Department of Pediatrics, Peking University First Hospital, Beijing, China.
Department of Pediatrics, Beijing Children's Hospital, Beijing, China.
Eur J Pediatr. 2024 Sep;183(9):4029-4039. doi: 10.1007/s00431-024-05664-7. Epub 2024 Jul 2.
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.
Electrocardiographic acceleration index can be used to predict the effectiveness of orthostatic training in treating children with POTS.
• 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.
• 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.
本研究旨在探讨心电图（ECG）中观察到的加速度指数在预测儿科体位性心动过速综合征（POTS）患者直立训练效果中的作用。
本研究聚焦于北京大学第一医院儿科自 2012 年 1 月至 2022 年 10 月期间诊断为 POTS 并接受直立训练的儿童。具体而言，2012 年 1 月至 2019 年 12 月住院的患者被纳入训练组（54 例），而 2020 年 1 月至 2022 年 10 月住院的患者被纳入外部验证组（37 例）。所有儿童均接受 3 个月的直立训练，并根据治疗前直立不耐受症状的频率计算基线症状评分（SS）。此外，我们通过电话在治疗后 3 个月随访期间确定治疗后的 SS。将治疗后 SS 降低≥基线的 50%的患儿视为有反应者；否则，视为无反应者。
收集所有儿童治疗前的人口统计学数据（年龄、性别和体重指数）、血流动力学参数（卧位血压、达到阳性直立试验的时间、直立试验中心率最大增加、直立试验中心率最大达到和直立试验中心率最大时的血压）和心电图参数（卧位时 RR 间期、直立时最短 RR 间期和加速度指数）。采用单变量和多变量回归分析探讨与直立训练疗效相关的因素。采用受试者工作特征（ROC）分析评估这些指标对儿童 POTS 直立训练疗效的预测价值，并使用验证集验证这些指标。在训练组的 54 例儿童中，28 例对直立训练有反应，26 例无反应。与无反应者相比，有反应者的加速度指数显著降低（P<0.01）。加速度指数预测价值的 ROC 曲线下面积为 0.81（95%置信区间：0.685-0.926）。当加速度指数阈值<27.93%时，预测儿童 POTS 直立训练疗效的灵敏度和特异性分别为 85.7%和 69.2%。外部验证结果表明，当加速度指数阈值<27.93%时，预测儿童 POTS 直立训练疗效的灵敏度、特异性和准确性分别为 89.5%、77.8%和 83.8%。
心电图加速度指数可用于预测直立训练治疗儿童 POTS 的效果。
•体位性心动过速综合征（POTS）是一种涉及多种机制的慢性直立不耐受。自主神经功能障碍是儿童 POTS 的主要机制之一，可以通过直立训练进行治疗。•为了提高儿童 POTS 直立训练的疗效，在治疗前识别以自主神经功能障碍为主要机制的患者尤为重要。
•我们发现心电图（ECG）的加速度指数可作为预测儿童直立训练治疗 POTS 效果的满意指标。•使用加速度指数预测儿童 POTS 直立训练的疗效在各级医院都很容易推广，因为它是非侵入性的、方便的，并且不贵。
