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Clinical impact of repolarization changes in supine versus upright body position
Affiliations- University Heart Center Zurich
- Department of Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany, Germany
- Department of cardiovascular surgery, Deutsches Herzzentrum Berlin, Germany
open access
Abstract
Background: The impact of postural changes on various electrocardiography (ECG) characteristics has only been assessed in a few small studies. This large prospective trial was conducted to confirm or refute preliminary data and add important results with immediate impact on daily clinical practice.
Methods: ECGs in supine and upright position from 1028 patients were analyzed. Evaluation was made according to changes in T-wave vector and direction, ST-segment deviation, heart rate, QT interval and QTc interval was performed. Findings were correlated with the medical history of patients.
Results: Positional change from supine to upright resulted in a significantly increased heart rate (8.05 ± 7.71 bpm) and a significantly increased QTc interval after Bazetts (18 ± 23.45 ms) and Fridericas (8.84 ± 17.30) formula. In the upright position significantly more T-waves turned negative (14.7%) than positive (5.7%). ST elevation was recorded in only 0.4% and ST depression in not more than 0.2% of all patients.
Conclusions: The majority of the patients do not show significant morphological changes in their ECG by changing the body position from supine to upright. Changes of QTc time instead, are significant and the interval might be overestimated in upright. Therefore assessment of the QTc interval should strictly be done in a supine position.
Abstract
Background: The impact of postural changes on various electrocardiography (ECG) characteristics has only been assessed in a few small studies. This large prospective trial was conducted to confirm or refute preliminary data and add important results with immediate impact on daily clinical practice.
Methods: ECGs in supine and upright position from 1028 patients were analyzed. Evaluation was made according to changes in T-wave vector and direction, ST-segment deviation, heart rate, QT interval and QTc interval was performed. Findings were correlated with the medical history of patients.
Results: Positional change from supine to upright resulted in a significantly increased heart rate (8.05 ± 7.71 bpm) and a significantly increased QTc interval after Bazetts (18 ± 23.45 ms) and Fridericas (8.84 ± 17.30) formula. In the upright position significantly more T-waves turned negative (14.7%) than positive (5.7%). ST elevation was recorded in only 0.4% and ST depression in not more than 0.2% of all patients.
Conclusions: The majority of the patients do not show significant morphological changes in their ECG by changing the body position from supine to upright. Changes of QTc time instead, are significant and the interval might be overestimated in upright. Therefore assessment of the QTc interval should strictly be done in a supine position.
Keywords
electrocardiography; electrophysiology; from supine to upright; QTc variations; long-QT
About this articleTitle
Clinical impact of repolarization changes in supine versus upright body position
Journal
Issue
Pages
589-594
Published online
2017-11-23
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3032
Article views/downloads
1598
DOI
Pubmed
Bibliographic record
Cardiol J 2018;25(5):589-594.
Keywords
electrocardiography
electrophysiology
from supine to upright
QTc variations
long-QT
Authors
Susanne Markendorf
Thomas F. Lüscher
Jin-Hong Gerds-Li
Felix Schönrath
Christian Marc Schmied
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