Andersons pediatric cardiology 2125
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Abstract
Thesuccessesofpediatriccardiologyandcardiacsurgeryhaveenableda
newcohortofwomen,bornwithcongenitallymalformedhearts,toreach
adulthood.Manyofthesewomenarenowconsideringpregnancy.Most
womeninthisnewcohortcananticipatesafeandsuccessfulpregnancies.
Pregnancy,however,impartsanadditionalhemodynamicload,is
prothrombotic,andincreasesthepropensitytoarrhythmias,allofwhich
increasetheriskofadversematernalcardiacevents.Inaddition,women
withheartdiseaseareathigherriskforfetalandneonatalcomplications.
Recognitionandappropriatemanagementofsuchrisks,whenpresent,
shouldoptimizeoutcomes,whereastheidentificationofwomenwith
congenitallymalformedheartswhoareatlowriskallowsforwelcome
reassurance.
Keywords
Adultcongenitalheartdisease;Pregnancy;Obstetric;Cardiology
Thesuccessesofpediatriccardiologyandcardiacsurgeryhaveenabledanew
cohortofwomen,bornwithcongenitallymalformedhearts,toreachadulthood.
Manyofthesewomenarenowconsideringpregnancy.Mostwomeninthisnew
cohortcananticipatesafeandsuccessfulpregnancies.Pregnancy,however,
impartsanadditionalhemodynamicload,isprothrombotic,andincreasesthe
propensitytoarrhythmias,allofwhichincreasetheriskofadversematernal
cardiacevents.Inaddition,womenwithheartdiseaseareathigherriskforfetal
andneonatalcomplications.Recognitionandappropriatemanagementofsuch
risks,whenpresent,shouldoptimizeoutcomes,whereastheidentificationof
womenwithcongenitallymalformedheartswhoareatlowriskallowsfor
welcomereassurance.
ImpactofPregnancyonthe
CardiovascularSystem
HemodynamicChangesDuringPregnancy
Manyphysiologicchangesoccurduringpregnancy.Thematernalbloodvolume
increasesbyapproximately50%,beginningduringthefirsttrimesterand
peakinginthethirdtrimester.Theaverageheartrateincreasesby10to20
beats/min.Beginningearlyinthefirsttrimester,thesystemicvascularresistance
andsystemicarterialpressurebegintodecreaseowingtothelow-resistance
circuitintheuterusandtotheeffectsofendogenousvasodilators.Thesystemic
vascularresistancedecreasesuntilmidpregnancy,plateaus,andthenbytheend
ofpregnancyrisestowardthelevelsexistingpriortopregnancy.Systemic
arterialpressurealsobeginstoreturntowardprepregnancylevelsinthethird
trimester.Thechangesinbloodvolume,vascularresistance,andheartrateall
contributetoanincreaseincardiacoutput,whichbeginsearlyinthefirst
trimester,continuestoincreaseuntilapproximatelytheendofthesecond
trimester,risingtolevelsbetween30%and50%higherthanthelevelsexisting
priortopregnancy,andthenplateausuntilterm.Cardiacoutputisaffectedby
position,beinghighestwhenthemotherislyingonherleftside.Thesupine
graviduteruscancompresstheinferiorcavalvein,whichlimitsvenousreturn
andmayresultinasubstantialreductionincardiacoutput.
Laborisassociatedwithafurtherincreaseofapproximately10%inbasal
cardiacoutput,augmentedbyanadditionalsurgewitheachuterinecontraction.
Anxiety,pain,tachycardia,andhypertensionorhypotensionalsocontributeto
cardiaccomplicationsatthetimeoflaboranddelivery.Followingdelivery,there
isafurtherincreaseincardiacoutputduetoreliefofcompressionontheinferior
cavalveinandautotransfusionfromthenowfullycontracteduterus.Rapid
mobilizationofinterstitialfluidintheimmediateperiodfollowingpregnancy
mayhaveasignificantnegativeimpactonawomanwithalreadycompromised
cardiacfunction.Althoughmanyofthedescribedchangesregresswithinthe
firstfewdaysafterdelivery,completeresolutionofpregnancy-inducedeffects
oncardiacfunctionmaynotoccuruntil6monthsafterdelivery.
CardiacSymptomsandSignsinNormal
Pregnancy
Duringpregnancywomenoftenexperiencefatigue,dyspnea,tachypnea,
palpitations,presyncope,anddecreasedexercisetolerance.Suchsymptomscan
beidenticaltothoseofcardiacdecompensation,andcliniciansmustbecarefulto
differentiatethispossibility.Bloodpressuredecreasesduringthefirstpartof
pregnancyandthen,duringthelast6weeks,reachesorexceedsprepregnancy
levels.Bloodpressureshouldbetakenwhenthemotherissittingorlyingonher
leftsidetoavoidafalselylowreadingcausedbysupinecavalvenous
compression,limitingvenousreturn.Thediastolicbloodpressurefallsmorethan
thesystolicpressure,resultinginawidepulsepressure.Theheartrateincreases.
Peripheraledemamaybenoted.Theremaybealaterallydisplacedapical
impulseduetomodestincreaseincardiacsize,aswellasupwarddisplacement
oftheheartbythegraviduterus.Thereisoftenprominenceofthejugular
venouspulsation.Theremaybewidesplittingofthefirstandsecondheart
sounds.Asystolicflowmurmuriscommon,secondarytothehyperdynamic
circulation,andisbestheardattheleftlowersternalborder.Thecontinuous
murmurofavenoushumintherightsupraclavicularfossaoramammarysouffle
overanengorgedbreastcanbecomeapparent.
