Author(s): Krishnan SC, Salazar M
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Abstract OBJECTIVES: The purpose of this study was to develop a better understanding of the pathophysiology of the condition, we studied the patterns by which the septum primum (SP) and septum secundum (SS) fuse. BACKGROUND: A patent foramen ovale (PFO) is a communication across the interatrial septum between a nonadherent SP and SS and is considered to be a risk factor for serious clinical syndromes. METHODS: We examined the interatrial septum in 94 randomly selected autopsied hearts, with a focus on the SP and SS and the patterns by which the 2 structures fuse. RESULTS: Of the 94 specimens that were suitable for analysis, 26 (27.66\%) had a PFO. Of the remaining 68 hearts, complete fusion of the SP and SS along the entire zone of overlap was seen in 27 (28.7\%) hearts. In the remaining 41 hearts (60.29\%), a PFO was absent, but incomplete fusion of the SP and SS was seen. Of 41 hearts, 37 (90\%) had a septal pouch that opened into the left atrial (LA) cavity. Four hearts (10\%) had a pouch accessible from the right atrium. Hearts with left-sided pouches tended to be younger (50 +/- 18 years of age) than hearts where there was complete fusion (age 63 +/- 23 years) (p = 0.06). CONCLUSIONS: Our data suggest that when a foramen ovale closes spontaneously, the SP and SS fuse initially at the caudal limit of the zone of overlap of the 2 structures. This incomplete fusion results in a pouch that, in the majority of instances, communicates with the LA cavity. Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
This article was published in JACC Cardiovasc Interv
and referenced in Journal of Clinical Case Reports