Arrhythmias & electrophysiologyResearch article

Temporal variability of the electromechanical window in long-QT syndrome and drug-induced QT prolongation: Value for enhanced arrhythmia-risk assessment

Heart RhythmPublished

  • Not stated

Authors' conclusion

Temporary accentuation of EMW negativity is a marker of impending VT in patients with LQTS and diQTP.

Study context

Population
Patients with congenital long-QT syndrome (LQTS) or drug-induced QT prolongation (diQTP), with or without ventricular tachyarrhythmia (VT), and controlsLQTS/-VT 47 · LQTS/+VT 18 · diQTP/+VT 9 · controls 26
Participants
47 / 18 / 9 / 26
Comparison
relationship between temporal QTc and electromechanical window (EMW) dynamics, and ventricular tachyarrhythmia (VT) timing in LQTS and diQTP
  • LQTS/-VTn = 47
  • LQTS/+VTn = 18
  • diQTP/+VTn = 9
  • controlsn = 26

Main finding

As reported in the abstract

EMW over time

controls

EMW remained stably positive over time

LQTS/-VT

EMW was negative without significant variation

LQTS/+VT and diQTP/+VT: transient accentuations of EMW negativity at the time point closest to VT, regardless of whether measured before or after VT
2 days [1-7] to arrhythmia

Further findings

Predictors of imminent VT in LQTS

ms

Optimal EMW cutoff
−75
Optimal ΔEMW cutoff
−39
EMW negativity and EMW dynamics (ΔEMW) independent predictors (multiple logistic regression)

Original publication

Temporal variability of the electromechanical window in long-QT syndrome and drug-induced QT prolongation: Value for enhanced arrhythmia-risk assessment. Heart Rhythm. Published 10 January 2026. doi:10.1016/j.hrthm.2026.01.013

Summarised from the published abstract; every number is checked against it