<Table> <Tr> <Th_colspan="2"> Foramen ovale (heart) </Th> </Tr> <Tr> <Td_colspan="2"> Sketch showing foramen ovale in a fetal heart . Red arrow shows blood from the inferior cava traveling to the right atrium and then to the left atrium . HF: right atrium, VF: left atrium . HH and VH: right and left ventricle . The heart still has a common pulmonary vein (LV), instead of four . </Td> </Tr> <Tr> <Td_colspan="2"> Heart of human embryo of about thirty - five days, opened on left side . </Td> </Tr> <Tr> <Th_colspan="2"> Details </Th> </Tr> <Tr> <Th> Precursor </Th> <Td> Septum secundum </Td> </Tr> <Tr> <Th> System </Th> <Td> Cardiovascular system </Td> </Tr> <Tr> <Th_colspan="2"> Identifiers </Th> </Tr> <Tr> <Th> Acronym (s) </Th> <Td> PFO </Td> </Tr> <Tr> <Th> MeSH </Th> <Td> A07. 541.459 </Td> </Tr> <Tr> <Th> TA </Th> <Td> A12. 1.01. 007 </Td> </Tr> <Tr> <Th> FMA </Th> <Td> 86043 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Foramen ovale (heart) </Th> </Tr>

Where is a pfo located in the heart