<record>
  <controlfield tag="001">70727</controlfield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">Electrocardiogram</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">morphological variability</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">repolarization</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">T-wave time-warping</subfield>
  </datafield>
</record>