USMLE题库Cardiology(二)11-20

Cardiology2题库Q11A34-year-oldCaucasianfemalewhoisbeingevaluatedforproteinuriaandafacialrashcomplainsofchestpain.Thepainissharpinqualityandincreaseswithinspiration.Itradiatestothetrapeziusridgeandispartiallyrelievedbysittingup.Whichofthefollowingisthemostlikelycauseofthispatient’schestpain?A.IntimalhyperplasiaofpulmonaryarteriesB.AorticdissectionC.PericardialinflammationD.Non-infectiouscardiacvalvevegetationsE.CardiactamponadeA11Correctanswer:CThepatientdescribedabovedisplayssymptomsofsystemiclupuserythematosus(SLE).Thischronicautoimmunediseaseaffectspredominantlywomen20-40yearsofageandpresentswithamalarfacialrash,photosensitivitywithexacerbationofcutaneousdiseaseaftersunexposure,andarthralgias.Constitutionalsymptomssuchaslow-gradefever,malaiseandweightlossarecommon.RenalinvolvementispresentinvirtuallyallpatientswithSLE,althoughitmaybeasymptomaticatthebeginningofthedisease.Inthepatientdescribedinthisclinicalvignette,proteinuriaisevidenceoflupusnephritis.InflammationoftheserousmembranesisanothercommonmanifestationofSLE.FibrinousexudationistypicalforacuteserositiscausedbySLE,whilechronicinflammationleadstofibrosisandpossibleobliterationofserouscavity.SLE-associatedserosalinflammationcancausepleuritisandpericarditis.PericarditisoccurscommonlyinpatientswithSLE;atleasthalfofpatientswithSLEwillexperiencethiscomplicationduringtheirlifetimes.Pericarditismanifestswithsevereandconstantmiddleorleftchestpainthatmayradiatetotheback,armsandshoulders.Thepainincreasesoninspiration(pleuritic)andisrelievedbysittingupandleaningforward(postural).Auscultationofthechestrevealsascratchysoundcalledapericardialfrictionrubthatisbestheardwiththepatientsittinguprightandleaningforward.(ChoiceA)Intimalhyperplasiaofthepulmonaryarteriesischaracteristicofbothprimaryandsecondarypulmonaryhypertension.Itpresentswithdyspnea,malaise,JVD,pedaledema,hepatomegalyandothersymptomsofrightventricularfailure.(ChoiceB)Aorticdissectionoccursinpatientswithlong-standinghypertensionandthosewithMarfanandEhlers-Danlossyndromes(thetwolatterconditionscausecysticmedialnecrosisoftheaorticwall).Itpresentswithabruptonsetofseveretearingchestpainthatradiatestotheback.(ChoiceD)AnotherSLE-relatedcardiovasculardiseaseisnon-bacterialendocarditis(Libman-Sacksendocarditis).Smallwart-likefibrinouslesionsandgeneralizedthickeningmaydeveloponanyoftheheartvalvesandleadtovalvularinsufficiencyorembolism.Clinicallythisconditionpresentswithheartmurmurandmaybeotherwiseasymptomatic.(ChoiceE)Cardiactamponadeisanaccumulationoffluidinpericardialspacecausingthehearttobeunabletoproperlyfillindiastole.Itpresentswithdyspneaandtachypnea.Physicalexaminationrevealsdistendedneckveins,hypotension,hepatomegaly,diminishedheartsoundsandpulsusparadoxus(dropinsystolicbloodpressureof20mmHgormoreoninspiration).Q12A10-year-oldimmigrantfromEasternEuropeisbroughttothephysicianbecauseofexertionaldyspneaandeasyfatigability.Accordingtohisparents,hewasdiagnosedwithacongenitalheartdiseaseininfancyforwhichtheyrefusedtreatment.Theycannotrecallthedetailsofhisdiagnosis.Physicalexaminationrevealstoecyanosisandclubbingbutnofingerabnormalities.Thispatientmostlikelysuffersfromwhichofthefollowing?A.Primum-typeatrialseptaldefectB.Secundum-typeatrialseptaldefectC.VentricularseptaldefectD.PatentductusarteriosusE.CoarctationoftheaortaF.TetralogyofFallotA12Correctanswer:DThispatientexhibits^differentialcyanosis,15ie,cyanosisofthelowerextremitiesbutnotoftheupperbody.Differentialcyanosisistheresultofreducedarterialoxygensaturationinthedistalaortacomparedtothatintheaortaproximaltotheleftsubclavianartery.Themostlikelycauseisright-to-leftshuntingofbloodthroughapatentductusarteriosus(PDA)intothejunctionbetweentheaorticarchandthedescendingaorta.AlthoughPDAsinitiallyinvolveleft-to-rightshunting,overtimetheresultantpulmonaryhypertensioncancausepulmonaryvascularsclerosis,increasedpulmonaryvascularresistance,andreversalofshuntflowacrosstheductus.(ChoicesA,B,andC)Atrialandventricularseptaldefectsinitiallypresentwithleft-to-rightintracardiacshuntingandarethereforenotassociatedwithcyanosisatbirth.Ifarterialoxygendesaturationdevelopslaterinlifebecauseofshuntreversal(Eisenmengersyndrome),theresultingcyanosisaffectstheupperandlowerbodyequally.(ChoiceE)Coarctationoftheaortaismostcommonlylocatedinthejuxtaductalregionjustdistaltotheleftsubclavianartery.Itcommonlypresentsinchildrenandadultsasabloodpressurediscrepancybetweentheupperandlowerextremities.Inneonates,severecoarctationcanmanifestwithheartfailure,especiallyoncetheductaltissuecollapses.Iftheductusarteriosusremainspatent,deoxygenatedbloodcanbypassthecoarctationandcausedifferentialcyanosisininfancy.However,patientswithseverecoarctationgenerallydevelopcongestiveheartfailureandareunlikelytosurvivebeyondinfancywithoutsurgicalcorrection.(ChoiceF)TetralogyofFallotgenerallypresentswithwhole-bodycyanosisatbirthastheresultofright-to-leftshuntingacrosstheventricularseptaldefect.Becausetheright-to-leftshuntisintracardiac,differentialcyanosislimitedtothelowerbodyisnotseen.Q13A23-year-oldCaucasianmalew