Arrhythmias & electrophysiology
Temporal variability of the electromechanical window in long-QT syndrome and drug-induced QT prolongation: Value for enhanced arrhythmia-risk assessment
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
- Outcome
- EMW over time
Main finding
As reported in the abstract
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.
Summarised from the published abstract; every number is checked against it