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Risk of sudden cardiac death associated with QRS, QTc, and JTc intervals in the general population

Jani T Tikkanen1, Tuomas Kentta1, Kimmo Porthan2

  • 1Research Unit of Internal Medicine, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.

Heart Rhythm
|April 26, 2022
PubMed

Insights

Prolonged QRS duration and corrected QT (QTc) interval increase sudden cardiac death (SCD) risk. The JTc interval, representing repolarization, does not independently predict SCD risk when separated from QRS duration.

Area of Science:

  • Cardiology
  • Electrocardiography
  • Public Health

Background:

  • Sudden cardiac death (SCD) is linked to QRS duration and corrected QT (QTc) interval.
  • The prognostic significance of the JTc interval (repolarization component of QTc) in the general population for SCD risk is unknown.

Purpose of the Study:

  • To evaluate the independent risk of SCD associated with QRS duration, QTc interval, and JTc interval.

Main Methods:

  • Analysis of 3 population cohorts (20,058 individuals, 30-61 years old at baseline) with 10-year follow-up.
  • Electrocardiograms measured QRS and QT intervals; JTc was calculated as QTc - QRS.
  • Cox proportional hazards models assessed SCD risk, controlling for clinical factors.

Main Results:

  • Over 9.7 years, 207 SCDs occurred.
  • Increased QRS duration significantly correlated with higher SCD risk (pooled HR 1.030 per ms).
  • QTc interval showed borderline to significant SCD association (pooled HR 1.007).
  • JTc interval as a continuous variable was not associated with SCD risk (pooled HR 1.001).

Conclusions:

  • Prolonged QRS duration and QTc interval are associated with increased SCD risk.
  • The JTc interval, representing cardiac repolarization, does not appear to have independent prognostic value for SCD when QTc is analyzed.
  • Risk stratification for SCD may benefit from considering QRS duration separately.
Abstract

Keywords:
DepolarizationElectrocardiographyEpidemiologyRepolarizationSudden cardiac death

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