Body mass index is decreased in children and adolescents with postural tachycardia syndrome

Predicting Therapeutic Efficacy of Pharmacological Treatments in Children with Postural Orthostatic Tachycardia Syndrome: A Mini-Review

Postural orthostatic tachycardia syndrome (POTS) is common in children, with an excessive increment in heart rate when moving from the supine to upright position. It has significant negative impacts on the daily life of pediatric patients. The pathogenesis of POTS includes peripheral vascular dysfunction, central hypovolemia, abnormal autonomic function, a high-adrenergic state, impaired skeletal-muscle pump function, the abnormal release of vasoactive factors, and autoimmune abnormalities. Therefore, the empirical use of pharmacological treatments has limited therapeutic efficacy due to the diversity of its mechanisms. A crucial aspect of managing POTS is the selection of appropriate treatment targeting the specific pathogenesis. This review summarizes the commonly used pharmacological interventions, with a focus on their predictive indicators for treatment response. Factors such as heart rate variability, plasma biomarkers, and cardiac-function parameters are discussed as potential predictors of therapeutic efficacy, enabling the implementation of individualized treatment to improve therapeutic effectiveness. This review consolidates the current knowledge on POTS, encompassing its clinical characteristics, epidemiological patterns, underlying pathogenic mechanisms, and predictive indicators for treatment response. Further research is warranted to enhance the understanding of POTS and facilitate the development of more effective therapeutic approaches for this challenging syndrome.

İnsülin Duyarlılığı ve Vücut Kitle İndeksinin Ortostatik İntolerans Üzerine Etkileri

Amaç: Çalışmanın amacı insülin duyarlılığı ve antropometrik ölçümlerin ortostatik intolerans sendromları üzerindeki etkilerini değerlendirmektir. Yöntem: Retrospektif bir çalışmadır. 7-18 yaş arası senkop öyküsü ile başvuran hastalarda insülin duyarlılık indeksleri hesaplandı ve antropometrik ölçümlerine değerlendirildi. Hastalar head-up tilt test sonuçlarına göre test pozitif ve test negatif olarak gruplandırıldı. Ayrıca tilt testi pozitif olan hastalar vazodepresör vazovagal senkop (VVS), kardiyoinhibitör VVS, mikst VVS ve postural ortostatik taşikardi sendromu olmak üzere dört alt gruba ayrıldı. Bulgular: Çalışmaya toplam 509 hasta dahil edildi. Yaş ortalaması 13,45 ± 2,82 yıldı ve %64,4'ü kızdı. Tilt testi 214 hastada pozitif, 295 hastada negatifti. Tilt testi sonuçları ile 173 hastaya VVS ve 41 hastaya (%19) POTS tanısı konuldu. İnsülin duyarlılık indekslerine göre gruplar arasında istatistiksel olarak anlamlı fark yoktu. Antropometrik ölçümlerde boy, boy standart deviasyonu, vücut kitle indeksi (VKİ) standart deviasyonu ve VKİ persentili (sırasıyla p=0,008, p=0,02, p=0,036, p=0,03) açısından iki grup arasında anlamlı farklılık gözlendi. Sonuç: Çalışmamızda özellikle genç kızlarda düşük VKİ ve uzun boylu olmak vazovagal senkop ataklarına zemin hazırlayan faktörler iken, insülin duyarlılık indeksleri ile pozitif head-up tilt test sonucu arasında ilişki bulunmadı. Tekrarlayan senkoplara neden olan faktörlere ışık tutarak uygun tedavinin sağlanması hastaların yaşam kalitelerine katkı sağlayabilir.

Postural orthostatic tachycardia syndrome: A conundrum for patients and healthcare providers

ABSTRACT

Postural orthostatic tachycardia syndrome is an underdiagnosed disorder of the autonomic nervous system. The median time to achieve correct diagnosis is 2 years and may take more than 10 years for some patients. Symptoms can be devastating to the daily life of patients and can result in long-term disability. Treatment availability is limited due to the need for further studies.

Role of NASA 10-minute Lean Test in diagnosing postural orthostatic tachycardia syndrome: a preliminary study in young population

Postural orthostatic tachycardia syndrome (POTS) is a form of autonomic imbalance characterized by abnormally increased heart rate (HR) and various symptoms of orthostatic intolerance (OI). This study aimed to determine POTS in adolescents using NASA 10-minute Lean Test. This crosssectional study was conducted at Government Medical College, Srinagar, J&K, India, between October 2017 and November 2019. Adolescents with symptoms of OI were enrolled for this study and NASA 10-minute Lean Test was performed. Characteristics of POTS group were the compared with non-POTS group. There was a significant difference in BMI (P< 0.0001) between POTS and non-POTS group. However, the number of females with features of POTS was greater than males. There was a significant difference in resting HR between the two groups (P<0.0001). During upright posture there was a significant difference in maximum upright HR between the two groups (P<0.0001), highest increment in upright HR also differed significantly (P<0.0001).POTS group had significantly higher HR than non-POTS group. It may be inferred from this preliminary study that NASA 10-minute Lean Test can be used to diagnose POTS.

Orthostatic Headache in Children Including Postural Tachycardia Syndrome and Orthostatic Hypotension: A Near-Infrared Spectroscopy Study

Background and aim: Although head and/or neck pain attributed to orthostatic hypotension is included in international guidelines, its mechanisms and relevance remain unknown. This study examined the term’s relevance and aimed to elucidate the associated clinical features. Methods: An active stand test was performed to evaluate fluctuations in systemic and cerebral circulation in children and adolescents reporting complaints in the absence of a confirmed organic disorder. The subjects were categorized based on orthostatic headache presence/absence, and their characteristics and test results were compared. Results: Postural tachycardia syndrome was observed in 50.0% of children with, and 55.1% without, orthostatic headache. For orthostatic hypotension, the respective values were 31.3% and 30.6%. A history of migraine was more prevalent in children with orthostatic headaches (64.1% vs. 28.6%; p < 0.01). The observed decrease in the cerebral oxygenated hemoglobin level was larger in children with orthostatic headaches (Left: 6.3 (3.2–9.4) vs. 4.1 (0.8–6.1); p < 0.01, Right: 5.3 (3.1–8.6) vs. 4.0 (0.8–5.9); p < 0.01). Conclusion: Fluctuations in cerebral blood flow were associated with orthostatic headaches in children, suggesting that the headaches are due to impaired intracranial homeostasis. As orthostatic headache can have multiple causes, the term “head and/or neck pain attributed to orthostatic (postural) hypotension” should be replaced with a more inclusive term.