Validation of Dipole Density Mapping During Atrial Fibrillation and Sinus Rhythm in Human Left Atrium

Abstract Background Ablation strategy targeting the core of atrial fibrillation (AF) rotors alone can lead to both stabilisation and destabilisation of rotational activity. Non-contact dipole density mapping system is designed to rapidly identify dynamic regional atrial activation patterns of interest (API) during AF. Purpose To assess the feasibility of an ablation strategy consisted of pulmonary vein isolation + targeting the core of APIs followed by linear ablation to the nearest non-conducting boundary to treat persistent AF. Methods The ablation strategy includes: 1. Antral pulmonary vein electrical isolation (APVI); 2. APIs (focal, localised rotational and localised irregular activation; Figure1) detection by dipole density mapping; 3. API core ablation followed by linear ablation to the nearest non-conduction barrier (APVI/mitral valve); 4. repeat step 2 and 3 in LA (RA, if necessary) until sinus rhythm is achieved. Results Consecutive 40 persistent AF patients (mean 62±12 years, 29 males, AF duration 10±4 months, LA diameter 42±9 mm) were included from 2 centres. An average of 2.0±0.7 APIs per patient were targeted post-APVI. Acute AF termination by ablation was achieved in 27/40 (68%) patients. The mean ablation time of APVI and “Core to block” was 33±12 mins and 31±22 mins, respectively. No major complication occurred. During a mean follow-up of 12±5 months, 32/40 patients (80%) maintained sinus rhythm. Conclusion APVI + “Core to block” guided by the dipole density mapping is feasible for treating persistent AF. A larger randomised study is needed to test the effectiveness of this ablation strategy. Acknowledgement/Funding None

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Electrical anatomy of the left atrium during atrial fibrillation

EP Europace ◽

10.1093/europace/euab116.239 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

P Adragao ◽

D Nascimento Matos ◽

F Costa ◽

P Galvao Santos ◽

G Rodrigues ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrium ◽

Pulmonary Vein ◽

Refractory Period ◽

Cycle Length ◽

Low Voltage ◽

Pulmonary Veins ◽

Density Mapping ◽

Superior Pulmonary Vein

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Twenty years ago, pulmonary veins (PV) ostia were identified as the left atrium (LA) areas with the shortest refractory period during sinus rhythm. Pulmonary veins isolation (PVI) became standard of care, but clinical results are still suboptimal. Today, a special tool using the Carto® electroanatomical mapping (EAM) allows for AF cycle length mapping (CLM), to identify the areas in the left atria with shortest refractory period, during atrial fibrillation. Using this EAM tool, our study aimed to find the LA areas with the shortest refractory period to better recognize electrical targets for catheter ablation. Methods Retrospective analysis of an unicentric registry of individuals with symptomatic drug-refractory AF who underwent PVI with Carto® EAM. CLM was performed with a high-density mapping Pentaray® catheter before and after PVI and in 4 redo procedures. We assessed areas of short cycle length (SCL) (defined as 120 to 250ms), and their relationships with complex fractionated atrial electrograms (CFAE), and low-voltage zones (from 0.1 to 0.3mV). Results A total of 18 patients (8 men, median age 63 IQR 58-71 years) were included. Most patients presented with persistent AF (n = 12, 67%), and 4 patients (22%) had a previous PVI. The mean shortest measured cycle length in AF was 140ms (SD ±27ms). All patients presented areas of SCL located in the PVs or their insertion, 70% in the posterior/roof region adjacent to the left superior pulmonary vein (LSPV) (figure 1) and 60% in the anterior region of the right superior pulmonary vein (RSPV). These two areas remained the fastest even after PVI. The anterior mitral region rarely presented SCL (17%). SCL were related to low-voltage areas in 94% and were adjacent to CFAE. Low-voltage areas and CFAE were more frequent and had a larger LA dispersion than SCL. Conclusion We confirmed in 3D mapping that PVs are the LA zones with shortest refractory period, not only in sinus rhythm but also during AF. The persistence of SCL areas in the border zones of the PVI lines suggest the benefit of a more extensive CLM guided ablation. Larger studies are needed. Abstract Figure 1

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Termination of atrial fibrillation during pharmacological cardioversion in the goat requires inter-atrial synchronisation of conduction

EP Europace ◽

10.1093/europace/euab116.563 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

V Sobota ◽

A Van Hunnik ◽

S Zeemering ◽

G Gatta ◽

D Opacic ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrium ◽

Conduction Velocity ◽

Right Atrium ◽

Path Length ◽

Cycle Length ◽

Final Phase ◽

Periodic Activity ◽

Bachmann’S Bundle

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ITN Networks PersonalizeAF: Personalized Therapies for Atrial Fibrillation. A Translational Approach, No. 860974; CATCH ME: Characterizing Atrial fibrillation by Translating its Causes into Health Modifiers in the Elderly, No. 633196; MAESTRIA: Machine Learning and Artificial Intelligence for Early Detection of Stroke and Atrial Fibrillation, No. 965286; AFib-TrainNet: EU Training Network on Novel Targets and Methods in Atrial Fibrillation, No. 675351 Netherlands Heart Foundation: CVON2014-09, RACE V Reappraisal of Atrial Fibrillation: Interaction between hyperCoagulability, Electrical remodeling, and Vascular Destabilization in the Progression of Atrial Fibrillation Background Few studies report on mechanisms leading to termination of atrial fibrillation (AF). Purpose To characterise electrophysiological parameters and conduction patterns during the transition from AF to sinus rhythm under various conditions of AF termination. Methods A retrospective evaluation of 6 goat studies was performed. AF was maintained for 3-4 weeks in 29 animals. Four animals were in SR. Unipolar electrograms were acquired with one 249-electrode array/atrium. Pharmacological termination of AF was evoked by various drugs; AP14145 (n = 5), PA6 (n = 7), XAF-1407 (n = 9) vernakalant (n = 8). In animals with sinus rhythm, AF was acutely induced and terminated spontaneously. Baseline AF and ≤3 recordings of the last 10 seconds preceding AF termination were analysed. Intervals with temporal continuous and periodic activity were distinguished in the recordings. AF cycle length (AFCL), conduction velocity and path length were determined for each interval. Results In total, 85 AF terminations were recorded. Switches between temporal continuous and periodic activity were seen frequently during AF. However, termination of AF was always preceded by a phase of periodic activity (PA). The final phase of PA persisted for a median number of 21 [IQR 10-28] cycles in the left atrium and somewhat shorter in the right atrium, Table 1. This final phase of PA was accompanied by a profound bi-atrial increase of AFCL, conduction velocity and path length and a disappearance of inter-atrial cycle length differences. Equipotent changes were not observed in the preceding PAs. During the final AF beats, the number of wave fronts were low, 1 or 2. Interestingly, 92% of the patterns during the last beats of AF involved the Bachmann’s bundle as main source of atrial conduction. Conclusion AF termination is preceded by an increased organisation of fibrillatory conduction, associated with abrupt prolongation of the path length. Propagation in atrial free walls regularly originated from the Bachmann’s bundle. These findings suggest that AF termination was not a random process but follows common spatiotemporal patterns. Final period of temporal organisation Left atrium Right atrium Final PA start Final PA end Final PA start Final PA end Af cycle length (ms) 163 ± 37 204 ± 50* 146 ± 44 207 ± 49* Conduction velocity (cm/s) 77 ± 15 96 ± 25* 83 ± 20 103 ± 24* Path Length (cm) 12.2 ± 2.7 19.3 ± 6.3* 12.0 ± 4.1 21.2 ± 6.4* Length of final periodic activity (beats) NA 21 [IQR 10-28] NA 15 [IQR 10- 25] Electrophysiological changes during the final period periodic activity (PA). Wilcoxon signed rank test. *p <0.05NA= not available

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GW29-e0824 Correlation of left atrial low voltage and fractionation substrate between sinus rhythm and atrial fibrillation: high density mapping study in persistent Atrial Fibrillation

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2018.08.670 ◽

2018 ◽

Vol 72 (16) ◽

pp. C144-C145

Author(s):

Juan Chen ◽

Amir Jadidi

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrial ◽

Low Voltage ◽

Persistent Atrial Fibrillation ◽

High Density ◽

Mapping Study ◽

Density Mapping

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“Stunning” of the left atrium after spontaneous conversion of atrial fibrillation to sinus rhythm

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(98)00508-7 ◽

1998 ◽

Vol 32 (7) ◽

pp. 2081-2086 ◽

Cited By ~ 48

Author(s):

Eric K Louie ◽

Dong Liu ◽

Sandra I Reynertson ◽

Henry S Loeb ◽

Thomas L McKiernan ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrium ◽

Spontaneous Conversion

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Experience of pharmacological cardioversion with refralon in persistent atrial fibrillation and flutter according to the data of the cardiology department of Orenburg regional clinical hospital

Jounal of arrhythmology ◽

10.35336/va-2021-3-13-20 ◽

2021 ◽

Vol 28 (3) ◽

pp. 13-20

Author(s):

L. K. Kozlova ◽

N. V. Sokolova ◽

A. V. Sivkova ◽

A. E. Kamyshanova ◽

O. Y. Abramova ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Total Dose ◽

Left Atrium ◽

Persistent Atrial Fibrillation ◽

Clinical Hospital ◽

The Third ◽

Cardiology Department ◽

The Mean ◽

Medical Histories

Aim. To assess the effectiveness and safety of refralon based cardioversion on the experience of the cardiology department of Orenburg Regional Clinical Hospital.Methods. The archival medical histories of 14 patients with persistent atrial fibrillation (AF) and 2 patients with persistent atrial flutter (AFL) (overall 16 patients), who underwent an attempt to restore sinus rhythm with refralon, were analyzed. The mean age of the patients was 51.7±10.4 years. The mean duration of AF/AFL since its last detection was 8.0±6.5 weeks (from 8 days to 8 months). Fifteen patients had hypertension, 3 of them had coronary artery disease (CAD), and 1 patient had CAD with type 2 diabetes mellitus. One of the patients had lone AF. Before cardioversion, all patients underwent the following examination: clinical and biochemical blood tests, clinical urine tests, electrocardiography (ECG), echocardiography (Echo), transesophageal Echo, Holter ECG, the determination of the level of thyroid-stimulating hormone, thyroxine, electrolytes, including potassium and magnesium.Results. According to Echo, initially, the transverse size of the left atrium in patients was 4.3±0.3 cm. Its increase was noted in 68.7% of patients (from 4.3 to 5.0 cm). Restoration of sinus rhythm after the first step of refralon administration at a dose of 10 μg/kg was achieved in 8 patients, after the second step of administration (total dose 20 μg/kg) - in 5 patients and after the third step (total dose 30 μg/kg) - in 2 patients. In 1 patient, restoration of sinus rhythm was not achieved after the administration of the third bolus. Out of 15 patients with restored sinus rhythm, AF recurrence occurred in three. In one of the patients with successful cardioversion, the sinus rhythm was restored the next day. The duration of the last episode of AF and the size of the left atrium did not significantly affect the effectiveness of cardioversion and amounted to 62±54 days and 4.3±0.35 cm, respectively, in patients with successful cardioversion, and with a recurrence of AF - 34.3±28 days and 4.2±0.35 cm (p=0.2; р=0.6). The efficacy of cardioversion with refralon was 71.4% in patients with AF, and 100% in patients with AFL. No adverse events of refralon were found in patients.Conclusion. At the time of discharge, sinus rhythm was recorded in 12 out of 16 patients (75%). The ineffectiveness of cardioversion with refralon was noted only in patients with AF; in all patients with AFL the sinus rhythm was restored.

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Delayed sinus rhythm restoration after thoracoscopic left atrium fragmentation (а report of two cases)

Clinical Practice ◽

10.17816/clinpract59550 ◽

2020 ◽

Vol 11 (4) ◽

pp. 90-95

Author(s):

Sergey A. Vachev ◽

Sergey V. Korolev ◽

Alexandr S. Zotov ◽

Robert I. Khabazov ◽

Alexander V. Troitskiy

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrium ◽

Persistent Atrial Fibrillation ◽

Clinical Cases

The article presents two clinical cases of delayed restoration of the sinus rhythm in patients with long-term persistent atrial fibrillation after the procedure of thoracoscopic radiofrequency fragmentation of the left atrium. The necessity of continuing attempts to restore the sinus rhythm up to the end of the "blind period" (90 days) is discussed.

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