Radiofrequency Catheter Ablation In Children Research Articles

Efficacy of Radiofrequency Catheter Ablation versus Antiarrhythmic Drugs in Treating High Burden Premature Ventricular Contractions in Children with Structurally Normal Heart

Abstract Background Scarce literature on whether antiarrhythmic drugs (AADs) or radiofrequency catheter ablation (RFCA) is more efficacious when treating idiopathic high burden premature ventricular contractions (PVCs) in children with many questions remain unanswered in this age group. Objectives To compare the efficacy of RFCA versus AADs on high burden idiopathic PVCs in children. Methods A total of 60 eligible child ≤18 years with High burden PVCs (≥10% of total beats per day) that were treated by either AADs (group A) or RFCA (group B). Both Baseline and followup clinical symptoms were collected, Physical examination, repeat standard ECG, standard or 12-lead Holter recording, and echocardiography were performed. Results Among RFCA (n = 30) and AADs (n = 30) groups, treatment success was 80.0% and 20.0% respectively, while AADs medications cessation was 73.3% and 26.7% respectively, the differences were statistically significant. Conclusion RFCA appears to be more efficacious than AADs in PVC reduction and consequently AADs medications cessation postablation. Performing RFCA in children with classical mapping and navigation was a safe and highly effective therapeutic option. Abbreviations AADs: antiarrhythmic drugs; BBB: bundle branch block; CCB: calcium channel blocker; ECG: electrocardiogram; LVEDD: left ventricular end-diastolic dimension; LVEF: left ventricular ejection fraction; LVESD: left ventricular end-systolic dimension; LVOT: left ventricular outflow tract; NSVT: non sustained ventricular tachycardia; PVC: premature ventricular contraction; RFCA: radiofrequency catheter ablation; RV: right ventricular/ventricle; RVOT: right ventricular outflow tract

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.

P1010Electrophysiological characteristics of paroxysmal tachycardia in children with short PQ interval

Abstract Introduction It is well known that children with short PQ interval can have different types paroxysmal tachycardia (PT). Combination of short PQ interval with PT is called Lown-Ganong-Levine (LGL) syndrome. We have hypothesized that in children with short PQ interval electrophysiological types of PT do not correlate with shortening of PQ interval. Purpose The aim of the study was to assess the PT types based on results of the electrophysiological studies and radiofrequencycatheter ablation (RFA), and to estimate the AV conduction parameters and their dynamic changes before and after the procedure. Materials and methods of research: 55 children with supraventricular tachycardia (SVT) and short PQ interval were examined. The examination included:ECG, 24-hour Holter monitor, transesophageal pacing study (TEPS), intracardiac electrophysiological study (EPS). 22 children underwent RFA procedure. During the period of the study 55 children had 111 TEPS and 28 EPS studies. Results 21 (38,2%) children had orthodromic AV reentrant tachycardia with accessory pathway (AVRT), 27 (49,1%) had typical (slow-fast) AV nodal reentrant tachycardia (AVNRT), 2 (3,6%) had atypical AVNRT, 1 (1,8%) had combination of typical and atypical AVNRT, 1 (1,8%) had atrial ectopic tachycardia combined with atypical AVNRT, 4 (7,3%) had spontaneous atrial fibrillation or atrial flutter, 3 (5,4%) had combination with typical AVNRT and 1 child (1,8%) had AVRT. PQ interval measured 107,2 ms (83–120ms). 22 (40%) children underwent RFA-13 children with typical AVNRT, 9 with AVRT. In children with AVNRT tachycardia cycle length was 229–425 ms (309,8±67,6ms). Primary RFA was effective in 10 (76,9%) children. The AVNRT recurrence was found in 3 (13,6%) cases after 7,2±4,3 month from the time of procedure. After slow pathway ablation PQ interval length didn't change (107,1±9,1ms compared to 108,2±7,1ms; p=0,2). No change occurred with the maximal rate of 1:1 conduction through AV node (187,8±14,8 imp/min compared to187±12,5 imp/min; p=0,2). Effective refractory period of AV node (AVNERP) increased by a small amount (288,9±14ms, compared to 266±42,7ms; p=0,06). 9 (40,9%) children underwent RFA of the accessory pathway (AP). In all of the cases there were concealed AP with the left-sided localization. AVRT cycle length was 259–382 ms (304,2±41,2ms). After RFA of concealed AP maximal rate of 1:1 conduction through AV node increased by a small amount (220±26,4 imp/min compared to 191,2±23,6 imp/min) and AVNERP decreased (256,7±25,2ms compared to 268,6±38,9ms; p=0,09).After RFA of AP PQ interval length didn't change (110±5,9ms compared to 110±5ms; p=0,1). Conclusion In children with short PQ interval PT was associated with dual physiology of AV connection or with concealed AP. After the successful RFA in children with AVNRT and AVRT there was no PQ interval normalization, which remained short in all examinations. Thus, short PQ- interval is a co-existing phenomenon in children with AVNRT and AVRT.

Application of transseptal puncture to radiofrequency catheter ablation in children with left accessory pathway induced paroxysmal supraventricular tachycardia

Objective To explore the value of transseptal puncture for left-sided accessory pathway in radiofrequency catheter ablation in children with paroxysmal supraventricular tachycardia(PSVT). Methods Thirty-three patients with PSVT who had underwent radiofrequency catheter ablation in the First Affiliated Hospital, Sun Yat-Sen University from January 2012 to December 2017 were retrospectively analyzed.All the cases were treated by transaortic approach(transaortic group) or transseptal approach(transseptal group). The immediate success rates, total fluoroscopy time and radiation exposure between 2 groups were compared, and the perioperative complications and recurrence rates were observed between 2 groups. Results Thirty-three cases of children were enrolled, 22 cases were male and 11 cases were female.Nineteen cases were treated by transaortic approach(transaortic group), while 18 cases were treated by transseptal approach(transseptal group), including 4 recurrent cases in the transaortic group who were switched to transseptal approach because of previous treatment failure.The age was (10.16±3.06) years and (10.67±2.20) years, and the weight was (37.68±14.28) kg and (37.33±8.64) kg, respectively.There were no significant diffe-rences in age and weight statistics between 2 groups(all P>0.05). The total fluoroscopy time was (20.16±11.41) minutes and (12.56±5.23) minutes, and the median dose of radiation exposure was 67.0 mGy and 33.5 mGy, respectively.The postoperative recurrence rate was 21% (4/19 cases) and 0 (0/18 cases), respectively.There were significant differences in total fluoroscopy time, radiation exposure and recurrence rate statistics between 2 groups(t=2.627, Z=-2.31, χ2=4.249, all P<0.05). No complications were found in both 2 groups. Conclusions It is safe and feasible by transseptal puncture for left-sided accessory pathway in radiofrequency catheter ablation in children with PSVT.Radiofrequency catheter ablation by transseptal approach could significantly reduce the postoperative recu-rrence rate, and should be the first choice for left-side accessory pathway in children. Key words: Child; Paroxysmal supraventricular tachycardia; Transseptal puncture; Left-sided accessory pathway; Catheter ablation

Electrophysiological study and radiofrequency catheter ablation in children with supraventricular tachycardias

Electrophysiological study and radiofrequency catheter ablation in children with supraventricular tachycardias

Clinical Features of Radiofrequency Catheter Ablation in Children with Atrioventricular Nodal Reentrant Tachycardia

Clinical Features of Radiofrequency Catheter Ablation in Children with Atrioventricular Nodal Reentrant Tachycardia

Efficacy and Safety of Radiofrequency Catheter Ablation of Tachyarrhythmias in 123 Children Under 3 Years of Age.

The risk-benefit ratio of radiofrequency catheter ablation (RFCA) in infants and toddlers remains controversial. Experience with RFCA in these patients is limited. This work is intended to describe the efficacy and safety of RFCA in children under 3 years of age with tachycardia complicated by drug resistance, drug intolerance, or tachycardia-induced cardiomyopathy. We retrospectively reviewed data from 123 consecutive children under 3 years of age (mean, 2.3 ± 0.8 years; weight, 13.6 ± 2.8 kg) with tachycardia complicated by drug resistance, drug intolerance, or tachycardia-induced cardiomyopathy; the children underwent an electrophysiology study between 1994 and 2014 at our center. Fifteen children had congenital heart disease, and 27 children were under 1 year of age. Among the 109 children who underwent RFCA, acute success rate (no inducible arrhythmia before procedure completion), 2-year rate of symptomatic tachyarrhythmia recurrence, and complication rate were assessed. Among the 123 children studied, 76.4% had atrioventricular reentrant tachycardia, 5.7% had atrioventricular nodal reentrant tachycardia, 2.4% had focal atrial tachycardia, 6.5% had atrial flutter, and 4.1% had idiopathic left ventricular tachycardia. For RFCA, the acute success rate was 94.5%, and the 2-year recurrence rate was 6.8%, without any major complications. RFCA appears to be an effective and safe therapeutic option in selected small children with tachycardia resistant to conventional medical management, tachycardia complicated by drug intolerance, or tachycardia-induced cardiomyopathy.

Radiofrequency catheter ablation can be performed with high success rates and very low complication rates in children and adolescents

Radiofrequency catheter ablation is a standard treatment for tachyarrhythmia in children. Recently, several centres using cryoenergy for ablation have reported high success and low complication rates, but an increased risk of recurrence of arrhythmia. The aim of this study was to report success, complications and recurrence rates for radiofrequency catheter ablation in children under current conditions. A retrospective cohort study of 333 consecutive children undergoing radiofrequency catheter ablation over the last two decades. Radiofrequency catheter ablation was performed successfully in 96.7% of patients, but was significantly less successful in patients with a right anterior or right anterolateral accessory pathway (81.8%). Overall mortality was 0%; there was only one (0.3%) major complication, a pericardial haemorrhage, and only 2.8% of the patients developed minor vascular complications at the puncture site. None of the patients developed a persistent atrioventricular block. Over a median observation time of 4.3 years (0.1; 17.8), recurrence of arrhythmia occurred in 9.3% of all patients, but 50% of children with right lateral accessory pathways. Radiofrequency catheter ablation can be performed with high success and very low complication rates in children. Recurrence rates are substantially lower than those reported for cryoablation in the literature.

Progress in the application of radiofrequency catheter ablation in children

Tachyarrhythmia is a common type of arrhythmia in children.Continuous of frequent tachy cardia can bring serious harm to children's physical and mental health.With the help of electrophysiological study,electrophysiological mechanisms of various arrhythmias have been stated constantly,while the medical technology develops rapidly.The treatment strategy in pediatric arrhythinia has undergone major reforms,and radiofrequency catheter ablation has come into being.Through the thermal efficiency of the radiofrequency current,radiofrequency catheter ablation can damage the arrhythmia foci or block the atrioventricular reentrant pathway,so achieve the purpose of cure.The clinical application of radiofrequency catheter ablation can avoid the inconvenience of antiarrhymic drugs.Comprehensive assessments of the impacts and possible prognosis should be achieved by clinicians.Strict indications are very important.Currently the ablation has matured in atrioventricular re entrant tachycardia,atrioventricular nodal reentrant tachycardia,ventricular tachycardia,atrial tachycardia and atrial flutter,with high successful rate and low recurrence rate.Complications are closely related to the experience of the surgeon. Key words: Tachyarrhythmia; Radiofrequency catheter ablation; Children

小児期WPW 症候群に対する 経皮的高周波カテーテルアブレーションの長期にわたる治療成績

小児期WPW 症候群に対する 経皮的高周波カテーテルアブレーションの長期にわたる治療成績

Radiofrequency Catheter Ablation in Children with Supraventricular Tachycardias: Intermediate Term Follow up Results

The Purpose of the StudyRadiofrequency (RF) catheter ablation represents an important advance in the management of children with cardiac arrhythmias and has rapidly become the standard and effective line of therapy for supraventricular tachycardias (SVTs) in pediatrics. The purpose of this study was to evaluate the intermediate term follow up results of radiofrequency catheter ablation in treatment of SVT in pediatric age group.MethodsA total of 60 pediatric patients (mean age = 12.4 ± 5.3 years, ranged from 3 years to 18 years; male: female = 37:23; mean body weight was 32.02 ± 12.3 kg, ranged from 14 kg to 60 kg) with clinically documented SVT underwent an electrophysiologic study (EPS) and RF catheter ablation at Children’s Hospital Mansoura University, Mansoura, Egypt during the period from January 2008 to December 2009 and they were followed up until October 2011.ResultsThe arrhythmias included atrioventricular reentrant tachycardia (AVRT; n = 45, 75%), atrioventricular nodal reentrant tachycardia (AVNRT; n = 6, 10%), and atrial tachycardia (AT; n = 9, 15%). The success rate of the RF catheter ablation was 93.3% for AVRT, 66.7% for AVNRT, and 77.8% for AT, respectively. Procedure-related complications were infrequent (7/60, 11.7%), (atrial flutter during RF catheter ablation (4/60, 6.6%); ventricular fibrillation during RF catheter ablation (1/60, 1.6%); transient complete heart block during RF catheter ablation (2/60, 3.3%)). The recurrence rate was 8.3% (5/60) during a follow-up period of 34 ± 12 months.ConclusionRF catheter ablation is an effective and safe method to manage children with SVT.

Novel method of signal analysis for ablation of Wolff-Parkinson-White syndrome

Identification of the site of successful radiofrequency catheter ablation (RFCA) for Wolff-Parkinson-White (WPW) syndrome may be subjective. The purpose of this study was to develop an automated signal analysis program to predict a successful ablation site. Patients who underwent successful RFCA for WPW from 2008- 2010 at our center were analyzed. Inclusion criteria were age <21 years, loss of preexcitation in <5 seconds, and sustained success at 3 months. Exclusion criteria were congenital heart disease and pacing during RFCA. The standard recording system signal was filtered into low frequency (LF 0-≤0.02 Hz) and high frequency (HF >0.02-≤0.45 Hz). Software identified the beginning of the HF signal, LF and R-wave peaks, LF/HF signal amplitude, and area under the HF/LF signals. Successful and unsuccessful (radiofrequency energy applied without accessory pathway block) signals were compared. Thirty patients were analyzed; 16 had both successful and unsuccessful signals, and 14 had a successful ablation with 1 radiofrequency application. Mean age was 13.7 ± 3.1 years, weight 54.9 ± 22.4 kg, and time to accessory pathway ablation 1.7 ± 1.4 seconds. Significant differences were found between successful and unsuccessful signals in area under HF signal, LF amplitude, LF to R time, HF ratio, and HF area × HF ratio. A receiver operating curve of HF area × HF ratio produced an area under the curve of 0.89. An HF area × HF ratio of 3.1 distinguished successful from unsuccessful signals with 100% specificity and 81% sensitivity. Automated signal analysis retrospectively differentiated successful from unsuccessful signals in patients undergoing RFCA for WPW. This software may improve the safety and efficacy of RFCA in children.

Results of radiofrequency catheter ablation in children and adolescent with tachyarrhythmia

Purpose : Radiofrequency catheter ablation (RFCA) has become an effective therapeutic modality for treating pediatric tachyarrhythmias. Using conventional RFCA catheters, ablation of parahisian accessory pathways may be difficult and have high risk for heart block. We reviewed the efficacy and complications of the RFCA in children and adolescent with arrhythmias including parahisian accessory pathways. Methods : We studied 48 patients (aged 2 years to 20 years) who had undergone RFCA from August 2003 to March 2007. We reviewed clinical findings, electrophysiologic studies, RFCA data, complications, and follow-up results of the patients. Results : Mean age of the patients was 13.1 years. Numbers and types of arrhythmias (age, acute success rate) were as follows: 19 WPW syndrome including 5 parahisian accessory pathways (13.7±4.6 yr, 18/19), 11 atrioventricular reentrant tachycardia with concealed bypass tract (12.3±5.0 yr, 10/11), 13 atrioventricular nodal reentrant tachycardia (12.6±4.4 yr, 13/13), 4 atrial flutter (13.0±7.4 yr, 3/4), and 1 ventricular tachycardia (20 yr, 1/1). Associated cardiac structural lesion was not detected in 48 patients. The recurrence rate was 6.5%, and the final success rate was 93.8%. Conclusion : These results suggest that RFCA is a highly effective treatment method in children and adolescent with tachyarrhythmia.

Electrophysiologic Characteristics and Radiofrequency Catheter Ablation in Children with Wolff‐Parkinson‐White Syndrome

The majority of cardiac arrhythmias in children are supraventricular tachycardia, which is mainly related to an accessory pathway (AP)-mediated reentry mechanism. The investigation for Wolff-Parkinson-White (WPW) syndrome in adults is numerous, but there is only limited information for children. This study was designed to evaluate the specific electrophysiologic characteristics and the outcome of radiofrequency (RF) catheter ablation in children with WPW syndrome. From December 1989 to August 2005, a total of 142 children and 1,219 adults with atrioventricular reentrant tachycardia (AVRT) who underwent ablation at our institution were included. We compared the clinical and electrophysiologic characteristics between children and adults with WPW syndrome. The incidence of intermittent WPW syndrome was higher in children (7% vs 3%, P=0.025). There was a higher occurrence of rapid atrial pacing needed to induce tachycardia in children (67% vs 53%, P=0.02). However, atrial fibrillation (AF) occurred more commonly in adult patients (28% vs 16%, P=0.003). The pediatric patients had a higher incidence of multiple pathways (5% vs 1%, P<0.001). Both the onset and duration of symptoms were significantly shorter in the pediatric patients. The antegrade 1:1 AP conduction pacing cycle length (CL) and antegrade AP effective refractory period (ERP) in children were much shorter than those in adults with manifest WPW syndrome. Furthermore, the retrograde 1:1 AP conduction pacing CL and retrograde AP ERP in children were also shorter than those in adults. The antegrade 1:1 atrioventricular (AV) node conduction pacing CL, AV nodal ERP, and the CL of the tachycardia were all shorter in the pediatric patients. This study demonstrated the difference in the electrophysiologic characteristics of APs and the AV node between pediatric and adult patients. RF catheter ablation was a safe and effective method to manage children with WPW syndrome.

Thermal-guided radiofrequency catheter ablation in children and adolescents

Radiofrequency (RF) catheter ablation for the treatment of supraventricular tachyarrhythmias in young patients has become standard therapy. Our initial experience with RF showed that, although it was effective, with only energy output used as a guide, we frequently developed impedance rises due to “boiling” at the tip of the electrode, with development of coagulum when the catheter was removed. This was especially true when delivering energy in areas of limited blood flow, (i.e., the coronary sinus) or when the catheter tip was positioned at 90° to the tissue plane. To examine the effects of catheter tip temperature monitoring with a themistor at the tip of the catheter, we compared results of RF prior to and following instituting this method. We procedure examined the results in 90 children who were “mechanism” matched in terms of their tachyarrhythmia and who had at least 3 months-follow-up evaluation. The non-temperature-monitored patients were taken from the immediate preceding period to prevent the “learning curve,” from biasing the results. Mechanisms included accessory connection (left free wall 18, septal 6, right free wall 8); atrioventricular node reentry tachycardia (AVNRT) 10; His ablation 3. Age and fluoroscopy time did not differ. However, the temperature-monitored group required fewer lesions (4.3 ± 4.8 vs 10.7 ± 8.9, P < .0005) and used more power (40.2 ± 9.8 versus 29.8 ± −7 W, P < .0005). Initial success was 82% in the nonmonitored group versus 98% in the temperature-monitored group ( P < .03). Recurrences in the nonmonitored group were not different from those in the monitored group (3 vs 1). In the left-sided pathways, successful temperature was 53.4 ± 2.3°C and in the right free wall 58.5 ± 2.8°C. No impedance rises occurred in the temperature-monitored group. In AVNRT, temperature monitoring appears to be less important, as the catheter tip is almost always parallel to the tissue plane and the large amount of blood passing through the tricuspid annulus acts as a heat sink to reduce the measured tip temperature. In a separate study of 49 patients with typical AVNRT, median age 14 years and with a 6-month follow-up evaluation, our best indicators of success were a typical M shaped pattern of the atrial electrograms recorded at the tricuspid annulus, with an atrial electrogram size about 50% that of the ventricular and the appearance of junctional ectopy during RF application. We had a 100% success rate, with one permanent atrioventricular block occuring in a 14-year-old patient who required a permanent pacemaker. In this study, total RF lesions were 7.3 ± 6.7 and power used was 38.8 ± 8.1 W. We conclude that overall success is higher with temperature monitoring with less lesions required and the ability to safely administer high energy without coagulum formation provided. This technique improves the safety of this procedure in young patients.

Accuracy of ECG Algorithms in Predicting Accessory Pathway Location Prior to Radiofrequency Catheter Ablation in Children With Wolff-Parkinson-White Syndrome. 122

Accuracy of ECG Algorithms in Predicting Accessory Pathway Location Prior to Radiofrequency Catheter Ablation in Children With Wolff-Parkinson-White Syndrome. 122

922-56 Radiofrequency Catheter Ablation Guided by Transesophageal Echocardiography in Children with Cavopulmonary Connection

Radiofrequency catheter ablation (RFCA) is a safe, effective therapy for accessory AV mediated tachycardia requiring precise positioning of the ablation catheter. Palliation of single ventricle with the Glenn or Fontan procedure creates obstacles for correct catheter placement. Transesophageal echocardiography(TEE) has been used to monitor RFCA in children without structural congenital heart disease (CHD) and during interventional catheterization procedures. This report describes our experience with TEE guidance of RFCA in children with palliated single ventricle. Biplane TEE imaging was used to guide mapping and RFCA in 4 children aged 1.5–13 yr. with wt 11–43 kg. Three patients had membranous tricuspid atresia (TA) with WPW and 1 patient had double inlet left ventricle (DILV) with a left atrial ectopic focus. All patients had previously undergone palliation for single ventricle: Glenn shunt (1) or modification of the Fontan procedure (3). On line TEE images guided 1-location of the tricuspid annulus in TA, 2- crossing of a surgically created ASD, 3-retrograde entry of the RV via a Glenn shunt, and 4- retrograde entry of the LV via a Stansel anastomosis. All 4 TEE guided ablations were successful with no early or late complications. Real time TEE images can successfully guide catheter placement in children with palliated single ventricle undergoing RFCA and is superior to fluoroscopy in identifying specific anatomic landmarks.

Follow-up of radiofrequency catheter ablation in children: Results in 100 consecutive patients

Objectives. The purpose of this study was to determine the outcome of a group of closely followed-up pediatric patients who had undergone radiofrequency ablation for cardiac arrhythmias.Background. Although radiofrequency ablation in children has been shows to be effective and safe in the short term, results of longer term follow-up of these children must he considered when determining the place of radiofrequency ablation in the management of pediatric arrhythmias.Methods. One hundred children aged 2 months to 17 years underwent a total of 119 radiofrequency ablation procedures for cure of tachycardia. Follow-up clinical data, electrocardiograms and 24-h Holter monitors were obtained and analyzed.Results. All patients were alive, and none were lost to follow-up after a mean follow-up of 21.5 months (range 6 to 50). Success at last follow-up included accessory pathways in 66 (89%) of 74 patients, atrioventricular (AV) node reentry in 15 (88%) of 17, intraatrial reentry in 2 (67%) of 3, atrial flutter in 3 (100%) of 3, atrial ectopic tachycardia in 2 (67%) of 3, junctional ectopic tachycardia in 1 (100%) of 1 and ventricular tachycardia in 2 (100%) of 2 (overall success, 90 [90%] of 100). All recurrences were observed within 6 months of ablation. Major and minor complicatons (7%) included chest burn (one patient), foot microembolus (two patients), hematoma without pulse loss (four patients), femoral arteriovenous fistula requiring repair (one patient) and transient Mobitz I AV block (one patient). Immediate success, recurrence and complication rates were similar in the ≥12-year old versus the < 12-year old group. Echocardiograms, available in 109 (92%) of 119 patients, showed possible procedure-related abnormalities in 2 (mitral regurgitation in 1, tricuspid regurgitation in 1, both mild), with no aortic insufficiency after 30 left-sided ablations performed by the retrograde approach. Follow-up Holter monitors, available in 77 (77%) of 100 patients, showed possible procedurerelated abnormalities in 5 (frequent atrial ectopic tachycardia in 2, atrial flutter in 1, accelerated ventricular rhythm in 2). There were no early or late deaths.Conclusions. In children, the risks of radiofrequency ablation are low at follow-up evaluation. Longer-term follow-up of children undergoing radiofrequency ablation will be necessary to determine whether coronary abnormalities or serious new arrhythmias will develop.

22 Significant reduction in the medical care costs associated with radiofrequency catheter ablation in children

22 Significant reduction in the medical care costs associated with radiofrequency catheter ablation in children

Biplanar transesophageal echocardiographic direction of radiofrequency catheter ablation in children and adolescents with the wolff-parkinson-white syndrome

Preliminary reports suggest that radiofrequency catheter ablation is a safe and effective method for the management of supraventricular tachyarrhythmias in children. 1 Transesophageal echocardiography (TEE) has recently been used to monitor various interventional cardiac catheterization procedures in children. The use of single-plane TEE has been described in 2 patients (aged 43 and 16 years) with Wolff-Parkinson-White (WPW) syndrome and left-sided accessory pathways undergoing radiofrequency ablation. 2 The present report summarizes our experience with biplanar TEE monitoring and guidance of radiofrequency catheter ablation in children and adolescents. The report focuses on the feasibility, safety and potential benefits of the procedure.