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

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.

A case report of left ventricular lead implantation via total three-dimensional transseptal puncture after tricuspid valve replacement

Background

Ventricular lead implantation is relatively difficult for patients with bradyarrhythmia after tricuspid valve replacement. Right atrial (RA) abnormalities often occurred in patients with tricuspid valve disease; conventional coronary sinus (CS) lead implantation is not easy to operate. Therefore, it is necessary to develop a safe method for implanting LV endocardial leads in patients after tricuspid valve replacement.

Case presentation

A 76-year-old Asian woman who had been implanted with a metal tricuspid valve replacement 4 years ago was admitted to the Department of Cardiology for pacemaker implantation due to transient blackout related to persistent atrial fibrillation with long pauses. The patient's family rejected the surgical placement of an epicardial LV lead. Therefore, we first intended to operate LV lead implantation through the CS; however, the orifice of the CS was virtually difficult to seek. Ultimately, we utilized total 3-dimensional (T3D) transseptal puncture (TSP) under the guidance of the CARTO 3 system; thus, we implanted the LV endocardial lead, which contributed to the accurate puncture of the central fossa ovalis and ensured the safety of TSP in the case of RA enlargement. Meanwhile, the CARTO 3 system contributed to the localization of the LV lead to the LV free wall during implantation. All the intraoperative and postoperative pacemaker parameters were favorable; no intraoperative or postoperative complications occurred.

Conclusions

This case report may provide a novel surgical approach for LV lead implantation in patients who underwent tricuspid valve replacement or patients who may benefit from cardiac resynchronization therapy but failed to implant CS lead.

Chinese expert consensus on the construction of the fluoroless cardiac electrophysiology laboratory and related techniques

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X-rays. X-rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three-dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X-rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac 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.

Effect of repeat catheter ablation vs. antiarrhythmic drug therapy among patients with recurrent atrial tachycardia/atrial fibrillation after atrial fibrillation catheter ablation: data from CHINA-AF registry

AIMS

Although several studies have proved that repeat catheter ablation is beneficial to recurrent atrial tachycardia (AT)/atrial fibrillation (AF) after AF catheter ablation, the hard endpoints of the effect of catheter ablation on recurrent AT/AF patients after AF catheter ablation remains unclear. Our study aims to compare the effect of catheter ablation and drug therapy on recurrent AT/AF patients after AF catheter ablation.

METHODS AND RESULTS

Four thousand nine hundred and thirteen consecutive patients with recurrent AT/AF after catheter ablation from the China-AF registry were enrolled. The patients were divided into two study groups: the repeat catheter ablation group and the medical therapy group. The primary endpoint is a composite of cardiovascular mortality or ischaemic stroke or major bleeding events. Secondary endpoints were each component of the primary endpoints and AF recurrence rate. Landmark analysis and Cox regression were used in the statistical analysis. We chose landmark 36 months as the primary landmark date. Over a median follow-up period of 40 ± 24 months, 4913 patients were divided into either the repeat ablation group or the medical therapy group. The cumulative incidence of the composite primary outcome was significantly lower in the repeat ablation group than the medical therapy group (adjusted hazard ratio = 0.56; 95% confidence interval: 0.35-0.89; P = 0.015) of landmark 36 months (2359 patients were included in medical therapy group and 704 patients were included in repeat ablation group at landmark 36 months). However, all secondary endpoints were not statistically different in the two groups, including cardiovascular mortality, ischaemic stroke, major bleeding events, and AF recurrence rate.

CONCLUSION

Based on this research, in recurrent AT/AF patients after a catheter ablation procedure, compared with medical therapy, repeat catheter ablation may significantly reduce the risk of the endpoint of composite cardiovascular mortality, ischaemic stroke, and major bleeding events.

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.

Rare left-sided accessory pathway successfully ablated with atrial insertion site at the left-side fossa ovalis

INTRODUCTION

Left-sided accessory pathway (AP) with atrial insertion away from the annulus is an atypical variation. Conventional mapping and ablation performed along mitral annulus (MA) is usually ineffective.

METHODS

A 14-year-old girl without structural heart disease presented with recurrent episodes of sudden onset palpitations and electrocardiogram (ECG) showed a narrow QRS complex tachycardia.

RESULTS

Electrophysiology study (EPS) was done and anterograde atrioventricular reentrant tachycardia (AVRT) with AP was diagnosed. Conventional mapping and ablation performed along TA and MA was failed. 3D-activation mapping found the retrograde atrial insertion site of AP on the left atrium fossa ovalis (FO), and AP was successfully abolished by radiofrequency ablation at that site.

CONCLUSION

As reported, this patient is the first report of ablating a left-sided AP with retrograde atrial insertion on the left atrium FO.

Zero-Fluoroscopy Cardiac Ablation: Technology Is Moving Forward in Complex Procedures—A Novel Workflow for Atrial Fibrillation

Simple Summary

Electrophysiological procedures are mainly performed using fluoroscopy, exposing both healthcare staff and patients to a non-negligible dose of radiation. To date, simple ablation procedures have often been approached with zero fluoroscopy. In complex ablation procedures, such as atrial fibrillation (AF) ablation, zero fluoroscopy is still challenging mainly because of transseptal puncture. We report a workflow to perform a complete zero-fluoroscopy AF ablation using a 3D electro-anatomical mapping system, intracardiac echocardiography and a novel steerable guiding sheath visible on the mapping system. We describe two cases, one with paroxysmal AF and the other with persistent AF during which this novel workflow was successfully applied with complete zero-fluoroscopy exposure and achieving pulmonary vein isolation.

Abstract

Background and Rationale. A fluoroscopy-based approach to an electrophysiological procedure is widely validated and has been recognized as the gold standard for a long time. The use of fluoroscopy exposes both the healthcare staff and the patient to a non-negligible dose of radiation. To minimize the risks associated with the use of fluoroscopy, it would be reasonable to perform ablation procedures with zero fluoroscopy. This approach is widely used in simple ablation procedures, but not in complex procedures. In atrial fibrillation (AF) ablation procedures, fluoroscopy remains the main technology used, in particular to guide the transseptal puncture. Main results and Implications. We present a workflow to perform a complete zero-fluoroscopy ablation for AF ablation procedures using a 3D electro-anatomical mapping system, intracardiac echocardiography and a novel steerable guiding sheath that can be visualized on the mapping system. We present two cases, one with paroxysmal AF and the other one with persistent AF during which we applied this novel workflow achieving a successful pulmonary vein isolation without complications and complete zero-fluoroscopy exposure.

A reliable fossa ovalis impedance mapping for safer transseptal puncture: A new vision beyond voltage

INTRODUCTION

Transseptal puncture (TSP) is widely used in clinical practice but is negatively affected by a nonneglectable rate of complications and X-ray exposure. To address these problems, we investigated whether or not impedance mapping could correctly identify fossa ovalis (FO) and safely guide TSP.

METHODS AND RESULTS

Electroanatomic mapping was performed with CARTO 3 system version 7 and a ThermoCool® SmartTouch® mapping catheter was employed. In each patient, an impedance map and a bipolar voltage map of the whole interatrial septum were collected, acquiring at least 150 points with a contact force ≥2 g and using the pattern matching filter. Thirty-five patients were enrolled. A low impedance area was clearly identified in 34 of them. In 30 patients (88%), the FO was located in the low impedance area. The map was obtained in sinus rhythm in 17 cases (50%); in 15 of these (88%), the TSP site, the patent foramen ovale, or the FO tenting area fell inside the low impedance area. The same numbers were observed when mapping during atrial fibrillation.

CONCLUSION

To the best of our knowledge, this is the first study that provides the reliability and reproducibility of impedance mapping in identifying FO, an affordable and feasible tool that could be potentially introduced into clinical practice.

Study on the Curative Effect and Safety of Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation via Zero-Fluoroscopy Transseptal Puncture under the Dual Guidance of Electroanatomical Mapping and Intracardiac Echocardiography

Aims

3D electroanatomical mapping combined with intracardiac echocardiography- (EAM-ICE-) guided transseptal puncture has been proven safe and effective during the radiofrequency catheter ablation (RFCA) procedure used to treat paroxysmal atrial fibrillation (PAF). In this study, we aimed to compare the curative effect and safety of RFCA via F (fluoroscopy) and zero-fluoroscopy transseptal puncture guided by EAM-ICE in patients with PAF.

Methods and Results

A prospective study in which 110 patients with PAF were included and assigned to two groups was conducted. Fifty-five (50%) patients were enrolled in the EAM-ICE group, whereas the other 55 (50%) patients were enrolled in the F group. There were no significant differences in baseline characteristics between the two groups. The transseptal duration time was longer in the EAM-ICE group (19.8 ± 3.0 min vs. 8.6 ± 1.2 min, p ≤ 0.01); however, fluoroscopy was not used in the EAM-ICE group compared with the F group (0 mGy vs. 109.1 ± 57.9 mGy). Similarly, there was also no significant difference in the recurrence rate of atrial fibrillation between the EAM-ICE and F groups (25.5% vs. 18.2%, p=0.356).

Conclusion

RFCA via EAM-ICE-guided zero-fluoroscopy transseptal puncture in patients with PAF is safe and effective for long-term follow-up.

Catheter ablation of atrial fibrillation in situs inversus dextrocardia: Challenge, improved procedure, outcomes, and literature review

INTRODUCTION

Catheter ablation for atrial fibrillation (AF-CA) in patients with situs inversus dextrocardia (SID) can be challenging because of the contrary anatomy and associated anomalies. Cases and literature regarding AF-CA in SID are rare and provide little information. Our study aims to present an improved procedure, ablation strategies, and evaluate the safety and outcomes of AF-CA in patients with AF and SID.

METHODS

A total of 10 patients with AF-SID (mean age, 60.4 ± 15.7 years; six paroxysmal AF, four persistent atrial fibrillation [PeAF]) were enrolled. For the improved procedure, images obtained by preacquired computed tomography and three-dimensional electroanatomical mapping, integrating intracardiac echocardiography, and x-ray imaging data are necessary to optimize the transseptal puncture and ablation procedure.

RESULTS

All patients successfully underwent 13 AF-CA procedures without complications, including three patients received repeat procedures. However, two PeAF patients presented sick sinus syndrome (SSS) after the AF-CA procedure, and one underwent permanent pacemaker implantation therapy during hospitalization. During the follow-up period (6-72 months), the outcomes were not favorable: three patients (30%) maintained sinus rhythm (SR) after the initial procedure; after repeated procedures, the overall SR rate was 40% (four patients).

CONCLUSION

With the improved strategy, AF-CA can be safely and effectively performed with low radiation exposure in patients with SID. However, the long-term outcomes were not favorable, even when managed at a tertiary center by a team of specialists. Moreover, patients with PeAF might also have masked SSS, which should be carefully considered.