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 《-》

Autonomic dysfunction presenting as postural orthostatic tachycardia syndrome in patients with multiple sclerosis.

Kanjwal K ，Karabin B ，Kanjwal Y ，Grubb BP ... -  《International Journal of Medical Sciences》

Gluten-free diet in postural orthostatic tachycardia syndrome (POTS).

Zha K ，Brook J ，McLaughlin A ，Blitshteyn S ... -  《-》

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 ... -  《-》

Differences in cardiac autonomic function contributes to heart rate abnormalities in POTS and IST.

Our objective was to examine the differences in cardiac autonomic function in Postural Tachycardia Syndrome (POTS) versus inappropriate sinus tachycardia (IST). Subjects (IST, n = 8; POTS, n = 12) were studied using standard measurements of the autonomic reflex screen, baroreflex function and spectral analysis. Data was compared to age/gender-matched controls (n = 20). The components of the autonomic reflex screen did not differ between groups. The exception was the significant but expected difference in postural heart rate increment on head-up tilt in POTS (47.9 ± 13.8; n = 12) compared to IST (30.9 ± 9.7; n = 8; p = 0.008). Accordingly the Orthostatic Intolerance Scale showed significantly greater orthostatic symptoms in POTS (2.6 ± 0.5; n = 12) versus IST patients (0.4 ± 0.5; n = 8; p < 0.001). Conversely, IST patients had a significantly higher resting heart rate (96 ± 12; n = 8) when compared to POTS patients (73 ± 12; n = 12; p = 0.001). There was a significant difference in vagal baroreflex sensitivity (BRSv) in POTS (8.21 ± 2.3, n = 12) compared to IST patients (5.30 ± 2.94, n = 8, p = 0.036) during the Valsalva maneuver. Only POTS subjects showed a significant increase in sympathovagal balance (LF/HF) with tilt (FFT, 8.29 ± 6.38; AR, 7.84 ± 5.24) compared to the supine position (FFT, 2.25 ± 1.75; AR, 1.99 ± 1.38; p < 0.05) for both frequency domains. Differences in cardiac autonomic function contribute to changes in positional and non-positional heart rate in postural tachycardia syndrome versus inappropriate sinus tachycardia. These findings shed further light on the autonomic dysfunction underlying POTS and IST.

Corkal JC ，Palamarchuk I ，Kimpinski K 《-》