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

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

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
R Kharbanda ◽  
C Kik ◽  
P Knops ◽  
A J J C Bogers ◽  
N M S De Groot

Abstract Funding Acknowledgements Prof. Dr. NMS de Groot is supported by funding grants from CVON-AFFIP (914728), NWO-Vidi (91717339), Biosense Webster USA (ICD 783454) and Medical Del Introduction Treatment of atrial fibrillation (AF) is still suboptimal as mechanisms underlying AF initiation and persistence are incompletely understood. Endo-Epicardial asynchrony (EEA) plays an important role in AF persistence and has so far only been demonstrated in the right atrium (RA). Purpose To investigate whether EEA also exists in the thin walled left atrium (LA) and to measure the maximal degree of EEA between the endo- and epicardial layers during sinus rhythm (SR). Methods Simultaneous endo-epicardial mapping of the LA was performed during SR in 3 male patients (73 ± 1.5 years) with history of paroxysmal AF undergoing cardiac surgery including rhythm surgery and LA appendage amputation. Simultaneous endo-epicardial mapping was performed with a mapping clamp containing two electrode arrays of 8x16 electrodes (diameters: 0.4mm, interelectrode distance: 2mm) positioned exactly opposite to each other. The mapping clamp was introduced through the LA appendage with its tip towards the superior pulmonary vein. Local endo-epicardial activation time differences were determined by selecting the median time delay within the exact opposite electrode and its 8 surrounding electrodes. The asynchrony map consisted of the maximum of 2 medians from direct opposite electrodes. EEA was defined as time differences ≥15ms. Conduction delay (CD) and conduction block (CB) were defined as differences in local activation times between neighboring electrodes of respectively ≥7 and ≥12ms. Results A total of 35 SR beats were analyzed. Mean total activation time of the whole endo-epicardial LA tissue was 42.4 ± 9.5ms and did not differ between both layers (epicardium: 31.2 ± 9.9ms; endocardium: 37.8 ± 10.3ms; P= 0.62). CD and CB were observed in respectively 3.2% and 6.3% at the epicardium and 3.3% and 3.0% at the endocardium. The lowest amount of CD (5.2%) and CB (0.3%) was observed in the patient who had his first AF episode only 11 days prior to surgery. Also, no EEA was present in this patient. In two patients with paroxysmal AF >6 months, the prevalence of EEA was respectively 2.7% and 41.4% and the degree of EEA ranged from 15 to 44ms. Interestingly, the patient with the highest degree of EEA was diagnosed with paroxysmal AF for almost 5 years (Figure 1). Conclusion Our data provides evidence for the existence of EEA in the human left atrium which appears to be already present during SR. Knowledge of EEA and the ability to stage AF based on the degree of EEA is essential for individualized and staged future therapy for AF. Abstract Figure 1. The maximal degree of endo-epi


2021 ◽  
Vol 10 (13) ◽  
pp. 2846
Author(s):  
Willemijn F. B. van der Does ◽  
Annejet Heida ◽  
Lisette J. M. E. van der Does ◽  
Ad J. J. C. Bogers ◽  
Natasja M. S. de Groot

Classification of atrial fibrillation (AF) is currently based on clinical characteristics. However, classifying AF using an objective electrophysiological parameter would be more desirable. The aim of this study was to quantify parameters of atrial conduction during sinus rhythm (SR) using an intra-operative high-resolution epicardial mapping approach and to relate these parameters to clinical classifications of AF. Patients were divided according to the standard clinical classification and spontaneous termination of AF episodes. The HATCH score, a score predictive of AF progression, was calculated, and surface ECGs were evaluated for signs of interatrial block. Conduction disorders mainly differed at Bachmann’s bundle (BB). Activation time (AT) at BB was longer in persistent AF patients (AT-BB: 75 (53–92) ms vs. 55 (40–76) ms, p = 0.017), patients without spontaneous termination of AF episodes (AT-BB: 53.5 (39.6–75.8) ms vs. 72.0 (49.6–80.8) ms, p = 0.009) and in patients with a P-wave duration ≥ 120 ms (64.3 (52.3–93.0) ms vs. 50.5 (39.6–56.6) ms, p = 0.014). HATCH scores also correlated positively to AT-BB (rho 0.326, p = 0.029). However, discriminatory values of electrophysiological parameters, as calculated using ROC-curves, were limited. These results may reflect shortcomings of clinical classifications and further research is needed to establish an objective substrate-based classification of AF.


2020 ◽  
Vol 9 (2) ◽  
pp. 558
Author(s):  
Lisette J.M.E. van der Does ◽  
Rohit K. Kharbanda ◽  
Christophe P. Teuwen ◽  
Paul Knops ◽  
Charles Kik ◽  
...  

The predisposition of atrial extrasystoles (AES) to trigger cardiac tachyarrhythmia may arise from intramural conduction disorders causing endo-epicardial asynchrony (EEA). This study aimed to determine whether spontaneous AES disturb endo-epicardial conduction. Simultaneous endo-epicardial mapping of the right atrium was performed in patients during cardiac surgery with two 128-electrode arrays. Sixty spontaneous AES were observed in 23 patients and were analyzed for incidence of conduction delay, conduction block and amount of EEA compared to the previous sinus rhythm beat. Both conduction delay and block occurred more often in AES compared to sinus rhythm. The difference in lines of conduction block between the epicardium and endocardium increased in AES causing a greater imbalance of conduction disorders between the layers. The incidence of EEA with differences ≥10 ms increased significantly in AES. AES caused delays between the epicardium and endocardium up to 130 ms and EEA to increase for up to half (47%) of the mapping area. Conduction disturbances between the epicardial and endocardial layer giving rise to EEA increase during AES. Asynchronous activation of the atrial layers increases during AES which may be a mechanism for triggering cardiac tachyarrhythmia under the right conditions but EEA cannot be recognized by current mapping tools.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Natasja de Groot ◽  
Lisette vd Does ◽  
Ameeta Yaksh ◽  
Paul Knops ◽  
Pieter Woestijne ◽  
...  

Introduction: Transition of paroxysmal to longstanding persistent atrial fibrillation (LsPAF) is associated with progressive longitudinal dissociation in conduction and a higher incidence of focal fibrillation waves. The aim of this study was to provide direct evidence that the substrate of LsPAF consists of an electrical double-layer of dissociated waves, and that focal fibrillation waves are caused by endo-epicardial breakthrough. Hypothesis: LsPAF in humans is caused by electrical dissociation of the endo- and epicardial layer. Methods: Intra-operative mapping of the endo- and epicardial right atrial wall was performed in 9 patients with induced (N=4), paroxysmal (N=1), persistent (N=2) or longstanding-persistent AF (N=2). A clamp of two rectangular electrode-arrays (128 electrodes; inter-electrode distance 2mm) was introduced through an incision in the right atrial appendage. Series of 10 seconds of AF were analyzed and the incidence of endo-epicardial dissociation (≥15ms) was determined for all 128 endo-epicardial recording sites. Results: In patients with LsPAF the averaged degree of endo-epicardial dissociation was highest (24.9% vs. 5.9%). Using strict criteria for breakthrough (presence of an opposite wave within 4mm and <15ms before the origin of the focal wave), the far majority (77%) of all focal fibrillation waves could be attributed to endo-epicardial excitation. Conclusions: During LsPAF considerable differences in activation of the right endo- and epicardial wall exist. Endo-epicardial fibrillation waves that are out of phase, may conduct transmurally and create breakthrough waves in the opposite layer. This may explain the high persistence of AF and the low succes rate of ablative therapies in patients with LsPAF.


Author(s):  
Mindy Vroomen ◽  
Bart Maesen ◽  
Justin L. Luermans ◽  
Jos G. Maessen ◽  
Harry J. Crijns ◽  
...  

Objective It is unknown whether epicardial and endocardial validation of bidirectional block after thoracoscopic surgical ablation for atrial fibrillation is comparable. Epicardial validation may lead to false-positive results due to epicardial tissue edema, and thus could leave gaps with subsequent arrhythmia recurrence. It is the aim of the present study to answer this question in patients who underwent hybrid atrial fibrillation ablation (combined thoracoscopic epicardial and endocardial catheter ablation). Methods After epicardial ablation of the pulmonary veins (PVs) and connecting inferior and roof lines (box lesion), exit and entrance block were epicardially and endocardially evaluated using an endocardial His Bundle catheter and electrophysiological workstation. If incomplete lesions were found, endocardial touch-up ablation was performed. Validation results were also compared to predictions about conduction block based on tissue conductance measurements of the epicardial ablation device. Results Twenty-five patients were included. Epicardial validation results were 100% equal to the endocardial results for the left superior, left inferior, and right inferior PVs and box lesion. For the right superior PV, 85% similarity was found. Based on tissue conductance measurements, 139 lesions were expected to be complete; however, in 5 (3.6%) a gap was present. Conclusions Epicardial bidirectional conduction block in the PVs and the box lesion corresponded well with endocardial bidirectional conduction block. Conduction block predictions by changes in tissue conductance failed in few cases compared to block confirmation. This emphasizes that tissue conduction measurements can provide a rough indication of lesion effectiveness but needs endpoint confirmation by either epicardial or endocardial block testing.


2015 ◽  
Vol 38 (9) ◽  
pp. 1039-1048 ◽  
Author(s):  
CHRISTOS A. GOUDIS ◽  
ELEFTHERIOS M. KALLERGIS ◽  
EMMANUEL M. KANOUPAKIS ◽  
HERCULES E. MAVRAKIS ◽  
NIKI E. MALLIARAKI ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258285
Author(s):  
Matthias Lange ◽  
Annie M. Hirahara ◽  
Ravi Ranjan ◽  
Gregory J. Stoddard ◽  
Derek J. Dosdall

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.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
T Yan ◽  
S.J Zhu ◽  
M Zhu ◽  
C.F Guo

Abstract Background Surgical treatment has assumed a more prominent role in the therapy of atrial fibrillation (AF) with favorable efficiency and acceptable safety during the last decades. The traditional Cox-Maze procedure and Wolf Mini-Maze procedure focused on left atrial ablation. However, it is ubiquitous that patients with long-standing persistent atrial fibrillation (LSPAF) typically suffer from biatrial electrical and structural remodeling. The left atrial procedures are still not enough in patients with LSPAF. Purpose Herein, we aimed to introduce a modified biatrial off-pump ablation procedure based on the Wolf Mini-Maze procedure and to detect the safety and efficacy of the surgery for patients with LSPAF. Methods Between January 2016 and September 2020, 102 patients of LSPAF underwent our modified Mini-Maze procedure using bipolar radiofrequency ablation. Those patients firstly underwent a Mini-Maze procedure using Dallas lesion set, including video-assisted bilateral mini-thoracotomy, left atrial appendage excision, bilateral pulmonary vein isolation, ganglionic plexi evaluation and destruction, left atrial roof connecting lesion, and a linear lesion connecting this roofline to the root of the aorta at the junction of the left coronary and the non-coronary cusp. Secondly, a purse-string suture was performed on the right atrium, and then four ablation lesions were made to the superior vena cava, to the inferior vena cava, to the appendix of the right atrium, and to the tricuspid valve annulus from the purse-string suture point by the bipolar radiofrequency clamp. After the operation, the patients were followed up at an interval of 3, 6, 12 months, and every 1 year after that. Results No mortality No surgical re-exploration for bleeding. No permanent pacemaker implantation. 99 patients were free from LSPAF upon discharge. A follow-up at interval of 3, 6, 12, 24, 36, and 48 months showed a success rate free from LSPAF was 95.1% (97/102), 94.4% (85/90), 94.8% (73/77), 91.5% (54/59), 90.3% (28/31) and 100% (9/9), respectively Conclusions The modified biatrial Mini-Maze suggested a safe and feasible procedure. Early follow-up demonstrated an acceptable success rate free from AF. It might have the potential to become another option for clinical treatment of LSPAF. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): General Program of the National Natural Science Foundation of China Schematic of the procedure


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