# Computational Flow Dynamic Analysis in Left Atrial Appendage Thrombus Formation Risk: A Review
## 3 Discussion  
Abnormal electrical impulses in the roots of the pulmonary vein primarily cause AF. These impulses induce an uneven and inefficient contraction of the LA. This atypical contraction pattern promotes thrombus development in the LAA and is five times more prevalent in people with AF than in healthy patients [46; 54]. Although several clinical investigations have analyzed the correlation between LAA morphology and stroke risk in individuals with AF, the underlying mechanisms are still unclear. Current risk categorization approaches for patients are obtained from major clinical trials based on demographic and clinical characteristics such as age, sex, hypertension, and a history of thromboembolic \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Ref**} & \multicolumn{2}{c}{**Number of**} & \multirow{2}{*}{**Population**} & \multirow{2}{*}{**Summary**} & \multirow{2}{*}{**Outcomes Measured**} \\  & & & Characteristics & & \\ \hline \multirow{4}{*}{[52]} & \multirow{4}{*}{—} & \multirow{4}{*}{AF} & A discussion regarding how the LAA is a frequent location of thrombus formation in patients with AF is reported. It reviews how recent studies have suggested that it is crucial to incorporate LAA geometrical and hemodynamic features to evaluate the risk of thrombus formation in LAA. & \multirow{4}{*}{LAA-related factors associated with thrombus formation and cardiomembolic events} \\ \cline{1-1} \cline{5-5}  & & & The researchers selected a LA chamber model and created a framework to connect the different LAAs from the other four patients to this model. These new anatomical models formed the computational domain for the CFD study. CFD simulations were conducted to evaluate the relation between LAA shape and blood flow characteristics in atrial fibrillation (AF) conditions. & \multirow{4}{*}{Velocity} \\ \cline{1-1} \cline{5-5}  & & & The researchers selected a LA chamber model and created a framework to connect the different LAAs from the other four patients to this model. These new anatomical models formed the computational domain for the CFD study. CFD simulations were conducted to evaluate the relation between LAA shape and blood flow characteristics in atrial fibrillation (AF) conditions. & \multirow{4}{*}{Leadance Time} \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._  
Figure 2: Flow diagram of study selection. disease [14]. Since they are all non-patient-specific, their predictive value for a particular patient could be enhanced by incorporating mechanical or local patient-specific indicators, such as cardiac morphology or blood flow. Developments in medical imaging, including TEE, MRI, and 3D computed tomography (CT), have opened up the possibility of applying computational fluid dynamic (CFD) tools for the analysis of intracardiac flow. Early research on LA CFD was performed using complete left-heart simulations; hence, CFD analyses focusing on LAA are comparatively recent [55]. Few publications provide numerical analyses of flow patterns in the LA, with some including the LAA model. According to the literature, the chicken wing morphology is the least critical when compared to the other geometries, which reveals a link between the LAA morphology and the risk of clot formation [33; 35; 36; 46]. However, varied quantifications of the risks can be found in the literature depending on the population that was analyzed; thus, it is difficult to generalize the significance of this association [5; 49]. Notably, the Cauliflower shape appears to be related to an increased risk of thrombus formation [4; 35; 36]. Several clinical investigations suggested that the risk of stroke could be reduced by utilizing hemodynamic data on the LA and mainly on the LAA [22; 26; 36; 38; 46; 53; 56].