An anthropomorphic phantom for atrial transseptal puncture simulation training

BACKGROUND

Transseptal puncture (TSP) is a critical prerequisite for left-sided cardiac interventions, such as atrial fibrillation (AF) ablation and left atrial appendage closure. Despite its routine nature, TSP can be technically demanding and carries a risk of complications. This study presents a novel, patient-specific, anthropomorphic phantom for TSP simulation training that can be used with X-ray fluoroscopy and ultrasound imaging.

METHODS

The TSP phantom was developed using additive manufacturing techniques and features a replaceable fossa ovalis (FO) component to allow for multiple punctures without replacing the entire model. Four cardiologists and one cardiology trainee performed TSP on the simulator, and their performance was assessed using four metrics: global isotropy index, distance from the centroid, time taken to perform TSP, and a set of 5-point Likert scale questions to evaluate the clinicians' perception of the phantom's realism and utility.

RESULTS

The results demonstrate the simulator's potential as a training tool for interventional cardiology, providing a realistic and controllable environment for clinicians to refine their TSP skills. Experienced cardiologists tended to cluster their puncture points closer to regions of the FO associated with higher global isotropy index scores, indicating a relationship between experience and optimal puncture localization. The questionnaire analysis revealed that participants generally agreed on the phantom's realistic anatomical representation and ability to accurately visualize the TSP site under fluoroscopic guidance.

CONCLUSIONS

The TSP simulator can be incorporated into training programs, offering trainees the opportunity to improve tool handling, spatial coordination, and manual dexterity prior to performing the procedure on patients. Further studies with larger sample sizes and longitudinal assessments are needed to establish the simulator's impact on TSP performance and patient outcomes.

Efficacy of catheter ablation in ganglionated plexus for malignant vasovagal syncope children

AIM

Malignant vasovagal syncope in children seriously affects their physical and mental health. Our study aimed to explore the efficacy of catheter ablation in ganglionated plexus with malignant vasovagal syncope children.

CONCLUSION

Catheter ablation of ganglionated plexus was safe and effective in children with malignant vasovagal syncope and can be used as a treatment option for these children.

METHODS

A total of 20 children diagnosed with malignant vasovagal syncope were enrolled in Beijing Children's Hospital, affiliated with Capital Medical University. All underwent catheter ablation treatment of ganglionated plexus. Ganglionated plexuses of the left atrium were identified by high-frequency stimulation and/or anatomic landmarks being targeted by radiofrequency catheter ablation. The efficacy of the treatment was evaluated by comparing the remission rate of post-operative syncopal symptoms and the rate of negative head-up tilt results. Safety and adverse events were evaluated.

RESULTS

After follow-up for 2.5 (0.6-5) years, the syncope symptom scores were decreased significantly compared with before treatment [3 (2-4) versus 5 (3-8) scores, P < 0.01]. Eighty-five per cent (17/20) children no longer experienced syncope, whilst 80% (16/20) children showed negative head-up tilt test after treatment. No adverse effects such as cardiac arrhythmia occurred in the children.

Angioplasty Guidewire-Assisted vs. Conventional Transseptal Puncture for Left Atrial Appendage Occlusion: a multicentre randomized controlled trial

AIMS

This study was performed to compare the usability, efficiency, and safety of a modified angioplasty guidewire-assisted transseptal puncture (TSP) technique vs. the conventional approach in facilitating access into the left atrium during left atrial appendage occlusion (LAAO) procedures for the treatment of atrial fibrillation.

METHODS AND RESULTS

The ADVANCE-LAAO trial (Angioplasty Guidewire-Assisted vs. Conventional Transseptal Puncture for Left Atrial Appendage Occlusion) was an investigator-initiated, prospective, multicentre, randomized controlled trial (NCT05125159). Patients with atrial fibrillation who underwent LAAO were prospectively enrolled from four centres and randomly assigned to an angioplasty guidewire-assisted TSP group (n = 131) or to a conventional Brockenbrough needle TSP group (n = 132). The primary endpoint was the one-time success rate of TSP. We also analysed the TSP procedure time, failure rate of the assigned TSP type, radiation dose, contrast dose, and procedural complications in both groups. All patients in the guidewire-assisted group underwent successful TSP, whereas five in the standard conventional group switched to the guidewire-assisted approach. The guidewire-assisted puncture improved the one-time success rate (92.4 vs. 77.3%, P = 0.001), shortened the TSP procedure time (109.2 ± 48.2 vs. 120.5 ± 57.6 s, P = 0.023), and tended to have a higher rate of good coaxial orientation of the sheath with the left atrial appendage during the LAAO procedure (66.4 vs. 54.5%, P = 0.059). No TSP-related complications occurred in the guidewire-assisted TSP group, whereas two complications occurred in the conventional TSP group. There was no significant difference in the failure rate of the assigned TSP type, the total procedure time, the total radiation dose, the rate of successful LAAO implantation, or the procedural complication rate between the two groups (all P > 0.05).

CONCLUSION

This study confirmed that angioplasty guidewire-assisted puncture can effectively improve the success rate of TSP during LAAO procedures. This novel technique has high potential for application in interventional therapies requiring TSP.

Design and Validation of a Soft Robotic Simulator for Transseptal Puncture Training

OBJECTIVE

Transseptal puncture (TP) is the technique used to access the left atrium of the heart from the right atrium during cardiac catheterization procedures. Through repetition, electrophysiologists and interventional cardiologists experienced in TP develop manual skills to navigate the transseptal catheter assembly to their target on the fossa ovalis (FO). Cardiology fellows and cardiologists that are new to TP currently train on patients to develop this skill, resulting in increased risk of complications. The goal of this work was to create low-risk training opportunities for new TP operators.

METHODS

We developed a Soft Active Transseptal Puncture Simulator (SATPS), designed to match the dynamics, static response, and visualization of the heart during TP. The SATPS includes three subsystems: (i) A soft robotic right atrium with pneumatic actuators mimics the dynamics of a beating heart. (ii) A fossa ovalis insert simulates cardiac tissue properties. (iii) A simulated intracardiac echocardiography environment provides live visual feedback. Subsystem performance was verified with benchtop tests. Face and content validity were evaluated by experienced clinicians.

RESULTS

Subsystems accurately represented atrial volume displacement, tenting and puncture force, and FO deformation. Passive and active actuation states were deemed suitable for simulating different cardiac conditions. Participants rated the SATPS as realistic and useful for training cardiology fellows in TP.

CONCLUSION

The SATPS can help improve catheterization skills of novice TP operators.

SIGNIFICANCE

The SATPS could provide novice TP operators the opportunity to improve their TP skills before operating on a patient for the first time, reducing the likelihood of complications.

Feasibility and safety of a three-dimensional anatomic map-guided transseptal puncture for left-sided catheter ablation procedures

AIMS

Transseptal puncture (TP) for left-sided catheter ablation procedures is routinely performed under fluoroscopic or echocardiographic guidance [transoesophageal echocardiography (TEE) or intracardiac echocardiography (ICE)], although three-dimensional (3D) mapping systems are readily available in most electrophysiology laboratories. Here, we sought to assess the feasibility and safety of a right atrial (RA) 3D map-guided TP.

METHODS AND RESULTS

In 104 patients, 3D RA mapping was performed to identify the fossa ovalis (FO) using the protrusion technique. The radiofrequency transseptal needle was visualized and navigated to the desired potential FO-TP site. Thereafter, the interventionalist was unblinded to TEE and the potential FO-TP site was reassessed regarding its convenience and safety. After TP, the exact TP site was documented using a 17-segment-FO model. Reliable identification of the FO was feasible in 102 patients (98%). In these, 114 3D map-guided TP attempts were performed, of which 96 (84%) patients demonstrated a good position and 18 (16%) an adequate position after TEE unblinding. An out-of-FO or dangerous position did not occur. A successful 3D map-guided TP was performed in 110 attempts (97%). Four attempts (3%) with adequate positions were aborted in order to seek a more convenient TP site. The median time from RA mapping until the end of the TP process was 13 (12-17) min. No TP-related complications occurred. Ninety-eight TP sites (85.1%) were in the central portion or in the inner loop of the FO.

CONCLUSION

A 3D map-guided TP is feasible and safe. It may assist to decrease radiation exposure and the need for TEE/ICE during left-sided catheter ablation procedures.

The long-term effect of thermal-guided second-generation cryoablation in paroxysmal and persistent atrial fibrillation

BACKGROUND

Second-generation cryoballoon ablation is safe and effective in patients with paroxysmal (PAF) and persistent atrial fibrillation (AF).

OBJECTIVE

This study aimed to assess the long-term clinical outcomes and freedom from AF in patients undergoing thermal-guided cryoablation without the use of an electrical mapping catheter.

METHODS

All patients who had undergone thermal-guided second-generation cryoablation without electrical mapping between January 2015 and April 2018 at Eastbourne District General Hospital were retrospectively analysed. Success was defined as freedom from atrial arrhythmia lasting >30 s during the follow up period.

RESULTS

The study included 234 patients with a mean age of 65.3 ± 10.6 years. There were 134 (57.0%) and 100 (42.7%) patients who had PAF and persistent AF respectively. Arrhythmia recurrence occurred in 38 of 134 (28.4%) PAF and 42 of 100 (42.0%) persistent AF patients after mean follow up of 40 ± 9.2 months. The patients with PAF had a significantly greater freedom from arrhythmia than patients with persistent AF (p = .040). The mean procedure time was 55.5 ± 12.2 min and the mean fluoroscopy time was 10.9 ± 4.8 min 73.5% of patients were discharged on the same day.

CONCLUSION

Thermal-guided cryoablation is feasible, safe and results in freedom from arrhythmia in the majority of paroxysmal and persistent AF patients in the long term. Randomised controlled trials are required to confirm the findings of this study.

[Puncture techniques in invasive cardiac electrophysiology]

Due to good results, increasing standardization and lack of equivalent alternatives, catheter ablation has been established as an increasingly common procedure in clinical routine. This article describes common and necessary puncture techniques in catheter ablation (puncture of the groin vessels, transseptal puncture, pericardial puncture) and represents a practical instruction for the catheter laboratory. This article is part of a series of manuscripts presenting topics of interventional electrophysiology in the course of electrophysiology training.

3-Dimensional Transseptal Puncture Based on Electrographic Characteristics of Fossa Ovalis: A Fluoroscopy-Free and Echocardiography-Free Method

OBJECTIVES

This study sought to define electrographic characteristics of the fossa ovalis (FO) and use these findings in developing a 3-dimensional (3D) transseptal puncture (TSP) technique that does not rely on fluoroscopy or echocardiography.

BACKGROUND

Traditional TSP method based on fluoroscopy or echocardiography is basically a 2-dimensional (2D) technique. A valid 3D method of TSP has not been sufficiently clarified.

METHODS

The shape of the FO and its center were "electrographically" defined by comparing their potential characteristics to those of the surrounding limbus. After validation by intracardiac echocardiography, this FO mapping was incorporated into 3D electroanatomical reconstruction of the right atrium. Using a new catheter connection, the transseptal needle could be visualized nonfluoroscopically and directed to the precise localization of the FO on the electroanatomic map.

RESULTS

A total of 276 patients who underwent atrial fibrillation ablation were included. The central FO was identified in all cases with atrial electrogram voltage at 0.33 ± 0.21 mV. The amplitude of atrial potential at the FO annulus was 1.70 ± 0.72 mV (p < 0.001). By incorporating the electrographically defined FO into the 3D electroanatomic mapping and using the transseptal needle visualization approach, TSP was successful in all patients, with 91% of the cases at the first attempt. Atrial fibrillation ablation was completed in all patients with no major complication.

CONCLUSIONS

Electrographic characteristics of the FO center are distinct from those of the surrounding regions. This information can be leveraged to define the FO on 3D electroanatomic mappings, thereby facilitating safe TSP without the need of ancillary imaging with fluoroscopy or echocardiography.

[Management of acute complications during electrophysiological procedures]

Catheter ablation is an established treatment option in patients suffering from symptomatic cardiac arrhythmias. However, despite technical advances, catheter ablation is still associated with an incidence of severe complications of up to 5%. Therefore, electrophysiologists should be trained to prevent complications, maintain a high index of suspicion to recognize them quickly and implement necessary treatment strategies. This article reviews the incidence, risk factors, management and preventative strategies of the major complications associated with ablation procedures such as transseptal puncture-related risks, cardiac tamponade, aortic puncture and air embolism.

Single transseptal puncture technique and contact force catheter: A simplified ablation strategy for paroxysmal atrial fibrillation

The present study aimed to evaluate the safety and efficacy of an optimized single transseptal puncture technique and contact force sensing atrial fibrillation (AF) radiofrequency catheter ablation (RFCA) strategy within a clinical setting. Fast anatomic mapping and contact force sensing ablation was applied to patients with paroxysmal AF (PAF) ablation between September 2014 and December 2016 using a single trans-septal sheath. Pulmonary vein isolation (PVI) and linear ablation were performed in PAF individually with a 10-20 g contact force with minimal fluoroscopy. Stimulation with 10 mA outputs on the lesions without capture was used as endpoint. A total of 419 consecutive patients who underwent first-time RFCA were enrolled in the current study, and acute PVI was achieved in all patients. The average procedure time was 74.5±9.7 min, with an average ablation time of 27.3±7.8 min. The average fluoroscopy time was 4.7±3.3 min and the average radiation dose was 24.3±25.2 mGy. At a mean follow-up time of 14.5 ± 4.1 months, sinus rhythm was maintained at 85.0%. Cardiac tamponade occurred in one case. The results indicated that this simplified technique was a simple, safe and effective approach for PAF ablation therapy.

Successful case of complex atrial flutter occurring in a patient with congenitally corrected transposition of the great arteries, aberrant left atrial appendage, and situs inversus

Background

Congenitally corrected transposition of great arteries (ccTGA) is a rare congenital cardiac defect with atrioventricular and ventriculoarterial discordance which leads to heart failure and limits patients’ lifespan. The extremely aberrant cardiac structure makes electrophysiological procedure and radiofrequency ablation very difficult to be performed in such patients. Until now, there were only sporadical cases that have reported the successful ablation of atrial flutter in ccTGA patients.

Case presentation

We report a case of a 36-year-old male who was diagnosed with dextrocardia, atrial septal defect and congenitally corrected transposition of great arteries (ccTGA) at a young age and received atrial septal defect repair and morphological tricuspid valve plasty in 2014. As for reasons of heart failure and atrial flutter, he frequently suffered from progressively worsening dyspnea and recurrent episodes of palpitations. Cardiac anatomic imaging reconstruction before electrophysiological test revealed an unusually huge left atrial appendage in this patient. After high-density mapping of both right atrium and left atrium, activation mapping showed reentry circuit loops were located in left atrium. Successful ablation strategy was performed under the guidance of high-density mapping and entrainment.

Conclusion

This is a clinical case showing high-density mapping and successful ablation of a complex dual-loop atrial flutter in a patient with ccTGA and aberrant left atrial appendage. The successful procedure corroborates clinical utility of high-density mapping approach in the treatment of the patients with complex congenital heart disease accompanied by rapid arrhythmia, can be simpler, safer and more effective.

Transseptal Techniques for Emerging Structural Heart Interventions

The development of new transseptal transcatheter interventions for patients with structural heart disease is fueling increasing interest in transseptal puncture techniques. The authors review contemporary transseptal puncture indications and techniques and provide a step-by-step approach to challenging transseptal access and procedural complications.

Novel Solutions Applied in Transseptal Puncture: A Systematic Review

Access to the left atrium is required for several minimally invasive cardiac interventions in the left heart. For this purpose, transseptal puncture (TSP) technique is often performed, perforating the atrial septum under fluoroscopic or/and ultrasound imaging guidance. Although this approach has been used for many years, complications/failures are not uncommon mainly in patients with abnormal atrial anatomy and repeated TSP. Thus, this study presents an overview of methods and techniques that have been proposed to increase the safety and feasibility of the TSP. A systematic review of literature was conducted through the analysis of the articles published between 2008 and 2015. The search was performed in PubMed, Scopus, and ISI Web of Knowledge using the expression “transseptal puncture.” A total of 354 articles were retrieved from the databases, and 64 articles were selected for this review. Moreover, these 64 articles were divided into four categories, namely: (1) incidence studies, (2) intraprocedural guidance techniques, (3) preprocedural planning methods, and (4) surgical instruments. A total of 36 articles focused on incidence studies, 24 articles suggested novel intraprocedural guidance techniques, 5 works focused on preprocedural planning strategies, and 21 works proposed surgical instruments. The novel 3D guidance techniques, radio-frequency surgical instruments, and pre-interventional planning approaches showed potential to overcome the main procedural limitations/complications, through the reduction of the intervention time, radiation, number of failures, and complications.

Management and Outcome of Periprocedural Cardiac Perforation and Tamponade with Radiofrequency Catheter Ablation of Cardiac Arrhythmias: A Single Medium-Volume Center Experience

Introduction

Cardiac tamponade (CT) is a life-threatening complication of radiofrequency ablation (RFA). The course and outcome of CT in low-to-medium volume electrophysiology centers are underreported.

Methods

We analyzed the incidence, management and outcomes of CT in 1500 consecutive RFAs performed in our center during 2011–2016.

Results

Of 1500 RFAs performed in 1352 patients (age 55 years, interquartile range: 41–63), 569 were left-sided procedures (n = 406 with transseptal access). Conventional RFA or irrigated RFA was performed in 40.9% and 59.1% of procedures, respectively. Ablation was performed mostly for atrioventricular nodal reentrant tachycardia (25.4%), atrial fibrillation (AF; 18.5%), atrial flutter (18.4%), accessory pathway (16.5%) or idiopathic ventricular arrhythmia (VA; 12.3%), and rarely for structural VA (2.1%). CT occurred in 12 procedures (0.8%): 10 AF ablations, 1 idiopathic VA and 1 typical atrial flutter ablation. Factors significantly associated with CT were older age, pre-procedural oral anticoagulation, left-sided procedures, transseptal access, AF ablation, irrigated RFA and longer fluoroscopy time (on univariate analysis), and AF ablation (on multivariable analysis). The perforation site was located in the left atrium (n = 7), right atrium (n = 3), or in the left ventricle or coronary sinus (n = 1 each). Upon pericardiocentesis, two patients underwent urgent cardiac surgery because of continued bleeding. There was no fatal outcome. During the follow-up of 19 ± 14 months, eight patients were arrhythmia free.

Conclusion

Incidence of RFA-related CT in our medium-volume center was low and significantly associated with AF ablation. The outcome of CT was mostly favorable after pericardiocentesis, but readily accessible cardiothoracic surgery back-up should be mandatory in RFA centers.