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Paced QT interval is a better predictor of mortality than the intrinsic QT interval: long-term follow-up study

Jung Myung Lee1, Ajit H Janardhan2, Ki-Woon Kang3

  • 1Division of Cardiology, Cardiovascular Center, Yonsei University College of Medicine, Seoul, Korea.

Heart Rhythm
|April 15, 2014
PubMed

Insights

A prolonged paced QTc interval predicts increased mortality in pacemaker patients. This measurement is a better predictor of poor prognosis than the intrinsic QTc interval, aiding in risk assessment.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Prognostics

Background:

  • Prolonged corrected QT (QTc) interval is linked to mortality and sudden cardiac death.
  • The predictive value of the paced QTc interval for mortality was previously uninvestigated.

Purpose of the Study:

  • To assess the relationship between the paced QTc interval and patient mortality.
  • To determine if the paced QTc interval is a better predictor of mortality than the intrinsic QTc interval.

Main Methods:

  • Study included 766 patients with intrinsic and ventricular paced rhythms post-pacemaker implantation.
  • Intrinsic and paced QTc intervals were measured via 12-lead ECG before and 1 month after implantation.
  • Mean follow-up was 7 years, with mortality data collected for all-cause and cardiac deaths.

Main Results:

  • A prolonged paced QTc interval (>511 ms) was associated with significantly higher all-cause and cardiac mortality compared to shorter intervals (<484 ms).
  • The paced QTc interval independently predicted all-cause mortality (aHR 2.08) and cardiac mortality (aHR 2.53).
  • The paced QTc interval demonstrated superior predictive capability for mortality compared to the intrinsic QTc interval.

Conclusions:

  • The paced QTc interval is a valuable marker for predicting poor prognosis in patients requiring a permanent pacemaker.
  • This measurement offers a more useful prognostic indicator than the intrinsic QTc interval.
Abstract

Keywords:
Intrinsic QTc intervalMortalityPaced QTc intervalPermanent pacemakerProlonged QTc intervalVentricular pacing

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