Radiofrequency catheter ablation in infants </=18 months old: when is it done and how do they fare?: short-term data from the pediatric ablation registry

The success rate of radiofrequency catheter ablation in Wolff-Parkinson-White-Syndrome patients: A systematic review and meta-analysis

INTRODUCTION

radiofrequency catheter ablation (RFA) is the first-line therapy for symptomatic Wolff Parkinson White (WPW) patients according to the American Heart Association. We conducted this study to assess the success rate, recurrence rate, and rate of complications associated with the utilization of radiofrequency catheter ablation for managing patients with WPW.

METHOD

We searched PubMed, Cochrane library, Web of Science and Scopus databases using all identified keywords and index terms through 4 January 2022. We included all studies conducted on WPW patients who were treated with ablation. We conducted the analysis using Open Meta Analyst and MedCalc version 19.1.

RESULTS

Among 2268 unique articles identified, only 11 articles met our inclusion criteria. The pooled effect estimates showed high success rate (94.1%[95%CI:92.3-95.9], p < 0.001)), low recurrence rate (6.2% [95%CI:4.5-7.8, p < 0.001]) and low rate of complications (1%[95%CI:0.4-1.5, p < 0.001]).

CONCLUSION

RFA showed a high success rate, low recurrence rate and low rate of complications in WPW patients.

Clinical Approach to Symptomatic and Asymptomatic Patients with Ventricular Pre-excitation

Despite extensive knowledge of the physiopathology of ventricular pre-excitation, management of asymptomatic patients with this condition remains controversial.

Ablation in Pediatric Patients and in Association with Congenital Heart Disease

Transcatheter ablation (TA) for treatment of pediatric tachyarrhythmias was first introduced in the early 1990s. Since then, its use as an alternative to antiarrhythmic drugs to treat supraventricular tachycardias caused by accessory pathway has been increasing. Nowadays, TA can be performed with high success rates and low complication rates even in very young children. Recently, the use of different types of energy (radiofrequency and cryoenergy), special ablation catheters, and 3D nonfluoroscopic mapping systems equipped with high technological tools has further improved safety and efficacy of TA, especially in difficult substrates and in patients with congenital heart disease.

Safety, Efficacy, and Intermediate-Term Outcomes of Radiofrequency Catheter Ablation for Pediatric Arrhythmias

Background

Arrhythmias are one of the reasons for emergency hospitalization among the pediatric population. Radiofrequency ablation is a major advancement in the management of children with cardiac arrhythmias.

Objectives

Our study was designed to describe the outcomes of catheter ablation in the pediatric population for atrial and ventricular arrhythmias in our center.

Methods

All patients between two and 18 years of age undergoing radiofrequency ablation after failed medical management for arrhythmias in our institute were included. Age less than two years, no previous medical management, and complex congenital heart disease were excluded. Baseline and electrophysiological characteristics were recorded. The patients were followed up for a clinical or electrocardiographic recurrence of arrhythmia.

Results

Thirty-six patients were included (mean age 12.8 ± 3.9 years (range 2-18 years), male 56%, average weight 36.39 ± 11.02 kg). The mean follow-up duration was 27.7 ± 15.9 months (range 3-58). Five-point five percent (5.5%) had tachycardiomyopathy. The arrhythmias included (1) atrioventricular nodal re-entrant tachycardia (AVNRT, n=16, 44%), (2) atrioventricular reciprocating tachycardia (AVRT, n=14, 39%), (3) atrial tachycardia (AT, n=2, 5.5%), (4) ventricular premature complexes (VPCs, n=2, 5.5%), (5) atrial flutter (AFL, n=1, 3%), and (6) ventricular tachycardia (VT, n=1, 3%). A transeptal puncture was done in 10 patients (28%). 3D mapping was done in six patients. The mean radiofrequency (RF) pulses were 2.3 ± 1.3. The acute procedural success rate was 100%. The long-term success was 97.2%. One (2.7%) developed recurrence. No major complications were reported.

Conclusion

Catheter ablation in the pediatric population is a safe procedure and can be done with more feasibility and fewer complications when done in experienced hands.

Pediatric Catheter Ablation: Characteristics and Results of a Series in a Tertiary Referral Hospital

INTRODUCTION AND OBJECTIVES

Catheter ablation has become the treatment of choice in an increasing number of arrhythmias in children and adolescents. There is still limited evidence of its use at a national level in Spain. The aim was to describe the characteristics and results of a modern monocentric series form a referral tertiary care centre.

METHODS

Retrospective register of invasive procedures between 2004 and 2016 performed in patients under 17 years and recorded clinical characteristic, ablation methodology and acute and chronic results of the procedure.

RESULTS

A total of 291 procedures in 224 patients were included. Median age was 12.2 years, 60% male. Overall, 46% patients were referred from other autonomous communities. The most frequent substrates were accessory pathways (AP) (70.2%,>50% septal AP localization) and atrioventricular nodal reentrant tachycardia (AVNRT) (15.8%). Congenital and acquired heart disease was frequent (16.8%). Cryoablation was used in 35.5% of the cases. Overall acute success of the primary procedure was 93.5% (AP 93.8%; AVNRT 100%). Redo procedures after recurrence were performed in 18.9% of all substrates, with a long-term cumulative efficacy of 98.4% (AP 99.3%; AVNRT 100%). One (0.37%) serious complication occurred, a case of complete atrioventricular block.

CONCLUSIONS

Our study replicated previous international reports of high success rates with scarce complications in a high complexity series, confirming the safety and efficacy of pediatric catheter ablation in our environment performed at highly experienced referral centers.

Safety and Efficacy of Radiofrequency Catheter Ablation for Tachyarrhythmia in Children Weighing Less Than 10 kg

An increasing number of children are undergoing radiofrequency catheter ablation (RFCA) for tachyarrhythmia. However, infants and toddlers undergoing RFCA are often resistant to medication or need to eliminate arrhythmia substrate, and the risks of RFCA complications are still high in infants and toddlers. From April 2008 and December 2016, 285 children who underwent radiofrequency catheter ablation (RFCA) were stratified according to body weight (group A, less than 10 kg, n = 22; group B, over 10 kg, n = 263) and the clinical features of RFCA were retrospectively reviewed in these groups. Indications for RFCA included drug-refractory tachyarrhythmia or symptomatic tachycardia and tachycardia-induced cardiomyopathy. The acute success rate in this group was 90.9%, with a relatively low recurrence rate (15.0%) after 7.0 ± 1.6 years follow-up. We performed RFCA using only 2-4 catheters in all cases. Major complications included complete right bundle branch block in one patient. No significant differences in rates of success, recurrence, or complications were noted between children weighing less and more than 10 kg. RFCA is safe and efficacious for tachyarrhythmia even in patients weighing less than 10 kg.

Utility of Echocardiography in Detecting Silent Complications After Pediatric Catheter Ablations

Although transcatheter arrhythmia ablation (TCA) has been performed in children for over two decades, guidelines for routine use of post-ablation transthoracic echocardiography (TTE) are absent. We sought to determine the efficacy of TTE after apparently uneventful TCA procedures in detecting adverse findings and identify predisposing factors. A retrospective review of clinical and procedural data on patients who underwent TCA for supraventricular arrhythmias from 2000 to 2015 was performed. Pre- and post-ablation TTE data were reviewed. All patients were followed at 1 week, 6 and 12 months post-TCA. A repeat TTE was performed at 12 months on patients in whom post-TCA abnormalities were found. Patients were divided into two groups: those with and without adverse TTE findings and comparative analysis between variables was performed. Data on 252 patients, 52% males, mean age 14 ± 3 years were analyzed. New onset or worsening atrioventricular valve regurgitation occurred in 17 (6.7%), a small pericardial effusion in 3 (1.2%) and worsened ventricular function in 2 patients (0.8%). Patients in the complication group had higher mean number of ablations (22.6 ± 15.3 vs. 16.8 ± 9.2, p 0.001) and required longer duration of ablation (sec) (254.6 ± 256.4 vs. 180.9 ± 158.9, p < 0.001). TCA location (including coronary sinus), energy source, arrhythmia substrate, and a trans-septal approach were noncontributory to any adverse findings. Routine post-ablation TTE uncovers asymptomatic self-resolving abnormalities that typically do not require any intervention.

The efficacy of radiofrequency ablation in the treatment of pediatric arrhythmia and its effects on serum IL-6 and hs-CRP

The aim of this study was to investigate the efficacy of radiofrequency ablation in the treatment of pediatric arrhythmia and to assess the changes in serum interleukin-6 (IL-6) and hs-CRP levels after treatment. Hundred and six children with tachyarrhythmia who were admitted to Xuzhou Children's Hospital from November, 2014 to December, 2015 were recruited for study. The efficacies of radiofrequency in the treatment of different types of arrhythmia were analyzed. Successful ablation was found in 104 cases (98.11%) and recurrence was found in 7 cases (6.73%). Among 62 cases of atrioventricular reentrant tachycardia (AVRT), successful ablation was found in 60 cases (96.77%) and recurrence was found in 3 cases (4.84%). Among 33 cases of atrioventricular nodal reentrant tachycardia (AVNRT), successful ablation was found in 33 cases (100%) and recurrence was found in 2 cases (6.06%). Among 5 cases of ventricular tachycardia (VT), successful ablation was found in 5 cases (100%) and no recurrence was found. Among 4 cases of atrial tachycardia (AT), successful ablation was found in 4 cases (100%) and recurrence was found in 1 case (25%). Among 2 cases of atrial flutter (AFL), successful ablation was found in both (100%) and recurrence was found in 1 case (50%). After operation, the levels of IL-6 and hs-CRP were increased and were continually increased within 6 h after operation. The levels of IL-6 and hs-CRP at 24 h after operation were reduced but still higher than preoperative levels. The duration of radiofrequency and ablation energy were positively correlated with the levels of IL-6 and hs-CRP, while the number of discharges was not significantly correlated with either. In conclusion, radiofrequency ablation is a safe and effective treatment for pediatric arrhythmia. Postoperative monitoring of IL-6 and hs-CRP levels is conducive to understanding postoperative myocardial injury and inflammatory response.

Non-fluoroscopic cardiac ablation of neonates with CHD

In current practice, children with anatomically normal hearts routinely undergo fluoroscopy-free ablations. Infants and children with congenital heart disease (CHD) represent the most difficult population to perform catheter ablation without fluoroscopy. We report two neonatal patients with CHD in whom cardiac ablations were performed without fluoroscopy. The first infant had pulmonary atresia with intact ventricular septum with refractory supraventricular tachycardia, and the second infant presented with Ebstein's anomaly of the tricuspid valve along with persistent supraventricular tachycardia. Both patients underwent uncomplicated, successful ablation without recurrence of arrhythmias. These cases suggest that current approaches to minimising fluoroscopy may be useful even in challenging patients such as neonates with CHD.

Morphometry of the triangle of Koch and position of the coronary sinus opening in cadaveric fetal hearts

AIMS

The aim of the present study was to determine the variations in the position of the coronary sinus (CS) ostium in normal cadaveric fetal (28 weeks or more) hearts and to assess the impact that these variations had on the dimensions of the triangle of Koch (TK).

METHODS

This cross-sectional analytical study was conducted on 28 fetal hearts. The dimensions and area of the TK were calculated by two methods, M1 (anatomical) and M2 (clinical). The position of the CS was defined with respect to the tendon of Todaro. Differences between M1 and M2 were estimated using the paired T test. Pearson's correlation coefficient and the adjusted correlation coefficient were used to estimate the strength of association between measurements made by the methods.

RESULTS

Ten (35.7%) cadavers were male and 18 (64.3%) female. The mean gestational age was 32.4±3.3 weeks. Using M1, the mean dimensions of the triangle in millimeters (mm) were 9.2±2.2, 6.6±1.8, and 6±2.4 respectively for a, b and c. Similarly, the dimensions using M2 were 7±2.1, 4.7±1.5, and 4.8±2.2. The area in mm² was 20.4±10.4 and 11.7±6.7 using M1 and M2 respectively. All measurements were significantly greater with M1. All correlation coefficients were high and significant. The CS ostium and tendon of Todaro maintained a relatively constant positional relationship.

CONCLUSIONS

Significantly higher values were noted in the dimensions of TK using M1. High significant positive correlations were observed in measurements made by the two methods. The CS ostium was relatively constantly placed within the TK.

Predictors of Pharmacological Therapy of Ectopic Atrial Tachycardia in Children

Ectopic atrial tachycardia (EAT) is a relatively common type of supraventricular tachycardia in the pediatric population, and it can be resistant to antiarrhythmic drugs and lead to tachycardia-induced cardiomyopathy (TIC) if not properly managed. The purpose of this study was to determine the predictors of the response to pharmacological therapy in children with EAT. From January 2009 to April 2014, 115 children were admitted to our hospital with a diagnosis of EAT and placed on antiarrhythmic drugs. We examined the clinical history, response to therapy, and follow-up of the children. The incidence of TIC secondary to EAT was 22.6% (n = 26) in children. Incessant EAT accounted for 44.3% of all patients. Control of EAT with antiarrhythmic therapy was achieved in 73.9% (n = 85) of the children. The combination of sotalol and propafenone performed well in controlling EAT in children [complete control in 35 (49.3%) of 71]. The mean time of conversion to sinus rhythm was 24 days, and the mean duration of therapy was 11 months in children with resolution. Multivariate predictors of the control of EAT were age at presentation (OR 0.289, P = 0.038) and tachycardia type (OR 0.276, P = 0.006). TIC occurs in 22.6% of children with EAT. Incessant EAT is more frequently complicated by TIC. Independent factors associated with a good response to pharmacological therapy include a younger age at presentation and non-incessant tachycardia in children with EAT.

Radiofrequency Catheter Ablation of Accessory Atrioventricular Pathways in Infants and Toddlers ≤ 15 kg

Accessory atrioventricular pathways (AP) are the most common substrate for paroxysmal supraventricular tachycardia in infants and small children. Up-to-date data on AP ablation in infants and small children are limited. The aim of the present study was to gain additional insight into radiofrequency (RF) catheter ablation of AP in infants and toddlers focusing on efficacy and safety in patients with a body weight of ≤ 15 kg. Since 10/2002, RF ablation of AP was performed in 281 children in our institution. Indications, procedural data as well as success and complication rates in children with a body weight ≤ 15 kg (n = 22) were compared with children > 15 kg (n = 259). Prevalence of structural heart anomalies was significantly higher among children ≤ 15 kg (27 vs. 5.7 %; p = 0.001). Procedure duration (median 262 vs. 177 min; p = 0.001) and fluoroscopy time (median 20.6 vs. 14.0 min; p = 0.007) were significantly longer among patients ≤ 15 kg. Procedural success rate did not differ significantly between the two groups (82 vs. 90 %). More RF lesions were required for AP ablation in the smaller patients (median 12 vs. 7; p = 0.019). Major complication rate was significantly higher in children ≤ 15 kg (9 vs. 1.1 %; p = 0.05) with femoral vessel occlusion being the only major adverse event in patients ≤ 15 kg. Catheter ablation of AP in children was effective irrespective of body weight. In children ≤ 15 kg, however, procedures were more challenging and time-consuming. Complication rate and number of RF lesions in smaller children were higher when compared to older children.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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 ablation on veno-arterial extracorporeal life support in treatment of very sick infants with incessant tachymyopathy

AIMS

To evaluate the use of extracorporeal membrane oxygenation (ECMO) in supporting infants who require radiofrequency ablation (RFA) for incessant tachyarrhythmias, with particular emphasis on modifications required to standard ablation techniques.

METHODS AND RESULTS

Three cases of RFA carried out in infancy on ECMO support were reviewed retrospectively. Two infants with permanent junctional reciprocating tachycardia (PJRT) and one with ventricular tachycardia (VT) presented in a low cardiac output state, owing to cardiomyopathy caused by incessant tachycardia. In each case antiarrhythmic drug therapy caused haemodynamic collapse, requiring emergency ECMO support. Drug therapy on ECMO was not successful. In one patient, the tachycardia was controlled on ECMO with antiarrhythmic drugs, but recurred following ECMO decannulation. Each patient had a successful RFA on ECMO support. Power delivery was low during ablation lesions. In the PJRT cases power as low as 3-5 Watts was effective. In the VT ablation, an irrigated tip RFA catheter was required when cooling remained poor even after temporarily stopping ECMO flow.

CONCLUSION

Extracorporeal membrane oxygenation provides a haemodynamically stable and safe platform for antiarrhythmic drug therapy and RFA in infants with incessant tachyarrhythmias. Once ECMO has been commenced, if the tachyarrhythmia remains difficult to control with antiarrhythmic drugs, RFA should be strongly considered, to avoid the risk of tachycardia recurrence following ECMO decannulation. Power delivery during ablation lesions may be low because of inadequate cooling of the catheter tip. Reducing or stopping flow in the ECMO circuit may not provide adequate cooling and an irrigated tip catheter may be required.

Optimizing outcomes of catheter ablation in infants and toddlers

Since the introduction of transcatheter ablation in the late 1980s, there has been significant technical development. With a very high success rate and low complication rate, ablation has now become the standard of care in children and adults. However, long-term data remain insufficient and the application of ablation therapy in small children is debatable. In this review, current treatment strategies and results in toddlers and infants will be discussed. There has been improvement in success rate and complication rate for ablation in small children. Technological advancements in non-fluoroscopic electroanatomical mapping systems (3D systems) have led to the reduction of radiation and have facilitated ablations in complex cases. However, long-term effects of ablation lesions in small children remain a potential concern.

Radiofrequency catheter ablation therapy in the young: current status

Since 1989, when radiofrequency ablation was introduced into clinical practice for pediatric patients with supraventricular tachycardias, radiofrequency catheter ablation techniques have evolved as the treatment of choice for many forms of tachycardia in young patients. This review discusses the current status of ablation therapy for the four most common forms of supraventricular tachycardias in children, including tachycardias based on accessory atrioventricular pathways, atrioventricular nodal reentrant tachycardia, atrial ectopic tachycardia and the permanent form of junctional reciprocating tachycardia. In addition, the report will focus on the current status and limitations of ablation therapy of ventricular tachycardias and atrial reentry tachycardias in patients after surgical correction of congenital heart defects.

Research accomplishments in pediatric electrophysiology: a historical review

Arrhythmia management in young patients plays a small but important role within the broader discipline of cardiac electrophysiology (EP). By virtue of its sharp focus on developmental cardiology, congenital heart defects, and hereditary channelopathies, pediatric EP has contributed in significant ways to improved understanding of rhythm disorders in patients of all ages. Scientific progress in the field was recently reviewed at the 2012 meeting of the Heart Rhythm Society, where historical details of pioneering investigations in pediatric EP were highlighted. In this article, we hope to summarize those details and acknowledge the roles of individuals and organizations that were instrumental in developing the subspecialty.

Radiofrequency catheter ablation for dyssynchrony-induced dilated cardiomyopathy in an infant

The relationship between accessory pathway-mediated ventricular preexcitation and left ventricular dyssynchrony-induced dysfunction has been described in patients with Wolff-Parkinson-White (WPW) syndrome in the absence of sustained supraventricular tachycardia (SVT). Supraventricular tachycardia in infants is usually successfully suppressed with antiarrhythmic medications, but catheter ablation has ultimately been required as definitive treatment in medically resistant cases. Catheter ablation has not been described in young infants for dyssynchrony-related dilated cardiomyopathy in the absence of SVT. We describe a case of an infant with WPW who did not have sustained supraventricular tachycardia, but who developed rapid progression of ventricular dysfunction after birth. Preexcitation could not be medically suppressed but was successfully ablated. This was followed by complete resolution of ventricular dysfunction within 2 months.

Radiofrequency ablation of drug-refractory arrhythmias in small children younger than 1 year of age: single-center experience

The use of radiofrequency ablation (RFA) for the management of supraventricular tachycardia (SVT) in infants and small children remains controversial. The aim of this study was to evaluate the safety and efficacy of RFA in critically ill small children (<1 year of age) with drug-resistant tachycardia accompanied by arrhythmogenic cardiomyopathy and heart failure. The study included 15 patients age 5.3 ± 3.7 months. Wolff-Parkinson-White syndrome and atrial tachycardia were detected in eight (53.3 %) and seven (46.7 %) of patients, respectively. Patients with structural heart pathology, including congenital heart diseases and laboratory-confirmed myocarditis, were excluded from the study. Indications for RFA included drag-refractory SVT accompanied by arrhythmogenic cardiomyopathy and heart failure. Unsuccessful ablation was observed in two 1-month-old patients who underwent successful ablation 3 months later. The follow-up period ranged from 0.5 to 8 years (average 3.9). Only one patient (6.7 %) had tachycardia recurrence 1 month after RFA. The short- and long-term RFA success rates were 86.7 and 93.3 %, respectively. The study did not show any procedure-related complications. Heart failure disappeared within 5-7 days. Complete normalization of heart chamber sizes was documented within 1 month after effective RFA. A three-dimensional CARTO system (Biosense Webster, Inc., USA) was used in three patients with body weight >7 kg. The use of the CARTO system resulted in a remarkable decrease of the fluoroscopy time without vascular injury or other procedure-related complications in all cases. Our study suggests that RFA may be considered the method of choice for SVT treatment in small children when drug therapy is ineffective and arrhythmogenic cardiomyopathy progresses.

Single-catheter radiofrequency ablation of a permanent junctional reciprocating tachycardia in a premature neonate

A 34-week premature neonate presented with drug-refractory permanent junctional incessant tachycardia and haemodynamic compromise. The patient underwent successful radiofrequency catheter ablation using a single-catheter approach. The child remains in sinus rhythm, without pharmacological treatment, 2 years after the procedure.

Outcomes of interventional electrophysiology in children under 2 years of age

BACKGROUND

Despite the increasing utilisation of interventional electrophysiology in adults and older children with arrhythmias, there are few data reflecting the safety and efficacy of this procedure in the age group under 2 years.

AIM

We describe our experience in assessing the efficacy and safety with this group of children.

METHODS

We undertook a retrospective review of all infants under 2 years of age who underwent an interventional electrophysiology procedure between 1995 and 2009 to determine indications, procedural details, short- and long-term success, and complication rate.

RESULTS

A total of 23 interventional electrophysiology procedures were performed in 17 patients initially under 2 years of age. Of these, three patients had congenital heart disease. The most common indication was arrhythmia resistant to pharmacological agents (59%), with the remaining cases being arrhythmia complicated by cardiovascular instability (41%). There was initial success in 15 patients after the first procedure, with early recurrence in four. Following six repeat procedures, there was long-term success in 15 patients (88%), with three repeat procedures being performed after 2 years of age. There was one non-procedural death related to persisting arrhythmia. There were three minor complications. In one patient, cryotherapy was used successfully.

CONCLUSIONS

The interventional electrophysiology procedure is a viable therapeutic option in infants under 2 years with arrhythmia resistant to other conventional medical management.