(CD)imagingforvisualizationofstructuresandflow,
respectively,areofgreatestsignificance.PulsedwaveDopplerandcontinuous
waveDopplerhaveimportanceinassessingstenosisandgradientsbetween
cavities.Tissueharmonicimagingprovidesimprovedimagequality.Currently,
thenegativepredictedvalueoftheabsenceofechosignsofIEeveninadultscan
reach97%.30
Transesophagealechocardiography(TEE)mayonlyoccasionallybeindicated
intechnicaldifficultiesinacquisitionoftransthoracicimages,abscesses,or
negativeTTEinstrongclinicalsuspicionofIE.Unlikeadults,TEEisonlyrarely
requiredandisusuallynotnecessarybecausethesensitivityofTTEisgreater
than90%forvegetationsandgreaterthan85%intotal.31
AsummaryofechocardiographyfindingsandrulesandindicationsforTEE
aresummarizedinBox56.3.EchocardiographyimagesofsignsofIEaswellas
matchingintraoperativefindingsareshowninVideos56.1to56.43.


Box56.3

EchocardiogrphyinInfectiveEndocarditis
EchocardiographySignsofIE:
■Vegetation:mobilehyperechogenicmassattachedtovalve,device,orwall
(2D)
■Regurgitationdueto:
■perforation:regurgitantjet(CD)acrossaninterruptionofleaflet
echo(2D)
■fistula:communication(CD)betweenneighboringcavities

throughperforation(2D)


■chordalruptureofAVvalve:centralregurgitantjet(CD)with
gap,freefloatingchordprolapsingtotheatrium,leafletprolapse
(2D)
■dehiscenceofprostheticmechanicalvalve:paravalvarleak(CD)
with/withoutrockingmotionoftheprosthesis
■aneurysm:saccularbulging(2D)
■Abscess:perivalvarthickened,nonhomogeneous,hyperechogenic
(echodense),orhypoechogenic(echolucent)area(2D)notcommunicating
withanycavity(CD)
■Pseudoaneurysm:pulsatileperivalvarecholucentarea(2D)withflow
communicatingwithlumen(CD)
■Intracardiacfistula:communicationbetweenavesselandacardiacchamber
■Blockedshuntorstentedvessel
EchocardiographyrulesofIE:
■Neithersensitivitynorspecificityofechocardiographyis100%and
thereforenegativeechocardiogramdoesnot100%excludeIE.
■Echogenicitydoesnotdiffersignificantlybetweenvegetation,thrombus,
andtumor.
■Comparetopreviousimages,ifavailable,asdysplasiamyxomatous
changesmayimitatevegetations.
■Donotrelyonstillimages,reviewloopsofatleastonecompletecycleat
lowspeed.
■Iftheinitialechocardiographywasnegativeandtheclinicalsuspicion
remainshigh,repeatedechoin7–10daysorearlierifS.aureusinfection.
■Serialexaminationshavesignificanceforguidingthemanagement.
Echocardiographyreportshouldinclude:
■Locationandsizeofvegetation,perforation,abscess,aneurysm

■Severityofstenosisorregurgitation
■Hemodynamicconsequencesofstenosisorregurgitationincludingcavity
size,ventricularfunction,andpulmonaryarterypressureassessment.


■Relationtopresumedunderlyingcause:valvarabnormality,ventricular
septaldefect,prostheticmaterialetc.
■IncaseofmultisiteIE,proximityeachlocationtoeachother.
TEEmaybeindicatedin:
■NegativetransthoracicechoinhighclinicalsuspicionofIE
■Prostheticvalveendocarditis
■Suspectedparavalvarabscess
■Childrenandadolescentswithinadequatetransthoracicimagingbecauseof
overweight/obesityandchestwalldeformities
2D,Two-dimensional;CD,colorDoppler;IE,infectiveendocarditis;TEE,
transesophagealechocardiography.
Theaddedvalueofthree-dimensionalechocardiographyremainstobe
established:itmightremainlowduetothecurrentlylowspatialresolution.
Targetedemergencyechomaybelifesaving.Itisbecomingincreasingly
importanttohaveatimelydiagnosisandmanagetheemergencyconditions
relatedtoemboliccomplicationsofIEortoheartfailurerelatedtoacutevalvar
regurgitations.Guidelinesforurgenttargetedechohavebeenadopted.32
Intracardiacechomayhaveaddedvalueforvisualizingintrastentvegetations.
IthasbeenshowntobeusefulforvisualizingvegetationsinIErelatedto
transcatheterimplantedpulmonaryvalves,33asupto50%remainnotvisualized
withTTEandTEE.Itisrarelyusedbecauseoftherareindicationsandrelatively
highprice.

ComputedTomography
High-resolutionmultislicegatedcardiaccomputedtomography(CT)with

contrastisoneoftheaddedmajorIEcriteriainthenew2015IEguidelines.1The
newestthird-generationdualsourceturboflashCTequipmentnotonlyhas
superiorspatialresolutionbutalsoallowstheacquisitionofimagesinminimal
amountsoftime,thusenablingtheinvestigationtobeperformedwithoutgeneral
anesthesiaandatverylowradiationexposure.
CThashighaddedvaluefordiagnosingIEinthefollowing: