Malmö POTS symptom score: Assessing symptom burden in postural orthostatic tachycardia syndrome.

Postural orthostatic tachycardia syndrome (POTS) is a common cardiovascular autonomic disorder characterized by excessive heart rate (HR) increase on standing and symptoms of orthostatic intolerance, posing significant limitations on functional capacity. No objective tool exists to classify symptom burden in POTS. We conducted a case-control study in 62 POTS patients and 50 healthy controls to compare symptom burden between groups using the newly developed, self-rating, 12-item, Malmö POTS Score (MAPS; 0-10 per item, total range 0-120) based on patients own perception of symptoms through visual analogue scale assessment. We have also explored correlations between symptom severity assessed by MAPS, basic clinical parameters and postural haemodynamic changes. POTS patients showed significantly higher total MAPS score (78 ± 20 vs. 14 ± 12, p < 0.001), higher baseline systolic blood pressure (BP), diastolic BP and HR (p < 0.001) compared with healthy controls. The most prominent symptoms in POTS were palpitations, fatigue and concentration difficulties. Haemodynamic parameters on standing were significantly correlated with palpitations in POTS after adjustment for age and sex (lower systolic and diastolic BP, and higher HR) (p < 0.001 for all). Orthostatic HR was significantly associated with concentration difficulties and total MAPS score. The optimal cut-point value of MAPS to differentiate POTS and healthy controls was ≥42 (sensitivity, 97%; specificity, 98%). Symptom severity, as assessed by MAPS score, is fivefold higher in POTS compared with healthy individuals. The new MAPS score can be useful as a semiquantitative system to assess symptom burden, monitor disease progression and evaluate pre-test likelihood of disease.

Spahic JM ，Hamrefors V ，Johansson M ，Ricci F ，Melander O ，Sutton R ，Fedorowski A ... -  《-》

Quantitative assessment of autonomic symptom burden in Postural tachycardia syndrome (POTS).

Postural tachycardia syndrome (PoTS) is a poorly understood disorder characterized by excessive tachycardia in the upright position. In addition, patients with PoTS often complain of non-postural symptoms, including fatigue, gastrointestinal and vasomotor fluctuations. The present study quantitatively assessed autonomic symptom burden in PoTS patients (n=32) using the COMPASS-31, compared to that of autonomic failure/neuropathy (AF/N; n=47) and asymptomatic, healthy controls (n=32). Using AIC model selection and regression analysis, we found differences in the contribution of individual COMPASS-31 domains, depending on the autonomic disorder. In PoTS, fatigue severity, orthostatic intolerance and pupillomotor symptom domains, contributed significantly to differences in COMPASS-31 scores compared to controls. In contrast, the secretomotor, gastrointestinal, bladder and vasomotor domains, contributed significantly to the AF/N model. Our results confirm an increase in autonomic symptoms across all functional domains in PoTS compared to controls, and with similar severity to AF/N, though with differing significant domain contributions. Our findings provide additional support that PoTS is indeed a syndrome of autonomic dysfunction beyond orthostatic intolerance, but also indicates the likelihood of disease-specific contributions to symptom burden, highlighting the need for application of expanded physiological assessment beyond orthostatic challenge, as well as disease-specific symptom assessment tools for use in PoTS.

Rea NA ，Campbell CL ，Cortez MM 《-》

Monitoring of cerebral oximetry in patients with postural orthostatic tachycardia syndrome.

Postural orthostatic tachycardia syndrome (POTS) is a disorder of unknown aetiology characterized by orthostatic intolerance and tachycardia with diverse other symptoms, including neurocognitive deficits. Cerebral oximetry non-invasively measures cerebral tissue saturation (SctO2) and has been shown to be informative in syncope evaluation. We aimed to assess SctO2 in POTS patients and those with normal response to orthostatic provocation, relative to haemodynamic parameters and symptoms. Thirty-four patients with POTS (29.1 ± 9.5 years; 26 females) and 34 age-/sex-matched controls with normal head-up tilt tests (HUTs) were included. SctO2 at rest and during HUT were compared between POTS and controls. The relation between SctO2, systolic blood pressure (SBP), and heart rate (HR) during HUT was linearly assessed. SctO2 values were related to dizziness or syncope during HUT. The minimum SctO2-value during HUT was lower (65.4 ± 5.6 vs. 68.2 ± 4.2%, P = 0.023) and changes in SctO2 from supine to minimum HUT value were more pronounced in POTS patients (-5.7 ± 2.9% vs. -4.3 ± 2.1%, P = 0.028). Decrease in SBP from supine to minimum HUT value (P = 0.004) and increase in HR from supine to HUT value at 3 min (P = 0.022) correlated with more pronounced SctO2 decrease in POTS but not controls. SctO2 did not predict syncope or dizziness during HUT. Postural orthostatic tachycardia syndrome patients have lower cerebral tissue saturation during orthostatic provocation compared with those subjects having normal haemodynamic response to tilt. Orthostatic decrease in cerebral saturation only weakly correlates with HR increase and does not predict vasovagal reflex in POTS. Other hitherto unknown factors may affect cerebral tissue saturation in POTS.

Kharraziha I ，Holm H ，Bachus E ，Melander O ，Sutton R ，Fedorowski A ，Hamrefors V ... -  《-》

Clinical characteristics of a novel subgroup of chronic fatigue syndrome patients with postural orthostatic tachycardia syndrome.

A significant proportion of patients with chronic fatigue syndrome (CFS) also have postural orthostatic tachycardia syndrome (POTS). We aimed to characterize these patients and differentiate them from CFS patients without POTS in terms of clinical and autonomic features. A total of 179 patients with CFS (1994 Centers for Disease Control and Prevention criteria) attending one of the largest Department of Health-funded CFS clinical services were included in this study. Outcome measures were as follows: (i) symptom assessment tools including the fatigue impact scale, Chalder fatigue scale, Epworth sleepiness scale (ESS), orthostatic grading scale (OGS) and hospital anxiety and depression scale (HADS-A and -D, respectively), (ii) autonomic function analysis including heart rate variability and (iii) haemodynamic responses including left ventricular ejection time and systolic blood pressure drop upon standing. CFS patients with POTS (13%, n = 24) were younger (29 ± 12 vs. 42 ± 13 years, P < 0.0001), less fatigued (Chalder fatigue scale, 8 ± 4 vs. 10 ± 2, P = 0.002), less depressed (HADS-D, 6 ± 4 vs. 9 ± 4, P = 0.01) and had reduced daytime hypersomnolence (ESS, 7 ± 6 vs. 10 ± 5, P = 0.02), compared with patients without POTS. In addition, they exhibited greater orthostatic intolerance (OGS, 11 ± 5; P < 0.0001) and autonomic dysfunction. A combined clinical assessment tool of ESS ≤9 and OGS ≥9 identifies accurately CFS patients with POTS with 100% positive and negative predictive values. The presence of POTS marks a distinct clinical group of CFS patents, with phenotypic features differentiating them from those without POTS. A combination of validated clinical assessment tools can determine which CFS patients have POTS with a high degree of accuracy, and thus potentially identify those who require further investigation and consideration for therapy to control heart rate.

Lewis I ，Pairman J ，Spickett G ，Newton JL ... -  《-》

Comorbidity of postural orthostatic tachycardia syndrome and chronic fatigue syndrome in an Australian cohort.

Patients with chronic fatigue syndrome (CFS) are frequently diagnosed with comorbid postural orthostatic tachycardia syndrome (POTS), suggesting a shared pathogenesis. The aim of this study was to examine the relationship between demographic characteristics, autonomic functioning and fatigue levels amongst CFS patients with and without comorbid POTS. All patients presenting to the CFS Discovery Clinic between 2009 and 2012 completed a 20-min standing task as part of their initial assessment. Heart rate and pulse pressure were recorded at baseline, at 2-min intervals poststanding, at the end of the task and following a recovery period. Average heart rate and pulse pressure variability were calculated from this data. Age, gender, length of illness and self-reported fatigue scores were also recorded. POTS patients were diagnosed by an orthostatic increase in heart rate >30 beats per min, concomitant symptoms of orthostatic intolerance and no orthostatic hypotension. Differences in autonomic functioning between POTS and CFS patients were compared using independent samples t-tests, whilst logistic and linear regressions were performed to examine the contribution of autonomic functioning to task completion and perceived fatigue, respectively. Comorbidity of CFS and POTS (CFS-POTS) was observed in 11% (33/306) of patients. CFS-POTS patients were significantly younger (P < 0.001), had a shorter length of illness (P = 0.034), experienced greater task difficulty (P = 0.002) and were able to stand for significantly shorter periods compared to the CFS-only patients (P < 0.001). CFS-POTS patients experienced significantly lower baseline diastolic blood pressure (P = 0.002), significantly higher heart rate and lower pulse pressures at each standing measurement. Early heart rate changes (P = 0.002) and overall heart rate change (P < 0.001) were significant predictors of completion status, whereas heart rate variability (P < 0.001) and female gender (P < 0.001) were significant predictors of increased perceived task difficulty. Haemodynamic and demographic differences between CFS-POTS and CFS-only patients suggest that the former group reflects a distinct subgroup of the CFS population. The findings highlight the utility of screening younger patients with fatigue for POTS, and identified heart rate variability as an important marker of fatigue for CFS patients in general.

Reynolds GK ，Lewis DP ，Richardson AM ，Lidbury BA ... -  《-》