Hakacova Nina, Bass Geoffrey D, Olson Charles W, Robinson Anna M C, Selvester Ronald H
Department of Pediatric Cardiology, Children's Cardiac Centre, Slovakia.
J Electrocardiol. 2009 Mar-Apr;42(2):158-64. doi: 10.1016/j.jelectrocard.2008.12.008. Epub 2009 Jan 22.
Simulation of the electrical activation of the heart and its comparison with real in vivo activation is a promising method in testing potential determinants of excitation. Simulation of the electrical activity of the human heart is now emerging as a step forward for understanding and predicting electrophysiologic patterns in humans. Initial points of excitation and the manner in which the activation spreads from these points are important variables determining QRS complex characteristics. It has been suggested that in humans, the initial excitation of the left ventricle is a primary determinant of QRS complex characteristics, and that excitation begins at the papillary muscles and septum, where the fascicles of the left bundle branch insert. The aim of this study is to test the hypothesis that QRS duration and direction of QRS axis in the frontal plane have excellent agreement between real QRS and simulated QRS using papillary muscle position to indicate the border of the origin of early ventricular activation.
Fourteen healthy adult volunteers were included in the study. Magnetic resonance imaging data were obtained to assess the papillary muscle positions. Twelve-lead electrocardiographic (ECG) recordings were used to obtain real ECG data for assessment of QRS duration and QRS axis in each subject. Simulation software developed by ECG-TECH Corp (Huntington, NY) was used to simulate the ECG of each subject to determine simulated QRS duration and QRS frontal plane axis. QRS duration and QRS axis data were compared between simulated and real ECG and agreement between these variables was calculated.
Seventy-nine percent of subjects had a difference of the QRS duration between real and simulated ECG of less than 10 milliseconds. The calculated strength of agreement between simulated and real QRS duration was 71% and considered as "good" (kappa statistics). In 70% of subjects, the difference in the QRS axis was less than 10 degrees . The calculated strength of agreement between simulated and real QRS axis was 80% and considered as "excellent" (kappa statistics).
The results of this study suggest that the sites of the initiation of electrical activity in the left ventricle, as assessed by the positions of papillary muscles, may be considered as primary determinants of the QRS duration and QRS axis in humans. This knowledge may help in predicting normal QRS characteristic on a patient-specific basis. In this study, simulation of the QRS complex was based on papillary muscles from human hearts.
模拟心脏的电激活并将其与真实的体内激活进行比较，是测试兴奋潜在决定因素的一种有前景的方法。模拟人类心脏的电活动正成为理解和预测人类电生理模式的一个进步。兴奋的起始点以及激活从这些点传播的方式是决定QRS波群特征的重要变量。有人提出，在人类中，左心室的初始兴奋是QRS波群特征的主要决定因素，并且兴奋始于乳头肌和室间隔，左束支的分支插入此处。本研究的目的是检验这一假设：使用乳头肌位置来指示早期心室激活起源的边界时，额面QRS波群持续时间和QRS轴方向在真实QRS和模拟QRS之间具有良好的一致性。
本研究纳入了14名健康成年志愿者。获取磁共振成像数据以评估乳头肌位置。使用12导联心电图（ECG）记录来获取每个受试者的真实ECG数据，以评估QRS波群持续时间和QRS轴。使用ECG-TECH公司（纽约州亨廷顿）开发的模拟软件来模拟每个受试者的ECG，以确定模拟的QRS波群持续时间和QRS额面轴。比较模拟和真实ECG之间的QRS波群持续时间和QRS轴数据，并计算这些变量之间的一致性。
79%的受试者真实ECG和模拟ECG之间的QRS波群持续时间差异小于10毫秒。计算得出的模拟和真实QRS波群持续时间之间的一致性强度为71%，被认为是“良好”（kappa统计）。70%的受试者QRS轴差异小于10度。计算得出的模拟和真实QRS轴之间的一致性强度为80%，被认为是“优秀”（kappa统计）。
本研究结果表明，通过乳头肌位置评估的左心室电活动起始部位可被视为人类QRS波群持续时间和QRS轴的主要决定因素。这一知识可能有助于在个体患者基础上预测正常的QRS特征。在本研究中，QRS波群的模拟基于人类心脏的乳头肌。
