scholarly journals Atrial slow conduction develops and dynamically expands during premature stimulation in an animal model of persistent atrial fibrillation

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258285
Author(s):  
Matthias Lange ◽  
Annie M. Hirahara ◽  
Ravi Ranjan ◽  
Gregory J. Stoddard ◽  
Derek J. Dosdall
Keyword(s):  
Atrial Fibrillation ◽  
Conduction Velocity ◽  
Conduction Block ◽  
Persistent Atrial Fibrillation ◽  
Therapeutic Strategies ◽  
Propagation Direction ◽  
Slow Conduction ◽  
Cycle Lengths ◽  
Image Position ◽  
Activation Times

Slow conduction areas and conduction block in the atria are considered pro-arrhythmic conditions. Studies examining the size and distribution of slow conduction regions in the context of persistent atrial fibrillation (AF) may help to develop improved therapeutic strategies for patients with AF. In this work, we studied the differences of size and number in slow conduction areas between control and persistent AF goats and the influence of propagation direction on the development of these pathological conduction areas. Epicardial atrial electrical activations from the left atrial roof were optically mapped with physiological pacing cycle lengths and for the shortest captured cycle lengths. The recordings were converted to local activation times and conduction velocity measures. Regions with slow conduction velocity (less than 0 . 2 m s) were identified. The size of the connected regions and the number of non-connected regions were counted for propagation from different orthogonal directions. We found that regions of slow conduction significantly increases in our 15 persistent AF goat recordings in response to premature stimulation (24.4±4.3% increase to 36.6±4.4%, p < 0.001). This increase is driven by an increase of size from (3.70±0.89[mm2] to 6.36±0.91[mm2], p = 0.014) for already existing regions and not by generation of new slow conduction regions (11.6±1.8 vs. 13±1.9, p = 0.242). In 12 control goat recordings, no increase from baseline pacing to premature pacing was found. Similarly, size of the slow conduction areas and the count did not change significantly in control animals.

scholarly journals An algorithm to automatically determine the cycle length coverage to identify rotational activity during atrial fibrillation – a simulation study

2016 ◽  
Vol 2 (1) ◽  
pp. 167-170
Author(s):  
Wenzel Kaltenbacher ◽  
Markus Rottmann ◽  
Olaf Dössel
Keyword(s):  
Atrial Fibrillation ◽  
Cycle Length ◽  
Visual Inspection ◽  
Persistent Atrial Fibrillation ◽  
Slow Conduction ◽  
Electrophysiological Studies ◽  
Objective View ◽  
Activation Times ◽  
Length Coverage ◽  
Wave Collision

AbstractAtrial fibrillation is the most common cardiac arrhythmia. Many physicians believe in the hypothesis that persistent atrial fibrillation is maintained by centers of rotatory activity. These so called rotors are sometimes found by physicians during catheter ablation or electrophysiological studies but there are also physicians who claim that they did not find any rotors at all. One reason might be that today rotors are mainly identified by visual inspection of the data. Thus we are aiming at an algorithm for rotor detection. We first developed an algorithm based on the local activation times of the intracardiac electrograms recorded by a multielectrode catheter that can automatically determine the cycle length coverage. This was done to get an objective view on possible rotors and therefore help to quantify whether a rotor was found or not. The algorithm was developed and evaluated in two different simulation setups, where it could reliably determine cycle length coverage. But we found out that effects like wave collision and slow conduction have strong influence on cycle length coverage. This prevents cycle length coverage from being suited as the only parameter to quantify whether a rotor is present or not. On the other hand we could confirm that rotors imply a cycle length coverage of >70% if the multielectrode catheter is centered in an area of <5 mm away from the rotor tip. Therefore cycle length coverage can at least be used in some situations to exclude the presence of possible rotors.

scholarly journals Rotational activity presence and its impact in persistent atrial fibrillation follow-up

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
G R Rios-Munoz ◽  
N Soto ◽  
P Avila ◽  
T Datino ◽  
F Atienza ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Treatment Success ◽  
Persistent Atrial Fibrillation ◽  
Recurrence Rates ◽  
National Budget ◽  
Funding Sources ◽  
Cycle Lengths ◽  
Public Grant ◽  
Af Recurrence

Abstract Introduction Treatment of atrial fibrillation (AF) remains sub-optimal, with low success in pulmonary vein isolation (PVI) ablation procedures in long-standing-persistent AF patients. The maintenance mechanisms of AF are still under debate. Rotational activity (RA) events, also known as rotors, may play a role in perpetuating AF. The characterisation of these drivers during electroanatomical (EA) guided ablation procedures in relationship with follow-up and recurrence ratios in AF patients is necessary to design new ablation strategies to improve the AF treatment success. Purpose We report an AF patient cohort of endocardial mapping and PVI ablation procedures with additional RA events detected during the EA study. We aim to study the presence and distribution of RA in AF patients and its impact on AF recurrence when only PVI ablation is performed. Methods 75 persistent consecutive AF patients (age 60.7±9.8, 74.7% men) underwent EA mapping and RA detection with an automatic algorithm. The presence of RA was annotated on the EA map based on the unipolar electrograms (EGMs) registered with a 20-pole catheter. RA presence was analysed at different left atrial locations (37.2±14.8 sites per patient). AF recurrence was evaluated in follow-up after treatment. Results At follow-up (9±5 months), 50% of the patients presented AF recurrence. Patients with RA had more dilated atria in terms of volumes (p=0.002) and areas (p=0.001). Patients with RA exhibited higher mean voltage EGMs 0.6±0.3 mV vs 0.5±0.2 mV (p=0.036), with shorter cycle lengths 169.1±26.0 ms vs. 188.4±44.2 ms (p=0.044). Finally, patients with RA presented more AF recurrence rates than patients with no RA events (p=0.007). No significant differences were found in terms of comorbidities, e.g., heart failure, hypertension, COPD, stroke, SHD, or diabetes mellitus. Conclusions The results show that patients with more RA events and those with RA outside the PVI ablated regions presented higher AF recurrence episodes than those with no RA or events inside the areas affected by radio-frequency ablation. The study suggests that further ablation treatment of the areas harboring RA might be necessary to reduce the recurrence ratio in AF patients. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III; Sociedad Española de Cardiología

Paroxysmal and persistent atrial fibrillation; does the clinical classification match the substrate?

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
W.F.B Van Der Does ◽  
A Heida ◽  
L.J.M.E Van Der Does ◽  
A.J.J.C Bogers ◽  
N.M.S De Groot
Keyword(s):  
Atrial Fibrillation ◽  
Conduction Block ◽  
Persistent Atrial Fibrillation ◽  
Conduction Delay ◽  
Clinical Classification ◽  
Activation Time ◽  
Conduction Disorders ◽  
Arrhythmogenic Substrate ◽  
Appropriate Therapy ◽  
The Right

Abstract Background/Introduction The classification of atrial fibrillation (AF) currently is based on clinical characteristics, however classifying underlying electropathology would assist in selecting appropriate therapy. In this study, we measured atrial conduction parameters in sinus rhythm (SR) using an intra-operative high resolution epicardial mapping approach in paroxysmal (PAF) and persistent AF (persAF) patients. Purpose To study whether the clinical classification is related to the amount and severity of conduction disorders in SR. Methods We included 47 PAF and 24 persAF patients for intra-operative measurements of SR at the right atrium (RA), Bachmann's Bundle (BB), the left atrium (LA) and the pulmonary vein area (PV). Various conduction parameters were calculated, including number of continuous conduction delay and block (cCDCB) lines, total activation time (TAT), and orientation of conduction block (CB) lines at BB. Results After adjustment for confounders, only TAT of BB was significantly longer in persAF patients, 75 [53–92] ms vs 55 [40–76] ms. This can be attributed to more CB line parts orientated perpendicular to the conduction direction and a higher number of cCDCB lines. Other conduction characteristics at BB and other atrial areas showed no difference between PAF and persAF patients. Conclusion(s) Patients with persAF have a longer activation time at BB compared to patients with PAF. Other conduction parameters show significant overlap between these groups at BB and in other atrial areas, suggesting that, in SR, the clinical classification does not match the arrhythmogenic substrate. Funding Acknowledgement Type of funding source: None

scholarly journals Cryoballoon ablation of the left atrial posterior wall reduces recurrence of persistent atrial fibrillation in patients with non-paroxysmal atrial fibrillation

2021 ◽  
Author(s):  
Takatoshi Shigeta ◽  
Yasuteru Yamauchi ◽  
Yuichiro Sagawa ◽  
Atsuhito Oda ◽  
Shinichi Tachibana ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Paroxysmal Atrial Fibrillation ◽  
Left Atrial ◽  
Conduction Block ◽  
Persistent Atrial Fibrillation ◽  
Posterior Wall ◽  
Cryoballoon Ablation ◽  
Acute Success ◽  
Af Recurrence

Introduction: Detailed clinical outcomes of cryoballoon ablation of the left atrial (LA) posterior wall (LAPW) in patients with non-paroxysmal atrial fibrillation (AF) have not been fully examined. Methods: We analyzed the outcomes of 191 patients with non-paroxysmal AF, of whom 135 underwent cryoballoon ablation of the LAPW including the LA roof in addition to pulmonary vein isolation with a cryoballoon. Results: Complete conduction block at the LA roof was obtained in 97.0% (131/135) of patients and LAPW was isolated in 85.2% (115/135) of patients. Over 372 days (range, 182–450 days) of follow-up, atrial arrhythmia recurrence was observed in 55 (40.7%) patients, and atrial tachycardia (AT) recurrence accounted for 25.5% of cases. The prevalence of LA roof cryoballoon ablation tended to be higher in patients without recurrence than those with (74.3% vs. 61.8%, respectively; p=0.11), especially those with persistent AF recurrence (74.5% vs. 46.2%, p=0.01). Multivariate analysis revealed that cryoballoon ablation of the LA roof was a predictor of freedom from persistent AF recurrence and that it was not associated with AT recurrence. Durable LA roof lesions were confirmed in 18 (72.0%) of 25 patients who underwent redo ablation. Conclusion: Cryoballoon ablation of the LAPW leads to a sufficient acute success rate of complete conduction block and durable lesions of the LA roof without increasing the risk of AT recurrence. The prevalence of persistent AF recurrence decreases after additional cryoballoon ablation of the LAPW in patients with non-paroxysmal AF.

scholarly journals Conduction left-to-right and right-to-left across the crista terminalis

2001 ◽  
Vol 280 (4) ◽  
pp. H1683-H1691 ◽  
Author(s):  
Kunihiro Matsuo ◽  
Kikuya Uno ◽  
Celeen M. Khrestian ◽  
Albert L. Waldo
Keyword(s):  
Atrial Fibrillation ◽  
Inferior Vena ◽  
Conduction Block ◽  
Vena Cava ◽  
Atrial Pacing ◽  
Crista Terminalis ◽  
Cycle Lengths ◽  
Bachmann’S Bundle ◽  
Atrial Activation ◽  
The Right

A line of block between the vena cava and the crista terminalis (CT) region is important for atrial flutter (AFL), but whether it is fixed or functional is controversial. To test the hypothesis that conduction across the CT normally occurs, but when block occurs in this region it is functional, we analyzed atrial activation during right and left atrial pacing (cycle lengths of 500–130 ms), AFL, and atrial fibrillation in 15 dogs with sterile pericarditis and 7 normal dogs. Electrograms from 396 right, left, and septal atrial sites were simultaneously recorded. Activation across the CT occurred during atrial pacing, AFL, and atrial fibrillation. Activation wave fronts from the right to the left atrium and vice versa traveled over several routes, including Bachmann's bundle and inferior to the inferior vena cava, as well as across the CT. In these models, there is no fixed conduction block across the CT, and when block in the CT region occurs, as during AFL, it is functional.

scholarly journals CVAR-Seg: An Automated Signal Segmentation Pipeline for Conduction Velocity and Amplitude Restitution

2021 ◽  
Vol 12 ◽  
Author(s):  
Mark Nothstein ◽  
Armin Luik ◽  
Amir Jadidi ◽  
Jorge Sánchez ◽  
Laura A. Unger ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Conduction Velocity ◽  
Matched Filter ◽  
Atrial Fibrillation Patient ◽  
Time Interval ◽  
Signal To Noise ◽  
Local Activation ◽  
Temporal Proximity ◽  
Atrial Activity ◽  
Activation Times

BackgroundRate-varying S1S2 stimulation protocols can be used for restitution studies to characterize atrial substrate, ionic remodeling, and atrial fibrillation risk. Clinical restitution studies with numerous patients create large amounts of these data. Thus, an automated pipeline to evaluate clinically acquired S1S2 stimulation protocol data necessitates consistent, robust, reproducible, and precise evaluation of local activation times, electrogram amplitude, and conduction velocity. Here, we present the CVAR-Seg pipeline, developed focusing on three challenges: (i) No previous knowledge of the stimulation parameters is available, thus, arbitrary protocols are supported. (ii) The pipeline remains robust under different noise conditions. (iii) The pipeline supports segmentation of atrial activities in close temporal proximity to the stimulation artifact, which is challenging due to larger amplitude and slope of the stimulus compared to the atrial activity.Methods and ResultsThe S1 basic cycle length was estimated by time interval detection. Stimulation time windows were segmented by detecting synchronous peaks in different channels surpassing an amplitude threshold and identifying time intervals between detected stimuli. Elimination of the stimulation artifact by a matched filter allowed detection of local activation times in temporal proximity. A non-linear signal energy operator was used to segment periods of atrial activity. Geodesic and Euclidean inter electrode distances allowed approximation of conduction velocity. The automatic segmentation performance of the CVAR-Seg pipeline was evaluated on 37 synthetic datasets with decreasing signal-to-noise ratios. Noise was modeled by reconstructing the frequency spectrum of clinical noise. The pipeline retained a median local activation time error below a single sample (1 ms) for signal-to-noise ratios as low as 0 dB representing a high clinical noise level. As a proof of concept, the pipeline was tested on a CARTO case of a paroxysmal atrial fibrillation patient and yielded plausible restitution curves for conduction speed and amplitude.ConclusionThe proposed openly available CVAR-Seg pipeline promises fast, fully automated, robust, and accurate evaluations of atrial signals even with low signal-to-noise ratios. This is achieved by solving the proximity problem of stimulation and atrial activity to enable standardized evaluation without introducing human bias for large data sets.

P6566Noninvasive Panoramic Mapping of Phase Singularities with Signal Complexity Analysis in Patients with Persistent Atrial Fibrillation

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M Chmelevsky ◽  
M Budanova ◽  
S Zubarev ◽  
D Potyagaylo ◽  
C Sohns ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Complexity Analysis ◽  
Conduction Block ◽  
Persistent Atrial Fibrillation ◽  
Positive Outcome ◽  
Inferior Wall ◽  
Ablation Therapy ◽  
Phase Singularities ◽  
The Mean ◽  
Signal Complexity

Abstract Background An assessment of positive outcome probability of ablation therapy based on the comprehensive signal complexity analysis is a promising working hypothesis while electrocardiographic imaging (ECGI) can detect and visualize zones of phase singularities (PS) associated with stable sources of atrial fibrillation (AF). Methods Ten consecutive patients with persistent AF (three female, median (min–max) – 63.5 (45–75) years) underwent ECGI using “Amycard 01C EP lab” system with cardiac MRI (1.5-T Magnetom Avanto) followed by pulmonary vein isolation. Each T-Q segment with a length >800 ms during AF was processed to find PS. Sites with rotations around stable pivot points were considered as PS and then marked and visualized on the reconstructed anatomical 3D atrial model. Finally, a signal complexity cluster analysis was performed to define and depict phase-aggregation zones. Results ECGI analysis identified a total number of 410 PS, with 196 (47.8%) occurring in the LA and 214 (52.2%) in the RA. The median (25–75% IQR) number of revealed PS per patient was n=20 (14–30) for RA and n=20 (11–22) for the LA. The majority of the PS in the LA was located on the inferior wall n=66 (min-max 1–17). In eight patients, comprehensive signal complexity analysis revealed stability of phase-clustered zones over time. The mean number (min-max) of PS in a clustered area was 10 (6–15). In two patients, PS were distributed disordered on the entire LA and RA surface. Distribution of phase singularities Conclusions This is the first clinical study demonstrating signal complexity analysis capability of clustering noninvasively mapped PS and relating them to specific atrial anatomical regions. Thereby obtained clusters may be a potential zones of conduction block, and could contribute to a better understanding of the temporal AF complexity.

COMPUTER ASSISTED CHARACTERIZATION OF RAPID REPETITIVE ELECTRICAL ACTIVATIONS IN THE PULMONARY VEINS DURING ATRIAL FIBRILLATION

2003 ◽  
Vol 13 (12) ◽  
pp. 3657-3663 ◽  
Author(s):  
P. LANGLEY ◽  
D. O'DONNELL ◽  
D. RAINE ◽  
S. S. FURNISS ◽  
J. P. BOURKE ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Electrophysiological Study ◽  
Pulmonary Veins ◽  
Persistent Atrial Fibrillation ◽  
Computer Assisted ◽  
Automatic Assessment ◽  
Cycle Lengths

Our group has described previously the identification of arrhythmogenic pulmonary veins by rapid local electrical activations during atrial fibrillation. We have now investigated an algorithm for automated computer detection of this phenomenon from catheter electrodes in the upper pulmonary veins and assessed its performance in identifying arrhymogenic veins. Ten patients with persistent atrial fibrillation scheduled for pulmonary vein isolation at this hospital were studied. Electrogram recordings in the upper pulmonary veins were recorded and analyzed. Arrhythmogenic veins were identified by focal activity during sinus rhythm at electrophysiological studies. Recordings were visually assessed by a cardiologist for the presence of rapid repetitive electrical activations during atrial fibrillation. An index of rapid repetitive electrical activity (RREA index), the ratio of the number of activations with cycle lengths in the range 50 ms to 100 ms to the number of activations with cycle lengths in the range 100 ms to 200 ms, was devised to describe the extent of such activity automatically. The index was assessed as a predictor of arrhythmogenic veins. Electrograms from 19 upper pulmonary veins were recorded. Rapid activity was evident in 15 veins by visual manual assessment. The mean (range) automatic RREA index was 0.07 (0 to 0.16) for those identified as having no such activity manually, and 0.83 (0.22 to 1.68) for those identified with rapid activity (p<0.0001). With a threshold of RREA index in the range 0.17 to 0.21, the identification of veins with rapid firing was exactly the same as for manual assessment. Eleven upper pulmonary veins were identified as arrhythmogenic during electrophysiological study, and the identification of these veins by both manual and automatic assessment of rapid repetitive electrical activations gave a sensitivity of 100% (11/11) and specificity of 50% (4/8). A technique for automatic characterization of electrogram cycle length has been demonstrated and could be used online as a tool for identifying candidate sites for pulmonary vein isolation in patients despite persistent atrial fibrillation.

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