Postural tachycardia syndrome from a pediatrics perspective

Postural orthostatic tachycardia syndrome in children and adolescents

Background: Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous disorder in children and adolescents. Recently, there have been some data concerning the prevalence of POTS in adults. However, current studies on POTS in children and adolescents are rare. Thus, many young patients with POTS are misdiagnosed with migraine or other diseases.Current Concepts: The diagnosis and treatment of POTS differ between pediatric and adult patients. POTS in children and adolescents is diagnosed with chronic symptoms of orthostatic intolerance, such as a heart rate rise of 40 beat per minute (bpm) or a heart rate exceeding 130 bpm without orthostatic hypotension. There are three major POTS categories: hypovolemic POTS, neuropathic POTS, and hyperadrenergic POTS. These categories are distinguished by their major mechanisms. The different subtypes of POTS in children and adolescents have their own clinical characteristics and laboratory findings.Discussion and Conclusion: Treatment of POTS in children and adolescents should always include lifestyle changes, nutritional adjustments, exercise, and drugs depending on the different subtypes of POTS.

Update of Individualized Treatment Strategies for Postural Orthostatic Tachycardia Syndrome in Children

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous disease that predominantly affects children and adolescents. There is a great difference between children and adults in the diagnosis and treatment of POTS patients. POTS in children and adolescents is marked by chronic symptoms of orthostatic intolerance with a heart rate (HR) rise of ≥40 bpm, or heart rate exceeding 130 bpm for 6-12-years-old children and exceeding 125 bpm for those 13-18 years old without orthostatic hypotension, which is different from adult patients. The three major clinical forms of POTS include hypovolemic POTS, neuropathic POTS, and hyperadrenergic POTS; these are distinguished by their major mechanisms. The different subtypes of POTS in children and adolescents each have their own clinical characteristics and biomarkers. Based on these, we propose individualized treatment strategies. Individualized management strategies based on different subtypes of POTS would largely improve the curative effects of drugs for children with POTS. However, a further clinical investigation is still required to better understand the pathophysiology and treatment options.

"Doesn't Anyone Believe How I Feel?": Postural Orthostatic Tachycardia Syndrome (POTS)

The school nurse is often the first person with whom a student may discuss untoward health symptoms and concerns. Being cognizant of the clinical features of postural orthostatic tachycardia syndrome (POTS) will help the nurse alleviate some of the student's anxiety. Due to misunderstandings and misconceptions about POTS, family and peers may disbelieve a student who is experiencing symptoms. Displaying compassion and support will help the student understand that someone does believe his or her symptoms. As the student's advocate, the school nurse will champion a plan for the student's health and safety in the academic environment.

Clinical features of hyperadrenergic postural tachycardia syndrome in children

BACKGROUND

Hyperadrenergic postural tachycardia syndrome (POTS) is the main phenotype of POTS. The aim of this study was to present our single-center experience of hyperadrenergic POTS in children and adolescents.

METHODS

Thirty-seven patients who met the diagnostic criteria for POTS were enrolled in our study. Their orthostatic serum norepinephrine levels were determined by high-performance liquid chromatography. In a retrospective analysis, based on clinical and serum norepinephrine criteria, we analyzed the clinical features of POTS cases between the POTS-alone group and the hyperadrenergic POTS group.

RESULTS

Nineteen patients (51.35%) met the diagnostic criteria for hyperadrenergic POTS and 18 patients were assigned to the POTS-alone group. Compared with the POTS-alone patients, dizziness, headache and tremulousness were more frequent in patients with hyperadrenergic POTS (P < 0.05). During the tilt table test, children with hyperadrenergic POTS had a greater increment of systolic blood pressure and heart rate than POTS-alone patients.

CONCLUSION

Patients with hyperadrenergic POTS should be identified and differentiated from those with neuropathic POTS. Hyperadrenergic POTS in children and adolescents should be considered when POTS patients suffer from frequent dizziness, headache, and tremulousness. In head-up tilt testing, children and adolescents with hemodynamic characteristics of hyperadrenergic POTS had greater increments of systolic blood pressure and heart rate.

Orthostatic hypertension in children and adolescents with postural tachycardia syndrome

OBJECTIVE

We described a heterogenous group of children disabled by postural tachycardia syndrome (POTS) and evident orthostatic hypertension (OHT).

METHODS

Twenty patients met the diagnostic criteria for POTS + OHT. Their clinical characteristics were compared with those in 76 patients with POTS alone and 20 healthy age-matched controls. Multivariate logistic regression analysis was used to identify independent risk factors for POTS + OHT.

RESULTS

Supine systolic blood pressure (SBP) was lower in the POTS + OHT group than in the POTS group (p < 0.05). Compared with the POTS group, the POTS + OHT group showed markedly increased upright SBP, upright heart rate (HR) and HR changes (p < 0.05). Headache was more common in the POTS + OHT group than in the POTS group (p < 0.05). Logistic regression analysis revealed that low supine SBP and headache were independent risk factors for OHT in POTS patients.

CONCLUSIONS

Headache and low supine SBP were the main clinical characteristics of a novel syndrome of POTS associated with OHT.

Orthostatic plasma norepinephrine level as a predictor for therapeutic response to metoprolol in children with postural tachycardia syndrome

Background

Postural tachycardia syndrome (POTS) is a heterogeneous disorder that creates challenges for treatment. Beta-blocker was one of the most commonly used drugs, but it is inconsistently effective. The purpose of this study is to explore whether orthostatic plasma norepinephrine level could be an indicator of therapeutic effectiveness of metoprolol for POTS in children.

Methods

Twenty-seven children with POTS were enrolled in our study. They received metoprolol treatment, and their orthostatic plasma norepinephrine levels were measured by high-performance liquid chromatography method. Three months after rmetoprolol treatment, 25 patients were followed up. A receiver-operating characteristic (ROC) curve was used to explore the predictive value of orthostatic plasma norepinephrine level.

Results

The symptom severity and increment of heat rate from supine position to upright of patients positively correlated with their orthostatic plasma norepinephrine level (r = 0.599, P < 0.001; r = 0.633, P <0.001, respectively). Orthostatic plasma norepinephrine level in responders to metoprolol was significantly higher than that of nonresponders (P = 0.028). A ROC curve on the predictive value of orthostatic plasma norepinephrine level showed that the area under the curve was 0.785. Using a cutoff value for orthostatic plasma norepinephrine level of 3.59 pg/ml yielded both sensitivity (76.9%) and specificity (91.7%) in predicting the efficacy of metoprolol therapy for POTS.

Conclusion

Orthostatic plasma norepinephrine level of > 3.59 pg/ml was an indicator of the effectiveness of metoprolol therapy for POTS in children and adolescents.

Postural orthostatic tachycardia syndrome with increased erythrocytic hydrogen sulfide and response to midodrine hydrochloride

OBJECTIVES

To evaluate the use of erythrocytic hydrogen sulfide (H2S) in predicting the therapeutic efficacy of midodrine hydrochloride for children with postural orthostatic tachycardia syndrome (POTS).

STUDY DESIGN

Fifty-five children were included in this study, involving 28 children with POTS (POTS group) and 27 healthy children (control group). Children in the POTS group received midodrine hydrochloride treatment. Erythrocytic H2S production was measured; a receiver operating characteristic curve was used to assess if erythrocytic H2S could predict the therapeutic response to midodrine hydrochloride treatment.

RESULTS

H2S production from erythrocytes was significantly higher in the POTS group than in the control group (P < .01). H2S production was also significantly higher in responders to midodrine hydrochloride than in non-responders (P < .05). The change in symptom score and baseline erythrocytic H2S production had a positive linear relationship (P < .01). There was also a positive correlation with the change in heart rate (P < .05). The receiver operating characteristic curve showed an area under curve value of 0.813. Erythrocytic H2S production yielded a sensitivity of 78.9% and a specificity of 77.8% in predicting the efficacy of midodrine hydrochloride therapy for children with POTS.

CONCLUSION

Erythrocytic H2S could serve as a useful predictor of therapeutic response to midodrine hydrochloride in children with POTS.

Twenty-four-hour urinary sodium excretion and postural orthostatic tachycardia syndrome

OBJECTIVE

To investigate whether 24-hour urinary sodium excretion could be an indicator of the effectiveness of salt supplementation in children with postural orthostatic tachycardia syndrome (POTS).

STUDY DESIGN

The patient group comprised 30 children with POTS, and the control group comprised 10 healthy children. Serum sodium and 24-hour urinary sodium excretion were measured in all children, and the relationship between 24-hour urinary sodium and symptom severity was analyzed in the 30 patients. At 1 month after initiation of salt supplementation, the receiver operating characteristic curve was used to explore the probability of correctly discriminating responders to salt supplementation from nonresponders using 24-hour urinary sodium excretion as an indicator.

RESULTS

Patients with POTS had lower 24-hour urinary sodium excretion than controls (P = .022). Symptom severity was negatively correlated with 24-hour urinary sodium excretion (OR, -0.754; P = .000). The receiver operating characteristic curve demonstrated a sensitivity of 76.9% and specificity of 93% for correct prediction of responders and nonresponders to salt supplementation when a 24-hour urinary sodium excretion of 124 mmol/24 hours was used as the cutoff value.

CONCLUSION

Our results indicate that 24-hour sodium excretion of <124 mmol/24 hours is an indicator of the effectiveness of salt supplementation in children and adolescents with POTS.