Heart rate and heart rate variability comparison between postural orthostatic tachycardia syndrome versus healthy participants; a systematic review and meta-analysis

Abstract

BackgroundA 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.MethodsMEDLINE (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.ResultsTwenty (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.ConclusionPOTS 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.

Heart Rate Variability in Head-Up Tilt Tests in Adolescent Postural Tachycardia Syndrome Patients

“…Previously, there have been reports of lower parasympathetic and sympathetic tone in POTS patients than in controls before HUT in recumbency, and during the HUT tests (Stewart, 2000;Baker et al, 2018a). However, in a meta-analysis there were no significant differences in HF, LF, or LF/HF in recumbency after HUT in POTS patients compared with controls (Swai et al, 2019).…”

“…In recent years, numerous studies of POTS patients’ head-up tilt (HUT) test describing HRV have been published ( Furlan et al, 1998 ; Corkal et al, 2014 ; Baker et al, 2018a ; Swai et al, 2019 ), but only a few with adolescent subjects ( Stewart, 2000 ; Swai et al, 2019 ). In one study, a different definition of POTS was used, in other words, a milder heart rate increase was accepted ( Yoshida et al, 2014 ).…”

The postural orthostatic stress syndrome in childhood: HRV analysis and the active standing test

“…As shown in table 1, the patient groups had a comparable age and the anthropometric data had a wide range and are clearly separated of cause the group definitions. A recent meta-analysis published by Swai J et al [8] indicates higher heart rates and lower HRV in POTS patients. In accordance with these data our regression analysis shows higher 24-hours heart rates in the linear regression analysis (T=2,6, p=0.01, table 4).…”

Postural Orthostatic Tachycardia Syndrome Misdiagnosed as Anxiety: A Case Report with a Review of Therapy and Pathophysiology

“…In contrast, the high-frequency band, the parasympathetic response, is instantaneous and of a lower peak, paralleling the withdrawal of vagal tone with the assumption of the erect posture ( Figure 1) [9]. In patients with POTS, head-up tilt table testing shows a higher low-frequency/high-frequency ratio implying a higher sympathetic tone upon assumption of the upright posture [10].…”

“…In patients with POTS, head-up tilt table testing shows a higher low-frequency/high-frequency ratio implying a higher sympathetic tone upon assumption of the upright posture [ 10 ].…”