scholarly journals Non-Pharmacological Therapy for Atrial Fibrillation: Managing the Left Atrial Appendage

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Sushil Allen Luis ◽  
Damian Roper ◽  
Alexander Incani ◽  
Karl Poon ◽  
Haris Haqqani ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Blood Flow ◽  
Blood Flow Velocity ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Pharmacological Therapy ◽  
Atrial Appendage ◽  
Ageing Population ◽  
Increased Risk

The prevalence of atrial fibrillation (AF) is increasing in parallel with an ageing population leading to increased morbidity and mortality. The most feared complication of AF is stroke, with the arrhythmia being responsible for up to 20% of all ischemic strokes. An important contributor to this increased risk of stroke is the left atrial appendage (LAA). A combination of the LAA's unique geometry and atrial fibrillation leads to low blood flow velocity and stasis, which are precursors to thrombus formation. It has been hypothesized for over half a century that excision of the LAA would lead to a reduction in the incidence of stroke. It has only been in the last 20–25 years that the knowledge and technology has been available to safely carry out such a procedure. We now have a number of viable techniques, both surgical and percutaneous, which will be covered in this paper.

scholarly journals Effect of the Alterations in Contractility and Morphology Produced by Atrial Fibrillation on the Thrombosis Potential of the Left Atrial Appendage

2021 ◽  
Vol 9 ◽  
Author(s):  
Danila Vella ◽  
Alessandra Monteleone ◽  
Giulio Musotto ◽  
Giorgia Maria Bosi ◽  
Gaetano Burriesci
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Fluid Dynamic ◽  
Atrial Appendage ◽  
Primary Role ◽  
Shear Strain Rate ◽  
Increased Risk

Atrial fibrillation (AF) is a common arrhythmia mainly affecting the elderly population, which can lead to serious complications such as stroke, ischaemic attack and vascular dementia. These problems are caused by thrombi which mostly originate in the left atrial appendage (LAA), a small muscular sac protruding from left atrium. The abnormal heart rhythm associated with AF results in alterations in the heart muscle contractions and in some reshaping of the cardiac chambers. This study aims to verify if and how these physiological changes can establish hemodynamic conditions in the LAA promoting thrombus formation, by means of computational fluid dynamic (CFD) analyses. In particular, sinus and fibrillation contractility was replicated by applying wall velocity/motion to models based on healthy and dilated idealized shapes of the left atrium with a common LAA morphology. The models were analyzed and compared in terms of shear strain rate (SSR) and vorticity, which are hemodynamic parameters directly associated with thrombogenicity. The study clearly indicates that the alterations in contractility and morphology associated with AF pathologies play a primary role in establishing hemodynamic conditions which promote higher incidence of ischaemic events, consistently with the clinical evidence. In particular, in the analyzed models, the impairment in contractility determined a decrease in SSR of about 50%, whilst the chamber pathological dilatation contributed to a 30% reduction, indicating increased risk of clot formation. The equivalent rigid wall model was characterized by SSR values about one order of magnitude smaller than in the contractile models, and substantially different vortical behavior, suggesting that analyses based on rigid chambers, although common in the literature, are inadequate to provide realistic results on the LAA hemodynamics.

scholarly journals Predictive Value of Left Atrial Appendage Functional Parameters on Left Atrial Thrombus or Spontaneous Echo Contrast in Patients with Nonvalvular Atrial Fibrillation

2022 ◽  
Author(s):  
Changsheng Ma ◽  
Li Wang ◽  
Yuzhu Miao ◽  
Jiali Fan ◽  
Bingyuan Zhou ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Atrial Appendage ◽  
Control Group ◽  
Nonvalvular Atrial Fibrillation ◽  
Increased Risk ◽  
High Incidence ◽  
Echocardiographic Parameters

Abstract Background: Left atrial appendage (LAA) spontaneous echocardiographic contrast (SEC), sludge and thrombus were associated with a high incidence of thrombus formation and thromboembolic events in patients with non-valvular atrial fibrillation (AF). We aim to identify the main echocardiographic parameters associated with LAA SEC or LAA sludge/thrombus in nonvalvular AF patients.Methods and results: 298 patients with nonvalvular atrial fibrillation were included in the current study between September 2019 and January 2021. Transthoracic echocardiography and transesophageal echocardiography were performed before scheduled electrical cardioversion. LA diameter and maximum left atrial appendage area were increased in the LAA SEC group than control group, and were further increased in patients with LAA sludge or thrombus. LAA-EV, LAA-FV, anterior mitral annular plane systolic excursion (MAPSE) and LAA FAC were lower in the group with LAA SEC than control group, and were further reduced in LAA sludge or thrombus group. Lower LAA FAC and anterior MAPSE were associated with an increased risk of LAA SEC or LAA sludge/thrombus, and LAA FAC and anterior MAPSE showed high accuracy on predicting LAA SEC or LAA sludge/thrombus.Conclusion: Left atrial appendage FAC and anterior MAPSE improves left atrial appendage stasis in patients with nonvalvular atrial fibrillation.

scholarly journals Large extracellular vesicles in the left atrial appendage in patients with atrial fibrillation—the missing link?

2021 ◽  
Author(s):  
Andreas Zietzer ◽  
Baravan Al-Kassou ◽  
Paul Jamme ◽  
Verena Rolfes ◽  
Eva Steffen ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Extracellular Vesicles ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Flow Cytometric Analysis ◽  
Heart Rhythm ◽  
Atrial Appendage ◽  
Peripheral Embolization

AbstractAtrial fibrillation (AF) is the most frequent arrhythmic disease in humans, which leads to thrombus formation in the left atrial appendage and stroke through peripheral embolization. Depending on their origin, large extracellular vesicles (lEVs) can exert pro-coagulant functions. In the present study, we investigated how different types of AF influence the levels of large EV subtypes in three distinct atrial localizations. Blood samples were collected from the right and left atrium and the left atrial appendage of 58 patients. 49% of the patients had permanent AF, 34% had non-permanent AF, and 17% had no history of AF. Flow cytometric analysis of the origin of the lEVs showed that the proportion of platelet-derived lEVs in the left atrial appendage was significantly higher in permanent AF patients compared to non-permanent AF. When we grouped patients according to their current heart rhythm, we also detected significantly higher levels of platelet-derived lEVs in the left atrial appendage (LAA) in patients with atrial fibrillation. In vitro studies revealed, that platelet activation with lipopolysaccharide (LPS) leads to higher levels of miR-222-3p and miR-223-3p in platelet-derived lEVs. Treatment with lEVs from LPS- or thrombin-activated platelets reduces the migration of endothelial cells in vitro. These results suggest that permanent atrial fibrillation is associated with increased levels of platelet-derived lEVs in the LAA, which are potentially involved in LAA thrombus formation.

scholarly journals Double-blind, placebo-controlled randomised clinical trial to evaluate the effect of ASPIRIN discontinuation after left atrial appendage occlusion in atrial fibrillation: protocol of the ASPIRIN LAAO trial

BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e044695
Author(s):  
Mu Chen ◽  
Qunshan Wang ◽  
Jian Sun ◽  
Peng-Pai Zhang ◽  
Wei Li ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Ethics Committee ◽  
Aspirin Therapy ◽  
Atrial Appendage ◽  
Control Group ◽  
Coronary Syndrome ◽  
Left Atrial Appendage Occlusion ◽  
Increased Risk

IntroductionIt is the common clinical practice to prescribe indefinite aspirin for patients with non-valvular atrial fibrillation (NVAF) post left atrial appendage occlusion (LAAO). However, aspirin as a primary prevention strategy for cardiovascular diseases has recently been challenged due to increased risk of bleeding. Therefore, aspirin discontinuation after LAAO in atrial fibrillation (ASPIRIN LAAO) trial is designed to assess the uncertainty about the risks and benefits of discontinuing aspirin therapy at 6 months postimplantation with a Watchman LAAO device in NVAF patients.Methods and analysisThe ASPIRIN LAAO study is a prospective, multicentre, randomised, double-blinded, placebo-controlled non-inferiority trial. Patients implanted with a Watchman device within 6 months prior to enrollment and without pre-existing conditions requiring long-term aspirin therapy according to current guidelines are eligible for participating the trial. Subjects will be randomised in a 1:1 allocation ratio to either the Aspirin group (aspirin 100 mg/day) or the control group (placebo) at 6 months postimplantation. A total of 1120 subjects will be enrolled from 12 investigational sites in China. The primary composite endpoint is stroke, systemic embolism, cardiovascular/unexplained death, major bleeding, acute coronary syndrome and coronary or periphery artery disease requiring revascularisation at 24 months. Follow-up visits are scheduled at 6 and 12 months and then every 12 months until 24 months after the last patient recruitment.Ethics and disseminationEthics approval was obtained from the Ethics Committee of Xinhua Hospital, Shanghai, China (reference number XHEC-C-2018-065-5). The protocol is also submitted and approved by the institutional Ethics Committee at each participating centre. Results are expected in 2024 and will be disseminated through peer-reviewed journals and presentations at national and international conferences.Trial registration numberNCT03821883.

Abstract 18516: Regional Dysfunction of Left Atrial Appendage and its Association with Stroke in Atrial Fibrillation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Abdullah A Alissa ◽  
Yuko Inoue ◽  
Jochen Cammin ◽  
Qiulin Tang ◽  
Elliot Fishman ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Atrial Appendage ◽  
Control Group ◽  
Prior History ◽  
Area Change ◽  
Increased Risk ◽  
History Of ◽  
Regional Dysfunction

Background: Atrial Fibrillation (AF) is associated with an increased risk of cardioembolic stroke. Previous studies demonstrate that the Left atrial appendage (LAA) is the most common site of intracardiac thrombus, and the LAA morphology alone may determine the risk of stroke. We aimed to determine the association between LAA regional dysfunction using novel, noninvasive, image-based motion-estimation CT (iME) and prior history of stroke in patients with AF. Methods: Among the patients with history of AF referred for ablation who underwent pre-ablation CT with retrospective ECG gating, we identified 18 patients with a prior history of stroke or TIA, and 18 age- and gender-matched controls. The patients in AF at the time of CT were excluded. Four-dimensional motion vector field was estimated from reconstructed CT images using iME at every 5% RR interval. To assess myocardial deformation, area change ratio and area change rate were calculated over the endocardial surface of the LA and LAA. Univariate and multivariate comparisons were made by using binary logistic regression model. Results: A total of 36 patients (mean age 67.6 ± 8.1 years, 66.7% male, 16.7% persistent AF) were included in the study. Univariate analysis showed that the LA pre-atrial contraction area change ratio and LAA maximum area change ratio were significantly lower (P= 0.02 and 0.04, respectively) in the stroke/TIA group compared to the control group. These changes remained statistically significant in multivariate analysis (P=0.03 and 0.04, respectively) after adjusting for age, sex, body mass index, LV ejection fraction, type of AF, and CHADS score. Conclusions: LAA regional dysfunction is associated with stroke/TIA in patients with AF. LAA regional dysfunction detected by iME could represent a marker for stroke and a possible therapeutic target.

P4731Procedure-related acute thrombosis after surgical left atrial appendage occlusion for atrial fibrillation

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Inoue ◽  
T Shimizu ◽  
A Yoshimoto ◽  
Y Suematsu
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Cardiac Ct ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Atrial Appendage ◽  
Full Cohort ◽  
Exact Test ◽  
Acute Thrombosis ◽  
Laa Closure

Abstract Background/Introduction Left atrial appendage (LAA) occlusion is an effective strategy for thromboembolism prevention in patients with atrial fibrillation (AF), and the novel methods of occlusion is various. The acute thrombosis after percutaneous LAA occlusion devices has been recently reported, but thrombus formation after surgical LAA occlusion is still unclear. Purpose This study aimed to analyse the incidence and prognosis of thrombus formation on closure stump line in patients with AF who underwent surgical LAA occlusion. Methods This study retrospectively analised the data from patients treated with two methods of surgical LAA closure, resection or clipping, from January 2014 to November 2018. Results A total of 187 consecutive patients with AF underwent surgical LAA closure (31 clipping and 156 stapler resection). 170 patients (91%) underwent cardiac CT for LAA imaging on postoperative day 2. The incidence of acute procedure-related thrombus formation in full cohort was 19% (35 cases). The incidence of acute thrombus in patients with clipping and resection was 19% and 16%, respectively (Fisher's exact test, p=0.8). All of 35 patients who had thrombus on LAA closure stump line underwent cardiac CT again 3 months after the primary CT. In all patients with secondary cardiac CT, thrombus on LAA closure stump line disappeared. No symptomatic thromboembolism occurred during the follow-up from operation to secondary CT scan. Conclusion(s) Thrombus formation on stump after surgical LAA closure may often occur on acute phase. The optimal LAA imaging and anti-coagulation therapy after surgical LAA occlusion will prevent patients with acute thrombus from thromboembolism.

scholarly journals Diagnosis and Management of Left Atrium Appendage Thrombosis in Atrial Fibrillation Patients Undergoing Cardioversion

Medicina ◽  
2019 ◽  
Vol 55 (9) ◽  
pp. 511 ◽  
Author(s):  
Enrico Melillo ◽  
Giuseppe Palmiero ◽  
Adele Ferro ◽  
Paola Elvira Mocavero ◽  
Vittorio Monda ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Rhythm Control ◽  
Atrial Appendage ◽  
Thromboembolic Complications ◽  
Left Atrial Appendage Thrombus ◽  
Increased Risk ◽  
Pharmacological Cardioversion

Atrial fibrillation is the most common cardiac arrhythmia and is associated with an increased risk of stroke and thromboembolic complications. A rhythm control strategy with both electrical and pharmacological cardioversion is recommended for patients with symptomatic atrial fibrillation. Anticoagulant therapy for 3–4 weeks prior to cardioversion is recommended in order to avoid thromboembolic events deriving from restoring sinus rhythm. Transesophageal echocardiography has a pivotal role in this setting, excluding the presence of left atrial appendage thrombus before cardioversion. The aim of this review is to discuss the epidemiology and risk factors for left atrial appendage thrombosis, the role of echocardiography in the decision making before cardioversion, and the efficacy of different anticoagulant regimens on the detection and treatment of left atrial appendage thrombosis.

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