Skiptocontent HypoplasticLeftHeartSyndrome(HLHS)OutpatientAppointments215-590-4040SecondOpinions,ReferralsandInformationAboutOurServices267-426-9600ContactUsOnlineWhatishypoplasticleftheartsyndrome(HLHS)?Hypoplasticleftheartsyndrome(HLHS)isaseverecongenitalheartdefectinwhichtheleftsideoftheheartisunderdeveloped.Inanormalheart,theheart'sleftsidehasthejobofpumpingoxygenatedbloodintotheaorta,thelargearterythatcarriesbloodtothebody.InachildwithHLHS:Themitralvalve,whichseparatesthetwoleftchambersoftheheart,istoosmallorcompletelyclosed(atretic).Theleftventricle(thelower,pumpingchamber)isverysmall.Theaorticvalve,whichseparatestheleftventricleandtheaorta,istoosmallorcompletelyclosed(atretic).InadditiontothemostcommonformofHLHSshownintheanimationbelow,thereareanumberofcomplexcardiacconditionswithvariationsinthestructuresasdescribed.Inthesechildren,whereoneventricleisalsosmall(sometimescalled"HLHSvariants")thetreatmentstrategyissimilartothosewiththemoretypicalHLHS,whichisshownintheanimationsbelow.ViewthisvideowithatranscriptLearnmoreaboutHLHSfromtheexpertsatChildren'sHospitalofPhiladelphia'sCardiacCenterinthisvideoseries.SignsandsymptomsofHLHSThefollowingsymptomsofhypoplasticleftheartsyndromemaybepresentatbirthorseveraldayslater:Blueorpurpletinttolips,skinandnails(cyanosis)DifficultybreathingDifficultyfeedingLethargy(sleepyorunresponsive)TestinganddiagnosisofHLHSOften,hypoplasticleftheartsyndromeisdiagnosedbeforebirth,withfetalechocardiogram(ultrasound).OurFetalHeartProgramcanhelpyouprepareaplanfordeliveryandcareimmediatelyafterbirth.SometimesHLHSisdiagnosedhoursordaysafterbirthandthebabywillneedimmediatetherapy.DiagnosisofHLHSmayrequiresomeorallofthesetests:Echocardiogram(alsocalled"echo"orultrasound):soundwavescreateanimageoftheheartElectrocardiogram(ECG):arecordoftheelectricalactivityoftheheartChestX-rayPulseoximetry:anoninvasivewaytomonitortheoxygencontentofthebloodCardiaccatheterization:athintubeisinsertedintotheheartthroughaveinand/orarteryineitherthelegorthroughtheumbi