title: Understanding the spectrum of sinus venosus interatrial communications.
abstract: BACKGROUND
  It is still thought by some that a common wall is to be found in the normal heart between the attachments of the caval and pulmonary veins, with absence of this wall underscoring the presence of sinus venosus defects. Recent findings using episcopic microscopy in developing mice have shown the deficiencies of this notion. Understanding that the superior rim of the oval fossa is a fold, rather than a true septum, which can be distorted in the presence of partially anomalous pulmonary venous drainage, has provided an alternative explanation for the morphogenesis of sinus venosus defects.
  
  
  METHODS
  We reviewed our experience with patients suspected of having a sinus venosus defect from August, 2011, through October, 2015, analysing the findings in light of the current hypotheses used to explain the development of the defects, along with correlations made by inspection of autopsy specimens.
  
  
  RESULTS
  We evaluated findings from 16 patients, with a mean age of 7.7 years, ranging from 2.7 to 15 years. Of the group, 13 were ultimately diagnosed with a superior sinus venosus defect, two with an inferior defect, and one with isolated anomalous pulmonary venous connection in the absence of an interatrial communication. Initially, two patients were thought to have oval fossa defects, one from each subtype, but were correctly diagnosed following cardiac magnetic resonance interrogation. Anomalous pulmonary venous connections were present in all cases.
  
  
  CONCLUSIONS
  Appreciation of the changes occurring during normal cardiac development helps in understanding the anatomical substrate underscoring the spectrum of sinus venosus defects. The lesions are veno-venous connections due to partially anomalous pulmonary venous connections, producing interatrial communications outside the confines of the interatrial septum.
authors.affiliation: 1Division of Pediatric Cardiology,New York University Langone Medical Center,New York,New York,United States of America.
authors.forename: Justin T
authors.initials: JT
authors.lastname: Tretter
authors.affiliation: 1Division of Pediatric Cardiology,New York University Langone Medical Center,New York,New York,United States of America.
authors.forename: Sathish
authors.initials: S
authors.lastname: Chikkabyrappa
authors.affiliation: 2Division of Pediatric Cardiology,University of Florida,Gainesville,Florida,United States of America.
authors.forename: Diane E
authors.initials: DE
authors.lastname: Spicer
authors.affiliation: 4Division of Cardiovascular Surgery,Ann & Robert H. Lurie Children's Hospital of Chicago,Northwestern University Feinberg School of Medicine,Chicago,Illinois,United States of America.
authors.forename: Carl L
authors.initials: CL
authors.lastname: Backer
authors.affiliation: 5Division of Congenital Cardiac Surgery,New York University Langone Medical Center,New York,New York,United States of America.
authors.forename: Ralph S
authors.initials: RS
authors.lastname: Mosca
authors.affiliation: 6Institute of Genetic Medicine,Newcastle University,Newcastle upon Tyne,United Kingdom.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Anderson
authors.affiliation: 1Division of Pediatric Cardiology,New York University Langone Medical Center,New York,New York,United States of America.
authors.forename: Puneet
authors.initials: P
authors.lastname: Bhatla
mesh_terms: D000015:Abnormalities, Multiple; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D017548:Echocardiography, Transesophageal; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000175:diagnosis*; D006801:Humans; D008297:Male; D011667:Pulmonary Veins / Q000002:abnormalities* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D054079:Vascular Malformations / Q000175:diagnosis*; D014683:Vena Cava, Superior / Q000002:abnormalities* / Q000000981:diagnostic imaging
keywords: Sinus venosus defect; anomalous pulmonary vein; atrial septal defect; cardiac development