Supraventricular Tachycardia In Children Research Articles

Supraventricular Tachycardia, Types and Immediate Management; Experience at a Tertiary Care Hospital of South Punjab

Objectives: The objective of this study was to determine efficacy of different optimal adenosine doses in children presenting with supraventricular tachycardia (SVT) at a tertiary care hospital. Methods: A descriptive case series design was undertaken at the Department of Cardiology at the Chaudhry Pervez Elahi Institute of Cardiology in Multan between June 2021 and June 2022. Both genders, age groups less than 14 years, and patients with SVT. The data collection procedure involved the use of a specialized proforma to record the findings of the study. Adenosine was quickly dispensed in escalating doses of 100, 200, and 300 μg/kg. The reaction was captured using a 12-lead ECG, and instances of pre-excitation were noted. The success of the therapy was assessed by identifying a sustained sinus rhythm for a period exceeding three minutes as a positive outcome. Results: A total of 71 participants were included in the study. Out of these, 55 (77.5%) were males. 33.8% presented with a predisposing factor. The most common predisposing factor was LRTI and diarrhea in 47 (66.2%) patients. As per our findings, out of 71 patients who were administered 100 ug per kg of adenosine for SVT, 27 (38.0%) while the remaining refractory 42 patients were administered 200 ug per kg of adenosine. Out of these 42, 26 (61.9%) reverted back to sinus rhythm i.e. 200 ug per kg dose of adenosine was effective in 61.9% cases of SVT. The remaining patients reverted back at 300 ug per kg dose of adenosine. Conclusion: A higher dose of 200 ug per kg was effective in 61.9% of cases. This indicates that a higher dose of adenosine is more effective in treating SVT in children. Additionally, the study found that LRTI and diarrhea were the most common predisposing factors for SVT in children. These findings can be useful in improving the management of SVT in children, especially when considering the optimal dose of adenosine for treatment. Keywords: Adenosine, Supraventricular tachycardia, Pediatric cardiology, Dose optimization, Predisposing factors Sinus rhythm

Inhaled Short-Acting Beta Agonist Treatment-Associated Supraventricular Tachycardia in Children: Still a Matter of Concern in Pediatric Emergency Departments?

Inhaled selective short-acting β-2 agonists (SABA), such as salbutamol, are the rescue treatment of choice for the relief of symptoms of acute asthma exacerbations: one of the leading causes of pediatric emergency department admission and hospitalization. Cardiovascular events, including supraventricular arrhythmias, are the most frequent side effects reported with inhaled SABA in children with asthma and are the main reason for a continuing debate about their safety, despite their widespread use. Although supraventricular tachycardia (SVT) is the most common potentially serious dysrhythmia in children, the incidence and risk factor of SVT after SABA administration is currently unknown. We here reported three cases and conducted a review of the literature in an attempt to gain insight into this issue.

Radiofrequency catheter ablation for paroxysmal supraventricular tachycardia in children: Insights on its safety and efficacy from a lower middle-income country.

OBJECTIVE: Radiofrequency catheter ablation (RFCA) is a safe and effective treatment for paroxysmal supraventricular tachycardia in adults. However, data on its use in children, particularly from low- and middle-income countries, are limited. This study aimed to evaluate the safety and efficacy of RFCA in children with paroxysmal supraventricular tachycardia from Vietnam. METHODS: A prospective study was conducted from January 2009 to July 2016 at the University Medical Center, Ho Chi Minh City, Vietnam. Ninety-five children diagnosed with paroxysmal supraventricular tachycardia were enrolled; 90 patients underwent cardiac electrophysiology and RFCA. The patients were followed up for 3-12 months, with a mean follow-up period of 7.5 ± 2.3 months. RESULTS: The average age of the patients was 10.5 ± 3 years, with the youngest patient being 4 years old; 46.3% of the patients were female and 53.7% were male. The patients' average weight was 35.2 ± 9.6 kg. Atrioventricular reentrant tachycardia accounted for 72.6% of the cases and atrioventricular nodal reentrant tachycardia for 27.4% of the cases; no patients had atrial tachycardia. The success rate of RFCA was 98.9% (89/90 patients). During the 12-month follow-up, 5.6% of the patients experienced recurrence but were successfully treated with a second ablation. No severe complications were reported during the procedure and follow-up. CONCLUSIONS: This study found RFCA to be a safe and effective treatment for paroxysmal supraventricular tachycardia in children. It demonstrated a high success rate and low recurrence and complication rates for RFCA in children, thereby highlighting the potential advantages of the procedure as a treatment option.

A Multicenter Retrospective Evaluation of Specialized Laboratory Investigations in the Workup of Pediatric Patients With New-Onset Supraventricular Tachycardia

IntroductionSpecialized laboratory evaluation of supraventricular tachycardia in children may occur, but the utility is unknown. The study objectives are to assess the type, frequency, and results of specialized laboratory testing performed in pediatric patients presenting with new-onset supraventricular tachycardia. We hypothesized that when specialized laboratory testing occurs (particularly for cardiac failure, toxicologic, inflammatory, and thyroid diseases), the results are generally within normal limits. MethodsThis is a retrospective descriptive study using an electronic health record database (TriNetX, Inc). We collected and evaluated the following data of subjects aged younger than 18 years with a first-time supraventricular tachycardia diagnosis: demographics, diagnostic codes, deaths, and laboratory codes/results (natriuretic peptide B, natriuretic peptide B prohormone N-terminal, troponin I, toxicology testing, inflammatory markers, and thyroid studies). ResultsA total of 621 subjects (524 [84.4%] without laboratory testing, 97 [15.6%] with laboratory testing) were included. Thyroid studies (65 [10.5%]) were the most frequent laboratory study performed followed by cardiovascular specific studies (35 [5.6%]), inflammatory markers (21 [3.4%]), and toxicology tests (10 [1.6%]) (P = .002). Obtained laboratory testing was more frequent with older subjects, females, and need for emergency, hospital, and critical care services. DiscussionCardiac-specific and noncardiac laboratory testing is frequently ordered for pediatric patients who present with supraventricular tachycardia. Thyroid studies were the most common laboratory testing ordered, but abnormal results only occurred in less than a quarter of subjects. These findings may highlight a quality improvement opportunity for emergency nurses and practitioners in the practice of obtaining laboratory tests to better reflect high-value evidence-based care for this vulnerable population.

Evaluation of Clinical Course and Maintenance Drug Treatment of Supraventricular Tachycardia in Children During the First Years of Life. A Cohort Study from Eastern Germany.

Supraventricular tachycardia (SVT) is considered the most common cause of arrhythmia in children and infants. Regarding the likelihood of a spontaneous resolution of SVTs during the first years of life, drug treatment aims to bridge the time until children 'grow out' out of the arrhythmia. The choice of antiarrhythmic agents and the planning of maintenance therapy are mainly based on clinical experience and retrospective single- and multi-institutional analyses and databases from all over the world approaching differently to this topic. The current study aimed to evaluate the clinical course, pharmacological treatment strategies, and constellations of risk for recurrences in the management of SVTs in children aged 3 < years. The database of the Heart Center Leipzig, Department of Pediatric cardiology, was searched for pediatric patients aged < 3years with a clinically documented SVT between 2000 and 2019 that received pharmacologic treatment. Patients with complex congenital heart disease or arrhythmias following cardiac surgery were excluded. 69 patients were included. Pharmacologic treatment, follow-up schedule, recurrences, outcomes, and risk factors for complicated courses are reported. Drug therapy of SVTs in young children remains a controversial topic with heterogeneous treatment and follow-up strategies applied. Risk factors for recurrences and/or stubborn clinical courses are difficult rhythm control with 3 or more antiarrhythmic drugs, ectopic atrial tachycardias, and a first occurrence of the SVT in the fetal period. Prospective studies are needed to sufficiently evaluate optimal treatment strategies.

Supraventricular tachycardias in neonates and infants: factors associated with fatal or near-fatal outcome.

Prognosis of supraventricular tachycardias in neonates and infants is thought to be excellent with rare fatal outcomes. Nevertheless, initial management can be challenging. The aim of this study was to perform a retrospective analysis in neonates/infants with non-pos-toperative supraventricular tachycardias regarding risk factors for clinical outcome and type of antiarrhythmic drug therapy. The data of 157 patients aged < 1 year who presented between 2000 and 2015 with symptomatic tachycardias were retrospectively reviewed. Pharmacological therapy was successful in 151 patients (96%); 1 patient (1%) required catheter ablation and 5 patients (3%) died (1 death linked to hemodynamical reasons after effective arrhythmia control). Serious complications following acute medical therapy occurred in 4 patients of survivors. Patients with complications or death had a lower bodyweight, more frequent intrauterine tachycardia, transplacental therapy, urgent caesarian section, higher PRISM II score, longer period to control tachycardia, more frequent proarrhythmia, and major adverse event-defined as life-threatening event without a documented new arrhythmia-compared to the group without complications. There was no significant difference between the groups regarding prematurity, structural heart disease, and type of tachycardia. Proarrhythmia occurred in 6 cases and was related to intravenous drug use with class IC antiarrhythmics in 3/6 cases, digoxin in 2/6 cases, and amiodarone in 1/6 cases. ECG signs of impending proarrhythmia without new-onset arrhythmia requiring cessation of therapy were detected in 6 patients.Conclusion: Although rare, non-post-operative supraventricular tachycardia in neonates and infants might be a serious disease. Acute intravenous pharmacological treatment to control tachycardia might pose a risk for fatal or near-fatal outcome. Detection of proarrhythmia related to class IC antiarrhythmics in neonates might be especially difficult and requires alertness. What is Known • Prognosis of supraventricular tachycardias in children are thought to be excellent with fatal outcomes being rare. • Mortality is increased in the very young and in those with structural heart disease. What is New • Complicated outcome of non-post-operative supraventricular tachycardias in neonates is associated with lower bodyweight, age, prenatal tachycardia, higher PRISM II score, longer period to control tachycardia, and proarrhythmia. • Detection of class IC proarrhythmic effect is especially difficult in neonates because of their narrow QRS and warrants alertness.

Acute outcomes of three-dimensional mapping for fluoroscopy reduction in paediatric catheter ablation for supraventricular tachycardia.

Catheter ablation is a safe and effective therapy for the treatment of supraventricular tachycardia in children. Current improvements in technology have allowed progressive reduction in radiation exposure associated with the procedure. To assess the impact of three-dimensional mapping, we compared acute procedural results collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to published results from the Prospective Assessment after Pediatric Cardiac Ablation study. Inclusion and exclusion criteria from the Prospective Assessment after Pediatric Cardiac Ablation study were used as guidelines to select patient data from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to compare acute procedural outcomes between cohorts. Outcomes assessed include procedural and fluoroscopy exposure times, success rates of procedure, and complications. In 786 ablation procedures, targeting 498 accessory pathways and 288 atrioventricular nodal reentrant tachycardia substrates, average procedural time (156.5 versus 206.7 minutes, p < 0.01), and fluoroscopy time (1.2 versus 38.3 minutes, p < 0.01) were significantly shorter in the study group. Success rates for the various substrates were similar except for manifest accessory pathways which had a significantly higher success rate in the study group (96.4% versus 93.0%, p < 0.01). Major complication rates were significantly lower in the study group (0.3% versus 1.6%, p < 0.01). In a large, multicentre study, three-dimensional systems show favourable improvements in clinical outcomes in children undergoing catheter ablation of supraventricular tachycardia compared to the traditional fluoroscopic approach. Further improvements are anticipated as technology advances.

НАДЖЕЛУДОЧКОВЫЕ ТАХИКАРДИИ, СИНДРОМ ВОЛЬФА-ПАРКИНСОНА-УАЙТА У ДЕТЕЙ РЕСПУБЛИКИ БЕЛАРУСЬ: ВОЗРАСТНЫЕ И ПОЛОВЫЕ ОСОБЕННОСТИ, ВЫЯВЛЕНИЕ, ЭЛЕКТРОФИЗИОЛОГИЧЕСКАЯ СТРУКТУРА

The goal is to establish the frequency of supraventricular tachycardias in children of the Republic of Belarus, to determine the structure and characteristics of these rhythm disturbances. An in-depth study of the properties of the conduction system of the heart was carried out by performing in the course of the esophageal electrophysiological study 108 children. A more rare detection of SVT in children in the neonatal period, in the first year of life and maximum detection at the age of 17 years, a comparatively rare finding (11.8 %) of concomitant pathology in children with SVT.

Supraventricular tachycardia in children from the perspective of a specialised between-hospital transport team

AimsThe aim of this study is to establish the incidence of supraventricular tachycardia (SVT) as a main reason for between-hospital transfer in children, as well as to describe the clinical presentation, prognosis and treatment, risk factors presenting with haemodynamic compromise, and to propose a specific management protocol for the transport. MethodsA retrospective observational study was conducted on all patients with supraventricular tachycardia transferred by the Hospital Vall d’Hebron Sistema de Emergencias Médicas Pediátricas (SEM-P) between January 2005 and June 2017. ResultsDuring the study period, 67 (0.9%) patients (out of a total number of 7348 transfers) suffered from SVT. The median age was 57 days (2 h-18 years old). There was clinical evidence of cardiogenic shock on admission in 14 (20.9%) patients. Age ≤1 year was the only independent risk factor associated with presenting with cardiogenic shock on admission, with an OR of 10.2 (95% CI: 1.2–89.9; p = 0.004). The majority of patients could be treated appropriately by the local hospital team, except for oral intubation and cardioversion that were performed mainly by the transport team on arrival at the local hospital. Median stabilisation time was 35 min (9–169), and median total transport time was 30 min (9–165). ConclusionsOnly 0.9% of transport cases are due to SVT, but this can be highly demanding as patients can be critically ill. Age ≤1 year was the only independent risk factor associated with presenting with cardiogenic shock on admission. Coordination between the local and the transport teams is crucial for a good clinical outcome.

Delayed adenosine therapy is associated with the refractory supraventricular tachycardia in children

ObjectivesTo study the association of time intervals on adenosine therapy with the occurrence of refractory supraventricular tachycardia (SVT) in children. MethodsWe reviewed 334 episodes of presumed SVT requiring adenosine in children (<18 years) who visited 4 academic hospital emergency departments (EDs) from July 2013 through June 2017. Refractory SVT was defined as an SVT episode persisting after 2 doses of adenosine. Clinical and electrocardiographic findings, and symptom-to-adenosine (symptom-to-ED plus ED-to-adenosine) time of refractory and responsive SVT episodes were compared. Multivariable logistic regression was performed to identify factors associated with the occurrence of refractory SVT. ResultsOf 211 SVT episodes, 42 episodes of refractory SVT (19.9%) were noted (overall sinus conversion rate, 79.6%). The refractory episodes were associated with a higher frequency of known structural heart diseases (9.5% vs. 1.8%; P = 0.030) and a longer median ED-to-adenosine time (15.5 vs. 11.0 min; P = 0.018). The association of the ED-to-adenosine time with refractory SVT remained significant after adjustment (for increment of 1 min; aOR, 1.02; 95% CI, 1.007–1.04). ConclusionsDelayed adenosine therapy is associated with the occurrence of refractory SVT in children, supporting the need for prompt adenosine therapy.

Diagnosis and Acute Therapy of Supraventricular Tachycardia in Children

Diagnosis and Acute Therapy of Supraventricular Tachycardia in Children

Electroanatomic mapping-guided catheter ablation of atrial tachycardia in children with limited/zero fluoroscopy.

Atrial tachycardia (AT) is an uncommon cause of supraventricular tachycardia in children and it is often resistant to medical therapy. Catheter ablation can be curative in children with AT. However, experience of ablation of pediatric AT is still very limited. The aim of this study, which is the largest series from a single center, was to assess the efficacy and safety of ablation of AT using an electroanatomical-mapping system. It was a retrospective review of 39 children with AT who underwent catheter ablation procedure using the EnSite Velocity system (St. Jude Medical, St. Paul, MN, USA) between July 2012 and April 2017. The mean patient age was 13.32±6.82 years. The location of AT was right sided in 25 and left sided in 13, and both sides in one patient. The mean procedure time was 184.23±60.19 min. Fluoroscopy was not used in 25 of 39 patients. The mean fluoroscopy time in the remaining patients was 5.53±5.22 min. Radiofrequency (RF) ablation was used in 22, cryoablation was used in 10, and both RF and cryoablation were used in seven. Acute success was achieved in 34 patients (87.2%). During a mean follow-up of 51.35±12.62 months, AT recurred in five patients. These patients underwent second ablation procedures and four of them were successful. Final success was achieved in 33 out of 39 patients (84.6%). There were no complications except for one patient who had an uneventful pericardial needle injury during transseptal puncture without effusion. Catheter ablation of AT in children can be performed safely and effectively with a limited fluoroscopy using electroanatomical mapping systems.

Abdominal Pain as an Initial Manifestation of Paroxysmal Supraventricular Tachycardia in Children

Objectives: The aim of this study was to evaluate the importance of abdominal pain in children with paroxysmal supraventricular tachycardia (PSVT). Methods: The authors reviewed the medical records of patients aged between three and 18 years old, who were diagnosed and treated for PSVT between March, 2011 and February, 2016. According to the presence of abdominal pain, they were grouped and analyzed for the difference of patient’s age, gender, interval between symptom onset and diagnosis, response to adenosine infusion, and the relationship with levels of N-terminal fragments of pro-brain natriuretic peptide (NT-proBNP). Results: A total of 43 patients (24 males and 19 females) were registered and the mean age at diagnosis of PSVT was 10.65 ± 4.81 years old. Although palpitation was the most common symptom (n = 29, 67.4 %), abdominal pain was also common (n = 18, 41.9%) with more frequent symptoms under 10 years old (n = 15/16, 93.8% versus n = 3/27, 11.1% in older than 10 years old). The PSVT patients with abdominal pain (group 1) were younger, had more frequent vomiting, less palpitation, and longer time to diagnosis of PSVT than subjects without this complication (group 2). In group 1, the level of NT-proBNP was shown significantly higher than group 2 (776.07 ± 913.57 versus 93.72 ± 51.25 pg/mL, P < 0.001). Conclusions: Abdominal pain may be an initial presentation of PSVT in children, especially under 10 years old.

Can troponin-I be used as an independent predictor of cardiac dysfunction after supraventricular tachycardia in children with structural normal heart?

Introduction. Elevated cardiac troponin gives excellent accuracy in the identification of myocardial damage in children, but it can also be elevated in a series of other diseases. Case report. We presented two children thirteen years of age with a high serum level of troponin-I after an acute episode of supraventricular tachycardia. We analyzed troponin- I levels in correlation with the maximum heart rate, duration of tachycardia and systolic left ventricular function (ejection fraction and fractional shortening). Conclusion. Abnormal troponin level can be seen in children with sustained supraventricular tachycardia and normal heart. Caution is advised in diagnosing cardiac dysfunction in children with supraventricular tachycardia and elevated troponin levels.

Efficacy and safety of three-dimensional electroanatomical mapping system for catheter ablation of paroxysmal supraventricular tachycardia in children

Objective: To evaluate the efficacy and safety of three-dimensional electroanatomical mapping system for catheter ablation of paroxysmal supraventricular tachycardiain (PSVT) children. Methods: Clinical data from 187 children with paroxysmal supraventricular tachycardia undergoing radiofrequency catheter ablation in our department between January 2012 and April 2016 were analyzed. Among the patients, 91 cases were treated with traditional two-dimensional X-ray radiofrequency ablation, 96 cases were treated with radiofrequency ablation guided by three-dimensional electroanatomical mapping system. Postoperative electrocardiogram and echocardiography follow-up was performed at 1, 3, 6, 12, and 24 months. The success rate, recurrence rate, complication rate, operation time and amount of X-ray exposure were compared between the two groups. Kaplan-Meier survival curve was used to analyze the PSVT-free survival rate of the patients between the 2 groups. Results: The mean follow-up time was (739±92) days. The success rate (95.8%(92/96) vs. 94.5%(86/91), P=0.912), recurrence rate (5.4%(5/92) vs. 4.7%(4/86), P=0.807), complication rate (4.2%(4/96) vs. 5.5%(5/91), P=0.379), operation time ((73±31)min vs. (79±36)min, P=0.124) were similar between the two groups. However, X-ray exposure time ((8.1±2.9)min vs. (21.3±8.4)min, P=0.026), amount of X-ray ((23±11)mGy vs. (58±23)mGy, P=0.013) were significantly lower in the three-dimensional electroanatomical mapping system group than in the traditional two-dimensional X-ray radio frequency ablation group. PSVT-free survival rate was similar between the two groups (χ(2)=0.060, P=0.807) . Conclusion: Three-dimensional electroanatomical mapping system is safe and effective for radiofrequency ablation of paroxysmal supraventricular tachycardia in children, and can significantly reduce the amount of radiation as compared to the traditional two-dimensional X-ray radiofrequency ablation.

Electroanatomic Mapping-Guided Catheter Ablation of Supraventricular Tachycardia in Children with Ebstein's Anomaly.

In Ebstein's anomaly (EA), tachycardia substrates are complex, and accessory pathway (AP) ablations are often challenging. This study demonstrates the utility of the EnSite Velocity system (St. Jude Medical, St Paul, MN) in the catheter ablation of supraventricular tachycardia in children with EA. Twenty patients [Female/Male = 8/12, median age 11.5years (2.6-18)] with EA who underwent catheter ablation guided by the EnSite Velocity system between December 2011 and December 2016 were retrospectively evaluated. Five patients had severe EA, and two of them were at Fontan palliation pathway. The most common indications for ablations were palpitations/syncope and treatment-resistant arrhythmias. Thirty-one tachycardia substrate foci (21 manifest AP, 2 concealed AP, 4 Mahaim AP, 3 focal atrial tachycardias, and 1 typical atrioventricular nodal reentrant tachycardia) were detected in 20 patients. There were multiple tachycardia substrates in 11 patients (55%). The patient-based acute procedure success rate was 19/20 (95%), and the tachycardia-based success rate was 30/31 (97%). The mean procedure time was 170 ± 43min (90-265). Fluoroscopy was not used in 15 (75%) patients. The mean fluoroscopy time in the remaining five patients was 3.6 ± 2.9min (0.7-7.8). During a mean follow-up of 35.1 ± 20.3months (6-60), tachycardia recurred in four patients (4/19, 21%). No complications were seen. Catheter ablation of arrhythmias can be performed effectively and safely in pediatric EA patients by using a limited fluoroscopic approach with the help of electroanatomical mapping systems. However, the rate of tachycardia recurrence at follow-up remains high.

Arrhythmia-Induced Cardiomyopathy.

Heart failure affects 1–2% of the population and is associated with elevated morbidity and mortality. Cardiac arrhythmias are often a result of heart failure, but they can cause left-ventricular systolic dysfunction (LVSD) as an arrhythmia-induced cardiomyopathy (AIC). This causal relationship should be borne in mind by the physician treating a patient with systolic heart failure in association with cardiac arrhythmia. This review is based on pertinent publications retrieved by a selective search in PubMed (1987–2017) and on the recommendations in current guidelines. The key criterion for the diagnosis of an AIC is the demonstration of a persistent arrhythmia (including pathological tachycardia) together with an LVSD whose origin cannot be explained on any other basis. Nearly any type of tachyarrhythmia or frequent ventricular extrasystoles can lead, if persistent, to a progressively severe LVSD. The underlying pathophysiologic mechanisms are incompletely understood; the increased ventricular rate, asynchronous cardiac contractions, and neurohumoral activation all seem to play a role. The most common precipitating factors are supraventricular tachycardias in children and atrial fibrillation in adults. Recent studies have shown that the causal significance of atrial fibrillation in otherwise unexplained LVSD is underappreciated. The treatment of AIC consists primarily of the treatment of the underlying arrhythmia, generally with drugs such as beta-blockers and amiodarone. Depending on the type of arrhythmia, catheter ablation for long-term treatment should also be considered where appropriate. The diagnosis of AIC is considered to be well established when the LVSD normalizes or improves within a few weeks or months of the start of targeted treatment of the arrhythmia. An AIC is potentially reversible. The timely recognition of this condition and the appropriate treatment of the underlying arrhythmia can substantially improve patient outcomes.

Paroxysmal Supraventricular Tachycardia in Children : The Role of Infectious Diseases and Its Relationship to Serum Enzyme

The records of 28 children whose first episode of paroxysmal supraventricular tachycardia occurred before 12 years (median age 10 months) were reviewed. There were 17 males and 11 females. In 17 cases the first attack occurred before the first year and in 11 of these it occurred after the first year. One case had congenital heart disease (ASD). The WPW syndrome was diagnosed in 3 cases. When first seen, most of the infants presented with signs of incipient or manifest congestive heart failure. In almost nine-tenth of cases there was an increased of serum enzymes (lactic dehydrogenase, creatine-phosphokinase and glutamic oxaloaccetic transaminase. Digitals was effective against congestive heart failure and when continued, might prevent failure during subsequent attacks. Antiarrhythmic agents other than digitals were not used. It is recommended to continue digitalis treatment for at least one year in all patients with SVT, whether or not the first episode terminated spontaneously.

P761Catheter ablation of supraventricular tachycardias in children using a limited fluoroscopic approach

P761Catheter ablation of supraventricular tachycardias in children using a limited fluoroscopic approach

An analysis of clinical characteristics and acute treatment of supraventricular tachycardia in children from a multicenter study

Objective: The study assessed the clinical characteristics and response to acute intravenous antiarrhythmic drug therapy of supraventricular tachycardia (SVT) in children. Methods: This was a multicenter prospective descriptive study including 257 children from First Hospital of Tsinghua University, Peking University First Hospital, Children's Hospital Affiliated to Capital Institute of Pediatrics and Beijing Anzhen Hospital who received intravenous antiarrhythmic drug therapy for SVT from July 2014 to February 2017. The clinical and tachycardia features, response to intravenous antiarrhythmic drug therapy of these children were characterized. Statistical analyses were performed using t test, Mann-Whitney U test, χ(2) test and H test. Results: The onset of SVT occurred at any age with a distribution with positive skewness, 57.6% (n=148) children<1 year, 17.5% (n=45) children1~<3 years, 10.5% (n=27) children 3~<6 years and 14.4% (n=37) children ≥ 6 years of age. The percentages of SVT types were 49.4% (n=127) for atrioventricular reentry tachycardia (AVRT), 4.3% (n=11) for atrioventricular nodal reentry tachycardia (AVNRT), 26.8% (n=69) for unclassified paroxysmal SVT and 19.5% (n=50) for atrial tachycardia (AT), respectively. Tachycardia-induced cardionyopathy (TIC) secondary to SVT developed in 30 of 225 (13.3%). Left ventricular ejection fraction (LVEF) of the 27 children attacked by TIC returned to normal after successful control of SVT (41.1%±6.3% vs. 60.3%±9.2%, t=-10.397, P=0.000). Complete termination of SVT by antiarrhythmic drugs was achieved in 164 of 257 (63.8%), partial termination rate was 18.7% (48 of 257) and failure to terminate rate was 17.5% (45 of 257). Propafenone (complete cardioversion in 98 (73.1%) of 134) and amiodarone (complete cardioversion in 23 (76.7%) of 30) showed better efficacy for SVT termination than adenosine (complete cardioversion in 26 (44.1%) 59) (χ(2)=20.524, P=0.000). Paroxysmal SVT had a higher termination rate on pharmacological therapy than AT (67.1% vs. 50.0%, χ(2)=6.337, P=0.042). Patients of different age groups had significantly different response to antiarrhythmic therapy (χ(2)=13.904, P=0.031). Children<1 year of age showed the least response to antiarrhythmic drug therapy with complete termination in 51 (55.4%) of 92. Adverse effects occurred in 9 patients (3.5%): Four patients had severe hypotensive shock using propafenone (n=3) and adenosine (n=1), and 3 patients had sinus arrest using adenosine. Conclusion: Most (57.6%) children with SVT have their first clinical episode within 1 year of age, and AVRT is the most common type. TIC occurs in 13.3% of children with SVT. Intravenous antiarrhythmic drug therapy has a 63.8% complete termination rate for children with SVT and incidence of adverse effects is 3.5%. Propafenone and amiodarone are more effective for SVT termination in children than adenosine. Serious adverse effects may occur when using propafenone.