Risk to patients from radiation associated with radiofrequency ablation for supraventricular tachycardia

Fluoroscopy-free cardioneuroablation for functional bradycardia: a single-center experience

BACKGROUND

Cardioneuroablation (CNA) is an emerging treatment for cardioinhibitory syncope and functional AV block. This study aimed to evaluate the safety and efficacy of a fluoroless CNA approach using three-dimensional mapping and extracardiac vagal stimulation (ECVS).

METHODS

This prospective observational study included 22 patients (mean age 21 years) with clinically significant functional bradycardia who underwent fluoroless CNA. Procedural success was defined as elimination or significant attenuation of the vagal response to ECVS.

RESULTS

CNA was successfully performed in all patients with a mean procedure time of 251 min. Fluoroscopy was avoided in 91% of cases. At a mean follow-up of 11.4 months, 77% of patients remained symptom-free. Among pacemaker patients, 90% did not require further pacing, and 6/10 (60%) have had their pacemakers turned off. No complications were seen during the procedure.

CONCLUSIONS

Fluoroscopy-free CNA is a safe and effective treatment for functional bradycardia, offering high procedural success rates and favorable symptom-free outcomes while minimizing radiation exposure.

[Long-term Reproducibility Evaluation of Fluoroscopy Dose Rate in Angiography Equipment]

PURPOSE

Diagnostic reference levels (DRLs) are defined as fluoroscopic dose rate measurements that are used for patient dose management in angiography. It is recommended that DRLs be measured at least once a year. This study aimed to evaluate the long-term fluctuations of fluoroscopic dose rate in an angiography system.

METHODS

An unconnected X-ray output analyzer was used to measure the fluoroscopic dose rate (air kerma rate) at the patient's entrance reference point for a specific angiography system. The target period was from 2015 to 2022, and four measurements per year were made. First, the fluoroscopic dose rate was measured, and the average value and standard deviation for the target period were calculated. Next, the uncertainty of the measured values and the coefficient of variation were calculated. Finally, we calculated the fluoroscopic dose rate measurement error.

RESULTS

The average±standard deviation of the fluoroscopic dose rate was 353.29±9.11 µGy/s. The maximum uncertainty and coefficient of variation for each year were 5.41 µGy/s and 0.03, respectively. The maximum measurement error was 4.67%, where the mean measured value was taken as the true value.

CONCLUSION

The fluctuation in the measured value of the fluoroscopic dose rate by an angiography system for 8 years is within ±5%, indicating stable X-ray output.

Longitudinal reduction in fluoroscopy with continued use of 3-dimensional electroanatomic mapping systems in catheter ablation of supraventricular tachycardia - then and now

BACKGROUND

Catheter ablation is a first-line treatment for symptomatic, recurrent supraventricular tachycardia (SVT). This study aims to demonstrate if 3D-electroanatomic mapping (EAM) during SVT ablation reduces fluoroscopy time (FT) and determine if further reductions in FT are observed longitudinally.

METHODS

All cases of SVT ablation between May 2011-May 2022 at a single tertiary centre were prospectively recruited. FT between the cohorts with and without EAM were compared. Within the EAM subset, the trend of FT across the years was analysed.

RESULTS

There were 1758 cases included, 563 without EAM, 1195 with EAM. EAM was associated with a longer procedure time (mean + 8.8 min, p = 0.001), but with mean reductions in FT and dose area product (DAP) by 19.6 min and 18 621 mGy*cm2 respectively (p < 0.001). There was comparable efficacy without any increase in complication rates. Over time (2011-2022), further reduction in FT of 0.9 min year on year was observed (p = 0.001). Between 2011 and 2017, there was a significant reduction in FT of 1.1 min year on year (p = 0.019), which was not observed from 2017 onwards (p = 0.061). The greatest reduction in FT was after the first year of adoption.

CONCLUSION

EAM in SVT ablation reduces fluoroscopy use. FT was initially observed to reduce further over time before plateauing, likely due to increased operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in complex cases.

A simple method for radiation exposure reduction during atrial fibrillation ablation: the lead-apron-free approach

BACKGROUND

Radiofrequency catheter ablation (RFCA) is a well-established treatment for atrial fibrillation (AF). Fluoroscopy, a widely used imaging method for RFCA, has significant implications for human health. Although no fluoroscopy or near-zero fluoroscopy strategies have gained popularity, they have limitations, such as long procedure times, additional equipment, and expertise. A simple and cost-effective radiation reduction method is needed for treating AF and is compatible with the daily workflow. We aimed to compare the efficacy and safety of fluoroscopy-free and lead apron-free (LAF) after transseptal puncture AF ablation with conventional ablation (CON).

METHODS

This retrospective study included all patients who underwent RF catheter AF ablation. The lead apron used for protection was removed immediately before 3D reconstruction of the left atrium (LA) after transseptal puncture (TSP), while fluoroscopy was performed on stand-by and locked-in. The pulmonary vein isolation (PVI) was performed using a 3D mapping system, a multielectrode catheter, and a Smart Touch contact force (CF) sensing catheter, via the lead-apron-free (LAF) method, which is similar to the conventional ablation (CON) method.

RESULTS

This study enrolled 152 consecutive patients, with 72 and 80 patients in the LAF and CON groups, respectively. The LAF group demonstrated significantly lower values in total fluoroscopy time (6.9 vs. 14 min, P<0.001) and dose area product (DAP) values (15.4±12.1 vs. 31.5±17.4 G/m2, P<0.001) than the CON group. However, there was no significant difference in the total procedure time (83.6±21.1 vs. 77.2±11.4 min, P=0.12) between the two groups. Only four procedures (5.5%) required repositioning of the apron, and no complications were observed with the LAF method. Pulmonary vein isolation was achieved in all patients.

CONCLUSIONS

The LAF method reduced fluoroscopy use compared with CON, with no change in procedure time or efficacy.

Impact of artificial intelligence arrhythmia mapping on time to first ablation, procedure duration, and fluoroscopy use

INTRODUCTION

Artificial intelligence (AI) ECG arrhythmia mapping provides arrhythmia source localization using 12-lead ECG data; whether this information impacts procedural efficiency is unknown. We performed a retrospective, case-control study to evaluate the hypothesis that AI ECG mapping may reduce time to ablation, procedural duration, and fluoroscopy.

MATERIALS AND METHODS

Cases in which system output was used were retrospectively enrolled according to IRB-approved protocols at each site. Matched control cases were enrolled in reverse chronological order beginning on the last day for which the technology was unavailable. Controls were matched based upon physician, institution, arrhythmia, and a predetermined complexity rating. Procedural metrics, fluoroscopy data, and clinical outcomes were assessed from time-stamped medical records.

RESULTS

The study group consisted of 28 patients (age 65 ± 11 years, 46% female, left atrial dimension 4.1 ± 0.9 cm, LVEF 50 ± 18%) and was similar to 28 controls. The most common arrhythmia types were atrial fibrillation (n = 10), premature ventricular complexes (n = 8), and ventricular tachycardia (n = 6). Use of the system was associated with a 19.0% reduction in time to ablation (133 ± 48 vs. 165 ± 49 min, p = 0.02), a 22.6% reduction in procedure duration (233 ± 51 vs. 301 ± 83 min, p < 0.001), and a 43.7% reduction in fluoroscopy (18.7 ± 13.3 vs. 33.2 ± 18.0 min, p < 0.001) versus controls. At 6 months follow-up, arrhythmia-free survival was 73.5% in the study group and 63.3% in the control group (p = 0.56).

CONCLUSION

Use of forward-solution AI ECG mapping is associated with reductions in time to first ablation, procedure duration, and fluoroscopy without an adverse impact on procedure outcomes or complications.

Deep learning in vivo catheter tip locations for photoacoustic-guided cardiac interventions

Significance

Interventional cardiac procedures often require ionizing radiation to guide cardiac catheters to the heart. To reduce the associated risks of ionizing radiation, photoacoustic imaging can potentially be combined with robotic visual servoing, with initial demonstrations requiring segmentation of catheter tips. However, typical segmentation algorithms applied to conventional image formation methods are susceptible to problematic reflection artifacts, which compromise the required detectability and localization of the catheter tip.

Aim

We describe a convolutional neural network and the associated customizations required to successfully detect and localize in vivo photoacoustic signals from a catheter tip received by a phased array transducer, which is a common transducer for transthoracic cardiac imaging applications.

Approach

We trained a network with simulated photoacoustic channel data to identify point sources, which appropriately model photoacoustic signals from the tip of an optical fiber inserted in a cardiac catheter. The network was validated with an independent simulated dataset, then tested on data from the tips of cardiac catheters housing optical fibers and inserted into ex vivo and in vivo swine hearts.

Results

When validated with simulated data, the network achieved an F 1 score of 98.3% and Euclidean errors (mean ± one standard deviation) of 1.02 ± 0.84    mm for target depths of 20 to 100 mm. When tested on ex vivo and in vivo data, the network achieved F 1 scores as large as 100.0%. In addition, for target depths of 40 to 90 mm in the ex vivo and in vivo data, up to 86.7% of axial and 100.0% of lateral position errors were lower than the axial and lateral resolution, respectively, of the phased array transducer.

Conclusions

These results demonstrate the promise of the proposed method to identify photoacoustic sources in future interventional cardiology and cardiac electrophysiology applications.

Combining conventional technique with fluoroscopy integration module in accessory pathway ablation

INTRODUCTION

Accessory pathway (AP) ablation is a straightforward approach with high success rates, but the fluoroscopy time (FT) is significantly longer in conventional technique. Electroanatomical mapping systems (EMS), reduce the FT, but anatomical and activation mapping may prolong the procedure time (PT). The fluoroscopy integration module (FIM) uses prerecorded fluoroscopy images and allows ablation similar to conventional technique without creating an anatomical map. In this study, we investigated the effects of combining the FIM with traditional technique on PT, success, and radiation exposure.

METHODS

A total of 131 patients who had undergone AP ablation were included in our study. In 37 patients, right and left anterior oblique (RAO-LAO) images were acquired after catheter placement and integrated with the FIM. The ablation procedure was then similar to the conventional technique, but without the use of fluoroscopy. For the purpose of acceleration, anatomical and activation maps have not been created. Contact-force catheters were not used. 94 patients underwent conventional ablation using fluoroscopy only.

RESULTS

FIM into AP ablation procedures led to a significant reduction in radiation exposure, lowering FT from 7.4 to 2.8 min (p < .001) and dose-area product from 12.47 to 5.8 μGym² (p < .001). While the FIM group experienced a reasonable longer PT (69 vs. 50 min p < .001). FIM reduces FT regardless of operator experience and location of APs CONCLUSION: Combining FIM integration with conventional AP ablation offers reduced radiation exposure without compromising success rates and complication.

Radiotherapy-Induced Atrial Myxoma: A Case Report and Literature Review

In this particular case study, we present a 66-year-old male who was diagnosed with an atrial myxoma eight years after receiving treatment for non-small cell lung cancer. The patient underwent chemo-radiotherapy (mediastinal area) in 2012 to address stage III-A adenocarcinoma of the lung. During follow-up imaging in 2020, a left atrial mass displaying characteristic features of a cardiac myxoma was detected. Upon reviewing a computed tomographic (CT) scan from 2017 within the previously irradiated mediastinal region, the cardiac mass was retrospectively identified. The surgical excision of the cardiac mass was performed, and a subsequent pathological examination confirmed the diagnosis of myxoma. To the best of our knowledge, this is the first reported case of a left atrial myxoma in a patient previously treated for adenocarcinoma of the lung and the first instance of an atrial myxoma occurring in a site that had undergone prior radiation therapy.

Fluoroless Catheter Ablation of Left Ventricular Summit Arrhythmias: A Step-by-Step Approach

Prolonged use of fluoroscopy during catheter ablation (CA) of arrhythmias is associated with a significant exposure to ionizing radiation and risk of orthopedic injuries given the need for heavy protective equipment. CA of ventricular arrhythmias (VAs) arising from the left ventricular (LV) summit is challenging, requiring a vast knowledge of the intricate cardiac anatomy of this area and careful imaging delineation of the different anatomical structures, which is frequently performed using fluoroscopic guidance. Certain techniques, including pericardial mapping and ablation, use of intracoronary wires, and mapping and ablation inside the coronary venous system have been proposed, further prolonging fluoroscopy time. Fluoroless CA procedures are feasible with currently available technology and appear to have similar safety and efficacy outcomes compared with conventional techniques. To successfully perform fluoroless CA of LV summit arrhythmias, it is important to be fully acquainted with intracardiac echocardiography (ICE) imaging and electroanatomic mapping (EAM). We will describe our approach to perform fluoroless CA in LV summit VAs.

Fluoroless left atrial access for radiofrequency and cryoballoon ablations using a novel radiofrequency transseptal wire

Purpose

Conventional catheter ablation for atrial fibrillation requires fluoroscopy, which has inherent risks of radiation exposure to patients and medical staff. Optimization of fluoroscopy parameters and use of three-dimensional electroanatomic mapping (EAM) and intracardiac echocardiography (ICE) have helped to reduce radiation exposure; however, despite growing evidence, there are still concerns about safety and added procedure time associated with fluoroless procedures, particularly in left-sided ablations, due to the potential risk of complications. Herein, we report our initial experience using a radiofrequency (RF) wire for completely fluoroless radiofrequency ablation (RFA) and cryoballoon ablation (CBA).

Methods

A retrospective analysis was conducted on ablation procedures for various cardiac arrhythmias performed non-fluoroscopically at two centers using the VersaCross RF wire transseptal system under EAM and ICE guidance.

Results

A total of 72 and 54 patients underwent RFA and CBA, respectively, successfully without any procedural complications. Transseptal access time for RFA was 14.5 ± 6.6 min from procedure start (including sheath and catheter placements ± right-sided ablation) or 2.8 ± 1.0 min from RF wire insertion into the femoral introducer. Transseptal access time for CBA was 19.2 ± 11.7 min from procedure start (including sheath and catheter placements ± right-sided ablation) or 3.5 ± 1.6 min from RF wire insertion into the femoral introducer. Average procedure time was 104.4 ± 38.0 min for RFA and 91.1 ± 22.1 min for CBA.

Conclusions

A RF wire can be used to achieve completely fluoroless transseptal puncture safely and effectively while improving procedural efficiency in both RFA and CBA.

Vital Signs Monitoring Based on Interferometric Fiber Optic Sensors

Due to the improvement of living standards, people’s attention to health has gradually increased. More and more people are willing to spend money and time on health management. This article reviews work on the vital signs monitoring system based on fiber optic interferometers, including the design of sensor structures, signal demodulation methods and data analysis. After a large number of trials, the system can achieve long-term stable heart rate (HR), respiration rate (RR) and body temperature monitoring, and the collected data can be used for health analysis. Due to the high sensitivity, low cost, and light weight of the interferometric fiber optic sensor, it can be integrated under a mattress or a cushion, which is very suitable for daily use. The system has great application prospects in the field of healthcare.

Cone-Beam Computed Tomography-Derived Augmented Fluoroscopy Improves the Diagnostic Yield of Endobronchial Ultrasound-Guided Transbronchial Biopsy for Peripheral Pulmonary Lesions

Background: Endobronchial ultrasound-guided transbronchial biopsy (EBUS-TBB) is used for the diagnosis of peripheral pulmonary lesions (PPLs), but the diagnostic yield is not adequate. Cone-beam computed tomography-derived augmented fluoroscopy (CBCT-AF) can be utilized to assess the location of PPLs and biopsy devices, and has the potential to improve the diagnostic accuracy of bronchoscopic techniques. The purpose of this study was to verify the contribution of CBCT-AF to EBUS-TBB. Methods: Patients who underwent EBUS-TBB for diagnosis of PPLs were enrolled. The navigation success rate and diagnostic yield were used to evaluate the effectiveness of CBCT-AF in EBUS-TBB. Results: In this study, 236 patients who underwent EBUS-TBB for PPL diagnosis were enrolled. One hundred fifteen patients were in CBCT-AF group and 121 were in non-AF group. The navigation success rate was significantly higher in the CBCT-AF group (96.5% vs. 86.8%, p = 0.006). The diagnostic yield was even better in the CBCT-AF group when the target lesion was small in size (68.8% vs. 0%, p = 0.026 for lesions ≤10 mm and 77.5% vs. 46.4%, p = 0.016 for lesions 10–20 mm, respectively). The diagnostic yield of the two study groups became similar when the procedures with a failure of navigation were excluded. The procedure-related complication rate was similar between the two study groups. Conclusion: CBCT-AF is safe, and effectively enhances the navigation success rate, thereby increasing the diagnostic yield of EBUS-TBB for PPLs.

Metal interference alert guided septal approach with 3 catheter positions on intracardiac echocardiography for a near-zero fluoroscopy catheter ablation of atrial fibrillation

BACKGROUND

Attempting to minimize radiation exposure during catheter ablation of atrial fibrillation (AF) for patients, operators and medical staffs should be performed. This study aimed to investigate the feasibility and safety of a metal interference alert guided septal approach using 3 intracardiac echocardiography viewing positions for near-zero fluoroscopy AF ablation procedures.

METHODS/RESULTS

A total of 668 procedures among 608 consecutive patients with AF (67.2 ± 7.3 years, 408 males) who underwent catheter ablation were retrospectively evaluated and divided into 2 groups, near-zero group (n = 42) and conventional group (n = 595). In the near-zero group, a metal interference alert guided septal approach with 3 different catheter intracardiac echocardiography positions to minimize the fluoroscopy time was applied, and a left atrial access with 2 long sheaths from a single septal puncture without fluoroscopy was successfully achieved in 41 out of 42 cases. The total fluoroscopy time was significantly shorter in the near-zero group than that in the conventional group (0.5 ± 2.0 vs. 21.4 ± 12.9 min p < 0.0001). The total procedure time and time to the septal puncture were both significantly longer in the near-zero group than those in the conventional group (131.4 ± 40.2 vs. 116.6 ± 46.4p = 0.0453, 31.6 ± 9.2 vs. 19.9 ± 10.2 min, p < 0.0001), The ablation time did not differ between the 2 groups (Near-zero: 99.8 ± 41.0 vs. Conventional: 96.8 ± 44.3 min, p = 0.6663). There were no significant differences in the complication rate between the 2 groups (Near-zero: 0 vs. Conventional 14 case, p = 0.6151).

CONCLUSION

A metal interference alert guided septal approach using 3 intracardiac echocardiography viewing positions was feasible and safe for a near-zero fluoroscopy catheter ablation of AF.

Minimising radiation exposure in catheter ablation of ventricular arrhythmias

Background

Conventional fluoroscopy guided catheter ablation (CA) is an established treatment option for ventricular arrhythmias (VAs). However, with the complex nature of most procedures, patients and staff bare an increased radiation exposure. Near-zero or zero-fluoroscopy CA is an alternative method which could substantially reduce or even eliminate the radiation dose. Our aim was to analyse procedural outcomes with fluoroscopy minimising approach for treatment of VAs in patients with structurally normal hearts (SNH) and structural heart disease (SHD).

Methods

Fifty-two (age 53.4 ± 17.8 years, 38 male, 14 female) consecutive patients who underwent CA of VAs in our institution between May 2018 and December 2019 were included. Procedures were performed primarily with the aid of the three-dimensional electro-anatomical mapping system and intra-cardiac echocardiography. Fluoroscopy was considered only in left ventricular (LV) summit mapping for coronary angiography and when epicardial approach was planned. Acute and long-term procedural outcomes were analysed.

Results

Sixty CA procedures were performed. Twenty-five patients had SHD-related VAs (Group 1) and 27 patients had SNH (Group 2). While Group 1 had significantly higher total procedural time (256.9 ± 71.7 vs 123.6 ± 42.2 min; p < 0.001) compared to Group 2, overall procedural success rate [77.4% (24/31) vs 89.7% (26/29); p = 0.20)] and recurrence rate after the first procedure [8/25, (32%) vs 8/27, (29.6%); p = 0.85] were similar in both groups. Fluoroscopy was used in 3 procedures in Group 1 where epicardial approach was needed and in 4 procedures in Group 2 where LV summit VAs were ablated. Overall procedure-related major complication rate was 5%.

Conclusions

Fluoroscopy minimising approach for CA of VAs is feasible and safe in patients with SHD and SNH. Fluoroscopy could not be completely abolished in VAs with epicardial and LV summit substrate location.

Minimal fluoroscopy approach for right-sided supraventricular tachycardia ablation with a novel ablation technology: Insights from the multicenter CHARISMA clinical registry

BACKGROUND

No data exist on the ability of the novel Rhythmia 3-D mapping system to minimize fluoroscopy exposure during transcatheter ablation of arrhythmias. We report data on the feasibility and safety of a minimal fluoroscopic approach using this system in supraventricular tachycardia (SVT) procedures.

METHODS

Consecutive patients were enrolled in the CHARISMA registry at 12 centers. All right-sided procedures performed with the Rhythmia mapping system were analyzed. The acquired electroanatomic information was used to reconstruct 3-D cardiac geometry; fluoroscopic confirmation was used whenever deemed necessary.

RESULTS

Three hundred twenty-five patients (mean age = 56 ± 17 years, 57% male) were included: 152 atrioventricular nodal reentrant tachycardia, 116 atrial flutter, 41 and 16 right-sided accessory pathway and atrial tachycardia, respectively. Overall, 27 481 s of fluoroscopy were used (84.6 ± 224 s per procedure, equivalent effective dose = 1.1 ± 3.7 mSv per patient). One hundred ninety-two procedures (59.1%) were completed without the use of fluoroscopy (zero fluoroscopy, ZF). In multivariate analysis, the presence of a fellow in training (OR = 0.15, 95% CI: 0.05-0.46; p = .0008), radiofrequency application (0.99, 0.99-1.00; p = .0002), and mapping times (0.99, 0.99-1.00; p = .042) were all inversely associated with ZF approach. Acute procedural success was achieved in 97.8% of the cases (98.4 vs. 97% in the ZF vs. non-ZF group; p = .4503). During a mean of 290.7 ± 169.6 days follow-up, no major adverse events were reported, and recurrence of the primary arrhythmia was 2.5% (2.1 vs. 3% in the ZF vs. non-ZF group; p = .7206).

CONCLUSIONS

The Rhythmia mapping system permits transcatheter ablation of right-sided SVT with minimal fluoroscopy exposure. Even more, in most cases, the system enables a ZF approach, without affecting safety and efficacy.

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.

The Grand SANS FLUORO (SAy No Series to FLUOROsopy) Study: Examining Fluoroscopy Use in More than 1,000 Ablation Procedures

The majority of electrophysiologists routinely use fluoroscopy (FLUORO) during ablation procedures for common arrhythmias despite the known complications of radiation exposure and protective lead use. This study assessed the safety of catheter ablation (CA) with FLUORO versus without FLUORO (SANS FLUORO) in patients with the following common arrhythmias: atrial fibrillation (AF), atrial flutter, supraventricular tachycardia, and ventricular tachycardia. A total of 1,258 CA procedures were performed in 816 consecutive patients over a 53-month period (SANS FLUORO CA: 609 patients; FLUORO CA: 209 patients). The secondary outcome was the efficacy of AF ablation in FLUORO versus SANS FLUORO patients. Ultimately, there was no statistically significant difference found concerning the safety of CA in the SANS FLUORO and FLUORO groups in terms of procedure time, vascular complications, tamponade, stroke, or death. FLUORO patients had markedly increased FLUORO time, increased radiation exposure, and increased dose-area product (all p < 0.0001). AF development after SANS FLUORO CA of AF was not different from that after FLUORO CA regardless of the pulmonary vein isolation (PVI) modality used (cryoablation versus radiofrequency) at 24 months (p = 0.21). Additionally, women fared just as well as men after CA ablation for AF. At 36 months, 58% of SANS FLUORO AF device patients were free from AF. As such, SANS FLUORO CA of common arrhythmias appears to be as safe as FLUORO CA but with a markedly reduced level of radiation exposure. Also, SANS FLUORO CA remains as effective as FLUORO CA in the prevention of AF for up to 24 months.

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.

Fluoroless Atrial Fibrillation Catheter Ablation: Technique and Clinical Outcomes

Fluoroscopy continues to be considered an indispensable part of atrial fibrillation (AF) ablation worldwide. Deleterious effects of radiation exposure to patients, physicians, and catheter laboratory personnel are gaining increased consideration. Safety and efficacy of a fluoroless approach for AF ablation is comparable with outcomes achieved with fluoroscopy use. This article focuses on AF ablation with zero fluoroscopy use as well as current evidence on efficacy and safety of this technique. In contrast, minimal fluoroscopy is an alternative. Relying on intracardiac echocardiography for transseptal access and electroanatomic mapping for catheter manipulation can help implement this approach on a wider scale.

Fluoroless Catheter Ablation of Cardiac Arrhythmias

Fluoroless catheter ablation of all endocardial cardiac arrhythmias is feasible using current, and often standard, electrophysiology laboratory equipment. This article lays out a road map for performing fluoroless ablations, safely and efficaciously. We outline optimizing intracardiac echocardiography, performing complex ablations with radiofrequency and cryoballoon technology.

Zero Fluoroscopy During Ablation of Right-Sided Supraventricular Tachycardia Substrates in a Pediatric Population - Initial Experience in Taiwan

Background

Zero fluoroscopy during ablation of arrhythmias has been introduced to reduce radiation exposure. However, the safety, feasibility and efficacy of the technique in pediatric populations have yet to be delineated.

Objectives

To investigate the safety, feasibility and effectiveness of zero fluoroscopic-guided transcatheter ablation of right-sided supraventricular tachycardia substrates in a pediatric population.

Methods

Patients < 20 years of age who received ablation of right-sided accessory pathway-mediated arrhythmia and atrioventricular nodal reentrant tachycardia at our hospital between January 2014 and July 2018 were enrolled, and their medical records were reviewed. Patients undergoing ablations with conventional fluoroscopic guidance were enrolled as the control group, and those undergoing ablations with zero fluoroscopic guidance were enrolled as the study group. Repaired or complex congenital heart disease patients were excluded.

Results

One hundred and two patients (55 male; 47 female) received a total of 109 ablation procedures: 68 procedures in the control group and 41 in the study group. The mean procedure duration was 104.7 ± 65.1 minutes in the control group and 98.6 ± 57.6 minutes in the study group (p = 0.62). The mean fluoroscopy time was 30.9 ± 23.9 minutes in the control group, while all procedures in the study group were performed without fluoroscopy (p < 0.001). In subgroup analysis, the results were similar. Acute procedural success rates were high in both groups (98.5% vs. 97.6%, p = 1.0). The recurrence rate was 11.5% (7/61) in the control group and 7.5% (3/40) in the study group (p = 0.78) at mid-term follow-up.

Conclusions

Using the zero fluoroscopy technique during pediatric ablation procedures for right-sided supraventricular tachycardia substrates is safe and significantly reduces radiation exposure.

From near-zero to zero fluoroscopy catheter ablation procedures

AIMS

The use of electroanatomical mapping (EAM) systems can reduce radiation exposure (RX) and it can also completely eliminate the use of RX. Radiation exposure related to conventional radiofrequency ablation procedures can have a stochastic and deterministic effect on health. The main aim of this study was to evaluate the safety and feasibility of an entirely nonfluoroscopic approach to catheter ablation (CA) using EAM CARTO3.

METHODS

In 2011 we started an RX-minimization programme in all procedures using the CARTO system with the deliberate intention to not resort to the aid of RX unless strictly necessary. We divided procedures into two groups (group 1: from 2011 to 2013; group 2: from 2014 to 2017). The only exclusion criteria were the need for transseptal puncture, and nonidiopathic ventricular tachycardia (VT).

RESULTS

From a total of 525 procedures, we performed CA entirely without RX in 78.5% of cases. From 2011 to 2013, we performed CA without RX in 38.5% of cases; from 2014 to 2017, we performed 96.2% of cases with zero RX. The use of RX was significantly reduced in group 2 (group 2: 1.4 ± 19.6 seconds vs group 1: 556.92 ± 520.76 seconds; P < .001). These differences were irrespective of arrhythmia treatment. There were no differences between the two groups in acute success, complications, or duration of procedures.

CONCLUSION

CA of supraventricular tachycardia and VT entirely without RX, guided by the CARTO system, is safe, feasible, and effective. After an adequate learning curve, CA can be performed entirely without RX.

Outcomes of 200 consecutive, fluoroless atrial fibrillation ablations using a new technique

INTRODUCTION

A technique was developed to eliminate radiation exposure for routine atrial fibrillation (AF) ablation, to simplify the procedure and to achieve cost effectiveness. We here report the outcomes of this approach.

METHODS

Two hundred consecutive AF ablations (55% paroxysmal) were performed by a single operator. Pulmonary vein isolation (PVI) was achieved by antral ablation without left atrial anatomic mapping, guided by contact force sensing and intracardiac echocardiogram (ICE). All ablations were performed using three ipsilateral 8 French catheters (ICE, Lasso, and ablation). Eighty-two percent of the patients underwent ablation of atrial flutter or non-pulmonary vein triggers. All patients underwent provocative testing after PVI.

RESULTS

No fluoroscopy was used for the entire study. Two ablations were performed without x-ray available due to unexpected equipment failure. The mean procedure time was 90.3 ± 17.7 (minutes) in patients who only required PVI and 106.2 ± 23.2 (minutes) for the entire cohort, with a success rate of 76% (mean follow-up of 11 months). In contrast, the procedure time and success rate were 127.9 ± 38.2 (minutes) (P < 0.01) and 74%, respectively, for the last 50 standard ablations guided by fluoroscopy (without contact force sensing). Complications included one case of partial right phrenic nerve palsy and one case of right femoral artery pesudoaneurysm. Compared to our previous ablation approaches, the new method resulted in catheter savings of $2,168-$4,568/case.

CONCLUSION

The new technique eliminated radiation exposure and shortened the procedure time without significant negative impact on safety or success rate. Substantial cost savings were also achieved by using a minimal number of mostly reprocessed catheters.

X-Ray Exposure in Cardiac Electrophysiology: A Retrospective Analysis in 8150 Patients Over 7 Years of Activity in a Modern, Large-Volume Laboratory

Background

Only a few studies have systematically evaluated fluoroscopy data of electrophysiological and device implantation procedures. Aims of this study were to quantify ionizing radiation exposure for electrophysiological/device implantation procedures in a large series of patients and to analyze the x‐ray exposure trend over years and radiation exposure in patients undergoing atrial fibrillation ablation considering different technical aspects.

Methods and Results

We performed a retrospective analysis of all electrophysiological/device implantation procedures performed during the past 7 years in a modern, large‐volume laboratory. We reported complete fluoroscopy data on 8150 electrophysiological/device implantation procedures (6095 electrophysiological and 2055 device implantation procedures); for each type of procedure, effective dose and lifetime attributable risk of cancer incidence and mortality were calculated. Over the 7‐year period, we observed a significant trend reduction in fluoroscopy time, dose area product, and effective dose for all electrophysiological procedures (P<0.001) and a not statistically significant trend reduction for device implantation procedures. Analyzing 2416 atrial fibrillation ablations, we observed a significant variability of fluoroscopy time, dose area product and effective dose among 7 different experienced operators (P<0.0001) and a significant reduction of fluoroscopy use over time (P<0.0001) for all of them. Considering atrial fibrillation ablation techniques, fluoroscopy time was not different (P = 0.74) for radiofrequency catheter ablation in comparison with cryoablation, though cryoablation was still associated with higher dose area product and effective dose values (P<0.001).

Conclusions

Electrophysiological procedures involve a nonnegligible x‐ray use, leading to an increased risk of malignancy. Awareness of radiation‐related risk, together with technological advances, can successfully optimize fluoroscopy use.

Five seconds of 50-60 W radio frequency atrial ablations were transmural and safe: an in vitro mechanistic assessment and force-controlled in vivo validation

Aims

Longer procedural time is associated with complications in radiofrequency atrial fibrillation ablation. We sought to reduce ablation time and thereby potentially reduce complications. The aim was to compare the dimensions and complications of 40 W/30 s setting to that of high-power ablations (50-80 W) for 5 s in the in vitro and in vivo models.

Methods and results

In vitro ablations-40 W/30 s were compared with 40-80 W powers for 5 s. In vivo ablations-40 W/30 s were compared with 50-80 W powers for 5 s. All in vivo ablations were performed with 10 g contact force and 30 mL/min irrigation rate. Steam pops and depth of lung lesions identified post-mortem were noted as complications. A total of 72 lesions on the non-trabeculated part of right atrium were performed in 10 Ovine. All in vitro ablations except for the 40 W/5 s setting achieved the critical lesion depth of 2 mm. For in vivo ablations, all lesions were transmural, and the lesion depths for the settings of 40 W/30 s, 50 W/5 s, 60 W/5 s, 70 W/5 s, and 80 W/5 s were 2.2 ± 0.5, 2.3 ± 0.5, 2.1 ± 0.4, 2.0 ± 0.3, and 2.3 ± 0.7 mm, respectively. The lesion depths of short-duration ablations were similar to that of the conventional ablation. Steam pops occurred in the ablation settings of 40 W/30 s and 80 W/5 s in 8 and 11% of ablations, respectively. Complications were absent in short-duration ablations of 50 and 60 W.

Conclusion

High-power, short-duration atrial ablation was as safe and effective as the conventional ablation. Compared with the conventional 40 W/30 s setting, 50 and 60 W ablation for 5 s achieved transmurality and had fewer complications.

Novel automated point collection software facilitates rapid, high-density electroanatomical mapping with multiple catheter types

INTRODUCTION

Manual, point-by-point electroanatomical mapping requires the operator to directly evaluate each point during map construction. Consequently, point collection can be a slow process. An automated 3D mapping system was developed with the goal of improving key mapping metrics, including map completion time and point density.

METHODS

Automated 3D mapping software that includes morphology and cycle length discrimination functions for surface and intracardiac electrograms was developed. In five swine, electroanatomical maps (EAMs) of all four cardiac chambers were generated in sinus rhythm. Four catheters were used: two different four-pole ablation catheters, a 20-pole circular catheter, and a 64-pole basket catheter. Automated and manual 3D mapping were compared for 12 different catheter-chamber combinations (paired sets of 10 maps for most combinations, for a total of 156 maps).

RESULTS

Automated 3D mapping produced more than twofold increase in the number of points per map, as compared with manual 3D mapping (P ≤0.007 for all catheter-chamber combinations tested). Automated 3D mapping also reduced map completion time by an average of 29% (P < 0.05 for all comparisons). The amount of manual editing of the maps acquired with automated 3D mapping was minimal.

CONCLUSION

Automated 3D mapping with the open-platform mapping software described in this study is significantly faster than manual, point-by-point 3D mapping. This resulted in shorter mapping time and higher point density. The morphology discrimination functions effectively excluded ectopic beats during mapping in sinus rhythm and allowed for rapid mapping of intermittent ventricular ectopic beats.

Maximizing the Effectiveness of Ablation for Arrhythmias in the Congenital Heart Patients

Arrhythmias are common in adults with congenital heart disease and account for a large proportion of hospitalizations. The complex anatomical heterogeneity, often in the presence of a delicate hemodynamic system, presents a significant electrophysiological challenge. This review outlines current clinical practice and advances in maximizing the effectiveness of ablation for arrhythmias in congenital heart patients.

[Ablation of supraventricular tachycardias : Complications and emergencies]

Catheter ablation is an established treatment of supraventricular tachycardias (SVT) with high success rates of > 95 %. Complication rates range from 3 to 5 %, with serious complications occurring in about 0.8 %. There are general complications caused either by the vascular access or the catheters (e. g. hematomas, hemo-pneumothorax, embolism, thrombosis and aspiration) und specific ablation related complications (e. g. AV block during ablation of the slow pathway). The complication risk is elevated in elderly and multimorbid patients. Furthermore, the experience of the treating physician and the respective team plays an essential role. The purpose of this article is to give an overview on incidences, causes and management as well as prevention strategies of complications associated with catheter ablation of SVT.

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.

Impact of Contact Force Technology on Atrial Fibrillation Ablation: A Meta-Analysis

Background

Catheter–tissue contact is essential for effective lesion formation, thus there is growing usage of contact force (CF) technology in atrial fibrillation ablation. We conducted a meta-analysis to assess the impact of CF on clinical outcomes and procedural parameters in comparison to conventional catheter for atrial fibrillation ablation.

Methods and Results

An electronic search was performed using major databases. Outcomes of interest were recurrence rate, major complications, total procedure, and fluoroscopic times. Continuous variables were reported as standardized mean difference; odds ratios were reported for dichotomous variables. Eleven studies (2 randomized controlled studies and 9 cohorts) involving 1428 adult patients were identified. CF was deployed in 552 patients. The range of CF used was between 2 to 60 gram-force. The follow-up period ranged between 10 and 53 weeks. In comparing CF and conventional catheter groups, the recurrence rate was lower with CF (35.1% versus 45.5%, odds ratio 0.62 [95% CI 0.45–0.86], P=0.004). Shorter procedure and fluoroscopic times were achieved with CF (procedure time: 156 versus 173 minutes, standardized mean difference −0.85 [95% CI −1.48 to −0.21], P=0.009; fluoroscopic time: 28 versus 36 minutes, standardized mean difference −0.94 [95% CI −1.66; −0.21], P=0.01). Major complication rate was lower numerically in the CF group but not statistically significant (1.3% versus 1.9%, odds ratio 0.71 [95% CI 0.29–1.73], P=0.45).

Conclusions

The use of CF technology results in significant reduction of the atrial fibrillation recurrence rate after atrial fibrillation ablation in comparison to the conventional catheter group. CF technology is able to significantly reduce procedure and fluoroscopic times without compromising complication rate.

A review of the safety aspects of radio frequency ablation

In light of recent reports showing high incidence of silent cerebral infarcts and organized atrial arrhythmias following radiofrequency (RF) atrial fibrillation (AF) ablation, a review of its safety aspects is timely. Serious complications do occur during supraventricular tachycardia (SVT) ablations and knowledge of their incidence is important when deciding whether to proceed with ablation. Evidence is emerging for the probable role of prophylactic ischemic scar ablation to prevent VT. This might increase the number of procedures performed. Here we look at the various complications of RF ablation and also the methods to minimize them. Electronic database was searched for relevant articles from 1990 to 2015. With better awareness and technological advancements in RF ablation the incidence of complications has improved considerably. In AF ablation it has decreased from 6% to less than 4% comprising of vascular complications, cardiac tamponade, stroke, phrenic nerve injury, pulmonary vein stenosis, atrio-esophageal fistula (AEF) and death. Safety of SVT ablation has also improved with less than 1% incidence of AV node injury in AVNRT ablation. In VT ablation the incidence of major complications was 5-11%, up to 3.4%, up to 1.8% and 4.1-8.8% in patients with structural heart disease, without structural heart disease, prophylactic ablations and epicardial ablations respectively. Vascular and pericardial complications dominated endocardial and epicardial VT ablations respectively. Up to 3% mortality and similar rates of tamponade were reported in endocardial VT ablation. Recent reports about the high incidence of asymptomatic cerebral embolism during AF ablation are concerning, warranting more research into its etiology and prevention.

Improved Segmentation of Multiple Cavities of the Heart in Wide-View 3-D Transesophageal Echocardiograms

Minimally invasive interventions in the heart such as in electrophysiology are becoming more and more important in clinical practice. Currently, preoperative computed tomography angiography (CTA) is used to provide anatomic information during electrophysiology interventions, but this does not provide real-time feedback and burdens the patient with additional radiation and side effects of the contrast agent. Three-dimensional transesophageal echocardiography (TEE) is an excellent modality for visualization of anatomic structures and instruments in real time, but some cavities, especially the left atrium, suffer from the limited coverage of the 3-D TEE volumes. This leads to difficulty in segmenting the left atrium. We propose replacing or complementing pre-operative CTA imaging with wide-view TEE. We tested this proposal on 20 patients for which TEE image volumes covering the left atrium and CTA images were acquired. The TEE images were manually registered, and wide-view volumes were generated. Five heart cavities in single-view and wide-view TEE were segmented and compared with atlas based-segmentations derived from the CTA images. We found that the segmentation accuracy (Dice coefficients) improved relative to segmentation of single-view images by 5, 15 and 9 percentage points for the left atrium, right atrium and aorta, respectively. Average anatomic coverage was improved by 2, 29, 62 and 49 percentage points for the right ventricle, left atrium, right atrium and aorta, respectively. This finding confirms that wide-view 3-D TEE can be useful in supporting electrophysiology interventions.