RT Journal A1 FORREST JN T1 THe persistent ostium primum atrial septal defect JF A.M.A. Journal of Diseases of Children JO A.M.A. Journal of Diseases of Children YR 1959 FD January 1 VO 97 IS 1 SP 42 OP 47 DO 10.1001/archpedi.1959.02070010044002 UL http://dx.doi.org/10.1001/archpedi.1959.02070010044002 AB Recent advances in the treatment of congenital heart disease have been made possible by the concomitant development of more accurate diagnostic techniques. Without this progress in clinical cardiology the ability and skill of the cardiac surgeon would frequently become wasted on useless exploratory operations.The purpose of this article is to illustrate how an anatomical variation of a relatively common and easily reparable congenital heart lesion1,2 may be suspected preoperatively and treatment planned accordingly.In 1956 Blount and his associates published their experience with the ostium primum atrial septal defect and pointed out how this lesion might be recognized clinically.3 Since that time I have seen two cases of ostium primum type of defect confirmed at surgery which were suspected prior to operation on the basis of criteria outlined by Blount.3 A third case of ostium primum defect of a slightly different variety, more properly referred to