Sequential ultrahigh‐density contact mapping of persistent atrial fibrillation: An efficient technique for driver identification

Atrial fibrillation (AF) ablation is increasingly used to maintain sinus rhythm yet its results are sub-optimal, especially in patients with persistent AF or prior unsuccessful procedures. Attempts at improvement have often targeted substrates that sustain AF after it is triggered, yet those mechanisms are debated. Many studies now challenge the concept that AF is driven by self-sustaining disordered wavelets, showing instead that localised drivers (rotors) may drive disorder via a process known as fibrillatory conduction. Novel mapping using wide-area recordings, physiological filtering and phase analysis demonstrates rotors in human AF. Contact mapping with focal impulse and rotor modulation (FIRM) shows that localised ablation at sources can improve procedural success in many populations on long-term follow up and some newer approaches to rotor mapping are qualitatively similar. This review critically evaluates the data on rotor mapping and ablation, which advances our conceptual understanding of AF and holds the promise of substantially improving ablative outcomes in patients with persistent AF.

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Catheter ablation with ethanol infusion in the vein of marshall for persistent atrial fibrillation: safety and procedure duration

EP Europace ◽

10.1093/europace/euab116.179 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

G Massoulie ◽

M Andronache ◽

A Pastorcici ◽

C Dauphin ◽

A Costea ◽

...

Keyword(s):

Atrial Fibrillation ◽

Learning Curve ◽

Persistent Atrial Fibrillation ◽

Efficient Technique ◽

Ethanol Injection ◽

Funding Sources ◽

Ethanol Infusion ◽

Initial Learning ◽

Procedure Duration ◽

Time Required

Abstract Funding Acknowledgements Type of funding sources: None. Background Ethanol Infusion in the Vein of Marshall (EIVOM) has been recently introduced as an efficient technique that helps achieving mitral isthmus block during ablation procedures for persistent atrial fibrillation (PAF) or peri-mitral atrial flutter. Purpose We have evaluated the safety of EIVOM and the duration required to perform this procedure. Methods We performed EIVOM in 121 patients for PAF (mean age of 65 years (range 40-83, 73% men; Mean EF 50%. The main steps of the EIVOM were as follows: the procedure commenced with catheterization of the coronary sinus, followed by the subsequent introduction of an angiography catheter that allowed for iodine contrast injection and vein of Marshall (VOM) localization, 1.5-2.5 mm angioplasty balloon over 0.014" guidewire placement and finally the ethanol injection up to 10 ml. Results No major complications were observed during the ablation procedure or before hospital discharge. In 62 patients in whom procedure duration data was available the mean EIVOM procedure time was 41 min (range from 13 to 105 min). After the first 20 procedures, where the learning curve for the operators has to be taken into consideration, a reduction in the time required to achieve EIVOM was consistently noted, with an average of less than 30 min. and for the last 20 procedures less than 20 min. Factors which increase the time required for successful EIVOM include: difficulty in visualizing the ostium of the VOM, a VOM ostium located proximally, difficulty in advancing the angioplasty wire into the VOM and balloon displacement and repositioning. Conclusions Ethanol infusion in the Vein of Marshall is a safe and efficient technique that can be performed in an acceptable amount of time after an initial learning curve. Abstract Figure. Image 1 VOM

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Automatic Extraction of Recurrent Patterns of High Dominant Frequency Mapping During Human Persistent Atrial Fibrillation

Frontiers in Physiology ◽

10.3389/fphys.2021.649486 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xin Li ◽

Gavin S. Chu ◽

Tiago P. Almeida ◽

Frederique J. Vanheusden ◽

João Salinet ◽

...

Keyword(s):

Atrial Fibrillation ◽

Persistent Atrial Fibrillation ◽

Dominant Frequency ◽

Recognition Algorithm ◽

Time Interval ◽

Contact Mapping ◽

Time Period ◽

Before And After ◽

Spatiotemporal Behavior ◽

Recurrent Patterns

Purpose: Identifying targets for catheter ablation remains challenging in persistent atrial fibrillation (persAF). The dominant frequency (DF) of atrial electrograms during atrial fibrillation (AF) is believed to primarily reflect local activation. Highest DF (HDF) might be responsible for the initiation and perpetuation of persAF. However, the spatiotemporal behavior of DF remains not fully understood. Some DFs during persAF were shown to lack spatiotemporal stability, while others exhibit recurrent behavior. We sought to develop a tool to automatically detect recurrent DF patterns in persAF patients.Methods: Non-contact mapping of the left atrium (LA) was performed in 10 patients undergoing persAF HDF ablation. 2,048 virtual electrograms (vEGMs, EnSite Array, Abbott Laboratories, USA) were collected for up to 5 min before and after ablation. Frequency spectrum was estimated using fast Fourier transform and DF was identified as the peak between 4 and 10 Hz and organization index (OI) was calculated. The HDF maps were identified per 4-s window and an automated pattern recognition algorithm was used to find recurring HDF spatial patterns. Dominant patterns (DPs) were defined as the HDF pattern with the highest recurrence.Results: DPs were found in all patients. Patients in atrial flutter after ablation had a single DP over the recorded time period. The time interval (median [IQR]) of DP recurrence for the patients in AF after ablation (7 patients) decreased from 21.1 s [11.8 49.7 s] to 15.7 s [6.5 18.2 s]. The DF inside the DPs presented lower temporal standard deviation (0.18 ± 0.06 Hz vs. 0.29 ± 0.12 Hz, p < 0.05) and higher OI (0.35 ± 0.03 vs. 0.31 ± 0.04, p < 0.05). The atrial regions with the highest proportion of HDF region were the septum and the left upper pulmonary vein.Conclusion: Multiple recurrent spatiotemporal HDF patterns exist during persAF. The proposed method can identify and quantify the spatiotemporal repetition of the HDFs, where the high recurrences of DP may suggest a more organized rhythm. DPs presented a more consistent DF and higher organization compared with non-DPs, suggesting that DF with higher OI might be more likely to recur. Recurring patterns offer a more comprehensive dynamic insight of persAF behavior, and ablation targeting such regions may be beneficial.

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