Consequence of use of lower dose flat plate fluoroscopy in pediatric patients undergoing ablation for supraventricular tachycardia

A novel image integration technology mapping system significantly reduces radiation exposure during ablation for a wide spectrum of tachyarrhythmias in children

Objective

Radiofrequency catheter ablation (RFCA) has evolved into an effective and safe technique for the treatment of tachyarrhythmia in children. Concerns about children and involved medical staff being exposed to radiation during the procedure should not be ignored. "Fluoroscopy integrated 3D mapping", a new 3D non-fluoroscopic navigation system software (CARTO Univu Module) could reduce fluoroscopy during the procedure. However, there are few studies about the use of this new technology on children. In the present study, we analyzed the impact of the CARTO Univu on procedural safety and fluoroscopy in a wide spectrum of tachyarrhythmias as compared with CARTO3 alone.

Methods

The data of children with tachyarrhythmias who underwent RFCA from June 2018 to December 2021 were collected. The CARTO Univu was used for mapping and ablation in 200 cases (C3U group) [boys/girls (105/95), mean age (6.8 ± 3.7 years), mean body weight (29.4 ± 7.9 kg)], and the CARTO3 was used in 200 cases as the control group (C3 group) [male/female (103/97), mean age (7.2 ± 3.9 years), mean body weight (32.3 ± 19.0 kg)]. The arrhythmias were atrioventricular reentrant tachycardia (AVRT, n = 78), atrioventricular node reentrant tachycardia (AVNRT, n = 35), typical atrial flutter (AFL, n = 12), atrial tachycardia (AT, n = 20) and ventricular arrhythmias [VAs, premature ventricular complexes or ventricular tachycardia, n = 55].

Results

① There was no significant difference in the acute success rate, recurrence rate, and complication rate between the C3 and C3U groups [(94.5% vs. 95.0%); (6.3% vs. 5.3%); and (2.0% vs. 1.5%); P > 0.05]. ② The CARTO Univu reduced radiation exposure: fluoroscopy time: AVRT C3: 8.5 ± 7.2 min vs. C3U: 4.5 ± 2.9 min, P < 0.05; AVNRT C3: 10.7 ± 3.2 min vs. C3U: 4.3 ± 2.6 min, P < 0.05; AT C3: 15.7 ± 8.2 min vs. C3U: 4.5 ± 1.7 min, P < 0.05; AFL C3: 8.7 ± 3.2 min vs. C3U: 3.7 ± 2.7 min, P < 0.05; VAs C3: 7.7 ± 4.2 min vs. C3U: 3.9 ± 2.3 min, P < 0.05. Corresponding to the fluoroscopy time, the fluoroscopy dose was also reduced significantly. ③ In the C3U group, the fluoroscopy during VAs ablation was lower than that of other arrhythmias (P < 0.05).

Conclusion

The usage of the "novel image integration technology" CARTO Univu might be safe and effective in RFCA for a wide spectrum of tachyarrhythmias in children, which could significantly reduce fluoroscopy and has a more prominent advantage for VAs ablation.

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.

The Benefit of a General, Systematic Use of Mapping Systems During Electrophysiological Procedures in Children and Teenagers: The Experience of an Adult EP Laboratory

Standard imaging during electrophysiological procedures (EPs) uses fluoroscopy. The aim of this study was to evaluate the feasibility, efficacy, safety and effect of an extended use of non-fluoroscopic mapping systems (NMSs) for imaging during paediatric EPs in an adult EP laboratory focusing on the amount of X-ray exposure. This study is a retrospective analysis that includes consecutive young patients (83 pts, aged between 8 and 18) who underwent EPs from March 2005 to February 2015. We compare the fluoroscopy data of two groups of pts: Group I, pts who underwent EPs from 2005 to 2008 using only fluoroscopy and Group II, pts who underwent EPs from 2008 to 2015 performed also using NMSs. The use of an NMS resulted in reduced fluoroscopy time in Group II {median value 0.1 min (95 % CI [0.00-1.07])} compared to Group I {median value 3.55 min (95 % CI [1.93-7.83]) (MW test, P < 0.05)}. There was a complementary reduction in the total X-ray exposure from 2.53 Gy cm(2) (95 % CI [1.51-4.66]) in Group I to 0.05 Gy cm(2) in Group II (95 % CI [0.00-1.22]) (MW test, P < 0.05). Regarding ablation procedures, the median effective dose decreased from 3.04 mSv (95 % CI [1.22-6.89]) to 0.25 mSv (95 % CI [0.00-0.60]) (MW test, P < 0.05). The use of an NMS dramatically reduces fluoroscopy time and total X-ray exposure during EPs in children and teenagers in an adult EP laboratory. In our experience, this reduction is mainly related to the systematic day-to-day use of NMSs.

Getting to zero: impact of electroanatomical mapping on fluoroscopy use in pediatric catheter ablation

PURPOSE

Over the past several years, alternative imaging techniques including electroanatomic mapping systems such as CARTO®3 (C3) have been developed to improve anatomic resolution and potentially limit radiation exposure in electrophysiology (EP) procedures. We retrospectively examined the effect of the introduction of C3 on patient radiation exposure during EP studies and ablation procedures at a children's hospital.

METHODS

All patients that underwent EP and ablation procedures between January 2012 and August 2015 were included; demographic information, fluoroscopy time (FT), total radiation dose (RAD), and dose-area product (DAP) were collected. Patients were stratified by time period (before vs. after C3 introduction) in three groups: (1) normal heart, (2) congenital heart disease (CHD), and (3) those requiring trans-septal (TS) access. The normal heart group was further separated by arrhythmia diagnosis (accessory pathway (AP), AV nodal reentry tachycardia (AVNRT), atrial, or ventricular arrhythmia). Mean values were compared using a single sample t test, as well as analysis of covariance to control for age, weight, and arrhythmia diagnosis.

RESULTS

Mean FT decreased after introduction of C3 in patients in all three patient groups (p < 0.01). When separated by arrhythmia diagnosis, FT decreased in the AP and AVNRT groups (p < 0.0001). After controlling for age, weight, and arrhythmia diagnosis, there was a statistically significant decrease in FT in all three groups and in both RAD and DAP in the normal heart group. Zero fluoroscopy was achieved in 50/159 (31 %) and ≤1 min of FT in 71/159 (45 %) of cases.

CONCLUSIONS

We have shown a significant decrease in multiple measures of radiation after introduction of C3. Continued refinements are needed to further decrease radiation utilization and achieve the goal of zero fluoroscopy.

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

AIM

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.

METHODS

A retrospective cohort study of 333 consecutive children undergoing radiofrequency catheter ablation over the last two decades.

RESULTS

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.

CONCLUSION

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.