Acute ischaemia: a dynamic influence on QT dispersion

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Updated: Nov 2, 2026

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
09:59

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

Published on: September 16, 2017

S C Sporton1, P Taggart, P M Sutton

  • 1Department of Academic, University College London Medical School, UK.

Lancet (London, England)
|February 1, 1997
PubMed

Insights

Acute myocardial ischemia significantly increases QT dispersion in patients with coronary artery disease. This inducible QT dispersion may help assess arrhythmia risk better than resting measurements.

Area of Science:

  • Cardiology
  • Electrophysiology

Background:

  • QT dispersion (QTd) is a measure of repolarization variability.
  • Assessing myocardial ischemia's impact on QTd is crucial for understanding arrhythmia risk.

Purpose of the Study:

  • To test if acute myocardial ischemia increases QT dispersion.
  • To evaluate the utility of inducible QT dispersion in coronary artery disease (CAD).

Main Methods:

  • 18 patients with CAD underwent incremental atrial pacing to induce ischemia.
  • QT dispersion was measured using a 12-lead electrocardiogram.
  • 6 patients with normal coronary arteries served as controls.

Main Results:

  • Patients with CAD showed significant increases in QT dispersion (mean 38 ms) during ischemia.
  • Control patients without ischemia had no significant change in QT dispersion.
  • Baseline QT dispersion did not differentiate between CAD patients and controls.

Conclusions:

  • Myocardial ischemia acutely increases QT dispersion in CAD patients.
  • Inducible QT dispersion may be a superior predictor of arrhythmic events compared to resting QT dispersion.
Abstract

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