BACKGROUND: Postural tachycardia syndrome (POTS) is a common childhood disease that seriously affects the patient's physical and mental health. This study aimed to investigate whether pre-treatment baseline left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) values were associated with symptom improvement after metoprolol therapy for children and adolescents with POTS. METHODS: This retrospective study evaluated 51 children and adolescents with POTS who received metoprolol therapy at the Peking University First Hospital between November 2010 and July 2019. All patients had completed a standing test or basic head-up tilt test and cardiac echocardiography before treatment. Treatment response was evaluated 3 months after starting metoprolol therapy. The pre-treatment baseline LVEF and LVFS values were evaluated for correlations with decreases in the symptom score after treatment (ΔSS). Multivariable analysis was performed using factors with a P value of <0.100 in the univariate analyses and the demographic characteristics. RESULTS: A comparison of responders and non-responders revealed no significant differences in demographic, hemodynamic characteristics, and urine specific gravity (all P > 0.050). However, responders had significantly higher baseline LVEF (71.09% ± 4.44% vs. 67.17% ± 4.88%, t = -2.789, P = 0.008) and LVFS values (40.00 [38.00, 42.00]% vs. 36.79% ± 4.11%, Z = -2.542, P = 0.010) than the non-responders. The baseline LVEF and LVFS were positively correlated with ΔSS (r = 0.378, P = 0.006; r = 0.363, P = 0.009), respectively. Logistic regression analysis revealed that LVEF was independently associated with the response to metoprolol therapy in children and adolescents with POTS (odds ratio: 1.201, 95% confidence interval: 1.039-1.387, P = 0.013). CONCLUSIONS Pre-treatment baseline LVEF was associated with symptom improvement after metoprolol treatment for children and adolescents with POTS.
Adolescent ; Child ; Humans ; Metoprolol/therapeutic use* ; Postural Orthostatic Tachycardia Syndrome/drug therapy* ; Retrospective Studies ; Stroke Volume ; Ventricular Function, Left

OBJECTIVEPostural tachycardia syndrome (POTS) is one of the major causes of orthostatic intolerance in children. We systematically reviewed the pathogenesis and the progress of individualized treatment for POTS in children.

DATA SOURCESThe data analyzed in this review are mainly from articles included in PubMed and EMBASE.

STUDY SELECTIONThe original articles and critical reviews about POTS were selected for this review.

RESULTSStudies have shown that POTS might be related to several factors including hypovolemia, high catecholamine status, abnormal local vascular tension, and decreased skeletal muscle pump activity. In addition to exercise training, the first-line treatments mainly include oral rehydration salts, beta-adrenoreceptor blockers, and alpha-adrenoreceptor agonists. However, reports about the effectiveness of various treatments are diverse. By analyzing the patient's physiological indexes and biomarkers before the treatment, the efficacy of medication could be well predicted.

CONCLUSIONSThe pathogenesis of POTS is multifactorial, including hypovolemia, abnormal catecholamine state, and vascular dysfunction. Biomarker-directed individualized treatment is an important strategy for the management of POTS children.

Adrenergic alpha-Agonists ; therapeutic use ; Adrenergic beta-Antagonists ; therapeutic use ; Catecholamines ; metabolism ; Humans ; Postural Orthostatic Tachycardia Syndrome ; drug therapy ; metabolism ; pathology ; therapy

OBJECTIVEThis study was designed to compare the short-term and long-term effects of oral rehydration salts, oral rehydration salts plus metoprolol or oral rehydration salts plus midodrine hydrochloride on the treatment of postural tachycardia syndrome (POTS) in children.

METHODA total of 118 children with POTS were divided into oral rehydration salts group (n = 39), metoprolol group (oral rehydration salts plus metoprolol, n = 10) or midodrine hydrochloride group (oral rehydration salts plus midodrine hydrochloride, n = 69). The patients were followed up in clinics or over telephone for 3 - 18 months, with a mean of (11.7 ± 4.1) months. The symptom scores were recorded before treatment, after 3 months and at the end of the follow-up. Reduction of the score by 2 points or more was considered that the treatment was effective. The effective rate in 3 months was applied to evaluate short-term effects of 3 different therapies by chi-square test. Taking futility as events, Kaplan-Meier curves were drawn to compare long-term effects of the 3 different therapies in treating POTS in children.

RESULTNo significant differences among the 3 groups were found in sex, age, body height, weight, the symptom scores before treatment or hemodynamic variables. Oral rehydration salts, metoprolol and midodrine hydrochloride improved clinical symptoms after 3 months. The symptom scores of the 3 groups before treatment and after 3 months were 2.4 ± 3.2 vs. 5.5 ± 2.9, 2.2 ± 3.0 vs. 6.1 ± 3.0 and 1.9 ± 1.6 vs. 5.9 ± 2.7, respectively. The difference was significant (P < 0.05). Descending order of the short-term effective rate was 91.3% in midodrine hydrochloride group, 80.0% in metoprolol group and 74.4% in oral rehydration salts group. The difference was significant (χ(2) = 5.85, P < 0.05). All the 3 different therapies improved clinical symptoms at the end of follow-up. The symptom scores were 2.6 ± 3.2 vs. 5.6 ± 2.9, 2.5 ± 3.1 vs. 6.1 ± 3.0 and 2.2 ± 2.1 vs. 6.0 ± 2.7, respectively. (P < 0.05). The result of the Kaplan-Meier curves showed that the long-term effect of midodrine hydrochloride was significantly superior to metoprolol group and oral rehydration salts group (P < 0.05). There was no significant difference between the latter two groups.

CONCLUSIONOral rehydration salts plus midodrine hydrochloride or plus metoprolol improved the efficacy of drugs in children with POTS. And the efficacy of midodrine hydrochloride was superior to that of metoprolol.

Adolescent ; Child ; Female ; Humans ; Male ; Metoprolol ; therapeutic use ; Midodrine ; therapeutic use ; Postural Orthostatic Tachycardia Syndrome ; drug therapy ; Prospective Studies ; Treatment Outcome ; Young Adult

OBJECTIVEThe study was designed to examine the effect of selective alpha1 receptor agonist midodrine hydrochloride in the treatment of children with postural orthostatic tachycardia syndrome.

METHODSFifty-five children (23 male, 32 female, age 5 - 19 yrs, mean age 12.3 +/- 3.1 yrs) who came from Peking University First Hospital were included in the study and clinical investigations as well as standing test, basic head-up tilt test and sublingual nitroglycerin-provocated head-up tilt test under quiet circumstance were conducted. They were randomly divided into treatment group (with midodrine hydrochloride and oral rehydration salt treatment) and control group (with oral rehydration salt treatment only). At last, the disease-free rate, improvement rate and effective rate of symptoms, and the rate of HUT from positive to negative response were compared between control group and treatment group. SPSS 10.0 software was used for the statistical analysis of these data.

RESULTSThe symptom improvement rate in treatment group was significantly higher than that of control group after three and six weeks of treatment (100.0% vs. 42.4%, P < 0.001; 100.0% vs. 42.4%, chi2 = 19.352, P < 0.001). The disease-free rate at follow-up end-point in treatment group was significantly higher than that of control group (77.3% vs. 27.3%, chi2 = 13.239, P < 0.001). The effective rate at follow-up end-point in treatment group was also significantly higher than that of control group (100.0% vs. 36.4%, chi2 = 22.647, P < 0.001). The rate of HUT changing from positive to negative response between two groups after three weeks of treatment was not significantly different (31.8% vs. 12.1%, P > 0.05), but it was significantly different (81.0% vs. 48.5%, P < 0.05) after six weeks of treatment.

CONCLUSIONSelective alpha1 receptor agonist midodrine hydrochloride is effective in the treatment of children with postural orthostatic tachycardia syndrome.

Adolescent ; Adrenergic alpha-Agonists ; therapeutic use ; Child ; Child, Preschool ; Female ; Humans ; Male ; Midodrine ; therapeutic use ; Postural Orthostatic Tachycardia Syndrome ; drug therapy ; Treatment Outcome ; Young Adult

BACKGROUNDThe incidence of postural tachycardia syndrome (POTS) has been increasing in children and adolescents, while clinical characteristics of POTS in the pediatric population are not fully understood.

METHODSAn observational study was performed in 150 pediatric patients aged between 5 and 18 years who underwent head-up tilt test (HUTT) with the diagnosis of POTS at Peking University First Hospital from March 2008 to August 2013. Demographic data, clinical presentation, autonomic parameters, laboratory findings, and treatments were recorded.

RESULTSPOTS in children commonly occurred in the age of 7-14 years. Dizziness (84.00%) was the most common symptom, followed by weakness (72.00%) and orthostatic syncope (62.67%). Positive family history of orthostatic intolerance (OI) was found in 24.64% of children with POTS. And 33.09% of them had preceding infection history as precipitating events. Ten percent of them suffered from orthostatic hypertension. Hyperadrenergic status was documented in 51.28% of 39 patients who were tested for the standing norepinephrine levels. More than half of POTS patients, with 24-hour urinary sodium level <124 mmol/24 hours, were suitable for treatment of salt supplementation. At least 25.74% of POTS patients were of positive acetylcholine receptor (AChR) antibody. Low iron storage in children with POTS was relatively rare. Most patients responded well to treatments, 43.51% of patients recovered, while 7.63% of them had relapse after symptoms disappeared.

CONCLUSIONSPOTS is a relatively common condition with complex pathophysiology and heterogeneous clinical manifestation. A comprehensive therapeutic regimen is recommended for the treatment.

Adolescent ; Blood Pressure ; physiology ; Child ; Child, Preschool ; Exercise Therapy ; methods ; Female ; Heart Rate ; physiology ; Humans ; Male ; Postural Orthostatic Tachycardia Syndrome ; diagnosis ; drug therapy ; therapy ; urine ; Retrospective Studies ; Salts ; therapeutic use ; Sodium ; urine