Atrial Ectopy Increases Asynchronous Activation of the Endo- and Epicardium at the Right Atrium

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.

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Simultaneous Endo‐Epicardial Mapping of the Human Right Atrium: Unraveling Atrial Excitation

Journal of the American Heart Association ◽

10.1161/jaha.120.017069 ◽

2020 ◽

Vol 9 (17) ◽

Author(s):

Rohit K. Kharbanda ◽

Paul Knops ◽

Lisette J. M. E. van der Does ◽

Charles Kik ◽

Yannick J. H. J. Taverne ◽

...

Keyword(s):

Sinus Rhythm ◽

Right Atrium ◽

Conduction Block ◽

Significant Degree ◽

Interquartile Range ◽

Human Right ◽

3 Dimensional ◽

Conduction Disorders ◽

Human Right Atrium ◽

History Of

Background The significance of endo‐epicardial asynchrony (EEA) and atrial conduction block (CB), which play an important role in the pathophysiology of atrial fibrillation (AF) during sinus rhythm is poorly understood. The aim of our study was therefore to examine 3‐dimensional activation of the human right atrium (RA). Methods and Results Eighty patients (79% men, 39% history of AF) underwent simultaneous endo‐epicardial sinus rhythm mapping of the inferior, middle and superior RA. Areas of CB were defined as conduction delays of ≥12 ms, EEA as activation time differences of opposite electrodes of ≥15 ms and transmural CB as CB at similar endo‐epicardial sites. CB was more pronounced at the endocardium (all locations P <0.025). Amount, extensiveness and severity of CB was higher at the superior RA. Transmural CB at the inferior RA was associated with a higher incidence of post‐operative AF ( P =0.03). EEA occurred up to 84 ms and was more pronounced at the superior RA (superior: 27 ms [interquartile range, 18.3–39.3], versus mid‐RA: 20.3 ms [interquartile range, 0–29.9], and inferior RA: 0 ms [interquartile range, 0–21], P <0.001). Hypertension ( P =0.009), diabetes mellitus ( P =0.018), and hypercholesterolemia ( P =0.015) were associated with a higher degree of EEA. CB ( P =0.007) and EEA ( P =0.037) were more pronounced in patients with a history of persistent AF compared with patients without AF history. Conclusions This study provides important insights into complex atrial endo‐epicardial excitation. Significant differences in conduction disorders between the endo‐ and epicardium and a significant degree of EEA are already present during sinus rhythm and are more pronounced in patients with cardiovascular risk factors or a history of persistent AF.

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

European Heart Journal ◽

10.1093/ehjci/ehaa946.0483 ◽

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

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P984Proof of endo-epicardial asynchrony of the left atrial wall in humans

EP Europace ◽

10.1093/europace/euaa162.290 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

R Kharbanda ◽

C Kik ◽

P Knops ◽

A J J C Bogers ◽

N M S De Groot

Keyword(s):

Left Atrium ◽

Conduction Block ◽

Conduction Delay ◽

Maximal Degree ◽

Electrode Arrays ◽

Epicardial Mapping ◽

Activation Time ◽

Opposite Electrode ◽

Activation Times ◽

The Right

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

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DDTA mode pacing in the treatment of complete conduction block from the right atrium to the ventricles and interatrial electrical dissociation after surgical procedures

Journal of Arrhythmia ◽

10.1016/j.joa.2012.12.005 ◽

2013 ◽

Vol 29 (4) ◽

pp. 235-237

Author(s):

Yuichi Nakamura ◽

Hitoshi Suzuki ◽

Hiroto Takeda ◽

Yasuchika Takeishi

Keyword(s):

Surgical Procedures ◽

Right Atrium ◽

Conduction Block ◽

The Right

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The Effects of Valvular Heart Disease on Atrial Conduction During Sinus Rhythm

Journal of Cardiovascular Translational Research ◽

10.1007/s12265-019-09936-8 ◽

2019 ◽

Vol 13 (4) ◽

pp. 632-639 ◽

Cited By ~ 1

Author(s):

Lisette J. M. E. van der Does ◽

Eva A. H. Lanters ◽

Christophe P. Teuwen ◽

Elisabeth M. J. P. Mouws ◽

Ameeta Yaksh ◽

...

Keyword(s):

Sinus Rhythm ◽

Left Atrium ◽

Conduction Delay ◽

Atrial Remodeling ◽

Strongly Correlated ◽

Maximal Degree ◽

Conduction Disorders ◽

History Of ◽

Bachmann’S Bundle ◽

Unipolar Electrogram

AbstractDifferent arrhythmogenic substrates for atrial fibrillation (AF) may underlie aortic valve (AV) and mitral valve (MV) disease. We located conduction disorders during sinus rhythm by high-resolution epicardial mapping in patients undergoing AV (n = 85) or MV (n = 54) surgery. Extent and distribution of conduction delay (CD) and block (CD) across the entire right and left atrial surface was determined from circa 1880 unipolar electrogram recordings per patient. CD and CB were most pronounced at the superior intercaval area (2.5% of surface, maximal degree 6.6%/cm2). MV patients had a higher maximal degree of CD at the lateral left atrium than AV patients (4.2 vs 2.3%/cm2, p = 0.001). A history of AF was most strongly correlated to CD/CB at Bachmann’s bundle and age. Although MV patients have more conduction disorders at the lateral left atrium, disturbed conduction at Bachmann’s bundle during sinus rhythm indicates the presence of atrial remodeling which is related to AF episodes.

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Simultaneous endo-epicardial mapping of programmed atrial extrasystoles in patients undergoing cardiac surgery

European Heart Journal ◽

10.1093/ehjci/ehaa946.0462 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

R Kharbanda ◽

M.S Van Schie ◽

Y.J.H.J Taverne ◽

C Kik ◽

F.R.N Van Schaagen ◽

...

Keyword(s):

Cardiac Surgery ◽

Heart Surgery ◽

Conduction Block ◽

Epicardial Mapping ◽

Atrial Wall ◽

3 Dimensional ◽

Conduction Disorders ◽

Post Operative Atrial Fibrillation ◽

Arrhythmogenic Effect ◽

The Right

Abstract Introduction Atrial extrasystoles (AES) are usually innocent, however they can also trigger (post-operative) atrial fibrillation (AF). It is unknown what the arrhythmogenic effect of AES is on 3-dimensional atrial conduction. Purpose Therefore, the aim of this study was to examine the effect of programmed AES (PAES) provoked in the right atrium (RA) on both endo- and epicardial conduction. Methods Simultaneous endo-epicardial mapping of the RA was performed during PAES provoked from the RA free wall in patients undergoing cardiac surgery (256 electrodes). Areas of conduction block (CB) were defined as conduction delays of ≥12ms and endo-epicardial asynchrony (EEA) as activation time differences of exact opposite electrodes of ≥15ms. Results Simultaneous endo-epicardial mapping of the RA during 15 PAES were analyzed and compared with sinus rhythm (SR) (n=12, 58% male, age 68±7 years). Eleven PAES were premature (>25% shortening cycle length (CL)), median preceding CL was 554.5ms [377.9–720.4] and median SR CL was 871ms [700.9–1021]. Amount of EEA (7.3% [2.6–17.8] vs 1% [1–2], p=0.002) and CB (9% [4.8–11.8] vs 1.4% [0.5–2.7, p=0.001) both increased during PAES compared to SR. Diabetes was the only cardiovascular risk factor associated with a higher incidence and degree of EEA and CB. Interestingly, CB during PAES was more severe in 4 patients (33.3%) who developed post-operative AF (11.9% [10.4–12.8] vs 5.4% [3.3–8.5], p<0.001). Conclusion Asynchronous activation of the atrial wall and conduction disorders, which play an important role in arrhythmogenesis, are enhanced during PAES compared to SR. Enhanced electropathology together with triggers provoked by heart surgery may initiate post-operative AF. Funding Acknowledgement Type of funding source: None

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Az interatrialis blokk és klinikai jelentősége. Egy EKG-entitás reneszánsza

Orvosi Hetilap ◽

10.1556/650.2018.30947 ◽

2018 ◽

Vol 159 (3) ◽

pp. 91-95

Author(s):

János Tomcsányi

Keyword(s):

Sinus Rhythm ◽

Clinical Significance ◽

Conduction Delay ◽

Interatrial Block ◽

The Right

Abstract: Interatrial block involves conduction delay between the right and left atria during sinus rhythm. The review describes the classification, pathomechanism and clinical significance of this under-recognised ECG sign, nominated Bayés syndrome. The presented ECGs help to recognise the differentypes of interatrial blocks. Orv Hetil. 2018; 159(3): 91–95.

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