Single center experience of fluoroless AVNRT ablation guided by electroanatomic reconstruction in children and adolescents

Zero-Fluoroscopy Catheter Ablation of Supraventricular Tachycardias in the Pediatric Population

Catheter ablation (CA) of supraventricular tachycardias (SVTs) is conventionally performed with the aid of X-ray fluoroscopy. Usage of a three-dimensional (3D) electro-anatomical mapping (EAM) system and intracardiac echocardiography (ICE) enables zero-fluoroscopy ablation, eliminating the harmful effects of radiation. We retrospectively analyzed the feasibility, effectiveness and safety of zero-fluoroscopy radiofrequency and cryoablation of various types of SVTs in pediatric patients. Overall, in 171 consecutive patients (12.5 ± 3.9 years), 175 SVTs were diagnosed and 201 procedures were performed. The procedural success rate was 98% (193/197), or more precisely, 100% (86/86) for AVNRT, 95.8% (91/95) for AVRT, 94.1% (16/17) for AT and 100% (2/2) for AFL. No complications were recorded. Follow-up was complete in 100% (171/171) of patients. During the mean follow-up period of 488.4 ± 409.5 days, 98.2% of patients were arrhythmia-free with long-term success rates of 98.7% (78/79), 97.5% (78/80), 100% (13/13) and 100% (2/2) for AVNRT, AVRT, AT and AFL, respectively. Zero-fluoroscopy CA of various types of SVTs in the pediatric population is a feasible, effective and safe treatment option.

Fluoroless catheter ablation of accessory pathways in adult and pediatric patients: a single centre experience

Catheter radio-frequency ablation (RFA) and cryo-ablation (CRA) procedures are an effective and safe treatment options for adult and pediatric patients with accessory pathway (AP) mediated tachycardias. Non-fluoroscopic techniques during catheter ablation (CA) procedures reduce potentially harmful effects of radiation. Our aim was to investigate the efficacy and safety of completely fluoroless RFA and CRA procedures in pediatric and adult patients with APs. Consecutive patients with AP-related tachycardia and high risk asymptomatic ventricular pre-excitation were assessed in retrospective analysis. Three-dimensional (3D) electro-anatomical mapping (EAM) and intra-cardiac echocardiography (ICE) were used as principal imaging modalities. Fluoroscopy was not used during any stage of the procedures. Among 116 included patients (22.76 ± 16.1 years, 68 patients < 19 years), 60 had left-sided APs, 16 right-sided APs and 40 septal APs. Altogether, 96 had RFA and 20 CRA procedures. The acute success rates (ASR) of RFA and CRA were 97.9% and 95%, respectively (p = 0.43), with recurrence rates (RR) of 8.33% and 40%, respectively (p < 0.0001). The outcome difference was principally driven by lower RR with RFA in septal APs (9.1% vs. 38.9%, p = 0.025). Pediatric patients with APs (12.21 ± 3.76 years) had similar procedural parameters and outcomes compared to adult patients. There were no procedure-related complications. In adult and pediatric patients with AP-related tachycardias, both CRA and RFA can be effectively and safely performed without the use of fluoroscopy. In addition, RFA resulted in better outcomes compared to CRA.

Fluoroless radiofrequency and cryo-ablation of atrioventricular nodal reentry tachycardia in adults and children: a single-center experience

BACKGROUND

Radiofrequency ablation (RFA) and cryo-ablation (CRA) have been traditionally performed with fluoroscopy which exposes patients and medical staff to the potential harmful effects of the X-ray. Therefore, we aimed to assess the feasibility, safety, and effectiveness of RFA and CRA of atrioventricular nodal reentry tachycardia (AVNRT) guided by the three-dimensional (3D) electro-anatomical mapping (EAM) system without the use of fluoroscopy.

METHODS

We analyzed 168 consecutive patients with AVNRT, 62 of whom were under 19 years of age (128 in RFA (age 34.04 ± 21.0 years) and 40 in CRA (age 39.41 ± 22.8 years)). All procedures were performed completely without the use of the fluoroscopy and with the 3D EAM system.

RESULTS

The acute success rates (ASR) of the two ablation methods were very high and similar (for RFA 126/128 (98.4%) and for CRA 40/40 (100%); p = 0.43). Total procedural time (TPT) was similar in RFA and CRA groups (75.04 ± 42.31 min and 73.12 ± 30.54 min, respectively; p = 0.79). Recurrence rates (1 (2.5%) and 8 (6.25%); p = 0.35) were similar. There were no complications associated with procedures in either group. In pediatric group, ASR (61/62 (98.38%) and 105/106 (99.05%), respectively; p = 0.69) and TPT (75.16 ± 42.2 min and 74.23 ± 38.3 min, respectively; p = 0.88) were similar to the adult group. High ASR was observed with both ablation methods (for RFA 49/50, 98%, and for CRA 12/12, 100%; p = 0.62] with very high arrhythmia-free survival rates (for RFA 98% and for CRA 100%; p = 0.62).

CONCLUSION

Based on these results, it can be suggested that fluoroless RFA or CRA guided by the 3D EAM system can be routinely performed in all patients with AVNRT without compromising safety, efficacy, or duration of the procedure.

State of Fluoroless Procedures in Cardiac Electrophysiology Practice

In the past decade, the use of interventional electrophysiological (EP) procedures for the diagnosis and treatment of cardiac arrhythmias has exponentially increased. These procedures usually require fluoroscopy to guide the advancement and frequent repositioning of intracardiac catheters, resulting in both the patient and the operator being subjected to a considerable degree of radiation exposure. Although shielding options such as lead gowns, glasses, and pull-down shields are useful for protecting the operator, they do not lessen the patient’s level of exposure. Furthermore, the prolonged use of lead gowns can exponentiate the onset of orthopedic problems among operators. Recent advancements in three-dimensional cardiac mapping systems and the use of radiation-free imaging technologies such as magnetic resonance imaging and intracardiac ultrasound allow operators to perform EP procedures with minimal or even no fluoroscopy. In this review, we sought to describe the state of fluoroless procedures in EP practice.

Intracardiac echocardiography versus fluoroscopy for endovascular and endocardial catheter navigation during cryo-ablation of the slow pathway in AVNRT patients

Background

A new zero-fluoroscopy technique for electrophysiology catheter navigation relying on intracardiac echocardiography (ICE) has been recently reported (Ice&ICE trial). We investigated potential differences in efficacy, safety or procedural performance between conventional fluoroscopy- and ICE-guided cryothermal ablation (CA) in symptomatic AVNRT patients.

Methods

Clinical and electrophysiological data of AVNRT patients included in the Ice&ICE trial (22 patients, 16 females; =zero-fluoroscopy group) were compared to those of consecutive AVNRT patients, who underwent fluoroscopy-guided CA (25 patients, 17 females; = fluoroscopy group) during the last 2 years in our institution.

Results

Slow pathway ablation or modulation was successful in all patients. Fluoroscopy time and radiation dose in the fluoroscopy group were 11.2 ± 9.0 min and 20.3 ± 16.2Gycm², whereas no fluoroscopy was used in the opposite group (p <  0.001, respectively). EPS duration was not different between the groups (zero-fluoroscopy:101.6 ± 40.2 min, fluoroscopy:99.4 ± 37.2 min, p = n.s.). Catheter placement time was significantly shorter in the fluoroscopy group (2.2 ± 1.6 min vs. 12.0 ± 7.5 min, p <  0.05), whereas cryo-application duration (from the first cryo-mapping to the last CA) was significantly shorter in the zero-fluoroscopy group (27.5 ± 37.0 min vs. 38.1 ± 33.9 min, p <  0.05). Mean cryo-mapping and CA applications were numerically lower in the zero-fluoroscopy group (CM:7.5 ± 5.7 vs. 8.8 ± 6.2; CA:3.1 ± 1.7 vs. 3.2 ± 2.0, p = n.s.). No major adverse events occurred in both groups. After 15.0 ± 4.2 months, arrhythmia recurrence was not different between the groups (4.5% vs. 8.0%, p = n.s.).

Conclusions

Zero-fluoroscopy ICE-guided EP catheter navigation shows comparable efficacy and safety to fluoroscopic guidance during CA in AVNRT patients. ICE visualization of catheters and endocardial structures within the triangle of Koch shortens the cryo-application duration, though time needed for catheter placement is longer, when compared with conventional fluoroscopic guidance, which results in similar mean EPS duration with both navigation techniques.

Trial registration

(German Clinical Trials Register ID: DRKS00011360; Registration Date 14.12.2016)

Electronic supplementary material

The online version of this article (10.1186/s12947-019-0162-2) contains supplementary material, which is available to authorized users.

Troponin T release comparing manually or magnetically guided radiofrequency ablation for AVNRT- a MAGMA AVNRT substudy

OBJECTIVES

Catheter ablation is regarded as first-line therapy for symptomatic atrioventricular nodal reentry tachycardia (AVNRT). Ablation induces intended myocardial damage and the extent of myocardial damage may differ between ablation methods. The objective of this MAGMA AVNRT(NCT00875914) substudy was to compare high-sensitive cardiac troponin T (hs-cTnT) levels as a surrogate marker for myocardial damage after manually guided (MAN) AVNRT ablation versus AVNRT ablation using remote magnetic navigation (RMN).

DESIGN

In total, 70 patients (mean age 44 ± 14 years, 26% male) undergoing catheter ablation for AVNRT in the MagMa-AVNRT-Trial were randomized to remote magnetic navigation (n = 34, 49%) or manually guided catheter ablation (n = 36, 51%). hs-cTnT was measured the day after the procedure.

RESULTS

The median follow-up time was 6.2 ± 1.1 years. Acute success was 100% in both groups. hs-cTnT release was significantly lower in the remote magnetic navigation group (52 ng/L versus 95 ng/L, p < .01), even though the ablation time was longer and number of applications was higher with remote magnetic navigation (4.2 min vs 2.8 min, p = .017; 4.9 vs 3.3 applications, p = .01). hs-cTnT released per minute ablation time was also lower with remote magnetic navigation (12 ng/L versus 34 ng/L, p < .01). Both groups exhibited similar clinical long-term follow up regarding recurrence and complications.

CONCLUSION

Remote magnetic navigation controlled catheter ablation of AVNRT has similar clinical outcome, but leads to less hs-cTnT release than manually guided catheter ablation. This might correspond to less unintended myocardial damage with RMN, which might be advantageous in complex ablation procedures.

Multicenter, randomized comparison between magnetically navigated and manually guided radiofrequency ablation of atrioventricular nodal reentrant tachycardia (the MagMa-AVNRT-trial)

BACKGROUND

Remote magnetic navigation (RMN) is attributed to diminish radiation exposure for both patient and operator performing catheter ablation for different arrhythmia substrates. The purpose of this prospective, randomized study was to compare RMN with manually guided catheter ablation for AV nodal reentrant tachycardia (AVNRT) regarding fluoroscopy time/dosage, acute and long-term efficacy as well as safety.

METHODS AND RESULTS

A total of 218 patients with AVNRT undergoing catheter ablation at three centers (male 34%, mean age 50 ± 17 years) were randomized to a manual approach (n = 113) or RMN (n = 105) using the Niobe^® magnetic navigation system. The primary study endpoint was total fluoroscopy time/dosage for patient and operator at the end of the procedure. Secondary endpoints included acute success, procedure duration, complications and success rate after 6 months. Fluoroscopy time and dosage for the patient were significantly reduced in the RMN group compared to the manual group (6 ± 6 vs. 11 ± 10 min; p < 0.001 and 425 ± 558 vs. 751 ± 900 cGycm², p = 0.002). A reduction in fluoroscopy time/dose also applied to the operator (3 ± 5 vs. 7 ± 9 min 209 ± 444 vs. 482 ± 689 cGycm², p < 0.001). Procedure duration was significantly longer in the RMN group (88 ± 29 vs. 79 ± 29 min; p = 0.03) and crossover from the RMN group to manual ablation occurred in 7.6% of patients (7.6 vs. 0.1%; p = 0.02). Acute success was achieved in 100% of patients in both groups. Midterm success after 6 months was 97 vs. 98% (p = 0.67). No complications occurred in both groups.

CONCLUSION

The use of RMN for catheter ablation of AVNRT compared to a manual approach results in a reduction of fluoroscopy time and dosage of about 50% for both patients and physicians. Acute and midterm success and safety are comparable. RMN is a good alternative to a manual approach for AVNRT ablation.

Comparison of 6-mm Versus 8-mm-Tip Cryoablation Catheter for the Treatment of Atrioventricular Nodal Reentrant Tachycardia in Children: A Prospective Study

Due to its safety profile, cryoablation (Cryo) for atrioventricular nodal reentrant tachycardia (AVNRT) is more commonly preferred over radiofrequency (RF) ablation in children in recent years. Recent studies demonstrated high long-term success rates comparable to radiofrequency ablation. The aim of this prospective study was to compare the efficacy and safety of an 8-mm-tip versus 6-mm-tip Cryo catheter in the treatment of AVNRT in children. A total of 125 consecutive patients over 10 years of age with AVNRT were included. EnSite system (St. JudeMedical, St Paul, MN, USA) was used to reduce or eliminate fluoroscopy. The acute procedural success was 100% in both groups. The prodecure duration for the 8-mm-tip group was shorter (151.6 ± 63.2 vs. 126.6 ± 36.7 min, p < 0.01, respectively). Fluoroscopy was used in only 7 patients. The mean follow-up duration was 14.6 ± 8.4 months (median 13.5 months, min. 3 months and max. 27 months). The recurrence rate for AVNRT was also comparable between the two groups (6-mm tip: 9.6 vs. 8-mm tip: 8%). Cryo of AVNRT is a safe and effective procedure with comparable acute and mid-term follow-up success rates using 6-mm and 8-mm-tip catheters in children. In addition, procedure duration is shorter with an 8-mm-tip Cryo catheter.

Radiofrequency catheter ablation of atrioventricular node reentrant tachycardia in children with limited fluoroscopy

BACKGROUND

Limited fluoroscopy cryo-ablation using a 3D electro-anatomical system (3DS) has been used for AVNRT in children. We aimed to facilitate a fluoroscopy limited approach of RF ablation of AVNRT in children.

METHODS

A retrospective study was performed of procedure parameters in children undergoing RF ablation of AVNRT in 75 consecutive children (June 2011 to November 2013 - Group A) using standard fluoroscopy techniques compared to those of 64 consecutive children (December 2013 to May 2015 - Group B), using a fluoroscopy limited approach with 3DS.

RESULTS

The acute success rate was 98.7% (74/75) and 98.4% (63/64) for groups A and B, respectively. The recurrence rate was 2.7% (2/74) and 0% (0/63) with a mean follow-up period of 45.5±12.1 and 14.3±6.1months for group A and group B, respectively. The mean procedure and fluoroscopy times were significantly lower for group B compared to group A (119±37 (43-203) and 0.83±1.04 (0.05-3.83) minutes versus 146±53 (72-250) and 16.1±8.9 (4.39-55) minutes, p<0.003 and p<0.0001, respectively). There were no ablation-related complications.

CONCLUSIONS

A fluoroscopy limited approach for RF ablation of AVNRT in children using a 3DS is easily acquired and adapted, and significantly reduces the fluoroscopy and procedure time with excellent efficacy, safety and low recurrence rate.

CONDENSED ABSTRACT

This study confirmed that a 3D mapping system (3DS) to guide ablations of AVNRT in children reduces radiation exposure. Combined, limited fluoroscopy and 3DS in a methodology that resembles the familiar conventional fluoroscopy approach for RF ablation of AVNRT in children is proposed. Combined limited fluoroscopy and RF-energy in children with AVNRT are associated with a shorter procedure time, minimal fluoroscopy time, a high success rate and a low recurrence rate.

How to Approach Difficult Cases of AVNRT

OPINION STATEMENT

Our approach to the ablation of atrioventricular nodal reciprocating tachycardia (AVNRT), the most common supraventricular tachycardia, is as follows: We first attempt ablation in the right atrial posteroseptum anterior to the coronary sinus ostium with a 4-mm non-irrigated tip catheter. If ablation within the triangle of Koch is unsuccessful with radiofrequency (RF), we switch to cryoablation and target a more superior (mid septal) region. We also utilize cryoablation if RF ablation produces transient VA block (absence of retrograde conduction during junctional rhythm) or a fast junctional rhythm (<350 msec). If cryoablation were to fail, or is not available, we would then suggest ablation within the coronary sinus targeting the roof (2-4 cm from the os) using a 3.5-mm irrigated tip catheter. If tachycardia were still inducible despite these measures, we would then proceed with transseptal puncture (given our greater experience with this over a retrograde aortic approach) and perform RF ablation along the posteroseptal left atrium and inferoseptal mitral annulus utilizing an irrigated tip catheter. In our experience, cryoablation reliably results in elimination of the slow pathway. The only left atrial ablation for AVNRT at our institution in the past year was performed because a patent foramen ovale allowed for rapid left atrial access, facilitating left atrial ablation of the slow pathway.

The Current State and Future Potential of Pediatric and Congenital Electrophysiology

Pediatric electrophysiologists specialize in the diagnosis and treatment of rhythm abnormalities in pediatric, congenital heart disease, and inherited arrhythmia syndrome patients. The field originated out of the unique knowledge base that rhythm management in young patients required. In the 1970s, pediatric electrophysiology was recognized as a distinct cardiac subspecialty and it has evolved rapidly since that time. Despite the considerable growth in personnel, technology, and complexity that the field has undergone, further opportunities to progress pediatric electrophysiology exist. In this review, we highlight some of the clinical focus of pediatric and adult congenital electrophysiologists to date and identify areas within this specialty where the pediatric and congenital electrophysiology community could come together in order to drive improvements in rhythm management for patients.

Near zerO fluoroscopic exPosure during catheter ablAtion of supRavenTricular arrhYthmias: the NO-PARTY multicentre randomized trial

AIMS

Aim of this study was to compare a minimally fluoroscopic radiofrequency catheter ablation with conventional fluoroscopy-guided ablation for supraventricular tachycardias (SVTs) in terms of ionizing radiation exposure for patient and operator and to estimate patients' lifetime attributable risks associated with such exposure.

METHODS AND RESULTS

We performed a prospective, multicentre, randomized controlled trial in six electrophysiology (EP) laboratories in Italy. A total of 262 patients undergoing EP studies for SVT were randomized to perform a minimally fluoroscopic approach (MFA) procedure with the EnSiteTMNavXTM navigation system or a conventional approach (ConvA) procedure. The MFA was associated with a significant reduction in patients' radiation dose (0 mSv, iqr 0-0.08 vs. 8.87 mSv, iqr 3.67-22.01; P < 0.00001), total fluoroscopy time (0 s, iqr 0-12 vs. 859 s, iqr 545-1346; P < 0.00001), and operator radiation dose (1.55 vs. 25.33 µS per procedure; P < 0.001). In the MFA group, X-ray was not used at all in 72% (96/134) of cases. The acute success and complication rates were not different between the two groups (P = ns). The reduction in patients' exposure shows a 96% reduction in the estimated risks of cancer incidence and mortality and an important reduction in estimated years of life lost and years of life affected. Based on economic considerations, the benefits of MFA for patients and professionals are likely to justify its additional costs.

CONCLUSION

This is the first multicentre randomized trial showing that a MFA in the ablation of SVTs dramatically reduces patients' exposure, risks of cancer incidence and mortality, and years of life affected and lost, keeping safety and efficacy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01132274.

Fluoroless catheter ablation in adults: a single center experience

BACKGROUND

Ablation procedures for arrhythmias have increased in frequency and complexity over the last decade. Improvements in technology have allowed for less reliance on fluoroscopy to guide these procedures. Ablation without fluoroscopy has been reported in small cohorts. We report a single center experience of fluoroless ablation after adoption of this technique for all endovascular ablations.

METHODS

This retrospective study evaluated 107 consecutive patients who underwent a catheter ablation procedure for an atrial or ventricular arrhythmias after adoption of a completely fluoroless technique. No fluoroscopy was used in any case. A mapping system was utilized in all cases. Intracardiac echocardiography (ICE) catheters were utilized in 75 of the ablation cases (70.4%). Of the 107 patients who underwent EP study, three patients did not undergo ablation as they were non-inducible for SVT. Of the remaining 104 patients, 56 patients (53.8%) underwent ablation for atrial fibrillation, 23 patients (22.1%) for SVT, 10 patients (9.6%) for lone atrial flutter, and 16 patients (15.4%) for a ventricular arrhythmia including PVC, idiopathic VT or ventricular tachycardia.

RESULTS

Catheters were able to be placed in 100% of patients without complication. Time to placement in the coronary sinus was 2.1 min ± 1.4 min. Mean transseptal time was 3.54 min ± 3 min. Mean procedure time for all ablations was 2 h 6 min ± 50 min. There were no complications in the series of patients.

CONCLUSIONS

Fluoroless ablation is feasible and safe with acceptable procedure times. Adoption of this technique is encouraged in order to eliminate unnecessary risk of fluoroscopy.

Catheter ablation of idiopathic ventricular tachycardia without the use of fluoroscopy

BACKGROUND

Catheter ablation is the treatment of choice for many patients with idiopathic ventricular tachycardia (VT). Unfortunately, conventional catheter ablation is guided by fluoroscopy, which is associated with a small but definite radiation risk for patients and laboratory personnel. The aim of our study is to assess feasibility, success rate and safety of idiopathic VT ablation procedure performed without the use of fluoroscopy.

METHODS

Nineteen consecutive patients undergoing idiopathic VT ablation at our institution have been included. The ablation procedures were performed under the guidance of electroanatomical mapping (EAM) system and intracardiac echocardiography (ICE).

RESULTS

Nineteen patients (mean age 38.7 years) underwent ablation procedure for idiopathic VT. Twelve (63%) had outflow tract VT, 3 (18%) fascicular tachycardia, 2 (11%) peri-tricuspidal VT, 1 (5%) peri-mitral VT, and 1 (5%) lateral left free-wall VT. The mean procedural time was 170.2 ± 45.7 min. No fluoroscopy was used in any procedural phase. Acute success rate was 100%. No complication was documented in any patients. After a mean follow up of 18 ± 4 months, recurrences occurred in 2 patients.

CONCLUSIONS

In our preliminary experience idiopathic VT ablation without the use of fluoroscopy was feasible and safe, using a combination of EAM and ICE. Success rate was excellent with no complication.

Catheter Ablation of Atrial Fibrillation Without Radiation Exposure Using A 3D Mapping System

Transcatheter ablation procedures have been traditionally performed under fluoroscopic guidance. However, x-ray exposure is afflicted by the risk of developing malignancies as well as other deterministic effects of radiation. For this reason, radiation doses in the interventional laboratory should be reduced "As Low As Reasonably Achievable", with respect to the safety of the patients and the medical staff. This is of utmost importance in atrial fibrillation (AF) ablations, which are usually lengthy procedures. With the improvement of technology, the development of additional imaging tools and the widespread of 3D electroanatomic mapping systems (EAM), near-zero fluoroscopy AF ablation procedure is becoming a reality, limiting fluoroscopy use mainly to guide transseptal puncture. In the present paper we reviewed the risks to health related to x-ray exposure and we discussed the current state of knowledge of catheter ablation of AF without fluoroscopy in the 3D EAM system era.