scholarly journals Atrial chamber colocalization for multiple 3D imaging techniques in atrial fibrillation

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
G Rios-Munoz ◽  
C Perez-Hernandez ◽  
F Fernandez-Aviles ◽  
A Arenal

Abstract Introduction There exist many imaging techniques and systems to reproduce atrial chambers in 3D. These technologies include electroanatomical (EA) mapping systems, noninvasive electrocardiographic imaging (ECGI), magnetic resonance imaging (MRI), or computed tomography (CT) scans. In the case of atrial fibrillation (AF), the most employed non-pharmacological treatment is catheter ablation to electrically isolate the pulmonary veins from the rest of the left atrium. Driver mechanisms such as focal or rotational activity have been proposed as possible initiating and maintaining mechanisms of AF. However, correspondence and validation of these sites when several systems are employed in the same patient remains a challenge, as they are mostly manually aligned based on visual inspection. Purpose To develop an automatic 3D alignment algorithm for cardiac 3D meshes to colocalize points between atrial maps generated with multiple EA mapping systems, ECGI, MRI, or CT scans. Methods A total of 25 left atrial meshes from persistent AF patients were exported from an EA mapping system. The total number of vertices for all the meshes was 2545444 points (101817.8±13593.3 points per map). A reference mesh was employed with minor modifications [1]. All meshes were manually segmented into 12 different left atrial regions, see Table for the region names. The method implements a non-rigid variant of the iterative closest point algorithm to transform the atrial mesh onto the reference one, see Figure. The geographical distance between the mean position of the 12 different segmented reference areas and the 12 transformed points was employed as the performance metric. Results The global error for all the fiducial points in all left atrial meshes was 11.57±2.55 mm. The average local errors for the 12 atrial areas are summarized in the Table. The best three aligned areas were the RSPV, atrial septum, and lateral wall. The areas with less alignment accuracy were the LAA, LSPV, and atrial roof. Conclusions The algorithm provides a promising solution to evaluate and validate site-related results from different systems, e.g., rotational activity presence between EA mapping and ECGI systems. The method works automatically for any given chamber anatomy or any number of points. No prior segmentation is needed since the transformation and co-localization are applied to the raw chamber mesh. Further analysis with a larger mesh database is needed. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III and Ministerio de Ciencia, Innovaciόn y Universidades

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
D Nairn ◽  
C Nagel ◽  
B Mueller-Edenborn ◽  
H Lehrmann ◽  
A Jadidi ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG) through DO637/22-3 Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg through the Research Seed Capital (RiSC) program. Introduction Presence of left atrial (LA) fibrotic low voltage substrate (LVS) is associated with high risk for arrhythmia recurrences in patients undergoing pulmonary vein isolation (PVI) for atrial fibrillation (AF). PVI and additional ablation of LVS - as identified by mapping in sinus rhythm (SR) or AF - has been reported to improve SR maintenance rates, despite differences of the extent and distribution of LA-LVS in SR versus AF.  Aims To study the relationship between SR and AF voltage maps, we sought to identify the optimal AF voltage threshold providing the highest concordance in the extent and distribution of LVS when comparing voltage maps in SR vs. AF. Methods Using the statistical shape modelling software Scalismo, the voltage information from the SR and AF maps (acquired prior to PVI) from 28 patients (66 ± 7 years, 46% male, 82% persistent AF) was projected onto a representative LA-geometry. Sensitivity and specificity of LVS identification were calculated for varying thresholds during AF and the correlation between the SR (threshold 0.5mV) and AF maps was assessed and areas of agreeing LVS classification (SR & AF) were identified for each patient. The data of all 28 patients were combined to a spatial histogram of agreement between SR and AF low voltage maps. Results  The correlation between SR and AF maps was high across all patients, with agreement at 60-95% of all mapped sites (Figure A: each red triangle represents one patient and the respective agreement of LVS classification and substrate extent).  The optimal AF threshold - to identify LA-LVS <0.5 mV in SR - was 0.29 mV (Q1-3: 0.20-0.37 mV) and was independent of the underlying extent of LVS during SR (Figure A: each blue asterisk represents one patient and the corresponding AF threshold and substrate extent). Agreement between LVS in AF vs. SR was high across most (>90) patients on the anterior LA, lateral LA and the left atrial appendage. Lower agreement (60% of patients) was observed in the posterior wall (Figure B). Conclusions SR and AF voltage maps reveal high spatial concordance in low voltage substrate at the anterior LA, lateral LA and LA appendage, however significant discordances in LVS are found in 40% of patients at the posterior LA. Further studies on an extended patient cohort should assess if regional voltage-thresholds would result in an improved substrate concordance between AF and SR substrate maps. Abstract Figure.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T Kawaji ◽  
K Ono ◽  
T Aizawa ◽  
M Kato ◽  
T Yokomatsu ◽  
...  

Abstract Background Atrial fibrosis is hallmark of structural remodeling in atrial fibrillation (AF), but the inflammatory mechanism remains unclear. The purpose of the present study was to identify the specific inflammatory biomarkers to atrial fibrosis evaluated by atrial low voltage (LV) in AF patients for clarification of the mechanism. Methods Forty inflammatory biomarkers were quantified in 16 consecutive AF patients measured left atrial low voltage during catheter ablation. Results Median %LV area was 17%. In Pearson's correlation analysis, interleukin (IL)-17A and interferon (IFN)-γ was the most significant positive and negative correlation with %LV (R=0.35 and 0.43, P<0.001). Furthermore, there was a significant correlation between IL-17A/IFN-γ ratio and %LV (R=0.65, P=0.007). The area under the receiver operator characteristics curve of IL-17A/IFN-γ ratio for significant LV (%LV >10% as a reference standard) was 0.88. IL-17A/IFN-γ ratio was significantly higher in patients with significant LV than those without (1.41 versus 0.97, P=0.01), Furthermore, the sensitivity, specificity, and accuracy for detecting significant LV were 60%, 100%, and 75.0% at the cutoff value of 1.3. The event free survival from recurrent atrial tachyarrhythmias was not significantly different between patients with and without IL-17A/IFN-γ ratio >1.3 (83.3% versus 80.0% at 1-year, P=0.81). Conclusions Among inflammatory biomarkers, IL-17A/IFN-γ ratio was a significant predictor for the severity of left atrial low voltage n AF patients. Further study is needed to reveal the association between IL-17A and IFN-γ for development of fibrosis in AF. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI GrantNumber JP19K17594


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Takahashi ◽  
T Kitai ◽  
T Watanabe ◽  
T Fujita

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


2021 ◽  
Vol 10 (14) ◽  
pp. 3129
Author(s):  
Riyaz A. Kaba ◽  
Aziz Momin ◽  
John Camm

Atrial fibrillation (AF) is a global disease with rapidly rising incidence and prevalence. It is associated with a higher risk of stroke, dementia, cognitive decline, sudden and cardiovascular death, heart failure and impairment in quality of life. The disease is a major burden on the healthcare system. Paroxysmal AF is typically managed with medications or endocardial catheter ablation to good effect. However, a large proportion of patients with AF have persistent or long-standing persistent AF, which are more complex forms of the condition and thus more difficult to treat. This is in part due to the progressive electro-anatomical changes that occur with AF persistence and the spread of arrhythmogenic triggers and substrates outside of the pulmonary veins. The posterior wall of the left atrium is a common site for these changes and has become a target of ablation strategies to treat these more resistant forms of AF. In this review, we discuss the role of the posterior left atrial wall in persistent and long-standing persistent AF, the limitations of current endocardial-focused treatment strategies, and future perspectives on hybrid epicardial–endocardial approaches to posterior wall isolation or ablation.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Ijuin ◽  
A Hamadanchi ◽  
F Haertel ◽  
L Baez ◽  
C Schulze ◽  
...  

Abstract Background Percutaneous left atrial appendage closure (LAAC) is being established as an alternative option for atrial fibrillation (AF) patients with high bleeding risk. Few studies reported the influence of percutaneous LAAC on left atrial (LA) performance, but most of the studies demonstrated no remarkable changes in their parameters after the procedure. Method The study included 95 patients (age: 75±6.7 years, 67% male) whom underwent percutaneous LAAC in a single center between September 2012 and November 2018. LA strain was evaluated at three different time intervals by transesophageal echocardiography (baseline, 45 days and 180 days after procedure). All data were analyzed using a dedicated. 70 patients had atrial fibrillation whereas 25 were in sinus rhythm. Analysis was performed for peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) from segment of lateral wall in mid-esophageal 4 chamber view. The validity of lateral wall left atrial analysis was recently shown by our group. PACS was obtained in patients with sinus rhythm during exams. Results Compared to baseline, PALS was significantly increased after 45 days (12.4±8.4% vs 16.0±10.7%, p=0.001) and remained stable after 180 days (13.8±9.0% vs 17.0±12.4%, p=0.098). Even in only patients with atrial fibrillation during exams, it was increased (10.8±7.7% vs 13.4±7.1%, p=0.012 and 8.5±5.1% vs 13.9±8.1%, p=0.014). Similarly, compared with the baseline, PACS was significantly increased after 45 days and 180 days (5.8±3.9% vs 10.6±7.6%, p=0.001 and 4.5±2.6% vs 7.9±3.1%, p=0.036). The Changes in PALS and PACS Conclusion Our study has demonstrated for the first time the improvement in LA strain following LAAC within 45 days of implantation by transesophageal echocardiography and these values were maintained at least for 6 months. Further appraisal is warranted for confirmation of these preliminary findings.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
G R Rios-Munoz ◽  
N Soto ◽  
P Avila ◽  
T Datino ◽  
F Atienza ◽  
...  

Abstract Introduction Treatment of atrial fibrillation (AF) remains sub-optimal, with low success in pulmonary vein isolation (PVI) ablation procedures in long-standing-persistent AF patients. The maintenance mechanisms of AF are still under debate. Rotational activity (RA) events, also known as rotors, may play a role in perpetuating AF. The characterisation of these drivers during electroanatomical (EA) guided ablation procedures in relationship with follow-up and recurrence ratios in AF patients is necessary to design new ablation strategies to improve the AF treatment success. Purpose We report an AF patient cohort of endocardial mapping and PVI ablation procedures with additional RA events detected during the EA study. We aim to study the presence and distribution of RA in AF patients and its impact on AF recurrence when only PVI ablation is performed. Methods 75 persistent consecutive AF patients (age 60.7±9.8, 74.7% men) underwent EA mapping and RA detection with an automatic algorithm. The presence of RA was annotated on the EA map based on the unipolar electrograms (EGMs) registered with a 20-pole catheter. RA presence was analysed at different left atrial locations (37.2±14.8 sites per patient). AF recurrence was evaluated in follow-up after treatment. Results At follow-up (9±5 months), 50% of the patients presented AF recurrence. Patients with RA had more dilated atria in terms of volumes (p=0.002) and areas (p=0.001). Patients with RA exhibited higher mean voltage EGMs 0.6±0.3 mV vs 0.5±0.2 mV (p=0.036), with shorter cycle lengths 169.1±26.0 ms vs. 188.4±44.2 ms (p=0.044). Finally, patients with RA presented more AF recurrence rates than patients with no RA events (p=0.007). No significant differences were found in terms of comorbidities, e.g., heart failure, hypertension, COPD, stroke, SHD, or diabetes mellitus. Conclusions The results show that patients with more RA events and those with RA outside the PVI ablated regions presented higher AF recurrence episodes than those with no RA or events inside the areas affected by radio-frequency ablation. The study suggests that further ablation treatment of the areas harboring RA might be necessary to reduce the recurrence ratio in AF patients. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III; Sociedad Española de Cardiología


2019 ◽  
Author(s):  
Jun Ding ◽  
Jing Xu ◽  
Wei Ma ◽  
Bingwei Chen ◽  
Peigen Yang ◽  
...  

Abstract Background : The optimal dosage for cryoablation of atrial fibrillation (Cryo-AF) is still unknown. To evaluate the efficacy of an individualized freeze duration, we compared the clinical outcome of patients treated with a time-to-pulmonary vein isolation (TT-PVI) or temperature-guided ablation protocol to the outcome of patients treated with a conventional ablation protocol. Methods: A total of 164 consecutive patients were included in the study. One method employed was a conventional dosing protocol (at least 2 applications of 180 seconds each)(the Cryo-AF Conventional group n=84), and the second method had a shorter protocol that was based on the TT-PVI or achievement of -40°C within 60 seconds (the Cryo-AF Dosing group n=80). Results: We treated 656 pulmonary veins (PVs) with 1420 cryotherapy applications. The mean number of applications per patient was 8.7±0.8, with no difference between groups (Cryo-AF Conventional , 8.7±0.8 versus Cryo-AF Dosing ,8.6±0.8; P =0.359). The Cryo-AF Dosing group required significantly less total cryotherapy application time (990.60±137.77versus 1501.58±89.60 seconds; P <0.001) and left atrial dwell time (69.91±6.91 versus 86.48±7.03 minutes; P <0.001) than the Cryo-AF Conventional group. Additionally, the Cryo-AF Dosing group required significantly less total procedure time (95.03±6.50 versus 112.43±7.11 minutes; P <0.001). We observed acute ATP-induced or spontaneous vein electric reconnections in 13 veins (1.98%) after 20 minutes. The reconnection rates between the Cryo-AF Conventional and Cryo-AF Dosing groups were similar in that 2.98% and 0.94% of the initially isolated veins were reconnected, respectively, ( P =0.061). There was no difference in the recurrence rate of free atrial arrhythmia after a 1-year follow-up, which were 78.75% in the Cryo-AF Dosing group versus 78.57% in the Cryo-AF Conventional group ( P =0.978). Conclusion: A novel Cryo-AF dosing protocol guided by temperature or the TT-PVI can be used to individualize an ablation strategy. This new protocol can lead to a significant reduction in duration of the procedure, the cryoenergy dosage and the left atrial dwell time. The procedure had equal safety and similar acute and 1-year follow-up outcomes compared to the conventional approach.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Blendea ◽  
S Istratoaie ◽  
S Pop ◽  
M Mansour

Abstract Introduction The effect of circumferential pulmonary vein isolation (PVI) for atrial fibrillation (AF) on left atrial (LA) function has not been well defined. Purpose The aim of this study was to evaluate the immediate impact of ablation on parameters of global and regional LA function using intracardiac echocardiography (ICE) Methods We studied 26 consecutive patients (age 56±10 years, 19 men) with paroxysmal AF using ICE before and immediately after circumferential PVI. All pulmonary veins were isolated in all patients. ICE measurements included LA fractional area shortening, peak A wave on transmitral Doppler flow, peak emptying velocity on the left atrial appendage (LAA) Doppler flow, as well as tissue Doppler myocardial velocities at the level of the posterior LA wall, interatrial septum, and lateral wall, which were used as parameters of regional LA function. Results The mean radiofrequency ablation time was 37±22min. Post ablation there was a significant reduction of the LA fractional area shortening from 27±8% to 22±6% (p<0.01). The tissue Doppler velocity of atrial contraction at the posterior wall decreased significantly post ablation: from 8.9±1.8 cm/s to 6.9±1.4 cm/s (p<0.01). There were no significant differences between the pre and post ablation values for tissue Doppler velocities at the level of the interatrial septum or LA lateral wall. The post ablation peak transmitral A wave and peak LAA Doppler velocities did not differ significantly from the pre ablation values. Conclusion In patients with paroxysmal atrial fibrillation, circumferential PVI results in an immediate decrease in LA function without a significant change in LAA function.


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