Getting the column names when using e.oldvalues?

How do I get the column names when using e.oldvalues?
Sub CustomerDetailsView_ItemUpdated(ByVal sender As Object, ByVal e As DetailsViewUpdatedEventArgs)
    If e.Exception Is Nothing Then
     Dim i As Integer
    For i = 0 To e.OldValues.Count - 1

      '********** CAN I GET THE COLUMN NAMES HERE ??????? **************
      MessageLabel.Text &= "Old Value=" & e.OldValues(i).ToString() & _
        ", New Value=" & e.NewValues(i).ToString() & "<br/>"
    Next

    Else
 'Code
    End If
End Sub
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