Proper Threshold of Low Voltage and Reduced Conduction Velocity in Atrial Fibrillation

Background: The efficacy of ablation targeting low-voltage areas (LVAs) is controversial, although LVA presence is well known to be associated with AF recurrence after ablation. Atrial fibrillation (AF) substrate may not localize within LVAs. Methods and results: This observational study enrolled 405 consecutive patients who underwent an initial AF ablation procedure. The left atrial voltage map was obtained after pulmonary vein isolation. LVAs were defined as areas with voltage < 0.5 mV. To estimate whole atrial electrophysiological degeneration, mean regional voltage at each of 6 regions and left atrial total conduction velocity were measured. LVAs existed in 143 of 405 (35.3%) patients. Patients with LVAs demonstrated lower mean regional voltages throughout all 6 regions than those without LVAs (1.3 [1.8, 0.8] vs. 0.6 [1.0, 0.2] for anterior wall, p<0.001). On the other hand, left atrial conduction velocity was lower in patients with LVAs than in those without (0.89 [1.01, 0.74] vs. 0.93 [1.03, 0.87] m/s, p<0.001). Multivariate analysis revealed that low left atrial total conduction velocity and a higher number of regions with mean voltage reduction were independently associated with AF recurrence, although LVA presence was not. Conclusion: Patients with localized left atrial LVAs were characterized by whole left atrial electrophysiological degeneration as assessed by mean regional voltage and conduction velocity. In addition, whole left atrial electrophysiological degeneration parameters were well associated with AF recurrence.

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Novel Low-Voltage MultiPulse Therapy to Terminate Atrial Fibrillation

JACC: Clinical Electrophysiology ◽

10.1016/j.jacep.2020.12.014 ◽

2021 ◽

Author(s):

Fu Siong Ng ◽

Ondřej Toman ◽

Jan Petru ◽

Petr Peichl ◽

Roger A. Winkle ◽

...

Keyword(s):

Atrial Fibrillation ◽

Low Voltage

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Relationship between left atrial strain and left atrial bipolar voltage in patients undergoing catheter ablation for atrial fibrillation

European Heart Journal ◽

10.1093/ehjci/ehaa946.0387 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

Y Takahashi ◽

T Kitai ◽

T Watanabe ◽

T Fujita

Keyword(s):

Atrial Fibrillation ◽

Left Atrial ◽

Speckle Tracking ◽

Longitudinal Strain ◽

Low Voltage ◽

Pulmonary Veins ◽

Global Longitudinal Strain ◽

Inferior Wall ◽

Bipolar Voltage ◽

Global Mean

Abstract Background Low-voltage zone (LVZ) in the left atrium (LA) seems to represent fibrosis. LA longitudinal strain assessed by speckle tracking method is known to correlate with the extent of fibrosis in patients with mitral valve disease. Purpose We sought to identify the relationship between LA longitudinal strain and LA bipolar voltage in patients with atrial fibrillation (AF). We tested the hypothesis that LA strain can predict LA bipolar voltage. Methods A total of 96 consecutive patients undergoing initial AF ablation were analyzed. All patients underwent transthoracic echocardiography including 2D speckle tracking measurement on the day before ablation during sinus rhythm (SR group, N=54) or during AF (AF group, N=42). LA longitudinal strain was measured at basal, mid, and roof level of septal, lateral, anterior, and inferior wall in apical 4- and 2-chamber view. Global longitudinal strain (GLS) was defined as an average value of the 12 segments. LA voltage map was created using EnSite system, and global mean voltage was defined as a mean of bipolar voltage of the whole LA excluding pulmonary veins and left atrial appendage. LVZ was defined as less than 1.0 mV. Results There was a significantly positive correlation between GLS and global mean voltage (r=0.708, p<0.001). Multivariate regression analysis showed that GLS and age were independent predictors of global mean voltage. There was a significant negative correlation between global mean voltage and LVZ areas. Conclusions There was a strong correlation between LA longitudinal strain and LA mean voltage. GLS can independently predict LA mean voltage, subsequently LVZ areas in patients with AF. Funding Acknowledgement Type of funding source: None

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Association of low-voltage areas with the regional wall deformation and the left atrial shape in patients with atrial fibrillation: A proof of concept study

IJC Heart & Vasculature ◽

10.1016/j.ijcha.2021.100730 ◽

2021 ◽

Vol 33 ◽

pp. 100730

Author(s):

Sotirios Nedios ◽

Soroosh Sanatkhani ◽

Michael Oladosu ◽

Timm Seewöster ◽

Sergio Richter ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Atrial ◽

Low Voltage ◽

Proof Of Concept ◽

Regional Wall ◽

Concept Study ◽

Wall Deformation

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P1151Structural remodeling and conduction velocity dynamics in the human left atrium: relationship with reentrant mechanisms sustaining atrial tachycardia and atrial fibrillation

EP Europace ◽

10.1093/europace/euy015.637 ◽

2018 ◽

Vol 20 (suppl_1) ◽

pp. i219-i219

Author(s):

S Honarbakhsh ◽

R J Schilling ◽

M Orini ◽

R Providencia ◽

E Keating ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Atrium ◽

Conduction Velocity ◽

Atrial Tachycardia

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P613Cardiac magnetic resonance imaging derived left ventricular mechanical function in patients with atrial fibrillation and left atrial low voltage zones

European Heart Journal ◽

10.1093/eurheartj/ehz747.0222 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

S Ulbrich ◽

R S Schoenbauer ◽

B Kirstein ◽

J Tomala ◽

Y Huo ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Atrial Fibrillation ◽

Magnetic Resonance ◽

Stroke Volume ◽

Left Atrial ◽

Low Voltage ◽

Left Ventricular ◽

Left Ventricular Stroke Volume ◽

Resonance Imaging ◽

Ventricular Filling

Abstract Background The relation of left atrial low voltage zones (LVZ) to left ventricular function in patients undergoing pulmonary vein isolation (PVI) is not known. Objective To explore the relationship of left atrial low voltage zones (LVZ) on left ventricular function in patients with atrial fibrillation. Methods From June to Nov. 2018, 107 (mean age 67y, 70 men, 73 persistent AF) consecutive patients with symptomatic AF underwent a PVI with LVZ mapping. Before PVI the left ventricular ejection fraction (EF) and stroke volume (SV) were measured by cardiac magnetic resonance imaging (CMR). From feature-tracking of CMR-cine images left ventricular global, systolic and diastolic longitudinal strains (GLS), circumferential strains (GCS) and radial strains (GRS) were calculated. Results Of 59 patients CMR scanning in sinus rhythm was performed, LVZ were present in 24 patients. LVEF was significantly lower in patients with left atrial LVZ (62±9% vs. 55±15%) (p=0,03). Left ventricular stroke volume was significantly decreased by the extent of LVZ (94±23 vs. 72±21ml), (p=0,03). The left ventricular diastolic strains during ventricular filling (caused by atrial contraction) of GLS (r=−0,52), GCS (r=−0,65) and GRS (r=−0,65) were highly signifcantly correlated to the occurence and extent of LVZ (each p<0,001 respectively). The only systolic ventricular strain was GLS, which decreased (r=−0,3, p=0,03) by the occurance of atrial low voltage. Conclusion The active, atrial part of diastolic left ventricular filling properties is impaired by the occurrence and extent of left atrial LVZ. In patients with left atrial LVZ the left ventricular stroke volume and ejection fraction is decreased already in sinus rhythm. It seems possible that atrial mechanical dysfunction and presence of atrial low voltage maybe predicted by LV diastolic strain analysis.

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Duration of Electrically Induced Atrial Fibrillation Is Augmented by High Voltage of Stimulus with Higher Blood Pressure in Hypertensive Rats

International Journal of Hypertension ◽

10.1155/2014/980505 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Tomomi Nagayama ◽

Yoshitaka Hirooka ◽

Akiko Chishaki ◽

Masao Takemoto ◽

Yasushi Mukai ◽

...

Keyword(s):

Atrial Fibrillation ◽

Blood Pressure ◽

Arterial Pressure ◽

High Voltage ◽

Spontaneously Hypertensive Rats ◽

Low Voltage ◽

Hypertensive Rats ◽

Spontaneously Hypertensive ◽

High Stimulus ◽

Wistar Kyoto

Objective.Many previous clinical studies have suggested that atrial fibrillation (AF) is closely associated with hypertension. However, the benefits of antihypertensive therapy on AF are still inconsistent, and it is necessary to explore the factors augmenting AF in hypertensive rats. The aim of the present study was to investigate the correlation between arterial pressure or voltage stimulus and to the duration of electrically induced AF in normotensive or hypertensive rats.Methods.AF was reproducibly induced by transesophageal atrial burst pacing in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). We did the burst pacing at high (20 V) or low (5 V) voltage.Results.Duration of AF did not correlate with systolic blood pressure (SBP) and stimulus voltage in WKY. However, only in SHR, duration of AF with high stimulus voltage significantly correlated with SBP and was significantly longer in high than in low voltage stimulus.Discussion and Conclusion.Duration of AF is augmented by high voltage stimulus with higher blood pressure in SHR.

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ATRIAL LOW VOLTAGE AREAS: A COMPARISON BETWEEN ATRIAL FIBRILLATION AND SINUS RHYTHM

10.22541/au.160430252.23780427/v1 ◽

2020 ◽

Author(s):

Ana Andres ◽

Carlos Roberto ◽

Francisco Javier Saiz ◽

Oscar Cano ◽

Laura Martínez-Mateu ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Low Voltage

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Low-voltage-area ablation in paroxysmal atrial fibrillation: Extended follow-up results of the VOLCANO trial

10.22541/au.161661216.67499040/v1 ◽

2021 ◽

Author(s):

Masaharu Masuda ◽

Mitsutoshi Asai ◽

Osamu Iida ◽

Shin Okamoto ◽

Takayuki Ishihara ◽

...

Keyword(s):

Atrial Fibrillation ◽

Paroxysmal Atrial Fibrillation ◽

Low Voltage ◽

Recurrence Rates ◽

Group A ◽

C 32 ◽

Group B ◽

Group D

Introduction: The randomized controlled VOLCANO trial demonstrated comparable 1-year rhythm outcomes between patients with and without ablation targeting low-voltage areas (LVAs) in addition to pulmonary vein isolation among paroxysmal atrial fibrillation (AF) patients with LVAs. To compare long-term AF/atrial tachycardia (AT) recurrence rates and types of recurrent-atrial-tachyarrhythmia between treatment cohorts during a > 2-year follow-up period. Methods: An extended-follow-up study of 402 patients enrolled in the VOLCANO trial with paroxysmal AF, divided into 4 groups based on the results of voltage mapping: Group A, no LVA (n=336); group B, LVA ablation (n=30); group C, LVA presence without ablation (n=32); and group D, incomplete voltage map (n=4). Results: At 25 (23, 31) months after the initial ablation, AF/AT recurrence rates were 19% in group A, 57% in group B, 59% in group C, and 100% in group D. Recurrence rates were higher in patients with LVAs than those without (group A vs. B+C, p<0.0001), and were comparable between those with and without LVA ablation (group B vs. C, p=0.83). Among patients who underwent repeat ablation, ATs were more frequently observed in patients with LVAs (Group B+C, 50% vs. A, 14%, p<0.0001). In addition, LVA ablation increased the incidence of AT development (group B, 71% vs. C, 32%, p<0.0001), especially biatrial tachycardia (20% vs. 0%, p=0.01). Conclusion: Patients with LVAs demonstrated poor long-term rhythm outcomes irrespective of LVA ablation. ATs were frequently observed in patients with LVAs, and LVA ablation might exacerbate iatrogenic ATs.

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Termination of atrial fibrillation during pharmacological cardioversion in the goat requires inter-atrial synchronisation of conduction

EP Europace ◽

10.1093/europace/euab116.563 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

V Sobota ◽

A Van Hunnik ◽

S Zeemering ◽

G Gatta ◽

D Opacic ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrium ◽

Conduction Velocity ◽

Right Atrium ◽

Path Length ◽

Cycle Length ◽

Final Phase ◽

Periodic Activity ◽

Bachmann’S Bundle

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ITN Networks PersonalizeAF: Personalized Therapies for Atrial Fibrillation. A Translational Approach, No. 860974; CATCH ME: Characterizing Atrial fibrillation by Translating its Causes into Health Modifiers in the Elderly, No. 633196; MAESTRIA: Machine Learning and Artificial Intelligence for Early Detection of Stroke and Atrial Fibrillation, No. 965286; AFib-TrainNet: EU Training Network on Novel Targets and Methods in Atrial Fibrillation, No. 675351 Netherlands Heart Foundation: CVON2014-09, RACE V Reappraisal of Atrial Fibrillation: Interaction between hyperCoagulability, Electrical remodeling, and Vascular Destabilization in the Progression of Atrial Fibrillation Background Few studies report on mechanisms leading to termination of atrial fibrillation (AF). Purpose To characterise electrophysiological parameters and conduction patterns during the transition from AF to sinus rhythm under various conditions of AF termination. Methods A retrospective evaluation of 6 goat studies was performed. AF was maintained for 3-4 weeks in 29 animals. Four animals were in SR. Unipolar electrograms were acquired with one 249-electrode array/atrium. Pharmacological termination of AF was evoked by various drugs; AP14145 (n = 5), PA6 (n = 7), XAF-1407 (n = 9) vernakalant (n = 8). In animals with sinus rhythm, AF was acutely induced and terminated spontaneously. Baseline AF and ≤3 recordings of the last 10 seconds preceding AF termination were analysed. Intervals with temporal continuous and periodic activity were distinguished in the recordings. AF cycle length (AFCL), conduction velocity and path length were determined for each interval. Results In total, 85 AF terminations were recorded. Switches between temporal continuous and periodic activity were seen frequently during AF. However, termination of AF was always preceded by a phase of periodic activity (PA). The final phase of PA persisted for a median number of 21 [IQR 10-28] cycles in the left atrium and somewhat shorter in the right atrium, Table 1. This final phase of PA was accompanied by a profound bi-atrial increase of AFCL, conduction velocity and path length and a disappearance of inter-atrial cycle length differences. Equipotent changes were not observed in the preceding PAs. During the final AF beats, the number of wave fronts were low, 1 or 2. Interestingly, 92% of the patterns during the last beats of AF involved the Bachmann’s bundle as main source of atrial conduction. Conclusion AF termination is preceded by an increased organisation of fibrillatory conduction, associated with abrupt prolongation of the path length. Propagation in atrial free walls regularly originated from the Bachmann’s bundle. These findings suggest that AF termination was not a random process but follows common spatiotemporal patterns. Final period of temporal organisation Left atrium Right atrium Final PA start Final PA end Final PA start Final PA end Af cycle length (ms) 163 ± 37 204 ± 50* 146 ± 44 207 ± 49* Conduction velocity (cm/s) 77 ± 15 96 ± 25* 83 ± 20 103 ± 24* Path Length (cm) 12.2 ± 2.7 19.3 ± 6.3* 12.0 ± 4.1 21.2 ± 6.4* Length of final periodic activity (beats) NA 21 [IQR 10-28] NA 15 [IQR 10- 25] Electrophysiological changes during the final period periodic activity (PA). Wilcoxon signed rank test. *p <0.05NA= not available

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