Synchronization of repolarization after cardiac resynchronization therapy: A combined clinical and modeling study

Nienke J Verzaal, Caroline J M van Deursen, Simone Pezzuto, Liliane Wecke, Wouter M van Everdingen, Kevin Vernooy, Tammo Delhaas, Angelo Auricchio, Frits W Prinzen*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


INTRODUCTION: The changes in ventricular repolarization after cardiac resynchronization therapy (CRT) are poorly understood. This knowledge gap is addressed using a multimodality approach including electrocardiographic and echocardiographic measurements in patients and using patient-specific computational modeling.

METHODS: In 33 patients electrocardiographic and echocardiographic measurements were performed before and at various intervals after CRT, both during CRT-ON and temporary CRT-OFF. T-wave area was calculated from vectorcardiograms, and reconstructed from the 12-lead electrocardiography (ECG). Computer simulations were performed using a patient-specific eikonal model of cardiac activation with spatially varying action potential duration (APD) and repolarization rate, fit to a patient's ECG.

RESULTS: During CRT-ON T-wave area diminished within a day and remained stable thereafter, whereas QT-interval did not change significantly. During CRT-OFF T-wave area doubled within 5 days of CRT, while QT-interval and peak-to-end T-wave interval hardly changed. Left ventricular (LV) ejection fraction only increased significantly increased after 1 month of CRT. Computer simulations indicated that the increase in T-wave area during CRT-OFF can be explained by changes in APD following chronic CRT that are opposite to the change in CRT-induced activation time. These APD changes were associated with a reduction in LV dispersion in repolarization during chronic CRT.

CONCLUSION: T-wave area during CRT-OFF is a sensitive marker for adaptations in ventricular repolarization during chronic CRT that may include a reduction in LV dispersion of repolarization.

Original languageEnglish
Pages (from-to)1837-1846
Number of pages10
JournalJournal of Cardiovascular Electrophysiology
Issue number8
Early online date3 Jun 2022
Publication statusPublished - Aug 2022


  • RISK
  • cardiac resynchronization therapy
  • computer modeling
  • heart failure
  • repolarization
  • vectorcardiography

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