现代心脏病学Word文档格式.docx

现代心脏病学Word文档格式.docx

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CherylL.Reid,MD

GeneralConsiderations

Physiology&

Etiology

ClinicalFindings

Treatment

Prognosis

ESSENTIALSOFDIAGNOSIS

Pregnancy

Historyofheartdisease

Symptomsandsignsofheartdisease

Echocardiographicevidenceofheartdisease

Heartdisease（mostfrequentlycongenitalorvalvulardiseases）occursin1–4%ofpregnancies,andtheincidenceisincreasing.Theuniquehemodynamicchangesassociatedwithpregnancymakediagnosisandmanagementofheartdiseaseinpregnantpatientsachallengetothephysicians,whomustconsidernotonlythepatientbutalsotheriskstothefetus.

DanzellJD:

Pregnancyandpre-existingheartdisease.JLaStateMedSoc1998;

150

（2）:

97.

A.CARDIOVASCULARPHYSIOLOGYOF“NORMAL”PREGNANCY

Normalpregnancyisaccompaniedbysignificantphysiologicchanges,althoughunderlyingmechanismsremainvirtuallyunknown（Table31–1）.Thenormalsignsandsymptomsassociatedwithpregnancymayobscurethediagnosisofheartdiseaseduringthattime.Theclinicianmust,therefore,haveathoroughknowledgeofthesenormalchangesandtheaspectsofthehistoryandphysicalexaminationthatsuggestthepresenceofheartdisease.

Table31–1.Cardiovascularchangesinnormalpregnancy.

1.Bloodvolume—Theincreaseinmaternalbloodvolumebeginsasearlyasthesixthweekofpregnancy,peaksatapproximately32weeksofgestation,andstaysatthatlevel（40–50%higherthanpregestationallevels）untildelivery.Theplasmavolumeshowsamorerapidandsignificantrisethantheredbloodcellmass,accountingfortheappearanceofphysiologicanemiaduringpregnancy.Theincreasedbloodvolumeismaintaineduntilafterdelivery,whenaspontaneousdiuresisoccurs.Thisrapidpostpartumchangeinbloodvolumeisacriticalperiodforpatientswithunderlyingheartdisease.

2.Cardiacfunction—Normalpregnancyischaracterizedbyenhancedmyocardialperformance.Numerousstudieshaveshownagradualincreaseinleftventricularsystolicfunctionattributedtoleftventricularafterloadreductionduetothelow-resistancerunoffoftheplacenta.Thenriseinleftventricularsystolicfunctionbeginsinearlypregnancy,peaksinthetwentiethweek,andthenremainsconstantuntildelivery.

3.Cardiacoutput—Oneofthemostsignificantchangesduringpregnancyistheincreaseincardiacoutput,whichbeginstoriseduringthefirsttrimesterandpeaksattwenty-fifthandthirty-fifthweeksofgestation.Totalcardiacoutputincreasesupto50%overpregestationallevels.Cardiacoutputistheproductofstrokevolumeandheartrate.Duringtheearlypartofpregnancy,theincreaseincardiacoutputispredominantlytheresultofanincreaseinstrokevolume,augmentedbyincreasedintrinsicmyocardialcontractility.Aspregnancyadvances,heartrateincreasesandstrokevolumemildlydecreases.Theincreasedcardiacoutputinlatepregnancyismaintainedbecauseoftheincreasedheartrate.

Auniqueaspectofpregnancyisthehemodynamicchangesinducedbyachangeinapatient'

sposition.Whenthepatientisinthesupineposition,thegraviduterusinducesprofoundmechanicalcompressionoftheinferiorvenacava,decreasingvenousreturntotheheart,andthus,cardiacoutput.Achangefromthesupinetotheleftlateralpositionresultsina25–30%increaseincardiacoutputbecauseofanincreaseinstrokevolume.

4.Intravascularpressuresandvascularresistance—Systolicanddiastolicpressuresdropduringpregnancy.Asmalldecreaseinsystolicbloodpressurebeginsinthefirsttrimester,peaksatmidgestation,andreturnstonearprepregnancylevelsatterm.Thediastolicbloodpressuredecreasesmorethanthesystolicbloodpressure,duetoasignificantfallinsystemicvascularresistance,andresultsinawiderpulsepressure.Thesystemicbloodpressureincreasesduringpregnancywiththepatient'

sageandparity.Italsovarieswiththepatient'

sposition.Thehighestlevelsarerecordedearlyinthepregnancywhenthepatientisupright,andlowestwhensheissupine.Duringthelatterpartofpregnancytheeffectofpositiononsystemicbloodpressuredependsontherelativedegreesofinferiorvenacavaandaorticcompression.Totalvascularresistance,includingboththesystemicandthepulmonary,decreaseduringpregnancy.Themechanismforthefallinresistancesispoorlyunderstoodbutisattributedtothelow-resistancecirculationofthepregnantuterusandtohormonalchangesassociatedwithpregnancy.

ThornburgKL,JacobsonSL,GiraudGDetal:

Hemodynamicchangesinpregnancy.SeminPerinatol2000;

24

（1）:

11.

GilsonGJ,SamaanS,CrawfordMHetal:

ChangesinHemodynamics,ventricularremodeling,andventricularcontractilityduringnormalpregnancy:

Alongitudinalstudy.ObstetGynecol1997;

89（6）:

957.

PoppasA,ShroffSG,KorcarzCEetal:

Serialassessmentofthecardiovascularsysteminnormalpregnancy.Roleofarterialcomplianceandpulsatilearterialload.Circulation1997;

20;

95（10）:

2407.

B.ETIOLOGYANDSYMPTOMATOLOGY

1.Congenitalheartdisease—Asmedicalandsurgicaltreatmentofsuchpatientshasimproved,congenitalheartdiseaseisfoundmorefrequentlyduringpregnancy.Asaresult,morewomenwitheitheruncorrectedorsurgicallycorrectedcongenitalheartdiseasesaresurvivingintotheadulthood（Table31–2）.

Table31–2.Commoncongenitalabnormalitiesfoundinpregnantwomen.

Onlyafewconditionsplaceapatientatahighrisktoadviseagainstpregnancy（Table31–3）.Amajorityofthepatientswithmildtomoderateacyanoticcongenitalheartdiseasetoleratepregnancy,labor,anddeliverywell.Treatmentshouldinvolvefrequentcounselingbytheobstetricianandcardiologist.Inseverecases,physicalactivityandsaltintakelimitation,earlytreatmentofanyinfection,heartfailure,andarrhythmiashouldbeundertaken.Cesareandeliveryshouldbereservedonlyforobstetricindicationsbecausemostpatientscanbesafelydeliveredvaginally.

Table31–3.Relativecontraindicationstopregnancy.

High-riskpatientswithseverecyanoticcongenitalheartdisease,decreasedfunctionalcapacity,orEisenmenger'

ssyndromeshouldbeadvisedagainstpregnancy.Antibioticprophylaxisforbacterialendocarditisisrecommendedinmostpatientswithcongenitalheartdisease.Theriskoffetalmalformationintheoffspringshouldbeconsideredcarefully.

a.Atrialseptaldefect—Secundumatrialseptaldefectisthemostcommoncongenitalcardiacabnormalityencounteredduringpregnancy.Patientswithuncomplicatedatrialseptaldefectsusuallytoleratepregnancywithlittleproblem.Patientsmaynotbeabletotoleratetheacutebloodlossthatcanoccuratthetimeofdeliverybecauseofincreasedshuntingfromlefttorightcausedbysystemicvasoconstrictionassociatedwithhypotension.Theincidenceofsupraventriculararrhythmiasmayincreaseinolderpregnantpatients,whichmayresultinrightventricularfailureandvenousstasisleadingtoparadoxicalemboli.Low-doseaspirin,oncedailyafterthefirsttrimesteruntildeliverymayhelppreventclotformation.Pulmonaryhypertensionfromanatrialseptaldefectusuallyoccurslateinlife,pastthechildbearingyears.Bacterialendocarditisprophylaxisisrecommendedonlyforostiumprimumdefectduetoassociatedaorticvalveabnormality.Vaginaldeliveryispreferredovercesarean.Riskintheoffspringisabout2.5%.

b.Ventricularseptaldefect—Mostisolatedventricularseptaldefectshaveclosedbyadulthood.Womenwithventricularseptaldefectsgenerallyfarewellinpregnancy.Congestiveheartfailureandarrhythmiaarereportedonlyinpatientswithdecreasedleftventricularsystolicfunctionpriortopregnancy.Endocarditisprophylaxisduringdelivery,preferablyvaginal,isrecommended.

c.Patentductusarteriosus—Mostpatientswithapatentductusarteriosusundergosurgicalrepairinchildhood.Anormalpregnancycanbeexpectedinpatientswithsmall-to-moderateshuntsandnoevidenceofpulmonaryhypertension.Patientswithalargepatentductusarteriosus,elevatedpulmonaryvascularresistance,andareversedshuntareatgreatestriskforcomplicationsduringpregnancy.Thedecreasedsystemicvascularresistanceassociatedwithpregnancyincreasestheright-to-leftshuntandtheintrauterineoxygendesaturation.Patientsdevelopingheartfailurearetreatedwithdigoxinanddiuretics.Thepreferredmodeofdeliveryisvaginalinmostpatientswithendocarditisprophylaxisandhemodynamicmonitoringconsideredatthetimeofdelivery.Theriskinanoffspringisabout4%.

d.Pulmonicstenosis—Thenaturalhistoryofpulmonicstenosisfavorssurvivalintoadulthoodevenwithsevereobstructiontorightventricularoutflow.Mild-to-moderatepulmonicstenosis（peakgradient£

100mmHg）usuallypresentsnoincreasedriskduringpregnancy.Patientswithseverepulmonicstenosismayoccasionallytoleratepregnancywithoutdevelopingcongestiveheartfailure.Vaginaldeliveryistoleratedwell.Idealtreatmentconsistingofballoonvalvuloplastyshouldbeperformedbeforegestation.Theriskintheoffspringisabout3.5%.

e.Coarctationoftheaorta—Inuncomplicatedcoarctationoftheaorta,pregnancyisusuallysafeforthemotherbutmaybeassociatedwithfetalunderdevelopmentbecauseofthediminisheduterinebloodflow.Thebloodpressuremaydecreaseslightly,asduringnormalpregnancy,butstillremainselevated.MaternaldeathsinthesepatientsareusuallytheresultofaorticruptureorcerebralhemorrhagefromanassociatedberryaneurysmofthecircleofWillis.Patientswiththegreatestriskduringpregnancyarethosewithseverehypertensionorassociatedcardiacabnormalities,sucha