Abstract：
The objective of this study was to examine the utility of the acceleration index observed in an electrocardiogram (ECG) for the prediction of the effectiveness of orthostatic training in pediatric patients diagnosed with postural orthostatic tachycardia syndrome (POTS). This investigation focused on children diagnosed with POTS and undergoing orthostatic training at the Department of Pediatrics of Peking University First Hospital from January 2012 to October 2022. Specifically, patients hospitalized from January 2012 to December 2019 were included in the training set (54 cases), while those hospitalized from January 2020 to October 2022 were included in the external validation set (37 cases). All children received a 3-month orthostatic training, and the baseline symptom score (SS) was calculated in agreement with the pretreatment orthostatic intolerance symptom frequency. Additionally, we determined post-treatment SS during follow-up via telephone after the 3-month treatment. Children with a decrease in post-treatment SS by ≥ 50% of the baseline were considered as responders; otherwise, they were considered as non-responders. Demographic data (age, sex, and body mass index), hemodynamic parameters (supine blood pressure, time to achieve a positive standing test, maximum increase in heart rate during the standing test, maximal heart rate reached during the standing test, and blood pressure at the point of maximal heart rate during the standing test), and electrocardiographic parameters (RR interval in the supine position, shortest RR interval in the upright position, and acceleration index) were collected from all the children prior to treatment. Univariate and multivariate regression analysis were conducted to investigate factors associated with the efficacy of orthostatic training. The predictive value of these indicators for the therapeutic effectiveness of orthostatic training in children with POTS was evaluated using receiver operating characteristic (ROC) analysis, and the indicators were validated using the validation set. Among the 54 children in the training set, 28 responded to orthostatic training, and 26 were nonresponsive. Compared with the non-responders, the responders demonstrated a significant reduction in acceleration index (P < 0.01). The ROC curve for the predictive value of the acceleration index exhibited an area under the curve = 0.81 (95% confidence interval: 0.685-0.926). With the acceleration index threshold < 27.93%, the sensitivity and specificity in the prediction of orthostatic training efficacy among children with POTS were 85.7% and 69.2%, respectively. The external validation results demonstrated that using acceleration index < 27.93% as the threshold, the sensitivity, specificity, and accuracy of predicting orthostatic training efficacy among children with POTS were 89.5%, 77.8%, and 83.8%, respectively.
CONCLUSIONS: Electrocardiographic acceleration index can be used to predict the effectiveness of orthostatic training in treating children with POTS.
BACKGROUND: • Postural orthostatic tachycardia syndrome (POTS) is a chronic orthostatic intolerance involving multiple mechanisms. Autonomic dysfunction is one of the main mechanisms of POTS in children and could be treated with orthostatic training. • In order to improve the efficacy of orthostatic training in children with POTS, it is particularly important to identify the patients with autonomic dysfunction as the main mechanism before the treatment.
BACKGROUND: • We found acceleration index of the electrocardiogram (ECG) can be used as a satisfactory index to predict the efficacy of orthostatic training in the treatment of POTS in children. • Using the acceleration index to predict the efficacy of orthostatic training on POTS in children is easy to be popularized in hospitals at all levels because it is non-invasive, convenient, and not expensive.
CONCLUSIONS: Electrocardiographic acceleration index can be used to predict the effectiveness of orthostatic training in treating children with POTS.
BACKGROUND: • Postural orthostatic tachycardia syndrome (POTS) is a chronic orthostatic intolerance involving multiple mechanisms. Autonomic dysfunction is one of the main mechanisms of POTS in children and could be treated with orthostatic training. • In order to improve the efficacy of orthostatic training in children with POTS, it is particularly important to identify the patients with autonomic dysfunction as the main mechanism before the treatment.
BACKGROUND: • We found acceleration index of the electrocardiogram (ECG) can be used as a satisfactory index to predict the efficacy of orthostatic training in the treatment of POTS in children. • Using the acceleration index to predict the efficacy of orthostatic training on POTS in children is easy to be popularized in hospitals at all levels because it is non-invasive, convenient, and not expensive.
摘要：
这项研究的目的是检查心电图（ECG）中观察到的加速度指数的实用性，以预测被诊断为体位性心动过速综合征（POTS）的儿科患者的体位训练的有效性。本次调查的重点是2012年1月至2022年10月在北京大学第一医院儿科接受体位训练的POTS患儿。具体来说,2012年1月至2019年12月住院的患者纳入培训集（54例），而2020年1月至2022年10月住院的患者被纳入外部验证集（37例）。所有的孩子都接受了3个月的体位训练,基线症状评分（SS）与治疗前直立不耐受症状频率一致。此外,我们在治疗3个月后通过电话随访确定了治疗后的SS.治疗后SS下降≥基线50%的儿童被视为应答者；否则，他们被认为是无应答者。人口统计数据(年龄，性别,和体重指数)，血液动力学参数（仰卧位血压，是时候实现积极的站立测试了，站立试验期间心率的最大增加，在站立测试期间达到的最大心率，和站立测试中最大心率时的血压)，和心电图参数(仰卧位的RR间期，直立位置的最短RR间隔，和加速指数）在治疗前从所有儿童中收集。采用单因素和多因素回归分析探讨与体位训练效果相关的因素。使用受试者工作特征（ROC）分析评估这些指标对POTS儿童体位训练的治疗效果的预测价值，并使用验证集验证指标。在训练集中的54名儿童中，28对立位训练有反应，26人没有反应。与非响应者相比，反应者的加速指数显着降低（P<0.01）。加速度指数预测值的ROC曲线显示曲线下面积=0.81(95%置信区间:0.685-0.926)。加速度指数阈值<27.93%时,POTS患儿体位训练效果预测的敏感性和特异性分别为85.7%和69.2%,分别。外部验证结果表明,以加速度指数<27.93%为阈值,灵敏度,特异性，预测POTS患儿体位训练效果的准确性为89.5%，77.8%,和83.8%，分别。
结论：心电图加速度指数可用于预测体位训练治疗POTS患儿的有效性。
背景：•体位性心动过速综合征（POTS）是一种涉及多种机制的慢性体位性不耐受。自主神经功能障碍是儿童POTS的主要机制之一，可以通过体位训练进行治疗。•为了提高POTS儿童体位训练的疗效，在治疗前明确以自主神经功能障碍为主要机制的患者尤为重要。
背景：•我们发现心电图（ECG）的加速度指数可以作为预测儿童POTS治疗中体位训练疗效的令人满意的指标。•使用加速度指数来预测儿童POTS体位训练的功效，由于它是非侵入性的，因此易于在各级医院推广。方便,而且不贵。
结论：心电图加速度指数可用于预测体位训练治疗POTS患儿的有效性。
背景：•体位性心动过速综合征（POTS）是一种涉及多种机制的慢性体位性不耐受。自主神经功能障碍是儿童POTS的主要机制之一，可以通过体位训练进行治疗。•为了提高POTS儿童体位训练的疗效，在治疗前明确以自主神经功能障碍为主要机制的患者尤为重要。
背景：•我们发现心电图（ECG）的加速度指数可以作为预测儿童POTS治疗中体位训练疗效的令人满意的指标。•使用加速度指数来预测儿童POTS体位训练的功效，由于它是非侵入性的，因此易于在各级医院推广。方便,而且不贵。
