-----------------------------------------------------------------------------------------------
qrstime                                                                                QRS time
-----------------------------------------------------------------------------------------------

                  type:  numeric (int)

                 range:  [40,182]                     units:  1
         unique values:  42                       missing .:  0/53

                  mean:   109.245
              std. dev:   31.9229

           percentiles:        10%       25%       50%       75%       90%
                                75        88       105       130       152

-----------------------------------------------------------------------------------------------
ivt                                                                                         IVT
-----------------------------------------------------------------------------------------------

                  type:  numeric (byte)
                 label:  yesno

                 range:  [0,1]                        units:  1
         unique values:  2                        missing .:  0/53

            tabulation:  Freq.   Numeric  Label
                            35         0  no
                            18         1  yes