Blesius Valeria, Schölzel Christopher, Ernst Gernot, Dominik Andreas
Life Science Informatics Group, Department of Mathematics, Natural Sciences and Informatics, Technische Hochschule Mittelhessen (THM) University of Applied Sciences, Giessen, Germany.
Department of Anaesthesiology, Kongsberg Hospital, Vestre Viken Hospital Trust, Kongsberg, Norway.
Front Cardiovasc Med. 2022 Apr 6;9:793535. doi: 10.3389/fcvm.2022.793535. eCollection 2022.
Heart rate turbulence (HRT) is a characteristic heart rate pattern triggered by a ventricular premature contraction (VPC). It can be used to assess autonomic function and health risk for various conditions, e.g., coronary artery disease or cardiomyopathy. While comparability is essential for scientific analysis, especially for research focusing on clinical application, the methodology of HRT still varies widely in the literature. Particularly, the ECG measurement and parameter calculation of HRT differs, including the calculation of turbulence slope (TS). In this article, we focus on common variations in the number of intervals after the VPC that are used to calculate TS (#TSRR) posing two questions: 1) Does a change in #TSRR introduce noticeable changes in HRT parameter values and classification? and 2) Do larger values of turbulence timing (TT) enabled by a larger #TSRR still represent distinct HRT? We compiled a free-access data set of 1,080 annotated long-term ECGs provided by Physionet. HRT parameter values and risk classes were determined both with #TSRR 15 and 20. A standard local tachogram was created by averaging the tachograms of only the files with the best heart rate variability values. The shape of this standard VPC sequence was compared to all VPC sequences grouped by their TT value using dynamic time warping (DTW) in order to identify HRT shapes. When calculated with different #TSRR, our results show only a little difference between the number of files with enough valid VPC sequences to calculate HRT (<1%) and files with different risk classes (5 and 6% for HRT0-2 and HRTA-C, respectively). In the DTW analysis, the difference between averaged sequences with a specific TT and the standard sequence increased with increasing TT. Our analysis suggests that HRT occurs in the early intervals after the VPC and TS calculated from late intervals reflects common heart rate variability rather than a distinct response to the VPC. Even though the differences in classification are marginal, this can lead to problems in clinical application and scientific research. Therefore, we recommend uniformly using #TSRR 15 in HRT analysis.
心率震荡（HRT）是一种由室性早搏（VPC）触发的特征性心率模式。它可用于评估各种疾病（如冠状动脉疾病或心肌病）的自主神经功能和健康风险。虽然可比性对于科学分析至关重要，特别是对于侧重于临床应用的研究，但HRT的方法在文献中仍然差异很大。特别是，HRT的心电图测量和参数计算不同，包括震荡斜率（TS）的计算。在本文中，我们关注用于计算TS的VPC后间期数量（#TSRR）的常见变化，提出两个问题：1）#TSRR的变化是否会导致HRT参数值和分类出现显著变化？2）更大的#TSRR所带来的更长的震荡起始时间（TT）值是否仍代表不同的HRT？我们整理了由Physionet提供的1080份带注释的长期心电图的免费数据集。分别使用#TSRR 15和20确定HRT参数值和风险类别。通过仅对具有最佳心率变异性值的文件的心动周期图进行平均来创建标准局部心动周期图。使用动态时间规整（DTW）将该标准VPC序列的形状与按TT值分组的所有VPC序列进行比较，以识别HRT形状。当使用不同的#TSRR进行计算时，我们的结果表明，具有足够有效VPC序列以计算HRT的文件数量之间只有微小差异（<1%），以及具有不同风险类别的文件数量之间也只有微小差异（HRT0 - 2和HRTA - C分别为5%和6%）。在DTW分析中，具有特定TT的平均序列与标准序列之间的差异随着TT的增加而增大。我们的分析表明，HRT发生在VPC后的早期间期，而从晚期间期计算的TS反映的是常见的心率变异性，而不是对VPC的独特反应。尽管分类差异很小，但这可能会在临床应用和科学研究中导致问题。因此，我们建议在HRT分析中统一使用#TSRR 15。
