Beat-to-Beat QT Variability: A Population Study of the QT
Variability Index Composition

J 2026

Beat-to-Beat QT Variability: A Population Study of the QT Variability Index Composition

ŘEHOŘ, Jan; Kateřina HELÁNOVÁ; Martina ŠIŠÁKOVÁ; Tomáš NOVOTNÝ; Irena ANDRŠOVÁ et al.

Základní údaje

Originální název

Beat-to-Beat QT Variability: A Population Study of the QT Variability Index Composition

Autoři

ŘEHOŘ, Jan; Kateřina HELÁNOVÁ; Martina ŠIŠÁKOVÁ; Tomáš NOVOTNÝ ; Irena ANDRŠOVÁ a Marek MALÍK

Vydání

Diagnostics, Basel, MPDI, 2026, 2075-4418

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

30201 Cardiac and Cardiovascular systems

Stát vydavatele

Švýcarsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 3.300 v roce 2024

Označené pro přenos do RIV

Ano

Organizační jednotka

Lékařská fakulta

Klíčová slova anglicky

QT variability index; healthy subjects; postural testing; heart rate variability; multivariable regression

Štítky

14110211, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 7. 4. 2026 14:00, Mgr. Tereza Miškechová

Anotace

V originále

Background/Objectives: One of the topics of electrocardiographic risk factor studies is investigations of beat-to-beat QT interval variability. The seminal study that reported QT variability as a prognostic risk factor introduced the so-called QT variability index (QTVi). QTVi quantification relies not only on the variance of QT intervals but also on correction factors, including RR interval variance, heart rate, and overall QT interval duration. This study investigated the influence of all the measured factors on QTVi values. Methods: Long-term electrocardiograms (ECGs) were obtained from 251 healthy subjects (mean age 33.6 +/- 9.1 years, 108 females) during repeated postural tests that involved supine, sitting, and standing positions maintained for 10 or 15 min. During each position, a 5-min ECG segment with a stable heart rate and without any ectopic disturbances was found. In these segments, standard deviations of normal-to-normal RR (NN) interval durations (SDNN) and of beat-to-beat QT interval durations (SDQT) were measured together with the means of NN and QT intervals. QTVi was subsequently calculated. For each subject, results obtained during each postural position were averaged. Results: In multivariable regression models, evaluated separately in female and male sex-subgroups of the population, QTVi values were significantly dependent on SDQT, SDNN, and mean NN intervals (all p < 0.001) but practically independent of mean QT interval durations. Conclusions: QTVi is significantly influenced by factors that are unrelated to the beat-to-beat changes in QT interval durations. This needs to be considered when interpreting QTVi values. In future studies, multivariable statistical models are needed to ensure that QTVi findings are independent of associated heart rate variability indices.

Citovat

ŘEHOŘ, Jan; Kateřina HELÁNOVÁ; Martina ŠIŠÁKOVÁ; Tomáš NOVOTNÝ; Irena ANDRŠOVÁ a Marek MALÍK. Beat-to-Beat QT Variability: A Population Study of the QT Variability Index Composition. Diagnostics. Basel: MPDI, 2026, roč. 16, č. 3, s. 1-24. ISSN 2075-4418. Dostupné z: https://doi.org/10.3390/diagnostics16030502.

@article{2565358,
   author = {Řehoř, Jan and Helánová, Kateřina and Šišáková, Martina and Novotný, Tomáš and Andršová, Irena and Malík, Marek},
   article_location = {Basel},
   article_number = {3},
   doi = {https://doi.org/10.3390/diagnostics16030502},
   keywords = {QT variability index; healthy subjects; postural testing; heart rate variability; multivariable regression},
   language = {eng},
   issn = {2075-4418},
   journal = {Diagnostics},
   title = {Beat-to-Beat QT Variability: A Population Study of the QT Variability Index Composition},
   url = {https://www.mdpi.com/2075-4418/16/3/502},
   volume = {16},
   year = {2026}
}

TY  - JOUR
ID  - 2565358
AU  - Řehoř, Jan - Helánová, Kateřina - Šišáková, Martina - Novotný, Tomáš - Andršová, Irena - Malík, Marek
PY  - 2026
TI  - Beat-to-Beat QT Variability: A Population Study of the QT Variability Index Composition
JF  - Diagnostics
VL  - 16
IS  - 3
SP  - 1-24
EP  - 1-24
PB  - MPDI
SN  - 20754418
KW  - QT variability index
KW  - healthy subjects
KW  - postural testing
KW  - heart rate variability
KW  - multivariable regression
UR  - https://www.mdpi.com/2075-4418/16/3/502
N2  - Background/Objectives: One of the topics of electrocardiographic risk factor studies is investigations of beat-to-beat QT interval variability. The seminal study that reported QT variability as a prognostic risk factor introduced the so-called QT variability index (QTVi). QTVi quantification relies not only on the variance of QT intervals but also on correction factors, including RR interval variance, heart rate, and overall QT interval duration. This study investigated the influence of all the measured factors on QTVi values. Methods: Long-term electrocardiograms (ECGs) were obtained from 251 healthy subjects (mean age 33.6 +/- 9.1 years, 108 females) during repeated postural tests that involved supine, sitting, and standing positions maintained for 10 or 15 min. During each position, a 5-min ECG segment with a stable heart rate and without any ectopic disturbances was found. In these segments, standard deviations of normal-to-normal RR (NN) interval durations (SDNN) and of beat-to-beat QT interval durations (SDQT) were measured together with the means of NN and QT intervals. QTVi was subsequently calculated. For each subject, results obtained during each postural position were averaged. Results: In multivariable regression models, evaluated separately in female and male sex-subgroups of the population, QTVi values were significantly dependent on SDQT, SDNN, and mean NN intervals (all p < 0.001) but practically independent of mean QT interval durations. Conclusions: QTVi is significantly influenced by factors that are unrelated to the beat-to-beat changes in QT interval durations. This needs to be considered when interpreting QTVi values. In future studies, multivariable statistical models are needed to ensure that QTVi findings are independent of associated heart rate variability indices.
ER  -

ŘEHOŘ, Jan; Kateřina HELÁNOVÁ; Martina ŠIŠÁKOVÁ; Tomáš NOVOTNÝ; Irena ANDRŠOVÁ a Marek MALÍK. Beat-to-Beat QT Variability: A Population Study of the QT Variability Index Composition. \textit{Diagnostics}. Basel: MPDI, 2026, roč.~16, č.~3, s.~1-24. ISSN~2075-4418. Dostupné z: https://doi.org/10.3390/diagnostics16030502.

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