Cai Hong, Wang Shuo, Zou Runmei, Li Fang, Zhang Juan, Wang Yuwen, Xu Yi, Wang Cheng
Department of Pediatric Cardiovasology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China.
Jishou University School of Medicine, Jishou, China.
Front Pediatr. 2021 May 13;9:644461. doi: 10.3389/fped.2021.644461. eCollection 2021.
This study aims to investigate the diurnal variability of heart rate (HR) increment after standing (ΔHR) in pediatric postural tachycardia syndrome (POTS) and explore appropriate cutoff values of ΔHR at different times for the POTS diagnosis. Seventy-eight patients (9-14 years) who presented with orthostatic intolerance symptoms were enrolled. Forty-three patients were diagnosed as POTS (ΔHR ≥40 bpm), and 35 patients were assigned to the non-POTS group (ΔHR <40 bpm). Twenty-six healthy children served as the control group. All subjects completed three standing tests in the morning, afternoon, and evening. Orthostatic HR parameters were analyzed to predict the diagnosis of POTS. Additionally, 41 patients were recruited as an external validation group. Orthostatic HR increments in both the POTS and non-POTS groups exhibited diurnal variability, which was markedly larger in the morning ( < 0.05), whereas it did not differ with the time of day in the control group. Among the POTS patients, 100% met the diagnostic criteria for POTS in the morning, 44.2% in the afternoon, and 27.9% in the evening. Almost half of the POTS patients (51.2%) displayed a positive result only in the morning standing test. However, in the three standing tests at different times, ΔHR from 1 to 10 min after standing and ΔHR were the highest in the POTS group compared with in the non-POTS and control groups ( < 0.05). Furthermore, the maximum ΔHR (ΔHR) and ΔHR at 5 and 10 min in the afternoon and evening standing tests yielded moderate predictive values for the POTS diagnosis. The external validation test showed that the afternoon ΔHR ≥30 bpm to diagnose POTS yielded sensitivity, specificity, and accuracy of 85, 71.4, and 78%, respectively, and the evening ΔHR ≥25 bpm yielded sensitivity, specificity, and accuracy of 85, 76.2, and 80.5%, respectively. The orthostatic HR increment exhibits diurnal variability in children and adolescents with POTS that may affect the diagnosis of POTS. Supplementary criteria are proposed for the POTS diagnosis based on diurnal variability.
本研究旨在调查小儿体位性心动过速综合征（POTS）患者站立后心率（HR）增量（ΔHR）的昼夜变化，并探索不同时间点用于POTS诊断的合适ΔHR截断值。纳入了78例出现体位性不耐受症状的患者（9 - 14岁）。43例患者被诊断为POTS（ΔHR≥40次/分钟），35例患者被归入非POTS组（ΔHR < 40次/分钟）。26名健康儿童作为对照组。所有受试者在上午、下午和晚上完成三项站立试验。分析体位性心率参数以预测POTS的诊断。此外，招募了41例患者作为外部验证组。POTS组和非POTS组的体位性心率增量均表现出昼夜变化，上午变化明显更大（<0.05），而对照组则不受一天中时间的影响。在POTS患者中，100%在上午符合POTS诊断标准，下午为44.2%，晚上为27.9%。几乎一半的POTS患者（51.2%）仅在上午站立试验中呈阳性结果。然而，在不同时间的三项站立试验中，与非POTS组和对照组相比，POTS组站立后1至10分钟的ΔHR和ΔHR最高（<0.05）。此外，下午和晚上站立试验中最大ΔHR（ΔHR）以及5分钟和10分钟时的ΔHR对POTS诊断具有中等预测价值。外部验证试验表明，下午ΔHR≥30次/分钟诊断POTS的敏感性、特异性和准确性分别为85%、71.4%和78%，晚上ΔHR≥25次/分钟的敏感性、特异性和准确性分别为85%、76.2%和80.5%。POTS患儿和青少年的体位性心率增量存在昼夜变化，这可能会影响POTS的诊断。基于昼夜变化为POTS诊断提出了补充标准。
