A Proof of Concept for Computational Fluid Dynamic Analysis of the Left Atrium in Atrial Fibrillation on a Patient-Specific Basis

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Alessandro Masci ◽  
Martino Alessandrini ◽  
Davide Forti ◽  
Filippo Menghini ◽  
Luca Dedé ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Risk Stratification ◽  
Left Atrium ◽  
Stroke Risk ◽  
Fluid Dynamic ◽  
Blood Stasis ◽  
Patient Specific ◽  
Computational Fluid Dynamic Analysis ◽  
Cerebrovascular Events ◽  
Hemodynamic Information

Abstract Atrial fibrillation (AF) is associated with a fivefold increase in the risk of cerebrovascular events, being responsible of 15–18% of all strokes. The morphological and functional remodeling of the left atrium (LA) caused by AF favors blood stasis and, consequently, stroke risk. In this context, several clinical studies suggest that the stroke risk stratification could be improved by using hemodynamic information on the LA and the left atrial appendage (LAA). The goal of this study was to develop a personalized computational fluid dynamics (CFD) model of the LA which could clarify the hemodynamic implications of AF on a patient-specific basis. In this paper, we present the developed model and its application to two AF patients as a preliminary advancement toward an optimized stroke risk stratification pipeline.

Abstract WP333: A Simplified Score to Predict Stroke Risk in Nonvalvular Atrial Fibrillation

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Clare T Garrard ◽  
Mahesh Amin ◽  
Abdul H Hakki
Keyword(s):  
Risk Factors ◽  
Atrial Fibrillation ◽  
Stroke Risk ◽  
Predictive Accuracy ◽  
Myocardial Infarct ◽  
Female Gender ◽  
Arterial Disease ◽  
Nonvalvular Atrial Fibrillation ◽  
Aortic Plaque ◽  
Cerebrovascular Events

The widely used CHADS2 score has been validated to predict the annual stroke risk (SR) in patients with non-valvular atrial fibrillation (AF). The CHA2DS2-VASc score incorporates 5 more risk factors including female gender, age 65 to 74 years, and peripheral arterial disease (PAD), prior myocardial infarct or aortic plaque. The two schemes have different SR and require separate tables to calculate SR (Table 1) . Table 1 An acronym (AFIB)2S4 + PaF2 (Table 2) is presented to predict SR that increases with higher scores, simplifies memorization of the score, incorporates all known risk factors and more accurately predicts SR without the use of tables. Table 2 The SR per 100 patient-years is calculated by adding (AFIB)2S4 + PaF2 scores. For example if all are positive including age 75 years then the SR is 15%, while if all are negative, including age <65 and male gender, then the SR is 0. To determine the predictive accuracy of the three scores, we reviewed the records of 100 consecutive patients admitted with acute cerebrovascular events and AF. The results showed 83% would have been classified as moderate to high risk (score>1) by CHADS2 , 95% by CHA2DS2-VASc , and 99% by (AFIB)2S4 + PaF2. (P <0.012). Conclusion: Compared to the CHADS2 , and CHA2DS2-VASc , (AFIB)2S4 + PaF2 more accurately predicts risk of acute cerebrovascular events in patients with AF. It is easy to remember and does not require the use of tables to assess SR in AF. Further studies are needed for validation. PEN ©

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 Validation of a Modified CHA 2 DS 2 -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Stroke ◽  
2016 ◽  
Vol 47 (10) ◽  
pp. 2462-2469 ◽  
Author(s):  
Tze-Fan Chao ◽  
Gregory Y.H. Lip ◽  
Chia-Jen Liu ◽  
Ta-Chuan Tuan ◽  
Su-Jung Chen ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Risk Stratification ◽  
Stroke Risk ◽  
Asian Patients

Non valvular atrial fibrillation stroke risk stratification by CHA2DS2-VASc score and short term outcomes

2016 ◽  
pp. 3370-3375
Author(s):  
Madhuri Pandharipande ◽  
Shivraj Shinde ◽  
Mrinalini Motlag ◽  
Keshav Nagpure ◽  
Rakhi Joshi ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Risk Stratification ◽  
Stroke Risk ◽  
Short Term
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