Source:http://linkedlifedata.com/resource/umls/id/C0225810
NCI: The superior portion of the heart located opposite to the apical portion. It is formed mainly by the left atrium.,FMA: Zone of heart which has as its parts the left atrium and the inflow part of right atrium.,NCI: The superior portion of the heart located opposite to the apical portion. It is formed mainly by the left atrium. (NCI)