scholarly journals Understanding AF Mechanisms Through Computational Modelling and Simulations

2019 ◽  
Vol 8 (3) ◽  
pp. 210-219 ◽  
Author(s):  
Konstantinos N Aronis ◽  
Rheeda L Ali ◽  
Jialiu A Liang ◽  
Shijie Zhou ◽  
Natalia A Trayanova

AF is a progressive disease of the atria, involving complex mechanisms related to its initiation, maintenance and progression. Computational modelling provides a framework for integration of experimental and clinical findings, and has emerged as an essential part of mechanistic research in AF. The authors summarise recent advancements in development of multi-scale AF models and focus on the mechanistic links between alternations in atrial structure and electrophysiology with AF. Key AF mechanisms that have been explored using atrial modelling are pulmonary vein ectopy; atrial fibrosis and fibrosis distribution; atrial wall thickness heterogeneity; atrial adipose tissue infiltration; development of repolarisation alternans; cardiac ion channel mutations; and atrial stretch with mechano-electrical feedback. They review modelling approaches that capture variability at the cohort level and provide cohort-specific mechanistic insights. The authors conclude with a summary of future perspectives, as envisioned for the contributions of atrial modelling in the mechanistic understanding of AF.

Author(s):  
Zsuzsanna Kis ◽  
Astrid Amanda Hendriks ◽  
Taulant Muka ◽  
Wichor M. Bramer ◽  
Istvan Kovacs ◽  
...  

Introduction: Atrial Fibrillation (AF) is associated with remodeling of the atrial tissue, which leads to fibrosis that can contribute to the initiation and maintenance of AF. Delayed- Enhanced Cardiac Magnetic Resonance (DE-CMR) imaging for atrial wall fibrosis detection was used in several studies to guide AF ablation. The aim of present study was to systematically review the literature on the role of atrial fibrosis detected by DE-CMR imaging on AF ablation outcome. Methods: Eight bibliographic electronic databases were searched to identify all published relevant studies until 21st of March, 2016. Search of the scientific literature was performed for studies describing DE-CMR imaging on atrial fibrosis in AF patients underwent Pulmonary Vein Isolation (PVI). Results: Of the 763 citations reviewed for eligibility, 5 articles (enrolling a total of 1040 patients) were included into the final analysis. The overall recurrence of AF ranged from 24.4 - 40.9% with median follow-up of 324 to 540 days after PVI. With less than 5-10% fibrosis in the atrial wall there was a maximum of 10% recurrence of AF after ablation. With more than 35% fibrosis in the atrial wall there was 86% recurrence of AF after ablation. Conclusion: Our analysis suggests that more extensive left atrial wall fibrosis prior ablation predicts the higher arrhythmia recurrence rate after PVI. The DE-CMR imaging modality seems to be a useful method for identifying the ideal candidate for catheter ablation. Our findings encourage wider usage of DE-CMR in distinct AF patients in a pre-ablation setting.


2021 ◽  
Vol 62 (1) ◽  
pp. 65-71
Author(s):  
Laura Rottner ◽  
Christian-Hendrik Heeger ◽  
Christine Lemes ◽  
Peter Wohlmuth ◽  
Tilman Maurer ◽  
...  

2017 ◽  
Vol 56 (1) ◽  
pp. 9
Author(s):  
C. G. HATZIGIANNAKIS (Χ.Γ. ΧΑΤΖΗΓΙΑΝΝΑΚΗΣ) ◽  
M. E. MYLONAKIS (Μ. Ε. ΜΥΛΩΝΑΚΗΣ) ◽  
M. N. SARIDOMICHELAKIS (Μ.Ν. ΣΑΡΙΔΟΜΙΧΕΛΑΚΗΣ) ◽  
M. PATSIKAS (Μ. ΠΑΤΣΙΚΑΣ) ◽  
D. PSALLA (Δ. ΨΑΛΛΑ) ◽  
...  

A 7-year old female collie (case 1), a 3-year old male Caucasian-cross (case 2) and three male German shepherds with an age of 11 (case 3), 8.5 (case 4) and 10 (case 5) years, respectively, were admitted with a history of decreased appetite, depression, exercise intolerance, dyspnea and progressive abdominal enlargement, for the last 10 to 60 days. Poor body condition (5/5), muffled heart sounds (5/5), weak femoral pulse (5/5), ascites (5/5), inspiratory or inspiratory-expiratory dyspnea (5/5), pulsus paradoxus (2/5) and jugular vein distension (2/5) were the prominent clinical findings, while mature neutrophilic leukocytosis (3/5), lymphopenia (3/5), eosinopenia (3/5), hypoproteinemia (5/5) and increased urea nitrogen (3/5) were the most prevalent clinicopathologic abnormalities. Apart from a space-occupying lesion onto the right atrial wall of one dog (case 4), radiographic and ultrasound examination showed a globe-shaped cardiac silhouette (5/5), pericardial effusion (5/5), ascites (5/5) and pleural effusion (4/5). A large amount of non-clotting hemorrhagic effusion was drained during pericardiocentesis, resulting in rapid clinical recovery. Physical, chemical and cytological evaluation of the pericardial fluid was non-contributory in the differentiation between neoplastic and non-neoplastic causes of these effusions. Case 3 died 25 days post-pericardiocentesis; right atrium hemangiosarcoma and pulmonary metastases were documented on post mortem histopathological examination. Another dog (case 5) died of unknown causes one month after pericardiocentensis. On the contrary, dogs 1, 2 and 4 were still clinically healthy for a followup period of 16, 2 and 8 months, respectively.


2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Felipe Bisbal ◽  
Eva Benito ◽  
Albert Teis ◽  
Francisco Alarcón ◽  
Axel Sarrias ◽  
...  

Background: Myocardial fibrosis is key for atrial fibrillation maintenance. We aimed to test the efficacy of ablating cardiac magnetic resonance (CMR)-detected atrial fibrosis plus pulmonary vein isolation (PVI). Methods: This was an open-label, parallel-group, randomized, controlled trial. Patients with symptomatic drug-refractory atrial fibrillation (paroxysmal and persistent) undergoing first or repeat ablation were randomized in a 1:1 basis to receive PVI plus CMR-guided fibrosis ablation (CMR group) or PVI alone (PVI-alone group). The primary end point was the rate of recurrence (>30 seconds) at 12 months of follow-up using a 12-lead ECG and Holter monitoring at 3, 6, and 12 months. The analysis was conducted by intention-to-treat. Results: In total, 155 patients (71% male, age 59±10, CHA 2 DS 2 -VASc 1.3±1.1, 54% paroxysmal atrial fibrillation) were allocated to the PVI-alone group (N=76) or CMR group (N=79). First ablation was performed in 80% and 71% of patients in the PVI-alone and CMR groups, respectively. The mean atrial fibrosis burden was 12% (only ≈50% of patients had fibrosis outside the pulmonary vein area). One hundred percent and 99% of patients received the assigned intervention in the PVI-alone and CMR group, respectively. The primary outcome was achieved in 21 patients (27.6%) in the PVI-alone group and 22 patients (27.8%) in the CMR group (odds ratio: 1.01 [95% CI, 0.50–2.04]; P =0.976). There were no differences in the rate of adverse events (3 in the CMR group and 2 in the PVI-alone group; P =0.68). Conclusions: A pragmatic ablation approach targeting CMR-detected atrial fibrosis plus PVI was not more effective than PVI alone in an unselected population undergoing atrial fibrillation ablation with low fibrosis burden. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02698631.


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