Application of recurrence plot analysis to characterise whole chamber propagation of atrial fibrillation

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
M Pope ◽  
P Kuklik ◽  
A Briosa E Gala ◽  
M Leo ◽  
J Paisey ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Charge Density ◽  
De Novo ◽  
Inverse Correlation ◽  
Right Atrial ◽  
Research Centre ◽  
Activation Patterns ◽  
Density Mapping ◽  
Distance Matrices

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Oxford Biomedical Research Centre Introduction Non-contact charge density mapping allows visualisation of whole chamber propagation during atrial fibrillation (AF). The identification of regions with repetitive or, conversely, more complex patterns of wavefront propagation may provide clues to mechanisms responsible for AF maintenance and lead to improved outcomes from catheter ablation. Our novel mapping approach based on signal recurrence plots has never been applied to whole chamber, bi-atrial recording of atrial fibrillation. Purpose To apply recurrence analysis to characterise whole chamber bi-atrial AF propagation. Methods Non-contact dipole signals from left and right atrial maps were obtained during simultaneous bi-atrial charge density mapping of AF. Signals were converted to phase and mean phase coherence calculated for the generation of recurrence distance matrices for the whole chamber and each anatomical region (6x LA and 4x RA) over the 30-second recording duration, where a value of 1 (purple, see figure panel A) represents uniform repetitive conduction, and 0 (red), irregular, non-repetitive activity. Whole chamber and regional mean recurrence values were calculated and correlated with the frequency of wavefronts of localised irregular activation patterns. Results Maps were obtained prior to ablation in 21 patients (5 paroxysmal (pAF), 16 persistent AF (persAF)) undergoing de-novo catheter ablation procedures. Whole chamber recurrence was higher in patients with pAF (0.40 ± 0.08) than persAF (0.34 ± 0.05), p < 0.0005. There was an inverse correlation between regional recurrence values and the number of localised irregular activations detected (-0.7021, p < 0.0005, figure panel B) with the lateral LA and anterior RA demonstrating the highest recurrence values in each chamber (figure panel C). Conclusion Use of recurrence distance matrices characterises global AF propagation phenotypes. Regional values are inversely correlated with the frequency of localised irregular activation patterns identified demonstrating an anatomic dependence in the level of AF propagation complexity, greatest in the anterior LA and septal RA. Comparison of strategies targeting regions with maximal vs. minimal values during catheter ablation may define an optimal approach to treatment of persistent AF. Abstract Figure. Recurrence abstract figure

scholarly journals Insights into electrophysiological mechanisms of atrial fibrillation propagation using simultaneous bi-atrial mapping

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
M Pope ◽  
P Kuklik ◽  
A Banerjee ◽  
A Briosa E Gala ◽  
M Leo ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Right Atrial ◽  
Research Centre ◽  
Density Mapping ◽  
Atrial Ablation ◽  
Novel Approach ◽  
Opposite Chamber ◽  
The Right ◽  
Procedural Outcome ◽  
Atrial Mapping

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Oxford Biomedical Research Centre Introduction Early evidence of pulmonary vein triggers initiating AF has led to focus on the left atrium (LA). Little work has been done to characterise the role of the right atrium (RA) in AF maintenance. Purpose To characterise the relative roles of the LA and RA in maintenance of atrial fibrillation and explore mechanisms of AF propagation. Methods Simultaneous bi-atrial mapping was carried out in patients undergoing first time catheter ablation using 2 linked non-contact charge density mapping systems to obtain 30-second recordings during AF. The predominant channel of communication between chambers was identified and the time difference across this channel measured (see figure). The proportion of signals earlier in each chamber was calculated and a dominant chamber identified if preceding the opposite chamber for ≥60% of the recording. AF was characterised in each chamber according to frequency of specific propagation patterns (localised rotational activation (LRA) and focal firing (FF)). The difference in AF characteristics in the LA and RA according to acute procedural outcome (termination with ablation vs. DCCV) was measured using 2-way ANOVA and predictors of AF termination identified using binomial logistic regression. Results Twenty-one patients were included (16 persistent AF, 5 paroxysmal AF, 11 in sinus rhythm at baseline) with 41 maps obtained prior to ablation. A dominant chamber was identified in 11 maps (in 9 patients). Of these, 5 maps (in 4 patients) were LA dominant, and 6 maps (in 5 patients) were RA dominant. The remainder showed balanced interatrial propagation. For patients with persistent AF, in the RA, those needing DCCV had more LRA than those with termination with ablation (79 activations, (95% CI 65-93) vs. 51 (30-71); p = 0.025). There was no difference in the LA in the two groups (77 vs 59, p = 0.541). There were fewer FFs in the RA vs LA in patients needing DCCV (123 (106-140) vs. 155 (137-172), p = 0.012)(see panel F). No differences in distribution of LIA were observed. The frequency of LRA (p = 0.003) and FF (p = 0.004) in the RA, and RA AFCL (p = 0.041), were predictors of acute procedural outcome. Conclusions Our novel approach of simultaneous bi-atrial mapping revealed that mechanisms responsible for AF maintenance were evenly distributed between atria whilst acute AF termination with left atrial ablation was dependent on the contribution of right atrial substrate. Strategies incorporating right atrial mechanisms may result in improved outcomes from AF ablation. Abstract Figure.

scholarly journals Diverse activation patterns during persistent atrial fibrillation by noncontact charge‐density mapping of human atrium

2020 ◽  
Vol 36 (4) ◽  
pp. 692-702 ◽  
Author(s):  
Rui Shi ◽  
Zhong Chen ◽  
Charlie Butcher ◽  
Junaid AB Zaman ◽  
Vennela Boyalla ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Charge Density ◽  
Persistent Atrial Fibrillation ◽  
Human Atrium ◽  
Activation Patterns ◽  
Density Mapping

P439Could regional electrogram desynchronization identified using mean phase coherence be potential ablation targets in persistent atrial fibrillation?

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
X Li ◽  
B Sidhu ◽  
T P Almeida ◽  
M Ehnesh ◽  
A Mistry ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Linear Regression Analysis ◽  
Conduction Block ◽  
Inverse Correlation ◽  
Persistent Atrial Fibrillation ◽  
Underlying Mechanism ◽  
Phase Coherence ◽  
Research Centre ◽  
Contact Mapping ◽  
Density Mapping

Abstract Funding Acknowledgements This work was supported by the NIHR Leicester Biomedical Research Centre. XL was funded by MRC(MR/S037306/1) and BHF (PG/18/33/33780) Background It remains controversial as to whether rotors detected using phase mapping during persistent atrial fibrillation (persAF) represent main drivers of the underlying mechanism as others found rotors to be located near line of conduction block. Regional electrogram desynchronization (RED) has been suggested as successful targets for persAF ablation, but automatic tools and quantitative measures are lacking. Purpose We aim to use mean phase coherence (MPC) to automatically identify RED regions during persAF. This method was compared with phase singularity density (PSD) maps. Methods Patients undergoing left atrial (LA) persAF ablation were enrolled (n = 10). 2048-channel virtual electrograms (VEGMs) were collected from each patient using non-contact mapping (St Jude Velocity System, Ensite Array) for 10 seconds.  To remove far field ventricular activities, QRS onset and T wave end locations were detected from ECG lead I (Figure 1A) and only the VEGM segments from T end to QRS onset were included in the analysis. VEGMs were reconstructed using sinusoidal wavelets fitting and the phase of VEGMs determined using Hilbert transform. Phase singularities (PS) were detected using the topological charge method and repetitive PSD maps were generated. RED was defined as the average of MPC of each node against direct neighbouring nodes on the 3D mesh (Figure 1A-B). Linear regression analysis was used to compare the average MPC vs. PSD and vs. the standard deviation of MPC (MPC_SD). Results A total of 221,184 VEGM segments were analysed with mean duration of 364.2 milliseconds.  MPC has shown the ability to quantify the level of synchronisation between VEGMs (Figure 1B). Inverse correlation was found between PSD and average MPC values for all 10 patients (p < 0.0001, Figure 1C). Average MPC and MPC_SD were found to be inversely correlated (p < 0.0001, Figure 1C). Spatially, similar graphic patterns can be found from LA MPC maps and PSD maps for all patients (Figure 1D). Conclusion We have proposed a method to quantify the level of synchronisation between VEGMs. Phase density mapping showed a considerable agreement with RED regions reflecting regional conducting delays, which supports the previous finding where rotors found at conduction block. Inverse correlation between local average MPC and MPC_SD suggests that conduction delays of the identified regions are not heterogenous, posing directional preferences. Rather than solely looking for rotational activities, this method could identify comprehensive RED regions, which may also explain the conflicting results from different studies targeting rotational activities, where incomplete subsets of RED regions could have been targeted. Atrial RED regions can easily be identified with simultaneously collected electrograms from multi-polar catheters and should be targeted in future persAF studies. Abstract Figure 1

scholarly journals Right atrial radiofrequency catheter ablation of paroxysmal atrial fibrillation

1996 ◽  
Vol 27 (2) ◽  
pp. 188 ◽  
Author(s):  
K.Ching Man ◽  
Emile Daoud ◽  
Brad Knight ◽  
Raul Weiss ◽  
Marwan Bahu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Paroxysmal Atrial Fibrillation ◽  
Radiofrequency Catheter Ablation ◽  
Right Atrial

P3778Long-term outcome of non-pharmacologial treatment of atrial fibrillation in hypertrophic cardiomyopathy: a large single-centre experience

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Dinshaw ◽  
M Lemoine ◽  
J Hartmann ◽  
B Schaeffer ◽  
N Klatt ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrial ◽  
High Density ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Density Mapping ◽  
Ablation Success

Abstract Introduction Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM) and is generally associated with a significant deterioration of clinical status. Non-pharmacological treatment such as surgical and catheter ablation has become an established therapy for symptomatic AF but in patients with HCM often having a chronically increased left atrial pressure and extensive atrial cardiomyopathy the long-term outcome is uncertain. Purpose The present study aimed to analyse the long-term outcome of AF ablation in HCM and the mechanism of recurrent atrial arrhythmias using high-density mapping systems. Methods A total of 65 patients (age 64.5±9.9 years, 42 (64.6%) male) with HCM undergoing AF ablation for symptomatic AF were included in our study. The ablation strategy for catheter ablation included pulmonary vein isolation in all patients and biatrial ablation of complex fractionated electrograms with additional ablation lines if appropriate. In patients with suspected atrial tachycardia (AT) high-density activation and substrate mapping were performed. A surgical ablation at the time of an operative myectomy for left ventricular outflow tract obstruction was performed in 8 (12.3%) patients. The outcome was analysed using clinical assessment, Holter ECG and continuous rhythm monitoring of cardiac implantable electric devices. Results Paroxysmal AF was present in 27 (41.6%), persistent AF in 37 (56.9%) and primary AT in 1 (1.5%) patients. The mean left atrial diameter was 54.1±12.5 ml. In 11 (16.9%) patients with AT high-density mapping was used to characterize the mechanism of the ongoing tachycardia. After 1.9±1.2 ablation procedures and a follow-up of 48.5±37.2 months, ablation success was demonstrated in 58.9% of patients. The success rate for paroxysmal and persistent AF was 70.0% and 55.8%, respectively (p=0.023). Of those patients with AT high-density mapping guided ablation was successful in 44.4% of patients. The LA diameter of patients with a successful ablation was smaller (52.2 vs. 58.1 mm; p=0.003). Conclusion Non-pharmacological treatment of AF in HCM is effective during long-term follow-up. Paroxysmal AF and a smaller LA diameter are favourable for successful ablation. In patients with complex AT the use of high-density mapping can guide ablation resulting in further ablation success in a reasonable number of patients.

P387Revealing channels of interatrial communication during atrial fibrillation

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
M Pope ◽  
P Kuklik ◽  
A Briosa E Gala ◽  
MICHAEL Mahmoudi ◽  
J O H N Paisey ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Right Atrial ◽  
Patient Specific ◽  
Density Mapping ◽  
Degree Of Coherence ◽  
Local Point ◽  
Electrophysiological Studies ◽  
Opposite Chamber

Abstract Introduction Interatrial propagation has been widely studied in anatomical specimens and electrophysiological studies during sinus rhythm or pacing. However, pathways of conduction during atrial fibrillation (AF) are poorly characterised in vivo. Purpose We sought to develop a method of identifying the dominant channel of communication between atria during AF with a view to characterising the role of localised mechanisms in maintaining AF between both chambers. Methods 10 patients undergoing simultaneous bi-atrial non-contact charge density mapping before and following pulmonary vein isolation (PVI) were analysed. Simultaneous 30s recordings during AF were obtained. Virtual electrograms from every vertex of the reconstructed left and right atrial (LA, RA) anatomies were exported and phase calculated using a method of sinusoidal recomposition and Hilbert transform. For each vertex, coherence between a sequence of activations between this point and every other point on the opposing chamber was calculated using mean phase coherence (MPC). The maximum of all MPC values was assigned to this local point to estimate the degree of coherence between activity at a given point and the entire opposing chamber. The regions with highest MPC value represent the channel of communication. Each activation of this zone is then evaluated and difference in local activation time between LA and RA determined (figure). Communication between atria is determined where a normal distribution of timing shift within this channel can be demonstrated (as opposed to a uniform histogram in the case of a lack of any correlation between electrograms). If seen to be preceding the opposite chamber for ≥60% of the recording then the chamber was deemed to be leading. Results A total of 18 maps were obtained (pre-PVI only in 2). A clear channel of interatrial propagation could be seen in 17 maps (MPC value 0.48 ± 0.16) with communication within this channel demonstrated in 13 of these (MPC 0.52 ± 0.16). In the RA the most common site was in the posterior inter-caval zone (in 13) and on the posterior septum of the LA (in 14). The LA was leading in 4 maps and the RA in 2 with balanced propagation in 7. Conclusion The method of average MPC identifies channels of inter-atrial communication during AF which appear to predominantly involve posterior interatrial connections. Further application of this technique to characterise interatrial propagation may help to define patient specific phenotypes of AF and guide targeted therapy. Abstract Figure 1

scholarly journals Right atrial compartimentalization using radiofrequency catheter ablation for management of patients with refractory atrial fibrillation

EP Europace ◽  
2001 ◽  
Vol 2 (Supplement_1) ◽  
pp. A6-A6
Author(s):  
Emanuele Bertaglia ◽  
Daniele D'Este ◽  
Francesca Zerbo ◽  
Marco Michieletto ◽  
Pietro Pascotto
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Radiofrequency Catheter Ablation ◽  
Right Atrial
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