How Imaging Techniques Improve Ventricular Arrhythmia Ablation: A Multimodality-Based Approach.

Although implantable cardioverter defibrillators offer the best protection against sudden cardiac death, catheter ablation for ventricular arrhythmias (VAs) can modify or prevent this event from occurring. In order to achieve a successful ablation, the correct identification of the underlying arrhythmogenic substrate is mandatory to tailor the pre-procedural planning of an ablative procedure as appropriately as possible. We propose that several of the imaging modalities currently used could be merged, including echocardiography (also intracardiac), cardiac magnetic resonance, cardiac computed tomography, nuclear techniques, and electroanatomic mapping. The aim of this state-of-the-art review is to present the value of each modality, that is, its benefits and limitations, in the assessment of arrhythmogenic substrate. Moreover, VAs can be also idiopathic, and in this paper we will underline the role of these techniques in facilitating the ablative procedure. Finally, a hands-on workflow for approaching such a VA and future perspectives will be presented.

Right-sided approach to left bundle branch area pacing combined with atrioventricular node ablation in a patient with persistent left superior vena cava and left bundle branch block: a case report.

BACKGROUND: Left bundle branch area pacing (LBBAP) is an alternative to right ventricular (RV) and biventricular (BiV) pacing in patients scheduled for pace and ablate treatment strategy. However, current delivery sheaths are designed for left-sided implantation, making the right-sided LBBAP lead implantation challenging. CASE PRESENTATION: We report a case of a right-sided LBBAP approach via right subclavian vein in a heart failure patient with a persistent left superior vena cava scheduled for pace and ablate treatment of refractory atrial flutter. To enable adequate lead positioning and support for transseptal screwing, the delivery sheath was manually modified with a 90-degree curve at the right subclavian vein and superior vena cava junction to allow right-sided implantation. The distance between the reshaping point and the presumed septal region was estimated by placing the sheath on the body surface under fluoroscopy. With the reshaping of the delivery sheath, we were able to achieve LBBAP with relatively minimal torque. Radiofrequency ablation of the atrioventricular node was performed the next day and the pacing parameters remained stable in short-term follow-up. CONCLUSION: With the modification of currently available tools, LBBAP can be performed with the right-sided approach.

Conventional fluoroscopy-guided versus zero-fluoroscopy catheter ablation of supraventricular tachycardias.

PURPOSE: The aim of this study was to evaluate the safety and efficacy of zero-fluoroscopy (ZF) catheter ablation (CA) for supraventricular tachycardias (SVT). METHODS: 584 consecutive patients referred to our institution for CA of SVT were analysed. Patients were categorised into two groups; zero-fluoroscopy (ZF) group and conventional fluoroscopy (CF) group. The ZF group was further divided into two subgroups (adults and paediatric). Patient characteristics, procedural information, and follow-up data were compared. RESULTS: The ZF group had a higher proportion of paediatric patients (42.2% vs 0.0%; p < 0.001), resulting in a younger age (30.9 ± 20.3 years vs 52.7 ± 16.5 years; p < 0.001) and lower BMI (22.8 ± 5.7 kg/m2 vs 27.0 ± 5.4 kg/m2; p < 0.001). Procedure time was shorter in the ZF group (94.2 ± 50.4 min vs 104.0 ± 54.0 min; p = 0.002). There were no major complications and the rate of minor complications did not differ between groups (0.0% vs 0.4%; p = 0.304). Acute procedural success as well as the long-term success rate when only the index procedure was considered did not differ between groups (92.5% vs 95.4%; p = 0.155; 87.1% vs 89.2%; p = 0.422). When repeated procedures were included, the long-term success rate was higher in the ZF group (98.3% vs 93.5%; p = 0.004). The difference can be partially explained by the operators' preferences. CONCLUSION: The safety and efficacy of ZF procedures in adult and paediatric populations are comparable to that of CF procedures.

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.

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.

Intracardiac echocardiography-guided transseptal puncture for fluoroless catheter ablation of left-sided tachycardias.

BACKGROUND: Integration of intracardiac echocardiography (ICE) and 3D electroanatomic mapping (EAM) system allows transseptal punctures (TSP) without the use of fluoroscopy. Compared with fluoroscopy, ICE provides better visualization of the anatomy relevant to TSP and early recognition of complications. The aim was to evaluate efficacy and safety of entirely ICE-guided TSPs in patients who underwent fluoroless catheter ablation of left-sided tachycardias. METHODS: Consecutive 524 adult and pediatric patients referred to our institution from July 2014 to December 2019 were analyzed. Patients with cardiac implantable electronic devices (CIEDs) were also included. All procedures were performed with ICE-guided TSP combined with 3D EAM. Adverse events following TSP and within 30 days of the procedure were analyzed. RESULTS: Altogether 949 TSPs (363 double punctures, 76.5%) were performed in 586 fluoroless ablation procedures: 451 (77%) were ablation of atrial fibrillation or atypical flutter, 75 (12.8%) of left-sided accessory pathway, 33 (5.6%) of ventricular tachycardia, and 27 (4.6%) of focal atrial tachycardia. Forty-six (7.8%) procedures were performed in pediatric population and 36 procedures (6.1%) in patients with CIED. Only 2 TSPs were unsuccessful (2/949, 0.2%). Overall procedural complication rate was 1.9% (11/586 procedures). There was only 1 TSP-related pericardial tamponade (2/949, 0.2%). In CIED patients, there was 1 lead dislocation following TSP. CONCLUSIONS: Entirely ICE-guided TSPs for different left-sided tachycardias can be safely and effectively performed in adult and pediatric population without the use of fluoroscopy. However, caution is advised in CIED patients due to possible lead dislocation risk.

Treatment of left-sided extension of AV node: A valuable integration of advance imaging modalities and cryoablation.

We present a case of successful cryoablation of the left extension of the atrioventricular (AV) node for treatment of a recurrent atrioventricular nodal reentry tachycardia without the use of fluoroscopy. Three-dimensional electroanatomic mapping system and intracardiac echocardiography were used to navigate catheters in the heart and position them according to anatomical landmarks. Due to the nature of cryoablation lesion formation, lesions were able to be applied safely in right atrium, as well as in left atrium, without damaging AV node or bundle of His.

Noninvasive programmed stimulation in the setting of ventricular tachycardia catheter ablation.

In the setting of catheter ablation of ventricular tachycardia (VT), invasive programmed ventricular stimulation (PVS) is considered an important tool to assess the (residual) inducibility of ventricular arrhythmias and determine the acute success of the procedure. In patients with cardiovascular implantable electronic devices, noninvasive programmed stimulation via implantable cardioverter-defibrillator (ICD) leads can be an alternative to the invasive PVS with intracardiac catheters. The advantages of noninvasive programmed stimulation include preprocedure planning of the electrophysiology procedure to ensure optimal conditions for successful catheter ablation of VT. Following the procedure, noninvasive programmed stimulation has been shown to be used as a guide for repeat early ablation, to offer better programming of ICD, to offer prognostic value regarding the VT recurrence, and to guide antiarrhythmic drug therapy. The noninvasive nature of noninvasive programmed stimulation makes it an attractive alternative to PVS in patients with ICD who have not undergone catheter ablation of VT to obtain prognostic value regarding the occurrence of VT.

Combined use of electro-anatomic mapping system and intracardiac echocardiography to achieve zero-fluoroscopy catheter ablation for treatment of paroxysmal atrial fibrillation: a single centre experience.

Fluoroscopy is the principal imaging method for catheter ablation (CA) of atrial fibrillation (AF). However, radiation exposure carries potential health risk to patients and operators alike. Our aim was to study safety and efficacy of zero-fluoroscopy CA of paroxysmal AF with a combined use of electroanatomic mapping system (EAM) and intracardiac echocardiography (ICE). In addition, impact of ICE/EAM automatic integration system and contact force (CF) sensing technology on procedural times were assessed. We included 144 consecutive patients (69% males, age 60 ± 10 years, BMI 29 ± 4,6) referred for CA of symptomatic paroxysmal AF. All procedures were performed only with EAM system and ICE. No fluoroscopy was used. The acute procedural success of complete pulmonary vein isolation was achieved in all patients (100%) and adverse events were detected in eight patients (5.6%). In 53 (37%) patients the use of ICE/EAM automatic integration system shortened procedural times compared to those performed without it (148 ± 35 vs. 187 ± 44 min, p < 0.05). Similarly, 89 (60%) procedures where CF sensing catheter was used were shorter compared to those performed without it (163 ± 41 vs. 188 ± 46 min, p < 0.05). Zero-fluoroscopy approach for treatment of paroxysmal AF seems feasible, safe, and acutely effective. Additional reduction of procedural times could be achieved with the use of ICE/EAM automatic integration system and CF sensing technology.