Andersons pediatric cardiology 767
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (117.91 KB, 3 trang )
Incidence
Interatrialcommunicationsaccountforupto10%ofallcongenitalcardiac
anomalies.Probepatencyoftheovalforamen,furthermore,isremarkably
frequent,beingfoundinupto33%ofheartsexaminedatautopsyirrespectiveof
age.1Thesuggestionthatprobepatencymayunderscoresomecasesofmigraine
broughtthisnormalfindingtoclinicalattention,2althoughthesuggested
associationhasyettobeproven.
Etiology
Therearenoknownintrauterineeventsthatpredisposetodeficientatrial
septation.Thusmostcasesoccursporadically,withnofamilyhistoryof
congenitalcardiacdisease.Nonetheless,thereisasignificantfamilialincidence
whenthelesionisassociatedwithcertainskeletalabnormalitiesoftheforearm
andhand,calledHolt-Oramsyndrome.Thishasnowbeenshowntobedueto
mutationsoftheTbx5gene,amemberoftheBrachyuryfamilyofgenes.3When
observedinfamilies,atrialseptaldefectsarealsoassociatedwithprolongationof
thePRinterval.4
MorphologyandClassification
NormalAtrialSeptum
Anunderstandingofthemorphologyandclassificationofinteratrial
communicationsdependsonknowledgeoftheextentofthenormalatrial
septum.5This,inturn,requiresanappreciationofthedifferencebetween
partitionsthatseparatetheatrialcavities,whichcanberemovedwithout
transgressingonthepericardialcavity,asopposedtotheremovaloffolds,which
doproduceacommunicationwiththeextracavitaryspace(Fig.29.1).6
FIG.29.1 (A)Arrangementofthepartitionsbetweentheatrialchambers
asseeninfrontalprojection.(B)Howtheflooroftheovalfossacanbe
removedwithouttransgressingonextracardiacspace.(C)Removalofthe
cranialrimofthefossa,however,createsacommunicationwiththe
pericardialcavity,sincetherimisaninfoldingbetweentheatrialwalls.We
