High-density bipolar voltage mapping for substrate-guided ablation of atrial fibrillation

2018 ◽  
pp. 1115-1115
Author(s):  
Maciej Wójcik ◽  
Łukasz Konarski ◽  
Robert Błaszczyk ◽  
Piotr Aljabali ◽  
Przemysław Zając
2020 ◽  
Vol 11 ◽  
Author(s):  
Deborah Nairn ◽  
Heiko Lehrmann ◽  
Björn Müller-Edenborn ◽  
Steffen Schuler ◽  
Thomas Arentz ◽  
...  

Background: Presence of left atrial low voltage substrate in bipolar voltage mapping is associated with increased arrhythmia recurrences following pulmonary vein isolation for atrial fibrillation (AF). Besides local myocardial fibrosis, bipolar voltage amplitudes may be influenced by inter-electrode spacing and bipole-to-wavefront-angle. It is unclear to what extent these impact low voltage areas (LVA) in the clinical setting. Alternatively, unipolar electrogram voltage is not affected by these factors but requires advanced filtering.Objectives: To assess the relationship between bipolar and unipolar voltage mapping in sinus rhythm (SR) and AF and identify if the electrogram recording mode affects the quantification and localization of LVA.Methods: Patients (n = 28, 66±7 years, 46% male, 82% persistent AF, 32% redo-procedures) underwent high-density (>1,200 sites, 20 ± 10 sites/cm2, using a 20-pole 2-6-2 mm-spaced Lasso) voltage mapping in SR and AF. Bipolar LVA were defined using four different thresholds described in literature: <0.5 and <1 mV in SR, <0.35 and <0.5 mV in AF. The optimal unipolar voltage threshold resulting in the highest agreement in both unipolar and bipolar mapping modes was determined. The impact of the inter-electrode distance (2 vs. 6 mm) on the correlation was assessed. Regional analysis was performed using an 11-segment left atrial model.Results: Patients had relevant bipolar LVA (23 ± 23 cm2 at <0.5 mV in SR and 42 ± 26 cm2 at <0.5 mV in AF). 90 ± 5% (in SR) and 85 ± 5% (AF) of mapped sites were concordantly classified as high or low voltage in both mapping modes. Discordant mapping sites located to the border zone of LVA. Bipolar voltage mapping using 2 vs. 6 mm inter-electrode distances increased the portion of matched mapping points by 4%. The unipolar thresholds (y) which resulted in a high spatial concordance can be calculated from the bipolar threshold (x) using following linear equations: y = 1.06x + 0.26mV (r = 0.994) for SR and y = 1.22x + 0.12mV (r = 0.998) for AF.Conclusion: Bipolar and unipolar voltage maps are highly correlated, in SR and AF. While bipole orientation and inter-electrode spacing are theoretical confounders, their impact is unlikely to be of clinical importance for localization of LVA, when mapping is performed at high density with a 20-polar Lasso catheter.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
R Adelino Recasens ◽  
L Llorca-Fenes ◽  
A Sarrias ◽  
A Teis ◽  
V Bazan ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND Left atrial fibrosis is a marker of atrial disease and it has an important role in the pathophysiology of atrial fibrillation (AF). Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is an emerging tool to detect left atrial fibrosis. However, data on the correlation between LGE-CMR detected fibrosis and low voltage areas to define fibrotic tissue is scarce. PURPOSE To assess the correlation and degree of concordance between LGE-CMR and high-density bipolar voltage mapping for the identification of left atrial abnormal tissue. METHODS Seven patients scheduled for AF ablation (including first and redo procedures) underwent a preprocedural 1.5 Tesla LGE-CMR including left atrial 3D inversion-recovery steady-state free precession sequence (ECG and respiratory triggering) 20 minutes after the injection of 0.2 mmol/kg of gadobutrol. A high-density electroanatomical voltage mapping was acquired with a 16-electrode grid configuration mapping catheter during sinus rhythm. LGE-CMR studies were analyzed off-line with an advanced image post-processing tool (ADAS 3D). Atrial wall intensity was normalized to blood pool, obtaining an image intensity ratio (IIR) value for each CMR point of the 3D model.  High-density bipolar voltage maps and LGE-CMR 3D left atrial reconstruction were merged (figure, panel A). Voltage points were projected to the LGE-CMR left atrial 3D model, allowing point-by-point correlation analysis between voltage (log transformed due to non-normal distribution) with IIR. Left atrial fibrosis area and percentage were quantified using the standard cut-off values (bipolar voltage <0.5mV and IIR >1.2). We assessed the degree of concordance for normal and abnormal (fibrosis) tissue classification between the two techniques using different cut-off values (< 0.5mV and <1mV for bipolar voltage and >0.9, >1, >1.1 and >1.2 for IIR).   RESULTS The average fibrosis area detected with LGE-CMR was lower than that detected with high-density bipolar voltage, using standard cut-off values (18.6 ± 5.7 cm2 vs. 40.6 ± 12.5 cm2, p = 0.13 respectively). There was a poor global point-by-point correlation between log-transformed voltage and IIR was r=-0.093, p < 0.001 (figure, panel B). The best concordance was obtained when using bipolar voltage and IIR of 0.5mV and 1.2, respectively (64.7 %; Kappa 0.101). However, the highest kappa index (0.142) for concordance was achieved with cutoff values of bipolar voltage <1mV and IIR >1, with an agreement percentage of 54.6%. CONCLUSIONS Left atrial tissue characterization between LGE-CMR and high-density bipolar voltage mapping showed significant but poor point-by-point correlation. Although the highest concordance was obtained using standard cutoff values, the Kappa index was best when applying non-standard cutoffs (1mV for bipolar voltage and >1 for IIR). Abstract Figure.


2020 ◽  
Vol 36 (12) ◽  
pp. 1956-1964 ◽  
Author(s):  
Pablo B. Nery ◽  
Wael Alqarawi ◽  
Girish M. Nair ◽  
Mouhannad M. Sadek ◽  
Calum J. Redpath ◽  
...  

EP Europace ◽  
2018 ◽  
Vol 20 (suppl_1) ◽  
pp. i155-i155
Author(s):  
M M Oliveira ◽  
P S Cunha ◽  
B Valente ◽  
N Silva ◽  
G Portugal ◽  
...  

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Schoenbauer ◽  
J Tomala ◽  
B Kirstein ◽  
Y Huo ◽  
T Gaspar ◽  
...  

Abstract Background Bipolar voltage mapping is a widely accepted approach to identify areas of arrhythmogenic substrate in patients presenting for atrial fibrillation (AF) ablation. However, until now little is known about the correlation of left atrial (LA) bipolar voltage distribution and LA transport function. Purpose To study the impact of LA low voltage zones (LVZ) on LA transport function. Methods 107 consecutive patients presenting for ablation of symptomatic AF (34 paroxysmal AF, 73 persistent AF) were prospectively enrolled. Each patient underwent cardiac magnetic resonance imaging (CMR) within 24 hours prior to the ablation procedure. 59 patients were in sinus rhythm (SR) and 48 in AF. LA phasic indexed volumes (LAVi) and ejection fractions were calculated using biplane area length formula. In addition LA phasic strains and strain rates were analyzed using dedicated software (Figure 1A & B). LA bipolar voltage mapping was performed prior to beginning of ablation in sinus rhythm using a 3-dimensional mapping system and LVZ were defined as areas of bipolar voltage <0.5mV. Results LVZ were present in 47 patients (23 in SR). The area of LVZ was 14.6cm2 (5.3–34.0). For patients in AF at the time of CMR only elevated minimal and maximal LAVi (p=0.001 and p=0.002 respectively) but no LA functional parameter was predictive for the occurrence of LVZ. In contrast for patients in SR all LA phasic volumes (endsystolic, pre atrial contraction and enddiastolic LAVi) and LA function parameters (passive, active and total ejection fraction (EF), reservoir, conduit and booster pump strains and strain rates) were predictive for the occurrence of LVZ. After clustered and pooled multivariate logistic regression only impaired booster pump strain rate was still predictive for occurrence of LVZ (OR 0.974, 95% CI 0.950–0.998, p=0.036). In addition Pearson correlation analysis revealed a strong link between LA booster pump functional parameters and cm2 expansion of LVZ areas: LA active EF, LA booster pump strain and SR (r=−0.42, p=0.044; r=−0.47, p=0.024; r=−0.65, p=0.001 [Figure 1C] respectively). Conclusion For patients in SR LA transport function is closely linked to the occurrence of LA LVZ and outperforms LA volumetric measurements for the prediction of LA LVZ. Furthermore LA booster pump function parameters show robust correlation to the extension of LA LVZ.


Medicine ◽  
2021 ◽  
Vol 100 (31) ◽  
pp. e26702
Author(s):  
Jongmin Hwang ◽  
Hyoung-Seob Park ◽  
Seongwook Han ◽  
Cheol Hyun Lee ◽  
In-Cheol Kim ◽  
...  

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