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

Zero fluoroscopy catheter ablation of premature ventricular contractions: a multicenter experience

BACKGROUND

Catheter ablation has become an established treatment option for premature ventricular complexes (PVCs). The use of fluoroscopy exposes patients and medical staff to potentially harmful stochastic and deterministic effects of ionizing radiations. We sought to analyze procedural outcomes in terms of safety and efficacy using a "zero fluoroscopy" approach for catheter ablation of PVCs.

METHODS

The present retrospective, multicenter, observational study included 131 patients having undergone catheter ablation of PVCs using "zero fluoroscopy" between 2019 and 2020 in four centers compared with another group who underwent the procedure with fluoroscopy.

RESULTS

Median age was 51.0 ± 15.9 years old; males were 77 (58.8%). Among the study population, 26 (19.8%) had a cardiomyopathy. The most frequent PVC origin was right ventricular outflow tract (55%) followed by the left ventricle (16%), LVOT and cusps (13.7%), and aortomitral continuity (5.3%). Acute suppression of PVC was achieved in 127 patients (96.9%). At 12 months, a complete success was documented in 109 patients (83.2%), a reduction in PVC burden in 18 patients (13.7%), and a failure was recorded in four patients (3.1%). Only two minor complications occurred (femoral hematoma and arteriovenous fistula conservatively treated).

CONCLUSIONS

The PVC ablation with a "zero" fluoroscopy approach appears to be a safe procedure with no major complications and good rates of success and recurrence in our multicenter experience.

Discovery of TBX20 as a Novel Gene Underlying Atrial Fibrillation

Atrial fibrillation (AF), the most prevalent type of sustained cardiac dysrhythmia globally, confers strikingly enhanced risks for cognitive dysfunction, stroke, chronic cardiac failure, and sudden cardiovascular demise. Aggregating studies underscore the crucial roles of inherited determinants in the occurrence and perpetuation of AF. However, due to conspicuous genetic heterogeneity, the inherited defects accounting for AF remain largely indefinite. Here, via whole-genome genotyping with genetic markers and a linkage assay in a family suffering from AF, a new AF-causative locus was located at human chromosome 7p14.2-p14.3, a ~4.89 cM (~4.43-Mb) interval between the markers D7S526 and D7S2250. An exome-wide sequencing assay unveiled that, at the defined locus, the mutation in the TBX20 gene, NM_001077653.2: c.695A>G; p.(His232Arg), was solely co-segregated with AF in the family. Additionally, a Sanger sequencing assay of TBX20 in another family suffering from AF uncovered a novel mutation, NM_001077653.2: c.862G>C; p.(Asp288His). Neither of the two mutations were observed in 600 unrelated control individuals. Functional investigations demonstrated that the two mutations both significantly reduced the transactivation of the target gene KCNH2 (a well-established AF-causing gene) and the ability to bind the promoter of KCNH2, while they had no effect on the nuclear distribution of TBX20. Conclusively, these findings reveal a new AF-causative locus at human chromosome 7p14.2-p14.3 and strongly indicate TBX20 as a novel AF-predisposing gene, shedding light on the mechanism underlying AF and suggesting clinical significance for the allele-specific treatment of AF patients.

Safety and efficacy of intracardiac echocardiography-guided zero-fluoroscopic cryoballoon ablation for atrial fibrillation: a prospective randomized controlled trial

AIMS

The development of intracardiac echocardiography (ICE) has enabled fluoroless atrial fibrillation (AF) ablation using three-dimensional electroanatomical mapping systems. However, fluoroless cryoballoon ablation (CBA) remains challenging, mainly because of the lack of a visual mapping system. Hence, this study aimed to investigate the safety and efficacy of fluoroless CBA for AF under ICE guidance.

METHODS AND RESULTS

Patients (n = 100) who underwent CBA for paroxysmal AF were randomly assigned to zero-fluoroscopic (Zero-X) and conventional groups. Intracardiac echocardiography was used to guide the transseptal puncture and catheter and balloon manipulation in all enrolled patients. The patients were prospectively followed for 12 months after CBA. The mean age was 60.4 years, and the left atrial (LA) size was 39.4 mm. Pulmonary vein isolation (PVI) was achieved in all patients. In the Zero-X group, fluoroscopy was used in only one patient because of unstable phrenic nerve capture during right-sided PVI. The procedure time and LA indwelling time in the Zero-X group were not statistically different compared with that in the conventional group. Fluoroscopic time (9.0 vs. 0.008 min) and radiation exposure (29.4 vs. 0.02 mGy) were significantly shorter in the Zero-X group than in the conventional group (P < 0.001). The complication rate did not differ between the two groups. During a mean follow-up of 663.3 ± 172.3 days, the recurrence rate was similar (16.0 vs. 18.0%; P = 0.841) between the groups. Multivariate analysis revealed that LA size was the only independent predictor of clinical recurrence.

CONCLUSION

Intracardiac echocardiography-guided fluoroless CBA for AF was a feasible strategy without compromising acute and long-term success or complication rates.

Special Issue: "Biophysics, Arrhythmias and Pacing"

Cardiac pacing technologies have been implemented during the last few decades, including leadless pacemakers and pacing of the conduction system, such as His bundle pacing and left bundle branch area pacing [...].

Impact of Systematic Use of Intracardiac Ultrasound during Transseptal Catheterization in the Electrophysiology Laboratory

AIMS

To explore the impact of the use of intracardiac echocardiography (ICE) in the ablation of supraventricular arrhythmias requiring transseptal catheterization (TSC), whilst analyzing the reduction in periprocedural complications and complications specifically related to TSC.

METHODS

A retrospective multicenter study collecting data from consecutive atrial fibrillation (AF) and supraventricular ablation procedures that required TSC was performed in five Italian centers. Based on physician discretion, TSC was performed with or without ICE. Periprocedural complications, separating all complications from complications directly related to TSC, were collected. Independent predictors of periprocedural complications and TSC-related complications were investigated.

RESULTS

A total of 2181 TSCs were performed on 1862 patients at five Italian centers from 2006 to 2021, in 76% of cases by AF ablation and in 24% by ablation of other arrhythmias with a circuit in the left atrium. Overall, 1134 (52%) procedures were performed with ICE support and 1047 (48%) without ICE. A total of 67 (3.1%) complications were detected, 19 (1.7%) in the ICE group and 48 (4.6%) in the no ICE group, p < 0.001. A total of 42 (1.5%) complications directly related to TSC: 0.9% in the ICE group and 3.1% in the no ICE group (p < 0.001). The independent predictors of all complications were age (OR 1,02 95% C.I 1.00-1.05; p = 0.036), TSC with the use of ICE (OR 0.27 95% C.I 0.15-0.46; p < 0.001) and AF ablation (OR 2,25 95%C.I 1.05-4.83; p = 0.037). The independent predictors for TSC complications were age (OR 1.03 95% C.I 1.01-1.06; p = 0.013) and TSC with the use of ICE (OR 0.24 95% C.I 0.11-0.49; p < 0.001).

CONCLUSIONS

ICE reduced periprocedural and TSC-related complications during electrophysiological procedures for ablation of left atrial arrhythmias.

Efficacy and safety of zero‐fluoroscopy ablation of ventricular arrhythmias originating from the right ventricular outflow tract: Comparison with fluoroscopy‐guided ablation without a three‐dimensional electroanatomic mapping system

Background

Radiofrequency catheter ablation is the preferred treatment choice for ventricular arrhythmias (VAs) originating from right ventricular outflow tract (RVOT) in symptomatic patients and is usually performed under fluoroscopy guidance. Zero-fluoroscopy (ZF) ablations using 3D mapping system applied for treatment of various types of arrhythmias are trending and practiced in many centers around the world, but rarely done in Vietnam. The objective of this study was to evaluate the efficacy and safety of zero-fluoroscopy ablation of RVOT VAs, compared with fluoroscopy-guided ablation without a 3D electroanatomic mapping (EAM) system.

Methods and Results

We conducted a nonrandomized, prospective single-center study including 114 patients with RVOT VAs that had electrocardiographic features of typical left bundle branch block, inferior axis QRS morphology, and a precordial transition ≥ V₃, from May 2020 to July 2022. The patients were assigned (without randomization) to two different approaches of either zero-fluoroscopy ablation under the guidance of the Ensite system (ZF group) or fluoroscopy-guided ablation without a 3D EAM (fluoroscopy group) in a 1:1 ratio. After a follow-up time of 5.0 ± 4.9 months and 6.9 ± 9.3 months in the ZF and fluoroscopy groups, respectively, the results showed a higher success rate in the fluoroscopy group than in the complete ZF group (87.3% vs 86.8%), although the difference was not statistically significant. No major complication was noted in both the groups.

Conclusion

ZF ablation for RVOT VAs can be done safely and effectively using the 3D electroanatomic mapping system. The results of ZF approach are comparable to that of the fluoroscopy-guided approach without a 3D EAM system.