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

The use of cardiac imaging in patients undergoing atrial fibrillation ablation

Cardiac imaging (CI), including echocardiography, multidetector computed tomography (MDCT), and cardiac magnetic resonance (CMR), is gaining increasing interest to aid atrial fibrillation (AF) ablation procedures, from pre-procedural planning to intra-procedural guidance. Transthoracic echocardiography is widely used for imaging, especially for preprocedural assessment, while transesophageal and intracardiac echocardiography (ICE) are used for intraprocedural guidance during transseptal puncture. Cardiac MDCT, leveraging its high spatial resolution, offers a detailed anatomical visualization of cardiac chambers and adjacent structures; moreover, left atrial wall thickness assessed by MDCT may guide radiofrequency energy titration to enhance procedural safety and efficiency. At the same time, CMR allows for detailed myocardial tissue characterization and the detection of fibrosis. ICE, MDCT, and CMR also permit intra-procedural image integration with electroanatomical maps, allowing to be aware of a greater amount of intra-procedural real-time information regarding the anatomy and the local characteristics of the tissue in contact with the ablation catheter. One of the primary objectives of performing CI-aided AF ablations is to increase procedural safety and to permit more personalized procedures, according to the characteristics of each patient. This review offers a comprehensive overview of the current applications of CI during the different phases of AF ablation and explores the potential future applications of CI in this context.

Targeting pulmonary vein myocardial sleeves with omnipolar mapping can reduce radiofrequency applications and procedure time: a proof-of-concept study

BACKGROUND

There remains an imperative need to accurately map the left atrium in the setting of atrial fibrillation. While the pulmonary vein segmental ostial isolation plays a significant role in atrial fibrillation, clinical attempts to selectively ablate near the pulmonary vein myocardial sleeves have demonstrated a higher recurrence rate of arrhythmia given less precise mapping modalities. However, novel omnipolar mapping technology coupled with Advisor™ HD Grid Mapping Catheter may provide an advantageous profile to map and selectively ablate near the myocardial sleeves.

METHODS

This retrospective cohort underwent ablation targeting the pulmonary vein myocardial sleeves with the use of omnipolar mapping technology and later wide area circumferential ablation (WACA) was performed.

RESULTS

The findings of this study demonstrated a few number of lesions were required to achieve all PVI targeting PVMS at 36 (95% CI 32-41) compared to WACA at 81 (95% CI 73-90). PVMS radiofrequency time was shorter at 314 s (95% CI 278-350 s) compared to 799 s (95% CI 692-906 s) for WACA. Mean procedure time to complete PVMS was 59 min (95% CI 53-65) and to complete WACA was 90 min (95% CI 80-100).

CONCLUSION

Precision ablation near PVMS coupled with omnipolar technology may provide a superior profile in reducing procedure time and number of ablative lesions compared to WACA in the setting of atrial fibrillation with possible similar results. Future investigation using randomized controlled trials can help further support these findings.

Use of three-dimensional electroanatomic mapping for epicardial access: needle tracking, electrographic characteristics, and clinical application

AIMS

Pericardiocentesis is usually completed under fluoroscopy. The electroanatomic mapping (EAM) system allows visualizing puncture needle tip (NT) while displaying the electrogram recorded from NT, making it possible to obtain epicardial access (EA) independent of fluoroscopy. This study was designed to establish and validate a technique by which EA is obtained under guidance of three-dimensional (3D) EAM combined with NT electrogram.

METHODS AND RESULTS

3D shell of the heart was generated, and the NT was made trackable in the EAM system. Unipolar NT electrogram was continuously monitored. Penetration into pericardial sac was determined by an increase in NT potential amplitude and an injury current. A long guidewire of which the tip was also visible in the EAM system was advanced to confirm EA. Epicardial access was successfully obtained without complication in 13 pigs and 22 patients. In the animals, NT potential amplitude was 3.2 ± 1.0 mV when it was located in mediastinum, 5.2 ± 1.6 mV when in contact with fibrous pericardium, and 9.8 ± 2.8 mV after penetrating into pericardial sac (all P ≤ 0.001). In human subjects, it measured 1.54 ± 0.40 mV, 3.61 ± 1.08 mV, and 7.15 ± 2.88 mV, respectively (all P < 0.001). Fluoroscopy time decreased in every 4-5 cases (64 ± 15, 23 ± 17, and 0 s for animals 1-4, 5-8, 9-13, respectively, P = 0.01; 44 ± 23, 31 ± 18, 4±7 s for patients 1-7, 8-14, 15-22, respectively, P < 0.001). In five pigs and seven patients, EA was obtained without X-ray exposure.

CONCLUSION

By tracking NT in the 3D EAM system and continuously monitoring the NT electrogram, it is feasible and safe to obtain EA with minimum or no fluoroscopic guidance.

Optimizing transseptal puncture guided by three-dimensional mapping: the role of a unipolar electrogram in a needle tip

AIMS

A three-dimensional electroanatomic mapping system-guided transseptal puncture (3D-TSP), without fluoroscopy or echocardiography, has been only minimally reported. Indications for 3D-TSP remain unclear. Against this background, this study aims to establish a precise technique and create a workflow for validating and selecting eligible patients for fluoroless 3D-TSP.

METHODS AND RESULTS

We developed a new methodology for 3D-TSP based on a unipolar electrogram derived from a transseptal needle tip (UEGM tip) in 102 patients (the derivation cohort) with intracardiac echocardiography (ICE) from March 2018 to February 2019. The apparent current of injury (COI) was recorded at the muscular limbus of the foramen ovalis (FO) on the UEGM tip (sinus rhythm: 2.57 ± 0.95 mV, atrial fibrillation: 1.92 ± 0.77 mV), which then disappeared or significantly reduced at the central FO. Changes in the COI, serving as a major criterion to establish a 3D-TSP workflow, proved to be the most valuable indicator for identifying the FO in 99% (101/102) of patients compared with three previous techniques (three minor criteria) of reduction in atrial unipolar or bipolar potential and FO protrusion. A total of 99.9% (1042/1043) patients in the validation cohort underwent successful 3D-TSP through the workflow from March 2019 to July 2023. Intracardiac echocardiography guidance was required for 6.6% (69/1042) of patients. All four criteria were met in 740 patients, resulting in a 100% pure fluoroless 3D-TSP success rate.

CONCLUSION

In most patients, fluoroless 3D-TSP was successfully achieved using changes in the COI on the UEGM tip. Patients who met all four criteria were considered suitable for 3D-TSP, while those who met none required ICE guidance.

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.

Implementation and first outcomes of a novel standard operating procedure for preprocedural transoesophageal echocardiography screening in course of atrial arrhythmia ablation

AIMS

Preprocedural transoesophageal echocardiography (TEE) screening for left atrial (LA) thrombi is the standard of care in many centres performing atrial fibrillation (AF) ablation. However, TEE imposes procedural risks for patients and is often challenging to implement in daily practice, besides causing patient discomfort. At our centre, a novel standard operating procedure (SOP) was implemented, aiming to identify patients that can be exempt from TEE screening. We aimed to assess whether this screening approach may reduce preprocedural TEEs without imposing patients of higher risks for cerebrovascular events (CVEs).

METHODS AND RESULTS

Data of 1874 consecutive patients treated by catheter ablation of LA arrhythmias between 2018 and 2022 were retrospectively analysed. A cohort of 937 patients, where decision to perform TEE screening was based on a new SOP (considering rhythm at admission, CHA2DS2-VASc score, and sufficient anticoagulation), was compared to a matched cohort receiving TEE before every procedure. Number of performed TEEs and incidences of CVEs were compared. Implementation of the new SOP led to a 67% reduction in TEEs performed (old SOP: 933 vs. new SOP: 305). No significant differences between the groups were detected regarding transitory ischaemic attack (old SOP: 5 vs. new SOP: 3; P = 0.48) and stroke (no events). No solid thrombi were detected during TEE screening.

CONCLUSION

The number of preprocedural screening TEEs before AF ablation procedures can be safely reduced by applying risk stratification based on rhythm at admission and CHA2DS2-VASc score, if anticoagulation was performed properly.

Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during cryoballoon ablation of atrial fibrillation: the SWEET-Cryo strategy

AIMS

Cryoballoon pulmonary vein isolation (CB-PVI) offers similar efficacy to point-by-point radiofrequency PVI for patients with atrial fibrillation (AF), but generally with higher X-ray exposure. Strategies aimed at reducing fluoroscopy mostly rely on other costly imaging techniques, limiting their applicability. We designed a Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during CB-PVI (SWEET-Cryo) strategy and analysed its impact on fluoroscopy use and acute procedural and clinical outcomes.

METHODS AND RESULTS

We enrolled 100 patients with paroxysmal or persistent AF undergoing CB-PVI by two operators with different levels of expertise. Patients treated with the SWEET-Cryo strategy (prospective cohort; n = 50) or conventional fluoroscopy (retrospective control cohort; n = 50) were compared. When applied by the senior operator, the SWEET-Cryo strategy significantly reduced the mean fluoroscopy time (FT) (2.6 ± 1.25 vs. 20.3 ± 10.8 min) and mean dose area product (DAP) (5.1 ± 3.8 vs. 35.3 ± 22.3 Gy cm2) compared with those of the control group, respectively (P < 0.001). Significant reductions in FT (6.4 ± 2.5 min vs. 32.5 ± 10.05) and DAP (13.9 ± 7.7 vs. 92.3 ± 63.8) were also achieved by the less experienced operator (P < 0.001). No difference was observed in acute and long-term complications or freedom from AF between fluoroscopy strategies during a 33-month median follow-up. Mean FT was maintained below 3 min in randomly selected cases performed during the follow-up period.

CONCLUSION

In contrast to conventional protocols and regardless of the operator's experience, the optimized SWEET-Cryo strategy dramatically reduced fluoroscopy exposure during CB-PVI. The efficacy, safety, or added costs of the ablation procedure were not compromised.

Occupational radiation exposure of electrophysiology staff with reproductive potential and during pregnancy: an EHRA survey

AIMS

Electrophysiology (EP) is a growing field in cardiology, with an increasing involvement of young people. Nevertheless, concerns about radiation exposure and its impact on reproduction and pregnancy may discourage the choice of an EP career. The study is aimed at investigating the level of awareness and main sources of concern about the effects of radiation on reproductive potential and pregnancy, exploring the safety measures adopted in different EP labs, and verifying the adherence to the current guidelines.

METHODS AND RESULTS

An online survey was conducted using the European Heart Rhythm Association (EHRA) infrastructure from April to June 2022. A total of 252 EP personnel (42% women) participated, from 50 countries and different professional roles. Most participants expressed concerns regarding the effects of radiation on reproductive capacity (67.1%) and offspring diseases (68.2%). Only 37.9% of participants were aware of the EHRA 2017 consensus document about occupational radiation exposure. Most participants (80.9%) considered that occupational radiation during pregnancy is not safe. EP female staff were not allowed to work in the EP lab during pregnancy in 48.1% of cases. Zero-fluoroscopy was the preferred choice to continue working in the EP lab during pregnancy.

CONCLUSION

EP staff, including both men and women, have concerns about the effects of radiation on reproductive capacity. Despite the recommendations issued by international bodies, implementation of the policies regarding pregnancy and occupational radiation exposure is heterogeneous. Zero-fluoroscopy is the preferred approach to ensure safety during pregnancy in the EP lab.

Transseptal Puncture Guided by Three-Dimensional Electroanatomical Mapping: Early Experience Using a Simplified Approach in Adults with Congenital Heart Disease

AIMS

The widespread use of three-dimensional (3D) mapping systems and echocardiography in the field of cardiac electrophysiology has made it possible to perform transseptal punctures (TSP) with low or no fluoroscopy. However, such attempts in adults with congenital heart disease (ACHD) who have previously undergone surgical or interventional treatment are limited. Therefore, we sought to explore the feasibility and safety of an approach to perform zero- or low-fluoroscopy TSP in ACHD patients undergoing left atrial cardiac ablation procedures.

METHODS AND RESULTS

This study included 45 ACHD patients who underwent TSP for ablation of left-sided tachycardias (left atrium or pulmonary venous atrium). Computed tomography (CT) of the heart was performed in all patients prior to ablation. 3D mapping of the right-sided heart chambers before TSP was used to superimpose the registered anatomy, which was subsequently used for the mapping-guided TSP technique. TSP was performed with zero-fluoroscopy in 27 patients, and the remaining 18 patients had a mean fluoroscopy exposure of 315.88 ± 598.43 μGy.m² and a mean fluoroscopy duration of 1.9 ± 5.4 min. No patient in this cohort experienced TSP-related complications.

CONCLUSION

Our study describes a fluoroscopy-free or low-dose fluoroscopy approach for TSP in ACHD patients undergoing catheter ablation of left-sided tachyarrhythmias who had been previously treated surgically or interventionally due to congenital heart defects. By superimposing 3D electroanatomic mapping with cardiac CT anatomy, this protocol proved to be highly effective, feasible and safe.

Practical guidance to reduce radiation exposure in electrophysiology applying ultra low-dose protocols: a European Heart Rhythm Association review

Interventional electrophysiology offers a great variety of treatment options to patients suffering from symptomatic cardiac arrhythmia. Catheter ablation of supraventricular and ventricular tachycardia has globally evolved a cornerstone in modern arrhythmia management. Complex interventional electrophysiological procedures engaging multiple ablation tools have been developed over the past decades. Fluoroscopy enabled interventional electrophysiologist throughout the years to gain profound knowledge on intracardiac anatomy and catheter movement inside the cardiac cavities and hence develop specific ablation approaches. However, the application of X-ray technologies imposes serious health risks to patients and operators. To reduce the use of fluoroscopy during interventional electrophysiological procedures to the possibly lowest degree and to establish an optimal protection of patients and operators in cases of fluoroscopy is the main goal of modern radiation management. The present manuscript gives an overview of possible strategies of fluoroscopy reduction and specific radiation protection strategies.