Background. Perimembranous ventricular septal defects (VSDs) are located in the left ventricle outflow tract beneath the aortic valve. They are the ...ForYouNews&PerspectiveDrugs&DiseasesCME&EducationAcademyVideoDecisionPointEdition:ENGLISHDEUTSCHESPAÑOLFRANÇAISPORTUGUÊSLogInSignUpIt'sFree!Edition:ENGLISHDEUTSCHESPAÑOLFRANÇAISPORTUGUÊSRegisterLogInNoResultsNoResultsForYouNews&PerspectiveDrugs&DiseasesCME&EducationAcademyVideoDecisionPointclosePleaseconfirmthatyouwouldliketologoutofMedscape.Ifyoulogout,youwillberequiredtoenteryourusernameandpasswordthenexttimeyouvisit.LogoutCancelhttps://profreg.medscape.com/px/getpracticeprofile.do?method=getProfessionalProfile&urlCache=aHR0cHM6Ly9lbWVkaWNpbmUubWVkc2NhcGUuY29tL2FydGljbGUvODk5OTk5LW92ZXJ2aWV3processing....Drugs&Diseases>Pediatrics:CardiacDiseaseandCriticalCareMedicinePerimembranousVentricularSeptalDefectUpdated:Dec29,2020Author:MichaelDTaylor,MD,PhD;ChiefEditor:HowardSWeber,MD,FSCAI more...ShareEmailPrintFeedbackCloseFacebookTwitterLinkedInGoogle+SectionsPerimembranousVentricularSeptalDefectSectionsPerimembranousVentricularSeptalDefectOverviewBackgroundEtiologyEpidemiologyPrognosisShowAllPresentationHistoryPhysicalExaminationShowAllDDxWorkupApproachConsiderationsImagingStudiesCardiacCatheterizationandAngiographyShowAllTreatmentApproachConsiderationsSurgicalInterventionCardiacCatheterizationandHybridProceduresOutpatientCareandMonitoringShowAllMedicationMedicationSummaryDiureticsAfterloadReducersInotropicAgentsShowAllReferencesOverviewBackgroundPerimembranousventricularseptaldefects(VSDs)arelocatedintheleftventricleoutflowtractbeneaththeaorticvalve.TheyarethemostcommonVSDsubtypeintheUnitedStates,occurringin75-80%ofcases.Defectsmayextendintoadjacentportionsoftheventricularseptum.Whentissueformsontherightventricularseptalsurface(oftenthoughttobetricuspidvalvularinorigin),itistermedananeurysmofthemembranousseptum.Suchtissueservesasamechanismofrestrictionorspontaneousclosure.Thedefectmaybepartiallyorcompletelyoccludedbythe