title: Frequency of normal coronary arteriograms in three academic medical centers and one community hospital.
mesh_terms: D000787:Angina Pectoris / Q000000981:diagnostic imaging / Q000188:drug therapy; D000792:Angiography; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging; D006764:Hospitals, Community; D006784:Hospitals, Teaching; D006785:Hospitals, University; D006801:Humans; D005996:Nitroglycerin / Q000627:therapeutic use; D010380:Peer Review; D012016:Reference Values; D012189:Retrospective Studies
chemical_list: D005996:Nitroglycerin