Observational Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Apr 26, 2019; 7(8): 940-950
Published online Apr 26, 2019. doi: 10.12998/wjcc.v7.i8.940
Association between ventricular repolarization variables and cardiac diastolic function: A cross-sectional study of a healthy Chinese population
Zhi-Dan Li, Xiao-Juan Bai, Lu-Lu Han, Wen Han, Xue-Feng Sun, Xiang-Mei Chen
Zhi-Dan Li, Xiao-Juan Bai, Lu-Lu Han, Wen Han, Department of Gerontology and Geriatrics, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
Xue-Feng Sun, Xiang-Mei Chen, Department of Kidney, General Hospital of Chinese People’s Liberation Army, Beijing 100853, China
Author contributions: Li ZD analyzed the data and drafted the manuscript; Bai XJ designed the manuscript and approved the manuscript for final submission; Han LL and Han W measured some important parameters; Sun XF and Chen XM participated in the coordination of the study; all authors read and approved the final manuscript.
Supported by the National Basic Research Program of China, No. 973-Program #2007CB507405.
Institutional review board statement: The study was approved by the ethics committee of General Hospital of Chinese People’s Liberation Army (Beijing, China).
Informed consent statement: All patients gave informed consent.
Conflict-of-interest statement: The authors declare no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Xiao-Juan Bai, PhD, Professor, Department of Gerontology and Geriatrics, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang 110004, Liaoning Province, China. xiaojuan_bai@126.com
Telephone: +86-24-62043437 Fax: +86-24-62043437
Received: December 26, 2018
Peer-review started: December 27, 2018
First decision: March 10, 2019
Revised: March 28, 2019
Accepted: April 9, 2019
Article in press: April 9, 2019
Published online: April 26, 2019
Abstract
BACKGROUND

Diastolic electromechanical couple, a well-described phenomenon in symptomatic heart failure, has not been well studied in healthy people. We hypothesized that ventricular repolarization variables, such as the QT interval, Tpeak-to-Tend (Tpe) interval and Tpe/QT ratio, are associated with cardiac diastolic function in the healthy Chinese population.

AIM

To assess the relationship between ventricular repolarization variables and cardiac diastolic function in apparently healthy Chinese individuals.

METHODS

This was a community-based cross-sectional study conducted in Shenyang, China. A total of 414 healthy subjects aged 35-91 years were enrolled. All subjects underwent standard 12-lead electrocardiography (ECG) and comprehensive echocardiography. ECG enabled the measurement of QT and Tpe intervals and Tpe/QT ratio. echocardiographic parameters, such as the ratio of mitral early diastolic inflow velocity (E) and late diastolic inflow velocity (A), E-wave deceleration time, left atrial volume (LAV) and LAV index, were measured to assess diastolic function. E/A < 0.75 was considered to indicate reduced diastolic function. ECG and echocardiography results were analyzed separately and in a blinded fashion. Correlation and regression analyses were applied to determine associations.

RESULTS

Ventricular repolarization variables, such as the QTc interval (393.59 ± 26.74 vs 403.86 ± 33.56; P < 0.001), Tpe interval (72.68 ± 12.41 vs 77.26 ± 17.86; P < 0.01), Tpec interval (76.36 ± 13.53 vs 83.32 ± 21.25; P < 0.001) and Tpe/QT ratio (0.19 ± 0.03 vs 0.20 ± 0.04; P < 0.01), were significantly different between the normal diastolic function group and the reduced diastolic function group. Significant associations were found between repolarization variables and diastolic function. After adjusting for all other possible confounders, the QTc and Tpec intervals were significantly associated with the E/A ratio (P = 0.008; P = 0.010). In men, the QTc interval was associated with abnormal diastolic function, and compared to the third QTc tertile, in the second QTc tertile, the odds ratio was 0.257 (95%CI: 0.102–0.649; P = 0.004).

CONCLUSION

Repolarization variables are associated with cardiac diastolic function even in healthy people. Moderate levels of the QTc interval exert a protective effect on diastolic dysfunction in men.

Keywords: QT interval, Tpeak-to-Tend interval, Diastolic dysfunction, Ventricular repolarization, Electrocardiography

Core tip: A community-based cross-sectional study conducted to assess the relationship between ventricular repolarization variables and cardiac diastolic function in apparently healthy Chinese individuals. We observed an independent association between ventricular repolarization variables and cardiac diastolic function parameters, and moderate levels of the QTc interval tend to have a protective effect on diastolic dysfunction in men. Electromechanical coupling may represent a relationship between heterogeneity of repolarization and abnormal myocardial mechanics.