通过T波非线性动力学和形态学标志物评估血液透析患者的血钾水平

Estimation of potassium levels in hemodialysis patients by T wave nonlinear dynamics and morphology markers.

作者信息

Bukhari Hassaan A, Sánchez Carlos, Srinivasan Sabarathinam, Palmieri Flavio, Potse Mark, Laguna Pablo, Pueyo Esther

机构信息

BSICoS group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain; Carmen team, Inria Bordeaux - Sud-Ouest, Talence, France; University of Bordeaux, IMB, UMR 5251, Talence, France.

BSICoS group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain; CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain.

出版信息

Comput Biol Med. 2022 Apr;143:105304. doi: 10.1016/j.compbiomed.2022.105304. Epub 2022 Feb 9.

DOI:10.1016/j.compbiomed.2022.105304

PMID:35168084

Abstract

OBJECTIVE

Noninvasive screening of hypo- and hyperkalemia can prevent fatal arrhythmia in end-stage renal disease (ESRD) patients, but current methods for monitoring of serum potassium (K) have important limitations. We investigated changes in nonlinear dynamics and morphology of the T wave in the electrocardiogram (ECG) of ESRD patients during hemodialysis (HD), assessing their relationship with K and designing a K estimator.

METHODS

ECG recordings from twenty-nine ESRD patients undergoing HD were processed. T waves in 2-min windows were extracted at each hour during an HD session as well as at 48 h after HD start. T wave nonlinear dynamics were characterized by two indices related to the maximum Lyapunov exponent (λ, λ) and a divergence-related index (η). Morphological variability in the T wave was evaluated by three time warping-based indices (d, reflecting morphological variability in the time domain, and d and d, in the amplitude domain). Kwas measured from blood samples extracted during and after HD. Stage-specific and patient-specific K estimators were built based on the quantified indices and leave-one-out cross-validation was performed separately for each of the estimators.

RESULTS

The analyzed indices showed high inter-individual variability in their relationship with K. Nevertheless, all of them had higher values at the HD start and 48 h after it, corresponding to the highest K. The indices η and d were the most strongly correlated with K (median Pearson correlation coefficient of 0.78 and 0.83, respectively) and were used in univariable and multivariable linear K estimators. Agreement between actual and estimated K was confirmed, with averaged errors over patients and time points being 0.000 ± 0.875 mM and 0.046 ± 0.690 mM for stage-specific and patient-specific multivariable K estimators, respectively.

CONCLUSION

ECG descriptors of T wave nonlinear dynamics and morphological variability allow noninvasive monitoring of K in ESRD patients.

SIGNIFICANCE

ECG markers have the potential to be used for hypo- and hyperkalemia screening in ESRD patients.

摘要

目的

对终末期肾病（ESRD）患者进行低钾血症和高钾血症的无创筛查可预防致命性心律失常，但目前监测血清钾（K）的方法存在重要局限性。我们研究了ESRD患者血液透析（HD）期间心电图（ECG）中T波的非线性动力学和形态变化，评估它们与血钾的关系并设计了一个血钾估计器。

方法

对29例接受HD的ESRD患者的ECG记录进行处理。在HD期间每小时以及HD开始后48小时，在2分钟窗口内提取T波。T波非线性动力学由两个与最大Lyapunov指数（λ，λ）相关的指标和一个与散度相关的指标（η）来表征。T波的形态变异性通过三个基于时间规整的指标来评估（d，反映时域中的形态变异性，以及d和d，反映幅度域中的形态变异性）。在HD期间及之后抽取血样测量血钾。基于量化指标构建阶段特异性和患者特异性的血钾估计器，并对每个估计器分别进行留一法交叉验证。

结果

分析的指标在与血钾的关系上显示出较高的个体间变异性。然而，它们在HD开始时和之后48小时的值都较高，对应于最高的血钾水平。指标η和d与血钾的相关性最强（Pearson相关系数中位数分别为0.78和0.83），并用于单变量和多变量线性血钾估计器。实际血钾与估计血钾之间的一致性得到证实，阶段特异性和患者特异性多变量血钾估计器在患者和时间点上的平均误差分别为0.000±0.875 mM和0.046±0.690 mM。