Echo-guiding percutaneous aortic stent implantation for coarctation of the aortic: A case report / 中国胸心血管外科临床杂志

@#Currently, transcatheter intervention has emerged as a first-line treatment for coarctation of the aortic. Due to the radiation exposure associated with catheter interventional therapy, there are numerous restrictions, which harms both patients and medical personnel and is dependent on sizable radiation apparatus. Here, we report for the first time a case of echo-guiding percutaneous aortic stent implantation for a 27 years female patient of reproductive age. After discharge, the patient's aortic coarctation pressure decreased to 18 mm Hg, and the surgical results were satisfactory.

Reconstruction and analysis of K-Clip surgery process based on finite element method / 中国胸心血管外科临床杂志

@#Objective     To investigate the effects of different types of tricuspid regurgitation, implantation positions, and device models on the treatment outcomes of K-Clip for tricuspid regurgitation using numerical simulations. Methods     Three-dimensional reconstruction of the heart model was performed based on CT images. Two different regurgitation orifices were obtained by modifying the standard parameterized tricuspid valve leaflets and chordae tendineae. The effects of different K-Clip models at different implantation positions (posterior leaflet midpoint, anterior-posterior commissure, anterior leaflet midpoint, posterior septal commissure) were simulated using commercial explicit dynamics software Ls-Dyna. Conclusion     For the two types of regurgitation in this study, clipping at the posterior leaflet midpoint resulted in a better reduction of the regurgitation orifice (up to 75% reduction in area). Higher clamping forces were required for implantation at the anterior leaflet midpoint and posterior septal commissure, which was unfavorable for the smooth closure of the clipping components. There was no statistical difference in the treatment outcomes between the 18T and 16T K-Clip components, and the 16T component required less clamping force. Therefore, the use of the 16T K-Clip component is recommended.

Contrast-zero ultrasound-guided transcatheter aortic valve replacement: A case report / 中国胸心血管外科临床杂志

@#Conventional transcatheter aortic valve replacement is normally recommended with transthoracic echocardiography, and contrast agent mediated fluoroscopy under anesthesia to guide a better implantation of the transcatheter valve. However, iodine-containing contrast agent possibly damages the patient’s kidney, and even induces the acute kidney injury. We reported a 75-year-old patient diagnosed with severe aortic valve stenosis, moderate regurgitation, and chronic renal failure. We performed the aortic valve replacement under the guidance of fluoroscopy and transesophageal ultrasound without contrast agent. Seven days after surgery, the patient recovered well and discharged with alleviated aortic stenosis and fixed transcatheter aortic valve.

Human anti-ACE2 monoclonal antibodies as pan-sarbecovirus prophylactic agents

Human monoclonal antibodies from convalescent individuals that target the SARS-CoV-2 spike protein have been deployed as therapeutics against SARS-CoV-2. However, nearly all of these antibodies have been rendered obsolete by SARS-CoV-2 variants that evolved to resist similar, naturally occurring antibodies. Here, we describe the development of human monoclonal antibodies that bind the ACE2 receptor rather than the viral spike protein. These antibodies block infection by all ACE2 binding sarbecoviruses, including emergent SARS-CoV-2 variants. Structural and biochemical analyses revealed that the antibodies target an ACE2 epitope that engages SARS-CoV-2 spike. Importantly, the antibodies do not inhibit ACE2 enzymatic activity, nor do they induce ACE depletion from cell surfaces. The antibodies exhibit favorable pharmacology and protect human ACE2 knock-in mice against SARS-CoV-2 infection. Such antibodies should be useful prophylactic and treatment agents against any current and future SARS-CoV-2 variants, as well as ACE2-binding sarbecoviruses that might emerge as future pandemic threats.

Inhibition of major histocompatibility complex-I antigen presentation by sarbecovirus ORF7a proteins

Viruses employ a variety of strategies to escape or counteract immune responses, including depletion of cell surface major histocompatibility complex class I (MHC-I), that would ordinarily present viral peptides to CD8+ cytotoxic T cells. As part of a screen to elucidate biological activities associated with individual SARS-CoV-2 viral proteins, we found that ORF7a reduced cell surface MHC-I levels by approximately 5-fold. Nevertheless, in cells infected with SARS-CoV-2, surface MHC-I levels were reduced even in the absence of ORF7a, suggesting additional mechanisms of MHC-I downregulation. ORF7a proteins from a sample of sarbecoviruses varied in their ability to induce MHC-I downregulation and, unlike SARS-CoV-2, the ORF7a protein from SARS-CoV lacked MHC-I downregulating activity. A single-amino acid at position 59 (T/F) that is variable among sarbecovirus ORF7a proteins governed the difference in MHC-I downregulating activity. SARS-CoV-2 ORF7a physically associated with the MHC-I heavy chain and inhibited the presentation of expressed antigen to CD8+ T-cells. Speficially, ORF7a prevented the assembly of the MHC-I peptide loading complex and causing retention of MHC-I in the endoplasmic reticulum. The differential ability of ORF7a proteins to function in this way might affect sarbecovirus dissemination and persistence in human populations, particularly those with infection- or vaccine-elicited immunity.

Antibody and memory B-cell immunity in a heterogeneously SARS-CoV-2 infected and vaccinated population

Global population immunity to SARS-CoV-2 is accumulating through heterogenous combinations of infection and vaccination. Vaccine distribution in low- and middle-income countries has been variable and reliant on diverse vaccine platforms. We studied B-cell immunity in Mexico, a middle-income country where five different vaccines have been deployed to populations with high SARS-CoV-2 incidence. Levels of antibodies that bound a stabilized prefusion spike trimer, neutralizing antibody titers and memory B-cell expansion correlated with each other across vaccine platforms. Nevertheless, the vaccines elicited variable levels of B-cell immunity, and the majority of recipients had undetectable neutralizing activity against the recently emergent omicron variant. SARS-CoV-2 infection, experienced prior to or after vaccination potentiated B-cell immune responses and enabled the generation of neutralizing activity against omicron and SARS-CoV for all vaccines in nearly all individuals. These findings suggest that broad population immunity to SARS-CoV-2 will eventually be achieved, but by heterogenous paths

Changes of ascending aortic diameter after transcatheter aortic valve replacement / 中国胸心血管外科临床杂志

@#Objective    To evaluate the changes of ascending aortic (AA) diameter after transcatheter aortic valve replacement (TAVR), and evaluate the safety and efficacy of TAVR in patients with AA dilation. Methods    We retrospectively included 87 patients who underwent TAVR at our center from 2016 to 2019. These patients were divided into 2 groups based on the preoperative AA diameter. There were 17 patients in the AA diameter≥45 mm group (including 10 males, aged 74.4±5.6 years), and 70 patients in the AA diameter<45 mm group (including 39 males, aged 75.9±7.0 years). Results     The baseline variables were similar between two groups (P>0.05). The overall device success rate was 97.7% (85/87). The median computed tomography (CT) follow-up time was 24.2±11.8 months in patients with AA diameter≥45 mm and 23.0±10.7 months in patients with AA diameter<45 mm, and the median annual dilation rate of AA were 0.36 mm/year and 0.00 mm/year, respectively. No statistical significance was observed between two groups (P>0.05). No adverse aortic events occurred during the follow-up period. Conclusion    TAVR is safe and effective in patients with preoperative AA diameter≥45 mm, and the AA diameter remains stable after the procedure. Patients with preoperative AA diameter≥45 mm and AA diameter<45 mm have similar annual dilation rates.

High genetic barrier to escape from human polyclonal SARS-CoV-2 neutralizing antibodies

The number and variability of the neutralizing epitopes targeted by polyclonal antibodies in SARS-CoV-2 convalescent and vaccinated individuals are key determinants of neutralization breadth and, consequently, the genetic barrier to viral escape. Using chimeric viruses and antibody-selected viral mutants, we show that multiple neutralizing epitopes, within and outside the viral receptor binding domain (RBD), are variably targeted by polyclonal plasma antibodies and coincide with sequences that are enriched for diversity in natural SARS-CoV-2 populations. By combining plasma-selected spike substitutions, we generated synthetic polymutant spike proteins that resisted polyclonal antibody neutralization to a similar degree as currently circulating variants of concern (VOC). Importantly, by aggregating VOC-associated and plasma-selected spike substitutions into a single polymutant spike protein, we show that 20 naturally occurring mutations in SARS-CoV-2 spike are sufficient to confer near-complete resistance to the polyclonal neutralizing antibodies generated by convalescents and mRNA vaccine recipients. Strikingly however, plasma from individuals who had been infected and subsequently received mRNA vaccination, neutralized this highly resistant SARS-CoV-2 polymutant, and also neutralized diverse sarbecoviruses. Thus, optimally elicited human polyclonal antibodies against SARS-CoV-2 should be resilient to substantial future SARS-CoV-2 variation and may confer protection against future sarbecovirus pandemics.

Antibody Evolution after SARS-CoV-2 mRNA Vaccination

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces B-cell responses that continue to evolve for at least one year. During that time, memory B cells express increasingly broad and potent antibodies that are resistant to mutations found in variants of concern1. As a result, vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals with currently available mRNA vaccines produces high levels of plasma neutralizing activity against all variants tested1, 2. Here, we examine memory B cell evolution 5 months after vaccination with either Moderna (mRNA-1273) or Pfizer- BioNTech (BNT162b2) mRNA vaccines in a cohort of SARS-CoV-2 naive individuals. Between prime and boost, memory B cells produce antibodies that evolve increased neutralizing activity, but there is no further increase in potency or breadth thereafter. Instead, memory B cells that emerge 5 months after vaccination of naive individuals express antibodies that are similar to those that dominate the initial response. While individual memory antibodies selected over time by natural infection have greater potency and breadth than antibodies elicited by vaccination, the overall neutralizing potency of plasma is greater following vaccination. These results suggest that boosting vaccinated individuals with currently available mRNA vaccines will increase plasma neutralizing activity but may not produce antibodies with breadth equivalent to those obtained by vaccinating convalescent individuals.

Longitudinal variation in SARS-CoV-2 antibody levels and emergence of viral variants: implications for the ability of serological assays to predict immunity.

BackgroundSerological assays are being deployed to monitor antibody responses in SARS-CoV-2 convalescents and vaccine recipients. There is a need to determine whether such assays can predict immunity, as antibody levels wane and viral variants emerge. MethodsWe measured antibodies in a cohort of SARS-CoV-2 infected patients using several high-throughput serological tests and functional neutralization assays. The effects of time and spike protein sequence variation on the performance and predictive value of the various assays was assessed. FindingsNeutralizing antibody titers decreased over the first few months post-infection but stabilized thereafter, at about 30% of the level observed shortly after infection. Serological assays commonly used to measure antibodies against SARS-CoV-2 displayed a range of sensitivities that declined to varying extents over time. Quantitative measurements generated by serological assays based on the spike protein were better at predicting neutralizing antibody titers than assays based on nucleocapsid, but performance was variable and manufacturer positivity thresholds were not able to predict the presence or absence of detectable neutralizing activity. Even though there was some deterioration in correlation between serological measurements and functional neutralization activity, some assays maintained an ability to predict neutralizing titers, even against variants of concern. InterpretationThe ability of high throughput serological assays to predict neutralizing antibody titers is likely crucial for evaluation of immunity at the population scale. These data will facilitate the selection of the most suitable assays as surrogates of functional neutralizing activity and suggest that such measurements may have utility in clinical practice.

Interpretation of the section of congenital heart diseases in Annual Report on Cardiovascular Health and Diseases in China (2019) / 中国胸心血管外科临床杂志

@#Congenital heart disease (CHD) is a birth defect with the highest incidence in China. In September 2020, Annual Report on Cardiovascular Health and Diseases in China (2019) was published by National Center for Cardiovascular Diseases. The present situation of prevention and treatment of CHD was briefly summarized in this report. In this paper, we presented the main opinions of Annual Report on Cardiovascular Health and Diseases in China (2019), supplied with relevant data, such as epidemiology, surgical treatment and interventional treatment of CHD, to further expand and explain this report.

Escape from neutralizing antibodies by SARS-CoV-2 spike protein variants

Neutralizing antibodies elicited by prior infection or vaccination are likely to be key for future protection of individuals and populations against SARS-CoV-2. Moreover, passively administered antibodies are among the most promising therapeutic and prophylactic anti-SARS-CoV-2 agents. However, the degree to which SARS-CoV-2 will adapt to evade neutralizing antibodies is unclear. Using a recombinant chimeric VSV/SARS-CoV-2 reporter virus, we show that functional SARS-CoV-2 S protein variants with mutations in the receptor binding domain (RBD) and N-terminal domain that confer resistance to monoclonal antibodies or convalescent plasma can be readily selected. Notably, SARS-CoV-2 S variants that resist commonly elicited neutralizing antibodies are now present at low frequencies in circulating SARS-CoV-2 populations. Finally, the emergence of antibody-resistant SARS-CoV-2 variants that might limit the therapeutic usefulness of monoclonal antibodies can be mitigated by the use of antibody combinations that target distinct neutralizing epitopes.

Safety and efficacy of percutaneous intervention for children with combined congenital heart abnormality solely guided by transthoracic echocardiography / 中华心血管病杂志

Objective@#To investigate the safety and efficacy of percutaneous intervention of children with combined congenital heart abnormality solely guided by transthoracic echocardiography (TTE) .@*Methods@#From September 2015 to June 2017, 21 children with combined congenital heart abnormality undergoing percutaneous interventional guided by TTE in Fuwai hospital were enrolled in our study, and the clinical data were retrospective analyzed. The atrial septal defect(ASD) closure, ventricular septal defect(VSD) closure, patent ductus arteriosus(PDA) closure or balloon pulmonary valvuloplasty were performed under the guidance of TTE. The procedural effect was evaluated by TTE after operation. The patients were followed up after discharged from the hospital.@*Results@#The age was (37.3±11.6) months, and there were 9 male and 12 female patients. There were 4 cases with ASD and VSD, 6 cases with VSD and PDA, 6 cases with ASD and PDA, 2 cases with VSD and pulmonary stenosis, 3 cases with ASD and pulmonary stenosis. The operations were successfully performed in all patients. No one required extra X ray guidance or open heart surgery. The operation time was (44.6±7.5)min. All patients did not require blood transfusion, inotropic support, and analgesia. There were no complications such as peripheral vascular injury and pericardialeffusion after the operation. The length of hospital stay time was (3.5±0.6) days. All patients were recovered well. The follow-up was (17.6±5.2) months, and post-procedural conduction disturbances, residual shunts, occlude fall off, thrombosis, and new onset of valvular regurgitation were not observed in these patients.@*Conclusion@#Percutaneous interventional of children with combined congenital heart abnormality solely guided by TTE is safe and effective, and the procedure can avoid the potential injuries of X ray and contrast agent.

Percutaneous induced thrombosis closure on small patent ductus arteriosus solely under echocardiography guidance / 中华实用儿科临床杂志

Objective To investigate the efficacy and safety of percutaneous induced thrombosis closure on small patent ductus arteriosus (PDA) solely under echocardiography guidance.Methods From June 2013 to September 2016,276 PDA patients were treated by femoral artery retrograde approach under echocardiography guidance.Twenty-five patients (14 boys,11 girls) among them with small PDA received percutaneous induced thrombosis closure because the delivery sheath could not pass PDA,with mean age (3.7 ± 1.6) years,mean body weight (16.6 ±5.4) kg and the mean diameter of the most narrow PDA was (1.3 ± 0.4) mm.All patients were assessed by transthoracic echocardiography,chest radiography and electrocardiography preoperatively.The intraoperative and postoperative effects were evaluated by echocardiography.Outpatient assessment was performed at 1,3,6 and 12 months after operation with electrocardiography and echocardiography,and yearly thereafter.Results Twenty-five patients were successfully treated with percutaneous induced thrombosis closure solely under echocardiography guidance.The mean operation time was (35.2 ± 6.1) minutes.The immediate residual shunt rates and 24 hours after operation were 28.0％ (7/25 cases) and 16.0％ (4/25 cases),respectively.All patients recovered and were discharged from hospital.The average hospitalization stay was (3.0 ± 0.6) days.The mean follow-up was (16.8 ± 12.3) months,residual shunt was observed in 2 patients (8.0％),and it decreased from 1.5 mm and 2.0 mm preoperatively to 0.8 mm and 1.0 mm postoperatively,respectively.All patients survived without peripheral vascular injury,cardiac perforation,PDA rupture or thrombembolia.Conclusions Percutaneous induced thrombosis closure of small PDA solely under echocardiography guidance is safe and effective.It can avoid occluder implantation and radiation injury.However,the residual shunt after operation needs following up closely.

Application of Percutaneous Ventricular Septal Defect Closure Under Solely Guidance of Echocardiography / 中国循环杂志

Objective: Traditional percutaneous ventricular septal defect (VSD) closure had disadvantages of radiation and contrast media reaction in relevant patients. We want to investigate the efifcacy and safety of percutaneous VSD closure under solely guidance of echocardiography. Methods: A total of 28 VSD patients treated by percutaneous VSD closure under solely guidance of trans-thoracic echocardiography in our hospital from 2014-02 to 2014-10 were summarized. The patients mean age was (9.5 ± 3.1) years with the body weight at (31.3 ± 7.7) kg. The average diameter of VSD was (4.6 ± 0.9) mm, and the clinical follow-up study was conducted by echocardiography at 1, 3, 6 and 12 months after the procedure. Results: There were 26 patients with successful treatment by percutaneous VSD closure under solely guidance of echocardiography. 1 patient was converted to perventricular closure with trans-esophageal echocardiography guidance because the catheter could not pass through the defect; another patient was converted to surgical repair because of the residual shunt > 2 mm. The average procedural time was (63.3 ± 11.7) min and the mean diameter of symmetrical occluder was (6.6 ± 1.0) mm. There were 2 patients with immediate post-operative residual shunt, and the average in-hospital time was (3.7 ± 1.3) days. All patients discharged without the complications as peripheral vascular injury or cardiac perforation. The average follow-up time was (6.2 ± 3.4) months. The residual shunt disappeared in 2 patients at 1 month follow-up time point. No patients suffered from pericardial effusion, occluder malposition, atrio-ventricular block and aortic valve regurgitation. Conclusion: Echocardiography guided percutaneous VSD closure is safe and effective, it may avoid the radiation and contrast media reaction in relevant patients.

Exploration Research of Ventricular Septal Defect Closure via Trans-jugular Approach Solely Under the Guidance of Echocardiography / 中国循环杂志

Objective: In order to avoid the radiation and contrast agent injury, and to extend the echocardiography guided percutaneous ventricular septal defects (VSD) closure, based on femoral artery approach, we assessed the efifcacy and safety of VSD closure via trans-jugular approach solely under the guidance of echocardiography. Methods: A total of 12 patients with peri-membranous VSD treated in our hospital from 2014-10 to 2015-04 were enrolled. The patients were at the age at (1.2-3.5 with the mean of 2.4 ± 0.8 ) years, the body weight at (7-15 with the mean of 11.6 ± 2.6) kg and the diameter of VSD was (3.5-6 with the mean of 4.8 ± 0.7) mm. The patients received percutaneous VSD closure via transjugular approach solely under the guidance of echocardiography. The procedural effect was evaluated by echocardiography and the follow-up study was conducted at 1, 3 and 6 month safter the procedures. Results: There were 9 patients successfully ifnished VSD closure via trans-jugular approach. 1 patient was converted to femoral artery approach because the wire could not pass through the defect of ventricular septal; 1 was converted to minimally invasive per-ventricular closure since the catheter could not pass through the defect; 1 was converted to conventional surgical repair due to the residual shunt was more than 2mm. The procedural time was (53-89 with the mean of 67.2±12.5) min, the diameter of symmetrical occluder was (6-8 with the mean of 7.0±0.9) mm. 2 patients had immediate post-operative residual shunt, all patients were recovered and discharged. No peripheral vascular injury and cardiac perforation occurred, the hospitalization time was (3-5 with the mean of 3.6 ± 0.7) days. The follow-up examination was conducted at (1-6 with the mean of 3.9 ± 2.1) months, the slight residual shunt in 2 patients disappeared at 1 month after procedure; no pericardial effusion, occluder malposition, aortic regurgitation and atria-ventricular block occurred. Conclusion: Echocardiography guided trans-jugular approach of VSD closure is safe and effective, it may particularly avoid the radiation and contrast agent injury in clinical practice.

Clinical Investigation of Transthoracic Minimally Invasive Patent Ductus Arteriosus Occlusion in Infants and Young Children / 中国循环杂志

Objective: To investigate the safety and efficacy of transthoracic minimally invasive patent ductus arteriosus (PDA) occlusion in infants and young children. Methods: We retrospectively analyzed 105 infants and young children who received the transthoracic minimally invasive PDA occlusion in our hospital from 2012-10 to 2014-10. According to PDA diameter, patients were divided into 2 groups:Group A, the patients with PDA diameter ≥ 4 mm,n=64 and group B, the patients with 2 mm ≤ PDA diameter Results: All 105 patients had successfully implanted PDA occluders. The patients’ gender, age, body weight, tracheal intubation time and the in-hospital time were similar between 2 groups,P>0.05. Compared with Group B, Group A had the larger diameters of PDA (5.7 ± 1.4) mm vs (2.7 ± 0.6) mm, P Conclusion: Transthoracic minimally invasive PDA occlusion is a safe and effective method to treat the relevant infants and young children, while the post-operative residual shunt and thrombocytopenia should be closely observed in patients with large PDA.

Predictive value of baseline plasma midregional fragment of pro-adrenomedullin level on long-term outcome of postural tachycardia syndrome children treated with midodrine hydrochloride / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the predictive value of baseline plasma midregional fragment of pro-adrenomedullin level (MR-proADM) on long-term survival of postural tachycardia syndrome (POTS) children treated with midodrine hydrochloride.</p><p><b>METHODS</b>Fifty-three children (male 26, mean age (14.5 ± 4.5) years old) with POTS were included in this study, and all of them were diagnosed as POTS in our department from December 2007 to January 2010. Fifty-three children with POTS were divided into two groups according to the baseline plasma content of MR-proADM. Group I consisted of 35 POTS children with plasma content of MR-proADM > 61.5 ng/L, and the group II consisted of 18 POTS children with plasma content of MR-proADM ≤ 61.5 ng/L. The mean follow-up time was (67 ± 7) months. The orthostatic intolerance symptom score and the symptom free survival were compared between the 2 groups.</p><p><b>RESULTS</b>At the 60 months follow-up, the symptom score of children in group I was significantly lower than that in group II (χ(2) = 4.985, P < 0.05). At 72 months follow up, the symptom score was similar between the 2 groups (χ(2) = 0.004, P > 0.05) while the symptom free survival of group I was significantly higher than that in group II (χ(2) = 4.566, P < 0.05).</p><p><b>CONCLUSION</b>The baseline plasma MR-proADM level is value in predicting the long-term survival of POTS children treated with midodrine hydrochloride.</p>

Safety and efficacy of percutaneous patent ductus arteriosus closure solely under thoracic echocardiography guidance / 中华心血管病杂志

<p><b>OBJECTIVE</b>To avoid the radiation injuries and use of contrast agent, we assessed the safety and efficacy of percutaneous patent ductus arteriosus closure solely under thoracic echocardiography guidance.</p><p><b>METHODS</b>From June 2013 to June 2014, thirty patients (mean age: (6.3 ± 2.5) years, mean body weight:(22.5 ± 7.3) kg) with pure patent ductus arteriosus were continuously included in this study. The mean diameter of patent ductus arteriosus was (3.8 ± 0.9) mm. Patients were all treated by percutaneous patent ductus arteriosus closure via right femoral artery solely under thoracic echocardiography guidance. The efficacy of the procedure was evaluated by thoracic echocardiography. Follow-up was performed at one month after procedure.</p><p><b>RESULTS</b>All 30 cases were successfully treated with percutaneous patent ductus arteriosus closure solely under thracic echocardiography guidance. The procedural time was (32.8 ± 5.7) minutes. The mean diameter of Amplatzer ADO II was (4.9 ± 1.0) mm. Postoperative trivial residual shunt occurred in six patients immediately after the procedure. All patients survived without peripheral vascular injury or complications such as cardiac perforation. Hospitalization time was (3.4 ± 0.7) days. At one-month follow-up, no complications such as residual shunt or pericardial effusion were observed.</p><p><b>CONCLUSION</b>Echocardiography guided percutaneous patent ductus arteriosus closure by femoral artery approach is safe and effective, and can avoid X-ray and the use of contrast agents.</p>

The follow-up study on the treatment of children with postural orthostatic tachycardia syndrome / 国际儿科学杂志

Objective To compare the short-term and long-term therapeutic effects of oral rehydration salts,metoprolol or midodrine hydrochloride in children with postural tachycardia syndrome (POTS).Methods Two hundred and forty-four children with POTS diagnosed in the First Hospital Peking University of from Dec.2004 to Jan.2013 were followed up in clinics or by telephone.They were divided into oral rehydration salt group (n =75),metoprolol group (n =66) and midodrine hydrochloride group (n =103).The patients were followed up for 3 ～ 100 months.Results After 3 months of treatment,the symptom scoring of the three groups was improved greatly as compared with the baseline data.Therapeutic effect of midodrine hydrochloride group was significantly superior to metoprolol group and oral rehydration salt group (x2 =8.750,P =0.013).One hundred and forty-two out of 244 children were followed up and their head-up tilt test(HUT)was repeated.The HR increment of children in 3 groups became smaller as compared with before treatment (P ＜ 0.05).After follow-up,the symptom scoring was improved greatly as compared with the baseline scoring (P ＜ 0.05).The short-term effect of midodrine hydrochloride group was significantly better than that of metoprolol group or oral rehydration salt group (x2 =8.750,P =0.013).The Kaplan-Meier curves showed that the long-term effect of midodrine hydrochloride group was significantly superior to metoprolol group and oral rehydration salt group (89.3％vs 78.8％,P =0.033;89.3％ vs 76.0％,P =0.002).Conclusion Oral rehydration salts,midodrine hydrochloride or metoprolol were all effective for POTS in children.And the short-term and long-term effect of midodrine hydrochloride might be superior to metoprolol and oral rehydration salts.