Advances in the pathogenesis of postural tachycardia syndrome in children / 国际儿科学杂志

Hypovolemic and hemodynamic disorders，autonomic nervous dysfunction and hyperadrenergic state are recognized pathogenesis of postural tachycardia syndrome（POTS）. According to this，POTS can be divided into three types：hypovolemic POTS，neurogenic POTS and hyperadrenergic POTS. Autoimmune abnormalities，changes in hormone levels，and gene mutations may also cause POTS. In addition，some patients have joint overactivity syndrome，functional gastrointestinal disorders，Ehlers Danlos syndrome，mast cell activation disorders and other diseases.Therefore，POTS is a complex clinical syndrome that may involve multiple mechanisms.This article aims to offer clinicians an improved understanding of the pathogenesis of pediatric POTS through a comprehensive review of this disease.

Value of metoprolol combined with Wenxin Keli in treatment of atrial tachycardia after catheter ablation due to atrial fibrillation / 中华老年心脑血管病杂志

Objective To explore the therapeutic value of metoprolol combined with Wenxin Keli(a Chinese patent drug)on atrial tachycardia(AT)after catheter ablation in patients with atrial fibrillation(AF).Methods A total of 290 patients who were diagnosed with AF and underwent catheter ablation successfully in the Department of Cardiovascular Medicine of Northern Jiangsu People's Hospital from May 2018 to January 2022 were enrolled,and were randomly divided into Wenxin Granule group(Group W),metoprolol group(Group M),combined group(Group MW)and blank control group(Group C).The times of AT,heart beats during the longest AT episode,average heart rate and adverse reactions were compared among the 4 groups.Results The mean heart rate,episodes of AT,heart beats during the longest AT episode,and numbers of premature atrial contractions(PAC)of class Ⅰ,Ⅱ and Ⅲ in Group C in 1 year after operation were all sig-nificantly higher than the baseline levels(P＜0.01),so were in the Group W,Group M and Group MW(P＜0.01).Group MW had obviously lower mean heart rate,episodes of AT,heart beats dur-ing the longest AT episode,and numbers of PAC of class Ⅰ,Ⅱ and Ⅲ when compared with Group W and Group M(P＜0.05).There was no significant difference in the total incidence of ad-verse reactions in Group W,Group M and Group MW(7.1％vs 13.9％vs 8.9％,P=0.301).Con-clusion Metoprolol combined with Wenxin Keli can be used to treat AT after AF catheter abla-tion.The combination can effectively reduce the average heart rate,episodes of AT,numbers of PAC and heart beats during the longest AT episode,and thus decrease the recurrence of postopera-tive AF with high safety.

Efficacy of metoprolol versus ivabradine in treatment of POTS in elderly patients after COVID-19 infection / 中华老年心脑血管病杂志

Objective To explore the difference in efficacy of metoprolol versus ivabradine in the treatment of postural orthostatic tachycardia syndrome(POTS)in the elderly after COVID-19 infection.Methods A total of 110 patients diagnosed with POTS at our department from Decem-ber 1,2022 to January 31,2023 were included.According to their drug regimen,they were divided into metoprolol group(62 patients)and ivabradine group(48 patients).On the 28th day of out-patient follow-up,the resting heart rate,heart rate of 10 min of standing,symptom disappearance rate,hospitalization rate,and mortality rate were compared between the two groups.Results On the 28th day of treatment,the resting heart rate and postural heart rate for 10 min were decreased in both groups when compared with the levels at initial diagnosis(P＜0.01).And there were no significant differences in the two types of heart rate between the two groups on the 28th day(71.0±7.0 vs 72.1±7.0,P=0.401;76.5±7.2 vs 77.4±7.6,P=0.573).No obvious differences were observed between the two groups in symptom disappearance rate,hospitalization rate,or mortality rate(88.7％vs 89.6％,3.2％vs2.1％,0％vs 0％,P＞0.05).Conclusion Metoprolol and ivabradine can effectively treat POTS in the elderly patients after COVID-19 infection.

The Effect of Yangyin Xifeng Tongluo Formula （养阴熄风通络方） and Its Core Herb-Pairs on Prevention of Aconitine-Induced Ventricular Precontraction in Rats / 中医杂志

ObjectiveTo observe the effect of Yangyin Xifeng Tongluo Formula （养阴熄风通络方） and its core herbs combination on prevention of ventricular precontraction （PVC）. MethodsExperiment 1： Forty SD rats were randomly divided into model group， formula group， core herb-pairs medium-dose group and amiodarone group， with 10 rats in each group. Rats in the model group were given 10 ml/（kg·d） of pure water by gavage， rats in the formula group were given 1.125 g/（kg·d） of Yangyin Xifeng Tongluo Granules （养阴熄风通络方颗粒） by gavage， rats in the core herb-pairs medium-dose group were given 0.585 g/（kg·d） of granules of core herb-pairs by gavage， and rats in the amiodarone group were given 18 mg/（kg·d） of amiodarone hydrochloride tablets by gavage. The rats in each group were gavaged once a day for 14 consecutive days， and then a PVC model was established using rat tail vein injection of aconitine 25 μg/kg to compare the mortality and incidence of PVC， ventricular tachycardia （VT） and ventricular fibrillation （VF）， the time of the appearance of PVC， and the duration of PVC in the rats in each group. Experiment 2： Sixty SD rats were randomly divided into model group， the amiodarone group， and the core herb-pairs of low， medium and high dose groups， 12 rats in each group. Rats in the model group were gavaged with 10 ml/（kg·d） of purified water， rats in the low， medium， and high dose groups were gavaged with 0.2925， 0.585， and 1.17 g/（kg·d） of the core herb-pairs granules respectively， and rats in the amiodarone group were gavaged with 18 mg/（kg·d） of amiodarone hydrochloride tablets. All of them were gavaged once a day. After 14 days， rats in each group were injected intravenously into the tail vein with aconitine 25 μg/kg， and then the rats in each group were observed to show the mortality and incidence of PVC， VT and VF， and the time of appearance and duration of PVC. ResultsExperiment 1： Compared with the model group， The difference in the incidence of PVC in rats of all groups was not statistically signi-ficant （P＞0.05）， and the mortality and incidence of VT and VF in rats in the formula group， the core herb-pairs medium-dose group， and the amiodarone group significantly reduced， with delayed time of the occurrence of PVC and shorter duration of the PVC （P＜0.05 or P＜0.01） as compared with the model group， whereas the difference between each group with medication intervention was not statistically significant （P＞0.05）. Experiment 2： There was no statistically significant difference in the incidence of PVC in all groups （P＞0.05）， and the mortality and incidence of VT and VF reduced in the core herb-pairs of low-， medium-， and high-dose groups and in the amiodarone group， and the appearance of PVC delayed and its duration shortened （P＜0.05 or P＜0.01） as compared with the control group， whereas the differences were not statistically significant in the comparison among groups with medication （P＞0.05）. ConclusionBoth Yangyin Xifeng Tongluo Formula and its core herb-pairs could delay the time of occurrence and shorten the duration of PVC.

Doble tormenta tiroidea y arrítmica en una gestante con múltiples taquicardias refractarias mediadas por un haz de kent intermitente ablacionado exitosamente

La tormenta tiroidea es un estado crítico y poco frecuente que condiciona la disfunción de múltiples órganos por el efecto del exceso de las hormonas tiroideas, esta disfunción endócrina tiene una elevada mortalidad y genera manifestaciones típicas como la taquicardia, fiebre, alteraciones gastrointestinales, cardiovasculares y del sistema nervioso central. El embarazo se ha asociado con un incremento en la incidencia de arritmias. Necesitan un tratamiento inmediato con drogas antiarrítmicas, cardioversión eléctrica o cesárea de urgencia. El WPW es una anormalidad cardiaca congénita que consiste en la presencia de un haz anómalo (Haz de Kent) que evita el sistema normal de conducción uniendo directamente aurículas y ventrículos. Veremos el caso de una gestante de 32 semanas que presenta un cuadro de tormenta tiroidea y múltiples episodios de taquicardia paroxística supraventricular (TPS), de tórpida y sombría evolución clínica mediada por un haz anómalo de Kent intermitente. Es evidente que la tormenta tiroidea en el contexto de la gestación produjo cambios en las propiedades electrofisiológicas del haz anómalo de Kent intermitente lo cual propició el desarrollo de múltiples taquicardias paroxísticas supraventriculares refractarias a la cardioversión eléctrica y farmacológica. Tampoco mejoró con la tiroidectomía total, solamente cedió por completo con la ablación por catéter de radiofrecuencia del haz anómalo de Kent.

Thyroid storm is a critical and infrequent state that conditions the dysfunction of multiple organs due to the effect of excess thyroid hormones. This endocrine dysfunction has a high mortality and generates typical manifestations such as tachycardia, fever, gastrointestinal, cardiovascular and heart disorders, and the central nervous system. Pregnancy has been associated with an increased incidence of arrhythmias. They need immediate treatment with antiarrhythmic drugs, electrical cardioversion, or emergency caesarean section. WPW is a congenital cardiac abnormality that consists of the presence of an abnormal bundle (Kent bundle) that prevents the normal conduction system, directly joining the atria and ventricles. We will see the case of a 32-week pregnant woman who presented symptoms of thyroid storm and multiple episodes of paroxysmal supraventricular tachycardia (PST), with a torpid clinical course mediated by an abnormal intermittent Kent bundle. It is evident that the thyroid storm in the context of pregnancy produced changes in the electrophysiological properties of the intermittent Kent bundle, which led to the development of multiple PST refractory to electrical and pharmacological cardioversion. Moreover, it also did not improve with total thyroidectomy, only resolved completely with radiofrequency catheter ablation of the Kent bundle.

Metoprolol for prevention of bucking at orotracheal extubation: a double-blind, placebo-controlled randomised trial

Abstract Background: Respiratory responses to extubation can cause serious postoperative complications. Beta-blockers, such as metoprolol, can interfere with the cough pathway. However, whether metoprolol can effectively control respiratory reflexes during extubation remains unclear. The objective of this study is to evaluate the efficacy of intravenous metoprolol in attenuating respiratory responses to tracheal extubation. Methods: Randomized, double-blinded, placebo-controlled trial. Setting: Tertiary referral center located in Brasília, Brazil. Recruitment: June 2021 to December 2021. Sample: 222 patients of both sexes with an American Society of Anesthesiologists (ASA) physical status I-III aged 18-80 years. Patients were randomly assigned to receive intravenous metoprolol 5 mg IV or placebo at the end of surgery. The primary outcome was the proportion of patients who developed bucking secondary to endotracheal tube stimulation of the tracheal mucosa during extubation. Secondary outcomes included coughing, bronchospasm, laryngospasm, Mean Blood Pressure (MAP), and Heart Rate (HR) levels. Results: Two hundred and seven participants were included in the final analysis: 102 in the metoprolol group and 105 in the placebo group. Patients who received metoprolol had a significantly lower risk of bucking (43.1% vs. 64.8%, Relative Risk [RR = 0.66], 95% Confidence Interval [95% CI 0.51-0.87], p = 0.003). In the metoprolol group, 6 (5.9%) patients had moderate/severe coughing compared with 33 (31.4%) in the placebo group (RR = 0.19; 95% CI 0.08-0.43, p < 0.001). Conclusion: Metoprolol reduced the risk of bucking at extubation in patients undergoing general anesthesia compared to placebo.

Torsades de pointes and myocardial infarction following reversal of supraventricular tachycardia with adenosine: a case report

ABSTRACT Adenosine is an antiarrhythmic drug that slows conduction through the atrioventricular node and acts as a coronary blood vessel dilator. This case report highlights two unusual life-threatening events following the use of adenosine to revert supraventricular tachycardia in a structurally normal heart: non-sustained polymorphic ventricular tachycardia and myocardial infarction. A 46-year-old woman presented to the emergency department with a two-hour history of palpitations and was diagnosed with supraventricular tachycardia. Vagal maneuvers were ineffective, and after intravenous adenosine administration, the patient presented with chest pain and hypotension. The rhythm degenerated into non-sustained polymorphic ventricular tachycardia and spontaneously reverted to sinus rhythm with ST elevation in lead aVR and ST depression in the inferior and anterolateral leads. The patient spontaneously recovered within a few minutes. Despite successful arrhythmia reversal, the patient was admitted to the intensive care unit because of an infarction without obstructive atherosclerosis. This report aims to alert emergency physicians about the potential complications associated with supraventricular tachycardia and its reversal with adenosine.

Taquicardia ventricular polimórfica tipo torsadess de pointes secundaria a estimulación por marcapasos / Polymorphic ventricular taquicardia "torsades de pointes" associated to abnormal pacemaker stimulation

La taquicardia ventricular polimórfica se origina en los ventrículos, cuyos complejos QRS son de morfología, amplitud y dirección variable, con frecuencias que oscilan entre 200 y 250 lpm, pudiendo ser autolimitadas o degenerar en una fibrilación ventricular. La TdP es un tipo de taquicardia ventricular polimórfica caracterizada por complejos con un eje eléctrico que gira alrededor de la línea isoeléctrica y que está asociada a QT largo. Se presenta el caso de una paciente portadora de marcapaso que presenta episodios de taquicardia ventricular polimórfica, con una morfología típica de TdP, sin documentación de QT prolongado previo ni actual, generada por la estimulación ventricular sobre onda T, de forma accidental por desplazamiento del electrodo auricular a Ventrículo Derecho (VD).

Polymorphic ventricular tachycardia is a tachycardia originating in the ventricles, where the QRS complexes have variable morphology, amplitude, and direction, with frequencies ranging between 200 and 250 bpm; it may be self-limited or degenerate into ventricular fibrillation. Torsades de Pointes (TdP) is a type of polymorphic ventricular tachycardia characterized by complexes with an electrical axis that rotates around the isoelectric line and that is associated with long QT interval. We present the case of a patient with a pacemaker who presents episodes of polymorphic ventricular tachycardia, with a typical morphology of TdP, without documentation of previous or current prolonged QT, generated by ventricular stimulation on the T wave, accidentally due to displacement of the atrial electrode to the Right Ventricle (RV).

Postural dysautonomia in response to head-up tilt in a military pilot aspirant: Aeromedical considerations

Intolerance to orthostasis encompasses a group of responses on assumption of upright posture. One such response is postural dysautonomia. One of the types of postural dysautonomia is postural orthostatic tachycardia syndrome, which is characterised by an increase in heart rate of more than 30 bpm without hypotension along with other features of dysautonomia on attaining an erect posture, either actively or passively. This paper brings out a case of postural dysautonomia in a pilot aspirant in response to Head-up tilt (HUT) test. A 23-year-old female military pilot aspirant reported for evaluation of Syncope and Air Sickness. She gave a history of solitary episode of loss of consciousness on ground while preparing for an early morning sortie. She was diagnosed with a case of neurocardiogenic syncope and was put back to flying training. Subsequently, after about 2 months, she developed features of air sickness while flying and also could not tolerate preliminary motion sickness desensitisation at her unit. A thorough medical evaluation failed to reveal any neurocardiological abnormality. Before commencing the air sickness desensitisation protocol at the Institute of Aerospace Medicine, she was subjected to HUT during which she developed signs and symptoms suggestive of postural dysautonomia. A test retest assessment with repeat HUT and passive standing test revealed similar responses.

Comportamiento del tiempo de conducción retrógrada al momento de la inducción de las taquicardias supraventriculares y su rol en el diagnóstico diferencial / Behavior of Retrograde Conduction Time at Supraventricular Tachycardia Induction and its Role in Differential Diagnosis

RESUMEN Antecedentes : El diagnóstico diferencial entre la taquicardia reentrante ortodrómica (TRO) y la taquicardia por reentrada nodal atípica (TRNa) puede ser dificultoso. Nuestra hipótesis es que las TRNa tienen más variabilidad en el tiempo de con ducción retrógrada al comienzo de la taquicardia que las TRO. Nuestros objetivos fueron evaluar la variabilidad en el tiempo de conducción retrógrada al inicio de la taquicardia en TRNa y TRO, y proponer una nueva herramienta diagnóstica para diferenciar estas dos arritmias. Métodos : Se midió el intervalo ventrículo-auricular (VA) de los primeros latidos tras la inducción de la taquicardia, hasta su estabilización. La diferencia entre el intervalo VA máximo y el mínimo se definió como delta VA (ΔVA). También contamos el número de latidos necesarios para que se estabilice el intervalo VA. Se excluyeron las taquicardias auriculares. Resultados : Se incluyeron 101 pacientes. Se diagnosticó TRO en 64 pacientes y TRNa en 37. El ΔVA fue 0 (rango intercuartílico, RIC, 0-5) milisegundos (ms) en la TRO frente a 40 (21-55) ms en la TRNa (p < 0,001). El intervalo VA se estabilizó significativamente antes en la TRO (1,5 [1-3] latidos) que en la TRNa (5 [4-7] latidos; p < 0,001). Un ΔVA < 10 ms diagnosticó TRO con 100% de sensibilidad, especificidad y valores predictivos positivo y negativo. La estabilización del intervalo VA en menos de 3 latidos predijo TRO con buena precisión diagnóstica. Los resultados fueron similares considerando sólo vías accesorias septales. Las TRN típicas tuvieron una variación intermedia. Conclusión : Un ΔVA < 10 ms es un criterio simple, que distingue con precisión la TRO de la TRNa, independientemente de la localización de la vía accesoria.

ABSTRACT Background : Differential diagnosis between orthodromic reentrant tachycardia (ORT) and atypical nodal reentrant tachy cardia (ANRT) can be challenging. Our hypothesis was that ANRT presents more variability in retrograde conduction time at tachycardia onset than ORT. Objectives : The objectives of this study were to assess retrograde conduction time variability at the start of tachycardia in ANRT and ORT, and postulate a new diagnostic tool to differentiate these two types of arrhythmias. Methods : The ventriculoatrial (VA) interval of the first beats after tachycardia induction was measured until stabilization. The difference between the maximum and minimum VA interval was defined as delta VA (ΔVA), and the number of beats needed for VA interval stabilization was also assessed. Atrial tachycardias were excluded. Results : In a total of 101 patients included in the study, ORT was diagnosed in 64 patients and ANRT in 37. ΔVA interval was 0 (interquartile range [IQR] 0-5) milliseconds (ms) in ORT vs. 40 (21-55) ms in ANRT (p <0.001). The VA interval significantly stabilized earlier in ORT (1.5 [1-3] beats) than in ANRT (5 [4-7] beats) (p<0.001). A ΔVA <10 ms diagnosed ORT with 100% sensitivity, specificity, and positive and negative predictive values. Ventriculoatrial interval stabilization in less than 3 beats predicted ORT with good diagnostic accuracy. The results were similar considering only accessory septal pathways. Typical NRTs presented an intermediate variation. Conclusion : Presence of DVA <10 ms is a simple criterion that accurately differentiates ORT from ANRT, independently of the accessory pathway localization.

Programmed ventricular stimulation in structural heart disease: Implications of patterns of ventricular arrhythmias induced to long-term outcomes

Introduction: Currently available data gives some credence to utility of VT induction studies in patients with stable ischemic cardiomyopathy, there are some unresolved questions as to define sensitive threshold for low-risk and the prognostic relevance of ill sustained or non-specific tachycardia on induction study. We evaluated potential ability of VT inducibility to predict likelihood of SHD (Structural heart disease) patients for subsequent arrhythmic or adverse cardiac events. Material and Methods: All consecutive patients with syncope/documented arrhythmia who had VT induction done were included and patients with VT storm, ACS,uncontrolled HF were excluded. We studied in 4 groups-monomorphic VT, sustained polymorphicVT, ill sustainedVT/VF and no VT/VF induced. The primary-endpoints were e Sudden death, all-cause mortality and secondary-endpoints were e MACE (AICD shock, death,HF, recurrence of VT). We screened 411 patients and included 169 within inducible (n ¼ 79) and non-inducible group (n ¼ 90). Results: There were a higher number of patients with coronary artery disease, LV dysfunction, patients on amiodarone in inducible group and no difference in usage of beta-blockers. Recurrence of VT, composite of MACE was significantly higher in inducible group (p < 0.05). Mortality was not different in 3 groups compared with no VT/VF group. We found that monomorphic VT group had significantly higher MACE as compared to others and also predicted recurrence of VT and AICD shock and showed a trend towards significance for prediction of mortality. Inducible patients on AICD had mortality similar to noninducible group. Conclusion: Induction of monomorphicVT/polymorphicVT with 3extrastimuli is associated with a higher number of MACE events on follow up. Induction of monomorphicVT predicts recurrence of VT/ICD shock.

A Young Healthy Woman with Supraventricular Tachycardia Reveals an Underlying Left Ventricular Non-compaction Cardiomyopathy: A Rare Case Report

LVNC (left ventricular non-compaction) is a rare congenital cardiomyopathy with a reported incidence of 0.05% in adults. It can occur in isolation or affect both ventricles. It’s characterized by prominent LV trabeculae and deep intertrabecular recesses which are filled with blood from the ventricular cavity without evidence of communication to the epicardial coronary artery system. Frequent premature supra ventricular tachycardia as unique finding in LVNC cardiomyopathy is rare manifestation of this disease. We report a case of a frequent persistent supraventricular tachycardia as first manifestation of a patient with LVNC cardiomyopathy in a young healthy woman who despite radio frequency ablation therapy of the supraventricular tachycardia remains symptomatic. The patient was later placed on medical therapy based on a non-cardio selective beta-blocker with a good clinical outcome without recurrent of supra-ventricular arrythmias.

Drug therapy and efficacy of heart failure caused by supraventricular tachycardia in infants / 中国小儿急救医学

Objective:To investigate the effect of drug therapy on heart failure caused by supraventricular tachycardia(SVT) in infants.Methods:Fifty-five infants with heart failure caused by SVT, including 24 boys and 31 girls, were treated at Beijing Children′s Hospital of Capital Medical University from January 2014 to December 2021.The drug treatment effects of heart failure caused by SVT were analyzed.Results:The average age of 55 infants at the first diagnosis was 5.8 months(1-11 months). All of them had heart failure, including three cases of atrial flutter, 23 cases of atrial tachycardia(13 cases of disordered atrial tachycardia and ten cases of monomorphic atrial tachycardia), and 29 cases of paroxysmal supraventricular tachycardia.Ultrasonic cardiogram showed that the left ventricular diameter increased and/or left ventricular systolic function decreased.Anti-heart failure therapy was effective in 55 cases(100.0%). Anti-arrhythmic drug therapy: atrial flutter and atrial tachycardia were mainly treated by controlling ventricular rate, digitalis combined with metoprolol was effective in 21 cases(80.8%, 21/26), digitalis alone was effective in four cases(15.4%, 4/26), and sotalol was effective in one case(3.8%, 1/26); paroxysmal supraventricular tachycardia was mainly treated with sinus rhythm conversion.The success rates of conversion were: ATP 20.7%(6/29), ATP combined with digitalis 26.1%(6/23), propafenone combined with digitalis 42.9%(3/7), amiodarone combined with digitalis 60.0%(3/5), and sotalol 92.9%(12/13). During follow-up period for 1 to 12 months, heart failure symptoms of all 55 cases(100.0%) improved, and ultrasonic cardiogram of 53 cases(96.3%)returned to normal.Conclusion:Anti-heart failure and anti-arrhythmic drugs for infants with heart failure caused by SVT need to be selected individually.Atrial tachycardia, especially disordered atrial tachycardia, is sensitive to digitalis.Sotalol can be used to treat refractory SVT.

Radiofrequency ablation for infants with incessant ventricular tachycardia and heart failure / 中国小儿急救医学

Objective:To investigate the effect of radiofrequency ablation on infants with incessant ventricular tachycardia(IIVT) and heart failure.Methods:Twenty-eight infants with IIVT combined with heart failure admitted to Beijing Children′s Hospital of Capital Medical University from January 2006 to December 2021 were selected, including 16 boys and 12 girls; 26 cases were treated with radiofrequency ablation.The characteristics of IIVT and heart failure and the results of radiofrequency ablation were analyzed.Results:The average age of the first diagnosis of 28 infants was 13.9 months old, and all of them had heart failure.Eleven infants had cardiogenic shock, three infants had cardiogenic syncope, two infants had respiratory failure for respiratory support, and one infant died.Color Doppler echocardiography showed that the left ventricular diameter increased and/or left ventricular systolic function decreased.Anti-heart failure treatment was effective in 27 cases(96.4%), electrical cardioversion in five cases, effective in three cases, and anti-arrhythmic drugs were effective in 17 cases(60.7%). Twenty-six cases(92.9%, 26/28) were treated with radiofrequency ablation, with immediate success in 23 cases(88.5%, 23/26) and effective in three cases(11.5%, 3/26). During the follow-up period for 3 to 36 months, cardiac function returned to normal in 25 cases(96.2%, 25/26) and recurred in three cases(11.5%, 3/26 cases), which were cured after radiofrequency ablation again.Temporary complications of atrioventricular block occurred in one case(3.8%, 1/26). In 26 cases of surgical children, 15 cases were measured by X-ray two-dimensional mapping and 11 cases were measured by three-dimensional mapping.The cumulative X-ray exposure was 87.0(51.5, 151.5) mGy and 1.2(0, 15.9) mGy, respectively, and the dose area product was 39.8(19.2, 427.8) μGy/m 2 and 2.8(0, 44.3) μGy/m 2.The cumulative X ray exposure and the dose area product were significantly reduced under the three-dimensional mapping method( P<0.001). Conclusion:The infants with IIVT combined with heart failure are prone to serious complications, and the effects of cardioversion and anti-arrhythmic drugs are limited.Radiofrequency ablation should be performed as soon as possible after heart failure is controlled.The application of three-dimensional mapping technology in surgery can significantly reduce ionizing radiation.

Progress on clinical diagnosis of postural tachycardia syndrome in children / 中国小儿急救医学

Postural tachycardia syndrome (POTS) is a common disease of the autonomic nervous system in childhood, characterized by sudden changes in posture or prolonged standing with abnormally rapid heart rate and chronic orthostatic intolerance such as headache, chest tightness or pain, fatigue, sighing, amaurosis, or syncope.The diagnostic criteria for POTS in children are different from those in adults, and the standing test and the head-up tilt test are still used as effective diagnostic tools.In recent years, it has been reported that significant progress has been made in the diagnosis of POTS in children, including characteristics of population age, changes of disease circadian rhythm, modify standing test applied in local hospitals, differential diagnosis of POTS by biological markers, etc.Early and rapid diagnosis of POTS in children can help children with timely intervention, which is conducive to the improvement of prognosis and quality of life.

Individualized treatment for pediatric postural orthostatic tachycardia syndrome / 中国小儿急救医学

Postural orthostatic tachycardia syndrome (POTS) is a common condition that results in syncope among children and adolescents.It primarily manifests as a range of chronic orthostatic intolerance symptoms, accompanied by an abnormal increase in heart rate upon standing, significantly impacting the learning and quality of life in young individuals.POTS demonstrates diversity and heterogeneity in clinical symptoms, underlying pathophysiological mechanisms, and associated complications.Consequently, relying on experience to treatment often fails to achieve desired clinical outcomes.Delving deeper into potential clinical biomarkers capable of predicting POTS treatment efficacy and implementing individualized treatment approaches are crucial for enhancing patient prognosis and quality of life.This review provided a comprehensive exploration of the latest research findings on biomarkers for predicting POTS clinical outcomes, aiming to offer perspectives and approaches for the clinical treatment of pediatric POTS.

Research progress on biomarkers for diagnosis and treatment of neurally mediated syncope in children / 中国小儿急救医学

Vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) are the most common types of neurally mediated syncope, which is prevalent in school-age children and adolescents, seriously affecting their daily life and learning quality, and increasing the risk of accidental injury due to syncope.Because the clinical signs of these two diseases are very similar, diagnosis between VVS and POTS can easily be confused, and the pathogenesis of these two is not the same, the curative effect of empirical treatment is not very ideal.Therefore, finding a sensitive and reliable method for differential diagnosis and formulating individualized treatment plans have become an urgent clinical need in pediatrics syncope.In recent years, pediatricians utilizing biomarkers for study on differentiating VVS from POTS and predicting individualized treatment outcomes have made significant progress, thus promoting the precise treatment of syncope in children.