Abstract 15570: Direct Evidence of Endo-Epicardial Dissociation of the Atrial Wall in Patients With Longstanding Persistent Atrial Fibrillation

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.

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Atrial Fibrillation Drivers: Redefining the Electrophysiological Substrate

10.1101/2020.12.14.20248171 ◽

2020 ◽

Author(s):

Markus Rottmann ◽

Anna Pfenniger ◽

Shin Yoo ◽

David Johnson ◽

Gail Elizabeth Geist ◽

...

Keyword(s):

Atrial Fibrillation ◽

Pulmonary Veins ◽

Persistent Atrial Fibrillation ◽

Right Atrial ◽

Atrial Pacing ◽

New Paradigm ◽

Density Mapping ◽

Right Atrial Appendage ◽

The Right ◽

Activation Delay

Background: We performed high-density mapping of persistent atrial fibrillation (AF) in animals and patients (1) to test that AF is due to greater than or equal 1 reentry, and (2) to characterize activation delay and reentries pre/ post pulmonary vein isolation (PVI). We determined electrophysiological characteristics that may predispose to the induction, maintenance, and reduction of AF. Methods and Results: This study includes 48 dogs and nine patients. 43 AF- and five sinus/ paced rhythm dogs (3-14 weeks rapid atrial pacing) were studied at open chest surgery with 117 epicardial electrograms (EGMs) (2.5mm dist.) in 6 bi-atrial regions. Rotational activity automatically detected with a new algorithm tracking the earliest and latest activation in all regions (5+/-2 per region) were stable over 424+/-505ms [120-4940ms]. Reentry stability was highest in the right atrial appendage (RAA) (405+/-219ms) and the posterior left atrium (PLA) (267+/-115ms) and anchored between >=3 zones of activation delay (15+/-5ms, median 13ms) defined as >10ms per 2.5mm. Cycle length (CL) and degree of focal fibrosis were highest in the PLA and left atrial free wall (LAFW) with 94+/-7ms, 96+/-5ms, and 49+/-14%, 47+/-19%. Fiber crossing density correlated with the stability of rotational activity (R=0.6, P<0.05). Activation delay was 2x higher in AF compared to sinus rhythm/paced rhythm (interval 200-500ms). Activation delay zones > 10ms were at the same locations, but increased 4x during AF vs. SR and were located at fiber crossings, fibrosis/ fat zones. Stability of rotational activity correlated with Organization Index (OI), Fraction Index (FI), Shannon's Entropy (ShEn), and CL (R>0.5, p< 0.0001). PVI in five hearts increased CL [2-14%] and reduced stability of rotational activity in nearly all regions remote to the pulmonary veins (PVs). Also in the clinical evaluation in nine patients using the HD-catheter (16 electrodes, 3mm dist.) activation delay at the reentrant trajectory was 2x higher at edges with maximal delay (20.5+/-8.1ms, median 19.6ms) vs (9.3+/-8.8ms, median 9.2ms) and 1.4 x higher during AF (13.0+/-18.7ms, median 7.2ms) compared to SR/ CS-pacing (18.0+/-11.6ms, median 17.7ms). Conclusion: Rotational activities in all bi-atrial regions anchored between small frequency-dependent activation delay zones in AF. PVI led to beneficial remodeling in bi-atrial regions remote to the PVs. These data may identify a new paradigm for persistent AF.

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Increased Fluorine-18 Fluorodeoxyglucose Uptake in the Right Atrial Wall in a Patient With Atrial Fibrillation

Clinical Nuclear Medicine ◽

10.1097/00003072-199902000-00020 ◽

1999 ◽

Vol 24 (2) ◽

pp. 136-137 ◽

Cited By ~ 3

Author(s):

HIROFUMI FUJII ◽

SEIEI YASUDA ◽

MICHIRU IDE ◽

WAKOH TAKAHASHI ◽

AKIRA SHOHTSU ◽

...

Keyword(s):

Atrial Fibrillation ◽

Right Atrial ◽

Atrial Wall ◽

The Right ◽

Fluorine 18 Fluorodeoxyglucose

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A jobb pitvari fülcse echokardiográfiás vizsgálata és annak klinikai jelentősége

Orvosi Hetilap ◽

10.1556/650.2019.31334 ◽

2019 ◽

Vol 160 (12) ◽

pp. 443-447

Author(s):

Attila Nemes ◽

Kálmán Havasi ◽

László Sághy ◽

Mária Kohári ◽

Tamás Forster

Keyword(s):

Atrial Fibrillation ◽

Clinical Data ◽

Thrombus Formation ◽

Atrial Appendage ◽

Present Review ◽

Right Atrial ◽

Right Heart ◽

Right Atrial Appendage ◽

The Right

Abstract: In case of atrial fibrillation, there is a higher risk of thrombus formation, which could affect the right heart as well. Visualization of the right atrial appendage is difficult; the aim of the present review was to demonstrate the role of routine echocardiographic techniques and to show related clinical data. Orv Hetil. 2019; 160(12): 443–447.

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Atrial anti-tachycardia pacing resulting in termination of atrial flutter: intracardiac electrograms providing insight into the mechanism of arrhythmia termination

Journal of International Medical Research ◽

10.1177/0300060519848919 ◽

2019 ◽

Vol 47 (7) ◽

pp. 3389-3393

Author(s):

Shingo Maeda ◽

Masahiko Goya ◽

Atsuhiko Yagishita ◽

Yoshihide Takahashi ◽

Mihoko Kawabata ◽

...

Keyword(s):

Atrial Fibrillation ◽

Atrial Flutter ◽

Randomized Study ◽

Right Atrial ◽

Dual Chamber Pacemaker ◽

Af Ablation ◽

Right Atrial Appendage ◽

Ablation Study ◽

The Right ◽

Insight Into

The “MINimizE Right Ventricular pacing to prevent Atrial fibrillation and heart failure” (MINERVA) multicenter randomized study demonstrated that atrial anti-tachycardia pacing (A-ATP) can effectively decrease the burden of atrial fibrillation (AF) in patients with bradycardia and atrial tachyarrhythmias. We herein describe the unique electrophysiological results of AF ablation in a patient for whom atrial flutter (AFL) was terminated by A-ATP from a Medtronic dual-chamber pacemaker. In this case, the atrial activation sequence indicated that the tachycardia was a right atrial typical flutter and that A-ATP from the right atrial appendage would thus be more likely to terminate the tachycardia. This is a novel case involving documented intracardiac electrograms captured during an AF ablation study in a patient in whom AFL was successfully terminated by A-ATP. These findings provide insight into the mechanisms by which A-ATP can terminate atrial arrhythmias.

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Transesophageal Echocardiographic Evidence of Atrial Fibrillation with Systolic Flow in the Right Atrial Appendage and Systolic Reversal Pulmonary Flow in a Patient with DDD Permanent Pacing

Echocardiography ◽

10.1046/j.1540-8175.2002.00145.x ◽

2002 ◽

Vol 19 (2) ◽

pp. 145-147 ◽

Cited By ~ 1

Author(s):

Carlo Oneglia ◽

Cesare Rusconi

Keyword(s):

Atrial Fibrillation ◽

Atrial Appendage ◽

Right Atrial ◽

Pulmonary Flow ◽

Permanent Pacing ◽

Right Atrial Appendage ◽

The Right ◽

Echocardiographic Evidence

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P979Persistent atrial fibrillation terminated within the left atrium without recurrence at follow-up demonstrates a gradual intracardiac organization during stepwise ablation

European Heart Journal ◽

10.1093/eurheartj/ehz747.0572 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

A Pithon ◽

A Luca ◽

A Buttu ◽

J M Vesin ◽

L Roten ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Atrium ◽

Persistent Atrial Fibrillation ◽

Right Atrial ◽

Linear Ablation ◽

The Right ◽

Dominant Frequencies ◽

Complex Fractionated Atrial Electrograms

Abstract Introduction We previously reported that patients (pts) with recurrence (Rec) after stepwise catheter ablation (step-CA) of persistent atrial fibrillation (pAF) exhibit high bi-atrial intracardiac dominant frequencies (DF) values before ablation, indicative of a severe bi-atrial electro-anatomical remodeling. Purpose Herein, we hypothesized that a gradual decrease in DF values during step-CA is associated with pAF termination and maintenance of sinus rhythm (SR) on the long term. Method In 40 consecutive pts (61±8 yo, sustained AF duration 19±11 months), pulmonary vein isolation (PVI) and left atrium (LA) ablation were performed until pAF termination or cardioversion. 10-sec intracardiac electrograms (EGMs) epochs were recorded before ablation (BL), during PVI and during complex fractionated atrial electrograms (CFAEs) and linear ablation (post_PVI) in the right atrial (RAA) and left atrial (LAA) appendages and in the coronary sinus (CS). DF was defined as the highest peak within the [3–15] Hz EGM spectrum. Rec was defined as any atrial arrhythmia lasting >30 sec during follow-up (FU). Results pAF was terminated within the LA in 70% (28/40, LT) of the pts, while 30% (12/40, NLT) were not. After a mean FU of 34±14 months, all NLT pts had a Rec, while LT pts presented a Rec in 71% (20/28, LT_rec) and remained in SR in 29% (8/28, LT_norec). Figure 1 shows: 1) a gradient in DF values measured in the LAA (panel A), RAA (panel B) and CS (panel C) with the highest values in NLT pts (red), intermediate values in LT_rec pts (yellow) and lowest DF values in LT_norec pts (green); 2) all three groups displayed a gradual intracardiac organization during LA ablation as shown by decreasing DF values (p<0.05, BL vs post_PVI), but the LT_norec pts (green) exhibited the highest relative changes in DF from BL (p<0.05, LT_norec vs NLT, Δ range: −5.31 to −9.69%). Figure 1. Effect of ablation on DF Conclusion Low DF values before ablation and gradual intracardiac organization until pAF termination are associated with maintenance of SR on the long term.

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Prominent Eustachian Valve Mimicking Thrombus in Right Atrium Diagnosed with Computed Tomography in a Patient with Atrial Fibrillation

Radiology and Medical Diagnostic Imaging ◽

10.31487/j.rdi.2020.02.02 ◽

2020 ◽

pp. 1-2

Author(s):

Ibrahim SARI ◽

Gülsüm Bingöl ◽

Ibrahim SARI ◽

Muharrem Nasıfov ◽

Özge Özden Tok ◽

...

Keyword(s):

Atrial Fibrillation ◽

Right Atrium ◽

Left Atrial Appendage ◽

Thrombus Formation ◽

Correct Diagnosis ◽

Atrial Appendage ◽

Right Atrial ◽

Eustachian Valve ◽

Right Atrial Appendage ◽

The Right

A 51-year-old man presented with paroxsysmal atrial fibrillation (AF). Transthoracic echocardiography revealed mass of 2.3x0.6 cm adjacent to the superior part of the right atrium (RA) compatible with thrombus. Although thrombus formation in the setting of AF is more common in left atrial appendage and left atrium it can also be seen in right atrial appendage and RA. We performed cardiac computerized tomography (CCT) in order to clarify the nature of mass in RA and exclude coronary stenosis. CCT showed prominent eustachian valve measuring 3.2 cm which was not clear on echocardiography. This case underscores the importance of complementary cardiovascular imaging to facilitate the correct diagnosis.

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Abstract 1837: Effects of the Gap Junction Modifier, GAP-134, on Conduction and Atrial Fibrillation/Flutter Inducibility in Dogs

Circulation ◽

10.1161/circ.116.suppl_16.ii_392-c ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Eric I Rossman ◽

Kun Liu ◽

Gwen A Morgan ◽

Robert E Swillo ◽

John Butera ◽

...

Keyword(s):

Atrial Fibrillation ◽

Gap Junction ◽

Adult Population ◽

Metabolic Stress ◽

Right Atrial ◽

Conduction Time ◽

Medical Need ◽

Cardiovascular Morbidity And Mortality ◽

Right Atrial Appendage ◽

The Right

Atrial fibrillation (AF) and atrial flutter (AFL), the most common sustained cardiac arrhythmias, are major contributors to cardiovascular morbidity and mortality in the adult population. Current pharmacologic treatment of AF/AFL is only moderately successful and not well tolerated among patients, highlighting an unmet medical need for safer, effective agents. GAP-134 is the first small molecule gap junction modifier developed for the prevention of AF/AFL. In preliminary experiments, this modified antiarrhythmic dipeptide with similar activity to the antiarrhythmic hexapeptide rotigaptide, significantly prevented conduction velocity slowing in rat atrial strips subjected to metabolic stress at 10 nM (5.6±9.4%) and 100 nM (0.4±5.0%) compared to controls (−29.1±5.3%). In the canine sterile pericarditis model, conduction time (CT, n=5) and AF/AFL inducibility (n=9) were measured 2–3 days post-operatively in closed chest studies, using electrodes placed at the right atrial appendage (RAA), the Bachmann’s bundle (BB), and the posterior left atrium (LA). CT, measured between the BB and LA, was significantly faster after GAP-134 infusion (average plasma concentration was 73.1 ng/ml) at RAA pacing rates of 200 bpm (66.2±1.0 ms vs 62.0±1.0 ms; p=2.49E-08), 300 bpm (64.4±0.9 ms vs 61.0±1.3 ms; p=2.67E-03), and 400 bpm (67.2±1.6 ms vs 65.0±1.9 ms; p=0.041). Induction of AF/AFL was attempted using a burst pacing protocol, at all three atrial sites, starting at 500 bpm and increasing at increments of 20 bpm until 800 bpm. The average number of successful AF/AFL inductions per animal was significantly decreased after GAP-134 infusion (2.7±0.6 vs 1.6±0.8; p=0.021), with the total number of inductions being decreased from 24 to 14. Mean AF/AFL duration per induction (603±119 s vs 260±116 s; p=0.021) and mean AF/AFL duration per animal (1364±419 s vs 705±483 s; p=0.049) were also significantly decreased after GAP-134 infusion, with total AF/AFL burden being decreased from 12280 s to 6348 s. In conclusion, GAP-134 shows consistent efficacy on measures of conduction and AF/AFL inducibility in the canine sterile pericarditis model. These findings, along with its oral bioavailability, underscore its potential as a highly effective atrial antiarrhythmic compound.

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