Effect of cardiac ventricular mechanical contraction on the characteristics of the ECG: A simulation study  

作　　者：Ismail Adeniran Jules C. Hancox Henggui Zhang 

机构地区：[1]Department of Physiology and Cardiovascular Laboratories, School of Medical Sciences, Bristol, United Kingdom [2]School of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom [3]School of Physics and Astronomy, The University of Manchester, Manchester, United KingdomSchool of Computer Sciences and Technology, Harbin Institute of Technology, Harbin, China

出　　处：《Journal of Biomedical Science and Engineering》2013年第12期47-60,共14页生物医学工程（英文）

摘　　要：Introduction: The 12-lead electrocardiogram (ECG) is the most widely-used tool for the detection and diagnosis of cardiac conditions including myocardial infarction and ischemia. It has therefore been a focus of cardiac modeling. However, the most contemporary in silico ECG investigations of the intact heart have assumed a static heart and ignored the mechanical contraction that is an essential component of cardiac function. The aim of this study was to utilize electromechanically coupled human ventricle models to explore the consequences of ventricular mechanical contraction on the ECG profiles. Methods and Results: Biophysically detailed human ventricular cell models incorporating contractile activity and a stretchactivated current (Isac) were incorporated into a 3D human ventricular model within a human torso, from which 12-lead ECGs were computed at a stimulation rate of 1 Hz. Compared to the static model, ventricular contraction without Isac had little effect on the QRS complex, but shifted the T-wave peak leftwards and reduced its peak amplitude. With Isac, ventricular mechanical contraction increased the QRS duration by 23% and QT interval by 5%. Conclusion: Mechanical contraction of the heart has a significant effect on the morphology and characteristics of the ECG particularly on the T-wave. The alteration of the cell membrane kinetics by stretch via Isac further exacerbates these effects. Our simulation data suggest that mechanical contraction should be considered in the interpretation of ECGs in pathological conditions, especially those in which mechanical contraction of the heart is impaired.Introduction: The 12-lead electrocardiogram (ECG) is the most widely-used tool for the detection and diagnosis of cardiac conditions including myocardial infarction and ischemia. It has therefore been a focus of cardiac modeling. However, the most contemporary in silico ECG investigations of the intact heart have assumed a static heart and ignored the mechanical contraction that is an essential component of cardiac function. The aim of this study was to utilize electromechanically coupled human ventricle models to explore the consequences of ventricular mechanical contraction on the ECG profiles. Methods and Results: Biophysically detailed human ventricular cell models incorporating contractile activity and a stretchactivated current (Isac) were incorporated into a 3D human ventricular model within a human torso, from which 12-lead ECGs were computed at a stimulation rate of 1 Hz. Compared to the static model, ventricular contraction without Isac had little effect on the QRS complex, but shifted the T-wave peak leftwards and reduced its peak amplitude. With Isac, ventricular mechanical contraction increased the QRS duration by 23% and QT interval by 5%. Conclusion: Mechanical contraction of the heart has a significant effect on the morphology and characteristics of the ECG particularly on the T-wave. The alteration of the cell membrane kinetics by stretch via Isac further exacerbates these effects. Our simulation data suggest that mechanical contraction should be considered in the interpretation of ECGs in pathological conditions, especially those in which mechanical contraction of the heart is impaired.

关 键 词：VENTRICLES MECHANICAL CONTRACTION ELECTROPHYSIOLOGY Simulation ECG 

分 类 号：R5[医药卫生—内科学]