Postural orthostatic tachycardia syndrome (POTS) affects up to 3,000,000 people in the United States, with at least one-third of them developing POTS before the age of 18. POTS as a disorder is ...similar in adult and pediatric populations, but there are factors specific to pediatric patients that affect how it presents and how it is experienced that make pediatric POTS different. This review discusses the both the similarities in this population to their adult counterparts and the unique challenges faced by pediatric POTS patients, including management of schooling and education as well as the complex interactions between these pediatric patients and their parents.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Postural orthostatic tachycardia syndrome (POTS), first described in 1992, remains an enigmatic, yet severely and variably debilitating, disorder. The pathophysiology of this syndrome is still not ...understood, and there remains no biomarker indicating the presence of POTS. Although research interest has increased in recent years, there are relatively fewer clinical and research studies addressing POTS in children and adolescents compared with adults. Yet, adolescence is when a large number of cases of POTS begin, even among adult patients who are subsequently studied. This article summarizes reported research in POTS, specifically in pediatric patients, including discussion of aspects of diagnostic criteria, risk factors and outcomes, neurohormonal and hemodynamic abnormalities, clinical assessment, and treatment. The goals of this review are increased recognition and acknowledgment of POTS among pediatric and adolescent providers, as well as to provide an understanding of reported abnormalities of homeostasis, such that symptomatic patients will be able to be recognized and appropriately managed, enabling them to return to their activities of daily living.
A one-dimensional coordination solid 1c is synthesized by reaction of a bispyridyl dithienylethene (DTE) photochromic unit with the highly anisotropic dysprosium-based single-molecule magnet ...Dy(Tppy)F(pyridine)2PF6. Slow magnetic relaxation characteristics are retained in the chain compound 1c , and photoisomerization of the bridging DTE ligand induces a single-crystal-to-single-crystal transformation that can be monitored using photocrystallography. Notably, the resulting chain compound 1o exhibits faster low-temperature relaxation than that of 1c , which is apparent in magnetic hysteresis data collected for both compounds as high as 4 K. Ab initio calculations suggest that this photomodulation of the magnetic relaxation behavior is due to crystal packing changes rather than changes to the crystal field splitting upon ligand isomerization.
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IJS, KILJ, NUK, PNG, UL, UM
Recent studies have revealed that ARID1A, encoding AT-rich interactive domain 1A (SWI-like), is frequently mutated across a variety of human cancers and also has bona fide tumor suppressor ...properties. Consequently, identification of vulnerabilities conferred by ARID1A mutation would have major relevance for human cancer. Here, using a broad screening approach, we identify ARID1B, an ARID1A homolog whose gene product is mutually exclusive with ARID1A in SWI/SNF complexes, as the number 1 gene preferentially required for the survival of ARID1A-mutant cancer cell lines. We show that loss of ARID1B in ARID1A-deficient backgrounds destabilizes SWI/SNF and impairs proliferation in both cancer cells and primary cells. We also find that ARID1A and ARID1B are frequently co-mutated in cancer but that ARID1A-deficient cancers retain at least one functional ARID1B allele. These results suggest that loss of ARID1A and ARID1B alleles cooperatively promotes cancer formation but also results in a unique functional dependence. The results further identify ARID1B as a potential therapeutic target for ARID1A-mutant cancers.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Patients with postural orthostatic tachycardia syndrome (POTS) have been shown to exhibit comorbid joint hypermobility manifested as Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorder ...(HSD). The prevalence of EDS and HSD in POTS has been demonstrated in smaller studies combining adult and pediatric patients. We examined a large series of pediatric patients to determine their prevalence in children with POTS.
Patients 18 years old, or less, at initial evaluation at our clinic were included. POTS was diagnosed based on at least six months of frequent debilitating symptoms of orthostatic intolerance, plus a consistent heart rate increase of at least 40 beats per minute without orthostatic hypotension on standing test. Patients with a Beighton score of at least 5/9 plus other systemic findings suggestive of EDS were further evaluated in Connective Tissue Disorders clinics.
There were 362 patients meeting inclusion criteria, of which 82 patients had EDS (22.7%) and 141 patients had HSD (39.0%). Patients with EDS had an earlier median age at symptom onset (12.1 vs. 13.5 years, p=0.004) and longer median symptom duration (2.5 vs. 1.5 years, p=0.0008) compared to patients without hypermobility.
Our evaluation of a large series of pediatric patients with POTS revealed that over one-fifth of patients had EDS and over one-third of patients had HSD. The awareness of the prevalence of comorbidities such as hypermobility disorders may help inform providers diagnosing and caring for these patients.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Purpose
Postural orthostatic tachycardia syndrome (POTS) in adults is defined as symptoms of chronic orthostatic intolerance (COI) and autonomic dysfunction (AD) with heart rate (HR) increase of 30 ...beats per minute (bpm), or HR > 120 bpm, during prolonged upright position. However, in adolescents, POTS is defined as symptoms of OI and AD with HR increase of ≥ 40 bpm, based on tilt table data. We assessed frequency of COI symptoms in pediatric patients versus HR criteria on prolonged standing to evaluate using criteria of increased HR of 30–39 bpm versus ≥ 40 bpm in our POTS Program.
Methods
Patients with COI with symptoms for > 3 months plus HR increase of ≥ 30 bpm on 10 min stand aged ≤ 18 years at diagnosis were included. Patients were divided into two groups: those with HR increase of 30–39 bpm, and those with HR increase of ≥ 40 bpm or upright HR of > 120 bpm. A total of 28 symptoms described prior to diagnosis were evaluated using chi-square testing to assess for significant differences.
Results
Only insomnia was found to be significantly different between the two groups. The other 27 symptoms showed no significant difference as a function of HR.
Conclusion
There are minimal statistically significant differences and no clinical differences between patients as a function of HR increase during standing. Thus, a 40-bpm threshold for adolescents on standing test may be too high, or a specific HR criteria threshold is neither predictive nor definitive in diagnosing POTS.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The first dysprosium complexes with a terminal fluoride ligand are obtained as air‐stable compounds. The strong, highly electrostatic dysprosium–fluoride bond generates a large axial crystal‐field ...splitting of the J=15/2 ground state, as evidenced by high‐resolution luminescence spectroscopy and correlated with the single‐molecule magnet behavior through experimental magnetic susceptibility data and ab initio calculations.
A strong donor terminal fluoride ligand generates large crystal‐field splittings within dysprosium(III) complexes and gives rise to new air‐stable single molecule magnets with large barriers to magnetic relaxation. High‐resolution luminescence spectroscopy data are presented and correlated with the single‐molecule magnet behavior through experimental magnetic susceptibility data and ab initio calculations.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Postural orthostatic tachycardia syndrome (POTS) is a chronic and often disabling disorder characterized by orthostatic intolerance with excessive heart rate increase without hypotension during ...upright posture. Patients often experience a constellation of other typical symptoms including fatigue, exercise intolerance and gastrointestinal distress. A typical patient with POTS is a female of child-bearing age, who often first displays symptoms in adolescence. The onset of POTS may be precipitated by immunological stressors such as a viral infection. A variety of pathophysiologies are involved in the abnormal postural tachycardia response; however, the pathophysiology of the syndrome is incompletely understood and undoubtedly multifaceted.
Clinicians and researchers focused on POTS convened at the National Institutes of Health in July 2019 to discuss the current state of understanding of the pathophysiology of POTS and to identify priorities for POTS research. This article, the first of two articles summarizing the information discussed at this meeting, summarizes the current understanding of this disorder and best practices for clinical care.
The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome. Once diagnosed, management typically begins with patient education and non-pharmacologic treatment options. Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Orthostatic intolerance (OI), having difficulty tolerating an upright posture because of symptoms or signs that abate when returned to supine, is common in pediatrics. For example, ∼40% of people ...faint during their lives, half of whom faint during adolescence, and the peak age for first faint is 15 years. Because of this, we describe the most common forms of OI in pediatrics and distinguish between chronic and acute OI. These common forms of OI include initial orthostatic hypotension (which is a frequently seen benign condition in youngsters), true orthostatic hypotension (both neurogenic and nonneurogenic), vasovagal syncope, and postural tachycardia syndrome. We also describe the influences of chronic bed rest and rapid weight loss as aggravating factors and causes of OI. Presenting signs and symptoms are discussed as well as patient evaluation and testing modalities. Putative causes of OI, such as gravitational and exercise deconditioning, immune-mediated disease, mast cell activation, and central hypovolemia, are described as well as frequent comorbidities, such as joint hypermobility, anxiety, and gastrointestinal issues. The medical management of OI is considered, which includes both nonpharmacologic and pharmacologic approaches. Finally, we discuss the prognosis and long-term implications of OI and indicate future directions for research and patient management.
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