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Predictive Value of T - T Indices for Adverse Outcomes in Acquired QT Prolongation: A Meta-Analysis

Gary Tse1,2, Mengqi Gong3, Lei Meng3

  • 1Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, Hong Kong.

Frontiers in Physiology
|September 21, 2018
PubMed

Insights

Patients with acquired QT prolongation experiencing torsade de pointes had longer Tpeak-Tend intervals and higher Tpeak-Tend/QT ratios. These electrocardiogram markers may predict adverse cardiac events in high-risk individuals.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Diagnostics

Background:

  • Acquired QT interval prolongation is associated with life-threatening ventricular arrhythmias like torsade de pointes, increasing sudden cardiac death risk.
  • Increased repolarization dispersion, indicated by prolonged Tpeak-Tend interval and elevated Tpeak-Tend/QT ratio, is a known pro-arrhythmic factor.
  • Systematic evaluation of these repolarization indices for predicting adverse outcomes in acquired QT prolongation is lacking.

Purpose of the Study:

  • To systematically evaluate the predictive value of Tpeak-Tend interval and Tpeak-Tend/QT ratio for adverse outcomes in patients with acquired QT prolongation.

Main Methods:

  • A comprehensive literature search was conducted across PubMed, Embase, and Cochrane Library databases up to February 14, 2018.
  • Five studies meeting inclusion criteria were selected for a meta-analysis, including 308 patients with drug-induced long QT syndrome (LQTS).

Main Results:

  • Patients with torsade de pointes exhibited significantly longer Tpeak-Tend intervals (mean difference [MD]: 76 ms, P = 0.003) compared to those without.
  • A higher Tpeak-Tend/QT ratio was observed in patients with torsade de pointes (MD: 0.14, P = 0.000).
  • High heterogeneity was noted for Tpeak-Tend interval (I² = 98%) but not for Tpeak-Tend/QT ratio (I² = 29%).

Conclusions:

  • Elevated Tpeak-Tend interval and Tpeak-Tend/QT ratio are characteristic of patients with acquired QT prolongation who experience torsade de pointes.
  • These electrocardiographic repolarization indices may serve as valuable tools for identifying individuals at higher risk of adverse cardiac events.

Keywords:
Tpeak—TendTpeak—Tend/QTdispersion of repolarizationrisk stratificationsudden cardiac deathventricular arrhythmia

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