Sleep disturbances and autonomic dysfunction in patients with postural orthostatic tachycardia syndrome

Resting heart rate variability as a diagnostic marker of cardiovascular dysautonomia in postural tachycardia syndrome

OBJECTIVES

Postural orthostatic tachycardia syndrome (POTS) is a disorder of the autonomic nervous system characterised by orthostatic intolerance and orthostatic tachycardia without hypotension. Heart rate variability (HRV) is the most reliable and objective tool for assessing autonomic dysfunction severity. In the present study, we aimed to investigate HRV changes in resting supine position, predicting severity and cardiovascular risk in patients with POTS.

METHODS

We compared 100 POTS patients with 160 healthy controls matched for age and gender in a case-control design. Along with clinical characterization, heart rate variability was evaluated using ambulatory 5 min ECG in lead II and expressed in frequency and time-domain measures.

RESULTS

The resting heart rate of patients with POTS was significantly higher than that of healthy controls. In HRV measures, root mean square successive difference of RR intervals (RMSSD), total and high frequency (HF) powers were statistically lower with an increased low frequency (LF) to high-frequency ratio in patients with POTS compared to healthy controls. Further, stepwise logistic regression analysis showed increased basal HR and LF/HF as significant predictors of POTS and its severity.

CONCLUSIONS

This is the first study on a large cohort of patients with POTS from India wherein HRV was assessed. The study showed reduced parasympathetic activity and increased sympathetic activity in patients with POTS compared to healthy controls. These findings of increased resting heart rate and LF/HF were found to be potential predictors of POTS and future cardiovascular risks, which need to be replicated in a larger and more homogenized cohort.

Sleep duration and disturbance are associated with orthostatic heart rate recovery: Findings from the Irish Longitudinal Study on Ageing

OBJECTIVE

To examine a novel measurement of autonomic innervation, the early heart rate response to orthostasis, in relation to sleep duration and disturbance (actigraphy-based and self-reported) in healthy older adults.

DESIGN

Cross-sectional analyses of a nationally representative prospective cohort study, the Irish Longitudinal Study on Ageing (TILDA).

PARTICIPANTS

Nine hundred sixty community-dwelling adults aged 50 and over (mean age 65.6 ± 8.1; 53% women).

MEASUREMENT

Orthostatic heart rate response was measured during an active stand test. Beat-to-beat heart rate was monitored over 3 minutes using noninvasive digital photoplethysmography. Mean values at each 10-second time point after standing were generated and differences from baseline at each time point were used for analysis. Actigraphy-based sleep measures were extracted from wrist-worn GENEactiv devices; self-reported sleep measures using interview questions.

RESULTS

Linear mixed-effects regression analyses, with inclusion of a large number of confounders, show that self-reported sleep duration and actigraphy-based sleep duration and disturbance were associated with altered orthostatic heart rate response, particularly within the first 20 seconds poststanding. Self-reported short sleep (β = -0.06; 95% confidence interval [CI]: -0.11, -0.01) and long sleep (β = -0.15; 95% CI: -0.24, -0.05) and actigraphy-based short sleep (β = -0.08; 95% CI: -0.14, -0.01) were characterized by a smaller increase at 10 seconds (p < .01). Actigraphy-based short sleep (β = 0.15; 95% CI: 0.08, 0.22) and sleep disturbance (β = 0.04; 95% CI: 0.02, 0.06) were associated with a slower return toward baseline at 20 seconds (p < .001).

CONCLUSIONS

Our findings suggest sympathetic dysregulation, impaired vagal reactivation, and/or decreased baroreceptor sensitivity in the presence of shortened or disturbed sleep.

Targeted Treatment of Inappropriate Sinoatrial Node Tachycardia Based on Electrophysiological and Structural Mechanisms

The purpose of this review is to determine the causal mechanisms and treatment of inappropriate sinoatrial tachycardia (IST), defined as a non-physiological elevation in resting heart rate. IST is defined as a resting daytime sinus rate >100 beats/minute and an average 24-hour heart rate >90 beats/minute. Potential causal mechanisms include sympathetic receptor hypersensitivity, blunted parasympathetic tone, or enhanced intrinsic automaticity within the sinoatrial node (SAN) pacemaker-conduction complex. These anomalies may coexist in the same patient. Recent ex-vivo near-infrared transmural optical imaging of the SAN in human and animal hearts provides important insights into the functional and molecular features of this complex structure. In particular, it reveals the existence of preferential sinoatrial conduction pathways that ensure robust SAN activation with electrical conduction. The mechanism of IST is debated because even high-resolution electroanatomical mapping approaches cannot reveal intramural conduction in the 3-dimensional SAN complex. It may be secondary to enhanced automaticity, intranodal re-entry, or sinoatrial conduction pathway re-entry. Different pharmacological approaches can target these mechanisms. Long-acting β blockers in IST can act on both primarily increased automaticity and dysregulated autonomic system. Ivabradine targets sources of increased SAN automaticity. Conventional or hybrid ablation may target all the described abnormalities. This review provides a state-of-the-art overview of putative IST mechanisms. In conclusion, based on current knowledge, pharmacological and ablation approaches for IST, including the novel hybrid SAN sparing ablation, are discussed.

The Goals and Outcomes of Adolescent and Young Adults with POTS Attending an Intensive Interdisciplinary Treatment Program

Postural Orthostatic Tachycardia Syndrome (POTS) affects approximately 1% of adolescents, however, little research has been done in this area. This retrospective chart review describes the treatment goals and perceived progress as measured by the Canadian Occupational Performance Measure (COPM) of 111 adolescents and young adults (AYAs) aged 12-22 (M = 15.8, SD = 1.8) diagnosed with POTS who were admitted to an interdisciplinary intensive pain treatment program (IIPT). This study also examined the change in progress and satisfaction in goals over a 3-week intensive pain treatment program, as well as the utility and validity of the COPM as an outcome measure for AYAs attending an IIPT. Results indicated adolescents and young adults endorsed treatment goals focused on self-care, school, and leisure and found that performance and satisfaction scores significantly improved from admission to discharge. The findings also suggest that the COPM is a useful and valid outcome measure for this population.

Brain fog in neuropathic postural tachycardia syndrome may be associated with autonomic hyperarousal and improves after water drinking

Background

Brain fog is a common and highly disturbing symptom for patients with neuropathic postural tachycardia syndrome (POTS). Cognitive deficits have been measured exclusively in the upright body position and mainly comprised impairments of higher cognitive functions. The cause of brain fog is still unclear today. This study aimed to investigate whether increased autonomic activation might be an underlying mechanism for the occurrence of brain fog in neuropathic POTS. We therefore investigated cognitive function in patients with neuropathic POTS and a healthy control group depending on body position and in relation to catecholamine release as a sensitive indicator of acute stress. The second aim was to test the effect of water intake on cardiovascular regulation, orthostatic symptoms, cognitive function and catecholamine release.

Methods

Thirteen patients with neuropathic POTS and 15 healthy control subjects were included. All participants completed a total of four rounds of cognitive testing: two before and two after the intake of 500 ml still water, each first in the supine position and then during head-up tilt. At the end of each cognitive test, a blood sample was collected for determination of plasma catecholamines. After each head-up tilt phase participants were asked to rate their current symptoms on a visual analogue scale.

Results

Working memory performance in the upright body position was impaired in patients, which was associated with self-reported symptom severity. Patients had elevated plasma norepinephrine independent of body position and water intake that increased excessively in the upright body position. The excessive increase of plasma norepinephrine was related to heart rate and symptom severity. Water intake in patients decreased norepinephrine concentrations and heart rate, and improved symptoms as well as cognitive performance.

Conclusion

Brain fog and symptom severity in neuropathic POTS are paralleled by an excessive norepinephrine secretion. Bolus water drinking down-regulates norepinephrine secretion and improves general symptom severity including brain fog.

Autonomic dysfunction in idiopathic hypersomnia: an overlooked association and potential management

There is a small yet robust body of literature regarding autonomic dysfunction in idiopathic hypersomnia as well as sleep disturbances in postural orthostatic tachycardia syndrome. This review aims at summarizing the current literature and highlighting gaps in the current knowledge. This article additionally presents the personal experience of one of the authors at the sleep center.

CITATION

Adra N, Reddy M, Attarian H, Sahni AS. Autonomic dysfunction in idiopathic hypersomnia: an overlooked association and potential management. J Clin Sleep Med. 2022;18(3):963-965.

Dysautonomia in the Ehlers-Danlos syndromes and hypermobility spectrum disorders-With a focus on the postural tachycardia syndrome

Dysautonomia (autonomic dysfunction) occurs in the Ehlers-Danlos syndromes (EDS) and hypermobility spectrum disorders (HSD). Symptoms include palpitations, dizziness, presyncope, and syncope, especially when standing upright. Symptoms of orthostatic intolerance are usually relieved by sitting or lying and may be exacerbated by stimuli in daily life that cause vasodilatation, such as food ingestion, exertion, and heat. Neurocardiovascular dysautonomia may result in postural tachycardia syndrome (PoTS), a major cause of orthostatic intolerance. It is defined by a rise in heart rate of >30 beats per minute (bpm) in adults and >40 bpm in teenagers while upright, without a fall in blood pressure (BP; orthostatic hypotension). In some, it can be compounded by the presence of low BP. For many, there is delay in clinicians recognizing the nature of the symptoms, and recognizing EDS or HSD, leading to delays in treatment. The onset of PoTS may be linked to an event such as infection, trauma, surgery, or stress. Gastrointestinal and urinary bladder involvement may occur, along with thermoregulatory dysfunction. In some, the mast cell activation syndrome may be contributary, especially if it causes vasodilatation. This paper reviews neurocardiovascular dysautonomia with an emphasis on PoTS, its characteristics, associations, pathophysiology, investigation, and treatment.

Occupational Therapy Interventions for Clients with Ehlers-Danlos Syndrome (EDS) in the Presence of Postural Orthostatic Tachycardia Syndrome (POTS)

Postural orthostatic tachycardia syndrome (POTS) is often seen in clients with Ehlers-Danlos syndrome (EDS), primarily hypermobile EDS. Research has shown clients with EDS and POTS may experience limitations affecting not only their physical function, but also their social, emotional, and mental well-being. Using a client-centered approach, occupational therapy practitioners assess health, well-being, symptomatology (fatigue, muscle pain, dizziness, etc.), participation and engagement in occupation, and provide interventions to improve quality of life. This paper will address occupational therapy interventions to treat common symptomatology for clients with EDS in the presence of POTS, including environmental modifications, use of adaptive equipment and orthoses, exercise and fall prevention, energy conservation and pacing, sleep hygiene, and routine and habit development to promote optimal engagement in meaningful occupations.

Deterioration of Sleep Quality According to Glycemic Status

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a progressive disease with multiple complications. The present study aimed to determine the effects of glycemic status on sleep quality in individuals with T2DM, prediabetes, and normal glucose tolerance (NGT).

METHODS

A total of 90 participants were categorized into three groups, T2DM (n=30), prediabetes (n=30), and NGT (n=30). Objective sleep quality was measured with the actigraph wrist-worn device over 3 nights and subjective sleep quality was evaluated with a questionnaire.

RESULTS

The duration of diabetes in the T2DM group was 2.23 years and the glycosylated hemoglobin (HbA1c) levels in the T2DM, prediabetes, and NGT groups were 7.83%, 5.80%, and 5.31%, respectively. Sleep efficiency decreased across the T2DM, prediabetes, and NGT groups (86.25%, 87.99%, and 90.22%, respectively; P=0.047). Additionally, HbA1c levels revealed a significant negative correlation with sleep efficiency (r=-0.348, P=0.001). The sleep quality questionnaire results were similar among the three groups.

CONCLUSION

Although the participants in the present study were not necessarily conscious of their sleep disturbances, deterioration in sleep quality progressed according to glycemic status.

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

Introduction: Postural tachycardia syndrome (POTS) is a suspected dysautonomia with symptoms of orthostatic intolerance and abnormally increased heart rate while standing. We aimed to study cardiac autonomic nervous system functioning in head-up tilt (HUT) in adolescents with POTS to find out if parasympathetic tone is attenuated in the upright position. Methods: We compared characteristics of a group of 25 (females 14/25; 56%) adolescents with POTS and 12 (females 4/12; 34%) without POTS aged 9-17 years. We compared heart rate variability with high- and low-frequency oscillations, and their temporal changes in HUT. Results: The high-frequency oscillations, i.e., HF, attenuated in both groups during HUT (p < 0.05), but the attenuation was bigger in POTS (p = 0.04). In the beginning of HUT, low-frequency oscillations, i.e., LF, increased more in POTS (p = 0.01), but in the end of HUT, an attenuation in LF was seen in the POTS group (p < 0.05), but not in the subjects without POTS. There were no associations of previous infections or vaccinations with POTS. Subjects with POTS were sleepier and their overall quality of life was very low. Conclusion: The results imply to an impaired autonomic regulation while standing in POTS, presenting as a lower HF and higher LF in the beginning of HUT and an attenuated LF in the prolonged standing position.

Pediatric-Onset Postural Orthostatic Tachycardia Syndrome in a Single Tertiary Care Center

AIM

We characterize the pediatric postural orthostatic tachycardia syndrome (POTS) population seen at a single tertiary care referral center.

METHOD

Retrospective chart review of all pediatric POTS patients seen in our center between 2015 and 2017. Pediatric POTS was defined as chronic, at least 3 months, symptoms of orthostatic intolerance associated with excessive orthostatic tachycardia as determined by tilt table testing with orthostatic heart rate increment of ≥40 bpm within 5 minutes of head-up tilt or absolute orthostatic heart rate ≥130 bpm for patients 13 years old and younger and ≥120 bpm for those 14 years and older. We looked at demographics, presenting symptoms, comorbidities, examination findings, investigation findings, treatment, and patient reported outcomes. Outcome measures were separated by patient report and group comparisons were made using 2-sample t tests or Mann-Whitney U tests for continuous variables and Fisher exact tests for categorical variables.

RESULTS

One hundred thirty-four patients with pediatric onset POTS were identified. The mean age was 15 years. Seventy-nine percent of patients were female and 90% were white. The most common presenting symptoms included dizziness/lightheadedness (88%), syncope (54%), and palpitations (40%). Many patients had significant comorbidities attributable to numerous bodily systems, most commonly headache syndromes (migraine 43%, nonspecific headache 22%, chronic daily headache 14%, and new daily persistent headache 5%) and chronic fatigue (60%). Low vitamin D and insufficient iron stores were commonly seen. The majority of patients improved or had resolution of symptoms following treatment (70%). When separated by outcome, statistically significant differences were found for glucose (patients whose symptoms resolved had higher median glucose), palpitations (patients whose symptoms resolved were less likely to have palpitations), constipation (patients whose symptoms were stable/worsened were more likely to have constipation), and unexplained pain (patients whose symptoms were stable/worsened were more likely to have unexplained pain).

CONCLUSIONS

Pediatric POTS is a chronic condition with a fairly good prognosis following appropriate treatment. It is associated with numerous comorbidities that necessitate multidisciplinary expert care.

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

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.

Heart Rate Variability Predicts Therapeutic Response to Metoprolol in Children With Postural Tachycardia Syndrome

PURPOSE

To improve the metoprolol therapeutic effectiveness, we aimed to explore whether baseline heart rate variability (HRV) indicators before metoprolol treatment were useful for predicting its efficacy for postural tachycardia syndrome (POTS).

METHODS

We recruited 45 children with POTS who received metoprolol and 17 healthy controls. All children underwent a standing test or basic head-up tilt test and 24-h dynamic electrocardiography before treatment. After 3 months of metoprolol, therapeutic responsiveness was evaluated. The usefulness of baseline HRV parameters in predicting the effectiveness of metoprolol was studied and the long-term cumulative symptom rate was analyzed.

RESULTS

The baseline HRV frequency domain indicators for power, ultra-low frequency, very-low frequency, low frequency (LF), high frequency (HF), and total power (TP) as well as time domain indicators were significantly lower for responders than non-responders to metoprolol; however, low-frequency normalized units and LF/HF ratio were markedly greater for responders than non-responders. On series-parallel analysis, combined baseline triangular (TR) index ≤ 33.7 and standard deviation of all normal-to-normal intervals (SDNN) index ≤ 79.0 ms as cut-off values yielded sensitivity, specificity and accuracy of 85.3, 81.8, and 84.4%, respectively, to predict therapeutic responsiveness to metoprolol. On long-term follow-up, the cumulative symptom rate was significantly higher with TR index > 33.7 and SDNN index ≤ 79.0 ms, TR index ≤ 33.7 and SDNN index > 79.0 ms or TR index > 33.7 and SDNN index > 79.0 ms than TR index ≤ 33.7 and SDNN index ≤ 79.0 ms (P < 0.05).

CONCLUSION

Combined TR index ≤ 33.7 and SDNN index ≤ 79.0 ms were useful preliminary measures to predict therapeutic response to metoprolol in pediatric POTS.

Evaluation of postural tachycardia syndrome (POTS)

The diagnostic evaluation of a patient with suspected postural tachycardia syndrome (POTS) requires a thoughtful diagnostic approach utilizing a careful clinical history and examination, laboratory, and autonomic testing. This article outlines the importance of a thorough history in identifying mechanism of symptom onset, clinical features, associated clinical conditions or disorders, and factors that may result in symptom exacerbation. The clinical examination involves an assessment of pupillary responses, an evaluation for sudomotor and vasomotor signs, and an assessment for joint hypermobility. Laboratory testing helps to exclude mimics of autonomic dysfunction, recognize conditions that may exacerbate symptoms, and to identify conditions that may cause or be associated with autonomic nervous system disease. The purpose of autonomic testing is to confirm a POTS diagnosis, exclude other causes of orthostatic intolerance, and may provide for characterization of POTS into neuropathic and hyperadrenergic subtypes. Other diagnostic studies, such as epidermal skin punch biopsy, exercise testing, radiographic studies, sleep studies, gastrointestinal motility studies, and urodynamic studies should be considered when clinically appropriate.

Cognitive and psychological issues in postural tachycardia syndrome

Postural tachycardia syndrome (POTS) is one of the most common forms of chronic orthostatic intolerance. In addition to orthostatic symptoms, many POTS patients report incapacitating cognitive dysfunction or "brain fog" even while lying down or seated. Consistent with these subjective reports, there is accruing objective evidence of specific cognitive difficulties in POTS, with studies showing mild to moderate cognitive impairment using standardized neuropsychological assessment batteries. The precise profile of cognitive dysfunction in POTS patients has been shown to vary among these studies potentially due to the neuropsychological tests used, postural position, comorbidities and length of illness, inclusion of adolescent versus adult patients, and sites of recruitment. The extent of the impact that this cognitive challenge has in patients justifies ongoing investigation and research into lifestyle and pharmacological treatments. Psychologically, patients face challenges congruent with many chronic illnesses, perhaps especially early in adjusting to the condition. POTS patients often exhibit mild to moderate depression symptoms as well as symptoms of anxiety disorders. Since even low levels of anxiety can exacerbate symptoms, and a high number of patients experience sub-clinical low mood and sleep disturbances, there is a likely role for psychotherapy in helping control adjustment-related issues, and possibly aberrant physiology, in POTS.

Pediatric sleep and autonomic complaints

Objectives:

Little is known about the relationship between autonomic dysfunction and sleep disturbances. This study aimed to identify patterns of sleep disturbances and autonomic dysfunction in children.

Methods:

A retrospective chart review of 14 children who underwent sleep and autonomic testing was performed. Subjects were divided into three groups based on sudomotor Composite Autonomic Severity Score Scale score and postural tachycardia syndrome criteria. Sleep quality, sleep architecture, and number of comorbidities were analyzed.

Results:

There were no statistically significant differences between groups in measures of sleep quality, sleep architecture, and number of comorbidities.

Conclusion:

Patients with postural tachycardia syndrome and autonomic dysfunction experience multiple sleep-related complaints. The low power of our study did not allow firm conclusions, but there is no pattern to these abnormalities.

Sleep disturbance linked to suicidal ideation in postural orthostatic tachycardia syndrome

OBJECTIVE

We investigated the prevalence of suicidal ideation in relationship with symptoms of sleep disruption in people with postural orthostatic tachycardia syndrome (POTS).

METHODS

Online surveys (including the Pittsburgh Sleep Quality Index and the Suicide Behaviors Questionnaire - Revised) were completed by 705 POTS patients and 170 non-POTS controls.

RESULTS

Poor sleep quality was reported in 98.4% of POTS patients with a calculated subjective sleep efficiency of 65.4%. The POTS group's sleep efficiency was significantly lower (t[873]= -11.32; p<0.001) and sleep disturbances because of pain were significantly higher (t[873]=15.36; p<0.001) than controls. Chi-square testing showed a larger proportion of individuals at high-risk for suicide among POTS patients than controls (c2 [1, n=875]=55.6; p<0.001). Multiple linear regression analysis showed that sleep scores (β=0.23, p<0.001), age (β=-0.03, p<0.001), and illness with POTS (β=0.68, p=0.05) were significantly associated with suicide ideation scores (F[4, 870]=38.34, p<0.001). This model explained 15% of variance (R2=0.15) in suicidal ideation scores.

CONCLUSION

Patients with POTS may suffer from increased sleep disturbance and suicidal ideation compared with the general population. Treatment to improve sleep efficiency and sleep quality is an important step toward better quality of life for POTS patients.

Health-related quality of life and suicide risk in postural tachycardia syndrome

PURPOSE

Postural tachycardia syndrome (POTS) is a disorder featured by orthostatic intolerance. The purpose of this study was to investigate the severity of quality of life issues in POTS patients.

METHODS

Online surveys for health related quality of life, sleep quality, fatigue, pain, and suicidal ideation were completed by 624 POTS patients and 139 controls.

RESULTS

People with POTS have significantly more days of poor physical health (p < 0.001), fewer days with good energy (p < 0.001), and significantly more days with activity limitations (p < 0.001) than controls. Pain severity was significantly higher for those with POTS (p < 0.001) while feelings of control over life was lower than controls (p < 0.001). Sleep quality and daytime fatigue were also significantly worse for those with POTS than controls (p < 0.001). Finally, those with POTS have a significantly higher risk of suicide compared with controls (p < 0.001).

INTERPRETATION

The myriad of symptoms from which many POTS patients suffer is associated with a decreased quality of life. Nearly half of our sample with POTS was at high risk for suicide. More work needs to be done to determine the underlying issues surrounding suicide in POTS so that an appropriate treatment regimen can be developed.

Objective Sleep Assessments in Patients with Postural Tachycardia Syndrome using Overnight Polysomnograms

STUDY OBJECTIVES

Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness, and diminished quality of life. The study objective was to assess objective sleep quality in POTS patients using overnight polysomnography.

METHODS

We studied 16 patients with POTS and 15 healthy control subjects performing daytime autonomic functions tests and overnight polysomnography at the Vanderbilt Clinical Research Center.

RESULTS

There were no significant differences in the objective sleep parameters including sleep efficiency, sleep onset latency, wake time after sleep onset, REM latency, percentage of time spent in N1, N2, N3, and REM sleep, arousal index, apnea-hypopnea index, or periodic leg movement index in POTS patients as compared with healthy control subjects. There were significant negative correlations between sleep efficiency and the change in HR from supine to stand (rs = -0.527; p = 0.036).

CONCLUSIONS

POTS patients do not have significant differences in objective sleep parameters as compared to control subjects based on overnight polysomnograms. Activation of the sympathetic nervous system may contribute significantly to the hyper arousal state and worsening of subjective estimates of sleep quality as previously reported in POTS patients.

A survey based study on sleep disturbance in postural tachycardia syndrome

BACKGROUND

Postural tachycardia syndrome (POTS) is an autonomic disturbance characterized by an excessive increase in heart rate when an individual moves from a sitting to an upright position. POTS patients often complain of fatigue, daytime sleepiness and insomnia, but there is limited evidence to elucidate the mechanism or the prevalence of sleep-related symptoms in POTS, as well as the effect on patient quality of life. Here, we investigated the prevalence of sleep disturbances in POTS patients, as well as the use of medication and effects on daily life.

METHODS

A survey was administered to 30 patients with POTS. The survey contained 22 questions on various characteristics of sleep disturbances in POTS. Answers were recorded on a five-point Likert rating scale.

RESULTS

The majority of the patients reported fatigue (96.7%) and low energy (93.3%) during the day. Most (83.3%) patients reported that they do not feel well rested when waking up in the morning. More than half of the patients reported trouble falling asleep at night (63.3%) and maintaining sleep through the night (62.1%). Despite the frequent complaint of sleep disturbance, a very low percentage of POTS patient actually report seeking treatment.

CONCLUSION

In this study, we explored the prevalence of sleep disturbance in patients with POTS. Almost all POTS patients reported trouble with sleep and fatigue; however, there is major discrepancy between the high percentage of symptoms and small percentage of patients seeking medical assistance for better sleep quality.

Sleep disorders in patients with postural tachycardia syndrome

OBJECTIVE

Patients with postural tachycardia syndrome (POTS) often describe symptoms of fatigue, sleepiness, and lack of refreshing sleep. We aimed to provide further objective measures of sleep in patients with POTS.

METHODS

POTS patients (n = 18) were selected based on autonomic testing and evaluation at our center. Controls (n = 16) of similar age, gender, and BMI were selected from new patients referred to the Stanford Sleep Disorders Clinic for any sleep-related complaint. All patients underwent polysomnography and completed several sleep questionnaires and a 2-week sleep diary.

RESULTS

POTS patients and control subjects were of similar age (27 ± 10.2 vs. 29 ± 5.4 years, p = 0.92) and Body Mass Index (21 ± 3.8 vs. 24 ± 4.1, p = 0.14). The majority of subjects in both groups were females (72 % POTS vs. 81 % controls). POTS patients scored higher on subjective fatigue scales but not sleepiness scales. POTS patients scored in the normal range on the BDI and the "evening" category on the MEQ. Their sleep diaries were not different from controls. With the exception of mild OSA, slightly reduced %REM and prolonged REM latency, their PSG data were normal and no different from controls.

CONCLUSIONS

It is unlikely that the sleep-related complaints of POTS patients are the result of a primary sleep disorder unique to POTS. We propose that a combination of factors such as body fatigue, chronic pain, and other somatic symptoms common in POTS patients might be the underlying reason for sleep-related symptoms in POTS.

Characterisation of sleep disturbances in postural orthostatic tachycardia syndrome: a polysomnography-based study

BACKGROUND AND AIM

Postural orthostatic tachycardia syndrome (PoTS) has been frequently associated with sleep disturbances but objective sleep data are lacking. In addition, although regional autonomic denervation has been described, less is known about autonomic nervous activity overnight in these patients.

PATIENTS/METHODS

A full polysomnography and heart rate variability were performed on 37 patients diagnosed with PoTS . In addition, a multiple sleep latency test (MSLT) was conducted on a subgroup of patients with excessive daytime sleepiness.

RESULTS

The polysomnographic data did not show major pathological findings except the percentage spent in rapid eye movement (REM) sleep which was slightly reduced at 18.4%. The MSLT did not confirm excessive daytime sleepiness as median mean sleep latency was 14.4 min (11.8-17.5). When comparing patients with and without subjective daytime sleepiness, it was found that the latter had a reduced parasympathetic activation at night as expressed by the average high frequency [6936.5 ms(2) (6028.2-8675.5) vs. 4689.5 (3922.7-7685.2) p < 0.05].

CONCLUSION

Patients with PoTS do not exhibit polysomnographic findings consistent with relevant sleep pathologies nor objective daytime sleepiness. Subjective daytime sleepiness is associated with enhanced activation of the parasympathetic nervous system.

A critical analysis of the proposal of the Institute of Medicine to replace myalgic encephalomyelitis and chronic fatigue syndrome by a new diagnostic entity called systemic exertion intolerance disease

The Institute of Medicine (IOM) recently published their report in response to an assignment "to define diagnostic criteria for Myalgic Encephalomyelitis (ME)/chronic fatigue syndrome (CFS), to propose a process for reevaluation of these criteria in the future, and to consider whether a new name for this disease is warranted". The basic pre-assumption of the IOM committee for the development of evidence-based diagnostic criteria for ME/CFS was that ME and CFS denote conditions with similar symptoms, hence ME/CFS. The IOM committee recommends: (1) that ME/CFS will be renamed 'systemic exertion intolerance disease' (SEID); and that a new code should be assigned to SEID in the International Classification of Diseases (ICD), replacing the existing codes for ME (a neurological disease: G93.3) and CFS ('signs, symptoms, and abnormal clinical and laboratory findings, not elsewhere classified': R53.82); (2) that a diagnosis of SEID should be made if the new diagnostic criteria are met; (3) that the Department of Health and Human Services develops a toolkit appropriate for screening and diagnosing patients; and (4) that a multidisciplinary group re-examines the new diagnostic criteria when necessary. This editorial reviews the working procedure of the IOM and two of the outcomes: the recommendation to introduce a new clinical entity (SEID) and new diagnostic criteria. Based upon the contents of the report, and the arguments of the IOM, a search of PubMed and the archive of the Journal of Chronic Fatigue Syndrome using the search terms ME (and old synonyms) and CFS, and a search of PubMed related to the five core symptoms of SEID was conducted. Reviewing the working method and the recommendations, it is concluded that the new diagnostic criteria for SEID are based upon important methodological shortcomings and that the introduction of SEID to replace both ME and CFS has several profound negative consequences outweighing the advantages.