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patientsandisassociatedwithapoorprognosis,with44%survivalat1yearand
lessthan25%survivalat5years.318Thesecondaryformmaybeclinically
apparentintheseconddecadeorearlier,dependingonthefrequencyof
transfusions.Thereiswidespreaddepositionofironintheliver,spleen,
pancreas,gonads,skin,andheart,whichleadstotheclinicalmanifestations.The
classictriadconsistsofhepaticcirrhosis,bronzepigmentationoftheskin,and
DM.Splenomegalyispresentinapproximatelyhalfthepatientswithidiopathic
hemochromatosisandinvirtuallyeverypatientwithβ-thalassemia.Cardiac
involvementresultsfromexcessivedepositsofhemosiderinintheheart.This
producesadilatedcardiomyopathywithcardiacfailure.Arestrictive
cardiomyopathyhasalsobeendescribed.319
Theheartisrusty-brownatpostmortem,withdilationofallcardiacchambers.
Concentrationofironisgreaterinthesubepicardialpartoftheheart,therefore
limitingtheuseofendomyocardialbiopsies.320Ironintheformofhemosiderin
initiallyadoptsaperinucleardistributionandthenextendsperipherallyasthe
amountofdepositsincreases.Thesearegreaterintheventriclesthaninthe
atriumsandtheconductiontissues.321
Low-voltageQRScomplexesareseenelectrocardiographicallywith
nonspecificST-segmentandT-wavechanges.AprolongedQTintervalmaybe
present,andtheremaybeevidenceofrightorleftventricularhypertrophy.
Disturbancesofrhythmarecommonandincludeatrialandventricularpremature
contractions,supraventricularandventriculartachycardias,andvaryingdegrees
ofatrioventricularblock.Cardiacenlargementandsignsofcardiacfailure,when
present,areseeninthechestradiograph.Echocardiographyshowsincreasedleft
ventricularmuralthickness,increasedleftventricularandleftatrialdimensions,
andareductioninfractionalshorteningandejectionfraction.322
Laboratorystudiesshouldincludemeasurementsofplasmairon,ferritin,and
saturationoftransferrin.Thesearetypicallyelevated.Measurementofthe
contentofironinsamplesobtainedbyneedlebiopsyoftheliverallowsaccurate
estimationsoftotalbodyiron.Advanceincardiacmagneticresonance
techniquesallowfornoninvasiveestimatesofcardiacironloading.323Malignant

hepatomaisanimportantlatecomplicationinolderpatients.Removalofironby
repeatedvenesectionorbychelationwithdesferioxamineinsecondaryiron
overloadmayreversecardiacmanifestationsexceptforthedisturbancesof
conduction.324Symptomaticheartblockrequiresinsertionofapacemaker.


AutoimmuneDiseases
JuvenileIdiopathicArthritis
Juvenileidiopathicarthritis(JIA)isthemostcommonformofchronicjuvenile
arthritis.Itistypicallycharacterizedbytheabsenceofpositiveserologictests.
Thediseaseisdividedintoseveralformsbasedontheprincipalfeaturesand
onset.
Patientswithsystemic-onsetidiopathicarthritis,orStilldisease,frequently
haveaquotidianfebrilepatternaccompaniedbyanevanescentrash,
hepatosplenomegaly,andgeneralizedlymphadenopathy.Arthritismayormay
notbepresent.Pleuritiswithinterstitialpulmonarydiseaseisfrequent.Themost
commoncardiacmanifestationispericarditis.325
Polyarticulardiseaseischaracterizedbysymmetricinvolvementofthewrist,
knee,andanklejoints.Thecervicalspineisfrequentlyaffected.Systemic
manifestationsareofamildernature.Rash,splenomegaly,and
lymphadenopathymaybepresent.
Thepauciarticularvarietyaffectssmallchildren.Thejointsinvolvedarethe
knees,ankles,elbows,orwrists.Systemicmanifestationsareinfrequent.Such
patientsareatriskofblindnessfromiridocyclitis.Thisformhasthebest
prognosis.Pericarditisisthemostcommonformofcardiacinvolvement,
althoughmyocarditisandendocarditiscanoccuraswell.326Pericarditisisbest
managedwithantiinflammatoriesand,whennecessary,pericardiocentesis.
ChildrenwithJIAmayalsobeatriskforlong-termcardiovasculardisease.
ThereareconflictingdataontheeffectofJIAonlipidprofilesandsystemic
bloodpressure,butthereisatrendtowardlowerhigh-densitylipoprotein,higher

triglycerides,andhighnormalbloodpressureinJIA;thereforecarefulrisk-factor
managementisimportantinthelongterm.327

SystemicSclerosis(Scleroderma)
Systemicsclerosisisadisorderofunknownetiologyresultingintighteningand
indurationoftheskin.Visceralmanifestationsincludegastrointestinaldisease
withdysphagiaandrefluxrelatedtoesophagealdysmotility;renaldiseasewith
azotemia,proteinuriaandhypertension;pulmonarydiseasewithinterstitial
fibrosisandpulmonaryvascularchangesleadingtopulmonaryarterial


hypertension;andcardiacdiseasewithconductiondisturbances,myocardial
fibrosis,coronaryarterydisease,andautonomicdysfunction.328,329Close
monitoringforthedevelopmentofpulmonaryhypertensionisrequired,asthis
remainsanimportantcauseofmorbidityandmortality,affectinguptoone-sixth
ofpatients.330Cardiacinvolvementisoftenasymptomaticbutfoundatautopsy
inone-thirdofpatients.331Diastolicandsystolicdysfunctionisfrequentlyseen
byechocardiographyeveninasymptomaticpatients.Subtleevidenceofright
ventriculardysfunctionmaybeanearlysignofasymptomaticpulmonary
hypertensionandmayallowforearlytreatment.332Treatmentofthis
complicationincludescurrentlyavailableagentsaimedatreducingpulmonary
vascularresistance,coupledwithcyclophosphamidetoaddressthepulmonary
interstitialfibrosis.333

TakayasuArteritis
Takayasuarteritis,alsoknownaspulselessdisease,isachroniclarge-vessel
vasculitisprimarilyaffectingtheaortaandtheproximalarteriessupplyingthe
headandneck,alongwiththeproximalpulmonaryarteries.Inflammationofthe
arterialwallsleadstothickening,fibrosis,andultimatelystenosiswithformation
ofthrombus.Aorticaneurysmscanalsooccurbutarelessfrequent.Thedisease

oftenpresentsinadolescentsoryoungadultswithnonspecificsymptomsof
activationoftheinflammatorysystem.Consequentlythediagnosismaybe
delayeduntilmoreovertevidenceofthediseasebecomesmanifest,including
reducedpulses,hypertension,vascularbruits,andaorticvalvardisease.334Often
theacutephasepresentswithsystemiccomplaints:weightloss,fatigueandnight
sweats,andanorexia.Treatmentconsistsofimmunosuppressionwithprolonged
corticosteroidregimens.Despitesteroidregimensof1to2years,almost50%of
patientsrelapseduringsteroidweaning.335Whencorticosteroidsarenot
effective,moreaggressivecytotoxicdrugscanbeused,suchas
cyclophosphamide,methotrexate,orazathioprine.336Angioplastyorthe
implantationofstentsissometimesnecessaryforseverestenosesunresponsive
tomedicalmanagement.

PolyarteritisNodosa
Polyarteritisnodosaisavasculiticsyndromeaffectingsmall-tomedium-sized
arteries,primarilyinthekidney,skin,andgastrointestinaltract.The