scholarly journals Anatomical Characteristics of the Left Atrium and Left Atrial Appendage in Relation to the Risk of Stroke in Patients with Versus without Atrial Fibrillation

2021 ◽  
Author(s):  
Jeff M. Smit ◽  
Judit Simon ◽  
Mohammed El Mahdiui ◽  
Lili Száraz ◽  
Philippe J. van Rosendael ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Suspected Coronary Artery Disease ◽  
Atrial Appendage ◽  
Volumetric Assessment ◽  
Study Population ◽  
Prior Stroke

Background - The left atrial appendage (LAA) has been regarded as an important source of cardiac thrombus formation and appears important in the contribution to thrombo-embolism in patients with atrial fibrillation (AF). Our aim was to evaluate the relationship between LAA morphology and previous stroke and/or transient ischemic attack (TIA) in two large and distinct patient cohorts with and without known AF. Methods - The study population consisted of patients with and without drug-refractory AF who underwent computed tomography (CT) prior to transcatheter AF ablation, or clinically indicated for suspected coronary artery disease (CAD). The CT data were used for volumetric assessment of the left atrium (LA) and LAA and to determine LAA morphology. The LAA was classified by 3 readers in consensus as chicken wing, swan, cauliflower or windsock, based on predefined morphology classification criteria. Results - In total, 1813 patients (mean age 59 ± 11 years, 42% female) who underwent CT were included in this analysis (908 patients with AF and 905 patients without known AF). Swan LAA morphology was independently associated with prior stroke/TIA in the overall study population (OR 3.40, P <0.001), and in patients with (OR 2.88, P = 0.012) and without known AF (OR 3.96, P = 0.011). Conclusions - Swan morphology of the LAA is independently associated with prior stroke and/or TIA in patients with known AF, as well as in patients not previously diagnosed with AF.

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 Left atrial appendage velocity as an instrument of predicting atrial fibrillation recurrence after successful catheter ablation – a useful tool?

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J Grade Santos ◽  
K Budzak ◽  
J Simoes ◽  
M Martinho ◽  
B Ferreira ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrium ◽  
Linear Correlation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Atrial Appendage ◽  
Af Ablation ◽  
Volumetric Assessment

Abstract Introduction Catheter ablation for the treatment of Atrial Fibrillation (AF) is a modality of treatment in growing expansion. However the sustained long term response in preventing AF recurrence is poor for most patients, namely in those with a dilated left atrium. Purpose Our aim was to assess the utility of an echocardiographic parameter for left atrium function, the left atrial appendage velocity (LAAV), in predicting recurrences after catheter ablation. Methods We performed a 9 year retrospective analysis of all patients who underwent a successful catheter ablation for the treatment of atrial fibrillation and had a valid pre-procedural transesophagic echocardiogram in a single expert centre. Medical records were analysed for demographic, procedural data and outcomes. Results Seventy-three (73) patients fulfilled all inclusion criteria and were analysed. The mean age was 62±11 with a male preponderance (58,7%). The majority of patients (82,7%) had preserved left ventricle ejection fraction. Only 46% of patient had a volumetric assessment of the left atrium dimensions prior to ablation, with slight, moderate and severe dilation of the left atrium in 20%; 8,6% and 28,6% of patients. Of the patients subjected to an AF ablation the average LAAV was 50,6±19 cm/s, with 78% of patients with normal atrial appendage velocities. Patients with low LAAV (&lt;40cm/s) had a higher proportion of AF recurrences at 3 and 6 months (58,3 vs 12,8% and 89% vs 21,7%; p&lt;0,05 for all) with a linear correlation between the presence of recurrences and LAAV (LAAV of 39,1 vs 57,5 cm/s; p&lt;0,05 OR 0,91 (CI 95% = 0,85–0,97); r2=0,34 at 3 months and LAAV of 43,5 vs 59 cm/s; p=0,01; OR 0,94 (CI 95% = 0,89–0,99); r2=0,24 at 6 months respectively). There was a trend towards association with recurrences at 1 year although it did not reach statistical significance. There was no significant difference in the use of antiarritmic drugs, either prior or post ablation, in both groups. It was not possible to assess the additive predictive value to the left atrium dimensions due to the low percentage of volumetric assessment of left atrium prior to AF ablation. Conclusions Patients with low left atrial appendage velocities had a lower long term success rate of catheter ablation, with higher rates of recurrence at 3 and 6 months and a trend towards higher recurrences at 1 year, with linear correlation which hypothesises the use of the left atrial appendage velocity as novel predictive parameter for an integrative model. FUNDunding Acknowledgement Type of funding sources: None.

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.

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.

A Stunning Left Atrial Appendage Thrombus

Cardiology ◽  
2016 ◽  
Vol 134 (4) ◽  
pp. 394-397
Author(s):  
Sajid Ali ◽  
Justin Ugwu ◽  
Yousuf Kanjwal
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Atrial Flutter ◽  
Pulmonary Vein ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Atrial Appendage ◽  
Transesophageal Echocardiogram ◽  
Left Atrial Appendage Thrombus

Background: Left atrial appendage thrombus formation is a known major complication of atrial fibrillation and atrial flutter which increases the risk of embolism and stroke. This risk of thrombosis is greatly increased with a lack of anticoagulation. After conversion to a normal sinus rhythm in these arrhythmias, the risk of thrombus formation in the left atrium persists through a phenomenon termed atrial myocardial stunning. Case: We present the case of a patient who previously underwent successful pulmonary vein isolation and was found to be in typical isthmus-dependent atrial flutter with a questionable recurrence of atrial fibrillation. The decision was made to return for atrial flutter ablation and for evaluation of prior pulmonary vein isolation. Initially, a transesophageal echocardiogram showed a normal ejection fraction, biatrial enlargement and no left atrial appendage thrombus. Ablation of the cavotricuspid isthmus was successfully accomplished with documented bidirectional block. A transesophageal echocardiogram probe was still in place prior to planned transseptal puncture for the evaluation of pulmonary veins. A large thrombus was now observed filling the left atrial appendage. Conclusion and Objective: Atrial stunning is a transient atrial contractile dysfunction that occurs whether sinus rhythm is restored spontaneously, electrically, pharmacologically or by ablation. We know after conversion that there is higher propensity to increased spontaneous echogenic contrast and decreased velocities; however, we do not have documented knowledge of exactly how soon after the conversion to a sinus rhythm a thrombus may be seen. We demonstrate a case of acute left atrial appendage thrombus formation immediately following the successful ablation of isthmus-dependent atrial flutter. Our report validates the belief that strategies of not interrupting anticoagulation prior to the conversion of these arrhythmias should be implemented.

scholarly journals Atrial Fibrillation Increases Production of Superoxide by the Left Atrium and Left Atrial Appendage

Circulation ◽  
2005 ◽  
Vol 112 (9) ◽  
pp. 1266-1273 ◽  
Author(s):  
Samuel C. Dudley ◽  
Nyssa E. Hoch ◽  
Louise A. McCann ◽  
Clegg Honeycutt ◽  
Laura Diamandopoulos ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Atrial Appendage

scholarly journals Inhibition of renin-angiotensin axis reduces the risk of thrombus formation in the left atrial appendage in patients with hypertension complicated by atrial fibrillation

2018 ◽  
Vol 19 (2) ◽  
pp. 147032031878262 ◽  
Author(s):  
Ya Suo ◽  
Zhiwei Zhang ◽  
Huaying Fu ◽  
Yue Zhang ◽  
Meng Yuan ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Thrombus Formation ◽  
Atrial Appendage ◽  
Renin Angiotensin ◽  
Echocardiographic Parameters ◽  
Hemostatic Markers ◽  
Ras Inhibitors

Aims: We examined whether the use of a renin-angiotensin-aldosterone system (RAS) inhibitor plays a role in protecting against left atrial appendage thrombus (LAAT) in patients with hypertension complicated by atrial fibrillation (AF). Methods: Two observational studies were conducted on patients with diagnoses of hypertension and AF, who were categorized into RAS inhibitor user or nonuser groups. Demographic characteristics, clinical characteristics, echocardiographic parameters and hemostatic markers were examined and the occurrence of LAAT during follow-up were recorded. Results: In the first study ( n = 131), LA peak systolic strain and LAA emptying flow velocity (LAA eV) were significantly increased in patients on RAS inhibitors compared with the nonuser group ( p < 0.05). Lower D-dimer and fibrinogen levels were observed in patients on RAS inhibitors ( p < 0.05). In the second study ( n = 99), 25.9% ( n = 11) of patients on RAS inhibitors developed LAAT, compared with 46.7% ( n = 21) in the nonuser group ( p < 0.05). After controlling for risk factors related to LAAT, use of RAS inhibitors remained associated with a significantly lower risk of developing LAAT (HR, 0.406; 95% CI, 0.191–0.862; p = 0.019). Conclusions: RAS inhibitors use was associated with a significant reduction in the risk of LAAT in patients with hypertension and AF.

scholarly journals Combined Catheter Ablation and Left Atrial Appendage Closure in Atrial Fibrillation Patients with and without Prior Stroke

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Bin-Feng Mo ◽  
Rui Zhang ◽  
Jia-Li Yuan ◽  
Jian Sun ◽  
Peng-Pai Zhang ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Atrial Appendage ◽  
Control Group ◽  
Left Atrial Appendage Closure ◽  
Combined Procedure ◽  
Stroke Group ◽  
Prior Stroke

Background. Combined atrial fibrillation (AF) ablation and left atrial appendage closure (LAAC) has been practiced for management of both the symptoms and the high stroke risk of AF. Data of the combined procedure in selected patients with prior stroke are limited. The aim of this study is to compare the safety and efficacy of combined catheter ablation and LAAC between AF patients with and without prior stroke. Methods and Results. This retrospective study enrolled 296 patients who underwent combined procedures of AF ablation and LAAC. Patients were divided into two groups: 81 patients with prior stroke (Stroke group) and 215 patients without prior stroke (Control group). Combined procedures were successfully performed in all the patients. Patients in the Stroke group had higher CHA2DS2-VASc scores (4.9 ± 1.2 vs. 3.2 ± 1.0, P < 0.001 ) and higher HAS-BLED scores (3.5 ± 1.1 vs. 3.0 ± 1.0, P < 0.001 ) compared with those in the Control group. Procedure-related complications in the Stroke group included two pericardial effusions and two groin hematomas, which did not differ significantly fromthe Control group (4.9% vs. 4.2%, P = 0.778 ). After a mean follow-up of 20 months, the AF-free rate of the Stroke group was comparable with that of the Control group (64.2% vs. 68.4%, P = 0.495 ). The relative risk reductions in stroke and bleeding (observed rate compared to that predicted from the CHA2DS2-VASc and HAS-BLED scores) were 80% and 79%, respectively, in the Stroke group, and 62% and 62%, respectively, in the Control group. Conclusions. The combination of catheter ablation and LAAC is safe and efficient in selected AF patients with prior stroke. It was observed that patients with prior stroke may benefit more from risk reductions of stroke and bleeding following the combined procedure.

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