BACKGROUND A number of published literature has reported that, physiologically, heart rate variability (HRV) in patients with postural orthostatic tachycardia syndrome (POTS) to be greatly confounded by age, sex, race, physical fitness, and circadian rhythm. The purpose of this study was to compare between POTS patients versus healthy participants, in terms of heart rate (HR) and HRV after Head-Up tilt test (HUTT), by systematic review and meta-analysis of available published literature. METHODS MEDLINE (using PubMed interphase), EMBASE and SCOPUS were systematically searched for observational studies comparing POTS patients versus healthy patients, in terms of HR and HRV. HRV was grouped into Time and frequency domain outcome measurements. The time domain was measured as mean RR- interval and mean the square root of the mean of squares of successive R-R waves (rMSSD) in milliseconds. The frequency domain was measured as mean values of Low frequency power (LF), High frequency power (HF), LF/HF-ratio, LF-normalized units (LF(n.u)) and HF-normalized units (HF(n.u)). Demographic data, comorbidities, and mean values of HR, RR- interval, rMSSD, LF, HF, LF/HF-ratio, LF-(n.u) and H.F-n.u were extracted from each group and compared, by their mean differences as an overall outcome measure. Computer software, RevMan 5.3 was utilized, at a 95% significance level. RESULTS Twenty (20) eligible studies were found to report 717 POTS and 641 healthy participants. POTS group had a higher mean HR (p < 0.05), lower mean RR-Interval (p < 0.05), lower rMSSD (p < 0.05) than healthy participants. Furthermore, POTS group had lower mean HF(p > 0.05), lower mean LF(p > 0.05), and lower mean HF(n.u) (p > 0.05), higher LF/HF-Ratio (p > 0.05) and higher LF(n.u) (p > 0.05) as compared to healthy participants. CONCLUSION POTS patients have a higher HR than healthy patients after HUTT and lower HRV in terms of time domain measure but not in terms of frequency domain measure. HR and time domain analyses of HRV are more reliable than frequency domain analysis in differentiating POTS patients from the healthy participants. We call upon sensitivity and specificity studies.

中文翻译：

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体位性体位性心动过速综合征与健康参与者之间的心率和心率变异性比较；系统的审查和荟萃分析。

背景技术许多公开的文献已经报道，在体位性体位性心动过速综合征（POTS）的患者中，生理上的心率变异性（HRV）受年龄，性别，种族，身体适应性和昼夜节律的影响很大。这项研究的目的是通过对现有文献进行系统回顾和荟萃分析，比较抬头向上倾斜测试（HUTT）后的POTS患者与健康受试者的心率（HR）和HRV。方法系统地搜索MEDLINE（使用PubMed中间相），EMBASE和SCOPUS，以进行观察性研究，以比较HR和HRV来比较POTS患者与健康患者。HRV分为时域和频域结果测量。将时域测量为平均RR间隔和连续RR波（rMSSD）的均方根的均方根（以毫秒为单位）。频域被测量为低频功率（LF），高频功率（HF），LF / HF比，LF归一化单位（LF（nu））和HF归一化单位（HF（nu））的平均值。从各组中提取并比较HR，RR间隔，rMSSD，LF，HF，LF / HF比，LF-（nu）和HF-nu的人口统计学数据，合并症和均值总体结果评估。使用的计算机软件RevMan 5.3的显着性水平为95％。结果发现二十（20）个合格研究报告了717个POTS和641个健康参与者。与健康参与者相比，POTS组的平均HR较高（p <0.05），平均RR间隔较低（p <0.05），rMSSD较低（p <0.05）。此外，POTS组的平均HF（p> 0.05）较低，平均LF（p> 0.05）较低，平均HF（nu）较低（p> 0.05），LF / HF比值较高（p> 0.05）和LF较高（nu）（p> 0.05）与健康参与者相比。结论在接受HUTT后，POTS患者的HR高于健康患者，在时域测量方面的HRV较低，而在频域测量方面的HRV较低。在区分POTS患者和健康参与者方面，HRV的HR和时域分析比频域分析更可靠。我们呼吁进行敏感性和特异性研究。结论在接受HUTT后，POTS患者的HR高于健康患者，在时域测量方面的HRV较低，而在频域测量方面的HRV较低。在区分POTS患者和健康参与者方面，HRV的HR和时域分析比频域分析更可靠。我们呼吁进行敏感性和特异性研究。结论在接受HUTT后，POTS患者的HR高于健康患者，在时域测量方面的HRV较低，而在频域测量方面的HRV较低。在区分POTS患者和健康参与者方面，HRV的HR和时域分析比频域分析更可靠。我们呼吁进行敏感性和特异性研究。