Table 1

Overview of markers and studies included

  MarkerFormulaN studiesN participants total
Median (IQR)
Range
QTvarEmbedded Image252262
59 (24–134)
11–396

Not on consecutive beats
QTVNEmbedded Image314209
54 (29–106)
16–805
Not normalised for RRSDqtEmbedded Image13369
20 (10–48)
1–86
MADqtEmbedded Image18
Consecutive beatsSTVqtEmbedded Image6418
52 (27–128)
9–152
RMSSDqtEmbedded Image7312
53 (20–68)
8–80
QTVIEmbedded Image898526
49 (24–99)
6–805
Normalised for RR (variability)Not on consecutive beatsEmbedded ImageEmbedded Image134

Consecutive beatsQTRREmbedded Image2123
61.5±9.262*
55–68
  • The sum of studies exceeds 109 because several papers cover more than one marker.

  • *Mean±SD.

  • HRm, mean heart rate; HRvar, heart rate variance; MADqt, median absolute difference of QT intervals; QTm, mean QT interval; QTvar, QT variance; QTVI, QT variability index; QTVN, QT variance normalised for mean QT interval; RMSSDqt, root mean square of the successive QT interval differences; SDqt, SD of QT intervals; STVqt, short-term variability of QT interval.