Repolarization variability independent of heart rate during sympathetic activation elicited by head-up tilt

Fatima El-Hamad, Michal Javorka, Barbora Czippelova, Jana Krohova, Zuzana Turianikova, Alberto Porta, Mathias Baumert

Research output: Contribution to journalArticle

Abstract

The fraction of repolarization variability independent of RR interval variability is of clinical interest. It has been linked to direct autonomic nervous system (ANS) regulation of the ventricles in healthy subjects and seems to reflect the instability of the ventricular repolarization process in heart disease. In this study, we sought to identify repolarization measures that best reflect the sympathetic influences on the ventricles independent of the RR interval. ECG was recorded in 46 young subjects during supine and then following 45 degrees head-up tilt. RR intervals and five repolarization features (QTend, QTpeak, RTend, RTpeak, and TpTe) were extracted from the ECG recordings. Repolarization variability was separated into RR-dependent and RR-independent variability using parametric spectral analysis. Results show that LF power of TpTe is independent of RR in both supine and tilt, while the LF power of QTend and RTend independent of RR and respiration increases following tilt. We conclude that TpTe is independent of RR and is highly affected by respiration. QTend and RTend LF power might reflect the sympathetic influences on the ventricles elicited by tilt. [Figure not available: see fulltext.].

Original languageEnglish
Pages (from-to)1753-1762
Number of pages10
JournalMedical and Biological Engineering and Computing
Volume57
Issue number8
DOIs
Publication statusPublished - Aug 1 2019

Keywords

  • Autonomic nervous system
  • Head-up tilt
  • Heart rate variability
  • QT interval
  • Repolarization
  • Sympathetic activation
  • Tpeak-Tend

ASJC Scopus subject areas

  • Biomedical Engineering
  • Computer Science Applications

Fingerprint Dive into the research topics of 'Repolarization variability independent of heart rate during sympathetic activation elicited by head-up tilt'. Together they form a unique fingerprint.

  • Cite this