Characteristics of Anatomy and Function of the Left Atrial Appendage and Their Relationships in Patients with Cardioembolic Stroke: A 3-Dimensional Transesophageal Echocardiography Study

Study on the correlation between false-positive filling defect in LAA CT and LAA structure in patients with atrial fibrillation based on TEE

OBJECTIVE

This study aims to explore the actual meaning of "false positive filling defect" in left atrial appendage (LAA) computed tomography (CT) in patients with atrial fibrillation (AF), with transesophageal echocardiography (TEE) as the gold standard.

METHODS

Patients with AF undergoing cardiac CT angiography and TEE examinations for proposed radiofrequency catheter ablation between October 2020 and October 2021 were selected as the study subjects. Transesophageal echocardiography was taken as the "gold standard," and spontaneous echocardiographic contrast (SEC) and thrombus events were defined as positive events. The CT manifestations were classified into three groups (true positive, false positive, and true negative) to evaluate the differences in left atrium (LA) anterior-posterior diameter (LAAP), LA anterior wall thickness, and LAA orifice long diameter and short diameter, area, and depth between the three groups.

RESULTS

(1) There was no statistical difference in LA anterior wall thickness between the three groups (p > .05); there was a statistical difference in LAAP (only) between the true-positive group and the true-negative group (p < .05). (2) There was a statistical difference in LAA orifice long diameter, short diameter, and area between the true-positive group and the true-negative group as well as between the false-positive group and the true-negative group (p < .05). (3) There was a statistical difference in LAA depth between the true-positive group and the false-positive group as well as between the true-positive group and the true-negative group (p < .05). (4) The area under the receiver operator characteristic curve (AUC) of LAA depth affecting the LAA thrombus and SEC was 0.863 (confidence interval = 0.718-1.000), the sensitivity was 77.8%, and the specificity was 90.6% for predicting the occurrence of LAA thrombus and SEC in patients with nonvalvular AF (NVAF) and an LAA depth of ≥50.84 mm.

CONCLUSIONS

There was a difference in LAA diameter between the TEE-based CT false-positive group and the other groups. A "CT false positive" is an objectively existing state, and CT might be able to identify the LAA hemodynamic disorder earlier than TEE. Furthermore, a CT + TEE combined application could more accurately evaluate LAA hemodynamics in patients with AF.

Association Between Ischemic Stroke and Left Atrial Appendage Morphology in Patients With Atrial Fibrillation and Low CHA2DS2-VASc Scores

Background

Patients with atrial fibrillation are at risk for ischemic stroke, even with low CHA2DS2-VASc scores. The left atrial appendage is a known site of thrombus formation in individuals with atrial fibrillation.

Methods

We conducted a prospective study, enrolling patients with nonvalvular atrial fibrillation and CHA2DS2-VASc scores of 0 or 1. Patients were divided into groups based on left atrial appendage morphology (determined by computed tomography): the “chicken wing” group and the non–chicken wing group. We followed patients for more than 1 year to observe the incidence of stroke.

Results

Of 509 patients with a mean (SD) age of 48.9 (11.6) years; 332 (65.2%) were men. The chicken wing group had fewer left atrial appendage lobes, a lower left atrial appendage depth, and a smaller left atrial appendage orifice area (all P &lt; .001). During the follow-up period, 5 of the 133 patients (3.8%) in the chicken wing group and 56 of the 376 patients (14.9%) in the non–chicken wing group experienced ischemic stroke (P &lt; .001). The following findings were significantly associated with the incidence of stroke: left atrial appendage depth (hazard ratio [HR], 1.98; 95% CI, 1.67-3.12; P = .03), left atrial appendage orifice area (HR, 2.16; 95% CI, 1.59–3.13; P &lt; .001), and non–chicken wing left atrial appendage morphology (HR, 1.16; 95% CI, 1.10–1.23; P &lt; .001).

Conclusion

For patients with atrial fibrillation and a low CHA2DS2-VASc score, the non–chicken wing left atrial appendage morphology type is independently associated with ischemic stroke.

Abnormal P-wave terminal force in lead V1 is associated with low left atrial appendage ejection velocity

BACKGROUND

Sinus P-wave abnormalities have been associated stroke in people with atrial fibrillation (AF). The majority of AF-related strokes occur from left atrial appendage (LAA) thromboembolism. Dysfunction of the left atrium (LA) and left atrial appendage (LAA) can increase rates of thromboembolic stroke. We studied whether abnormal P wave terminal force in V1 (aPTFV1) is associated with decreased LAA ejection velocity (LAAV) on transesophageal echocardiography (TEE).

METHODS

We conducted a retrospective cross-sectional study reviewing patients at a tertiary care medical center who underwent TEE in sinus rhythm and had an interpretable sinus ECG within 12 months of TEE. Participants were excluded for complex congenital heart disease, age <18, cardiac transplantation, and chronic atrial pacing. Logistic regression analysis was used to estimate the odds ratios of LAAV<40 cm/s for aPTFV1.

RESULTS

In our final cohort of 169 patients (28% of which had LAAV <40), the multivariate odds ratio of aPTFV1 for LAAV<40 cm/s after adjustment for CHA₂DS₂VASc variables, heart rate during TEE, history of atrial arrhythmias, and left atrial volume index was 2.24 (95% CI of 1.13-6.00).

CONCLUSION

Abnromal P-wave terminal force in lead V1 is associated with low LAAV after adjustment for potential confounders. Future research is needed for validation of our findings and determination of clinical utility.

Left and right atrial appendage functional features as predictors for voltage-defined left atrial remodelling in patients with long-standing persistent atrial fibrillation

It was hypothesised that left atrial (LA) fibrosis identified by the presence of low-voltage areas (LVA) may influence the mechanical and electrical function of the left (LAA) and right (RAA) atrial appendage among the long-standing persistent atrial fibrillation (LSPAF) population. 140 consecutive patients underwent voltage mapping of LA with a multielectrode catheter following pulmonary vein isolation and restoration of sinus rhythm with cardioversion. Echocardiography determined LAA peak outflow and inflow velocities and intracardiac catheter-based mean LAA and RAA AF cycle length (AFCL) were obtained during AF before ablation. The impact of flow velocities and AFCL on the prevalence and location of LVA was further evaluated. LVA were detected in 54% of the patients. 14% of the patients presented severe global LVA burden > 20% of the total LA surface area. 29% of the patients presented a disseminated pattern of remodelling as 3 out of 5 LA segments were affected. LAA AFCL, RAA AFCL, LAA flow velocities did not predict the absolute presence of LVA. However LAA AFCL > 155 ms predicted disseminated LVA pattern and LAA AFCL > 165 ms severe LVA incidence. LAA AFCL > 155 ms was predictive for existence of LVA within antero-septal LA segments whilst LAA emptying velocity ≤ 0.2 m/s within lateral wall. Moreover RAA AFCL > 165 ms was strongly related to the presence of LAA AFCL > 15 ms and > 165 ms. LAA and RAA functional assessment was predictive of the presence of advanced stages of voltage-defined LA fibrosis and its regional distribution among LSPAF population.

Impact of left atrial appendage location on risk of thrombus formation in patients with atrial fibrillation

Most strokes in patients with atrial fibrillation (AF) are thought to arise from thrombus formation in the left atrial appendage (LAA). Assessing the hemodynamics in LAA and left atrium (LA) may provide some insights in the evaluation of the risk of thrombus formation. This study aims to find out the impact of different LAA locations with respect of LA on the risk of thrombus formation within LAA in patients with AF. Three different LAA locations at LA were modeled and a fully coupled fluid-structure interaction analysis was performed. A discrete phase method was used for particle residence analysis to evaluate risk of the thrombus formation. The results showed that LAA positions on the LA affected the LAA flow velocity distribution, passive contraction ability, and particle residence. In particular, the left pulmonary veins (PVs) had a greater influence on the LAA hemodynamics than the right PVs. The LAA had the lowest contractibility when it was located between left superior and left inferior PVs, and in this case, a larger number of particles were resided, which indicated a higher risk of thrombus formation. The present work provides a quantitative way to evaluate the risk of thrombus formation within LAA in patients with AF.

Morphological and functional parameters of left atrial appendage play a greater role in atrial fibrillation relapse after radiofrequency ablation

This study was to quantitatively investigate the role of morphological and functional parameters of the left atrium (LA) and left atrial appendage (LAA) with 256-slice spiral computed tomography (CT) in the recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA). Eighty-three patients with AF who underwent RFA for the first time were divided into the recurrence (n = 27) and non-recurrence (n = 56) groups. All patients underwent a 256-slice spiral CT examination before the operation. The clinical data and quantitative measurement of the morphology and functional parameters of the LA and LAA were analyzed, including the maximal and minimal volume, ejection fraction and volume, and volume strain of LAA and LA (LAAVmax, LAAVmin, LAAEF, LAAEV, and LAA-VS, LAVmax, LAVmin, LAEF, LAEV and LA-VS, respectively). The CHA2DS2-VASc score and the proportion of patients with heart failure were significantly (P < 0.05) higher in the recurrence than non-recurrence group. The LAAVmax, LAAVmin, LAVmax, LAVmin, LAAV and LAV were all significantly greater in the recurrence than non-recurrence group (P < 0.05), and the perimeter, major and minor axes of LAA orifice and LAA depth were also significantly greater in the recurrence than non-recurrence group. The LAAEF, LAEF and LAA-VS were significantly (P < 0.05) lower in the recurrence than non-recurrence group (P < 0.05). Heart failure, CHA2DS2-VASC score, LAEF, LAV, LAAEF and LAA-VS were univariately significant (P < 0.05) risk factors for AF recurrence after ablation. Multivariate analysis revealed LAAEF (HR: 0.790, 95% CI: 0.657–0.950, P = 0.012) and LAAV (HR: 1.160, 95% CI: 1.095–1.229, P <0.001) to be two significant independent predictors of recurrence. ROC curve analysis showed that LAAEF <44.68% had the highest predictive value for recurrence after radiofrequency ablation, with the sensitivity of 90% and specificity of 67.4%, whereas LAA volume >9.25 ml had the highest predictive value for AF recurrence after RFA, with the sensitivity of 85.2% and specificity of 67.9%. In conclusion, the volume of left atrium, volume and morphology of left atrial appendage have all significantly increased while the ejection fraction and volume strain of left atrium and left atrial appendage have both significantly decreased in recurrence than in non-recurrence after radiofrequency ablation. The ejection fraction and volume of left atrial appendage are significant independent predictors of atrial fibrillation recurrence after radiofrequency ablation.

Correlation between LAA Morphological Features and Computational Fluid Dynamics Analysis for Non-Valvular Atrial Fibrillation Patients

The left atrial appendage (LAA) is a complex cardiovascular structure which can yield to thrombi formation in patients with non-valvular atrial fibrillation (AF). The study of LAA fluid dynamics together with morphological features should be investigated in order to evaluate the possible connection of geometrical and hemodynamics indices with the stroke risk. To reach this goal, we conducted a morphological analysis of four different LAA shapes considering their variation during the cardiac cycle and computational fluid dynamics (CFD) simulations in AF conditions were carried out. The analysis of main geometrical LAA parameters showed a huger ostium and a reduced motility for the cauliflower and cactus shapes, as well as a lower velocity values from the CFD analysis. Such findings are in line with literature and highlight the importance of coupling dynamics imaging data with CFD calculations for providing information not available at clinical level.

Left atrial cross-sectional area is a novel measure of atrial shape associated with cardioembolic strokes

OBJECTIVE

Cardioembolic (CE) stroke carries significant morbidity and mortality. Left atrial (LA) size has been associated with CE risk. We hypothesised that differential LA remodelling impacts on pathophysiological mechanism of major CE strokes.

METHODS

A cohort of consecutive patients hospitalised with ischaemic stroke, classified into CE versus non-CE strokes using the Causative Classification System for Ischaemic Stroke were enrolled. LA shape and remodelling was characterised by assessing differences in maximal LA cross-sectional area (LA-CSA) in a cohort of 40 prospectively recruited patients with ischaemic stroke using three-dimensional (3D) echocardiography. Flow velocity profiles were measured in spherical versus ellipsoidal in vitro models to determine if LA shape influences flow dynamics. Two-dimensional (2D) LA-CSA was subsequently derived from standard echocardiographic views and compared with 3D LA-CSA.

RESULTS

A total of 1023 patients with ischaemic stroke were included, 230 (22.5%) of them were classified as major CE. The mean age was 68±16 years, and 464 (45%) were women. The 2D calculated LA-CSA correlated strongly with the LA-CSA measured by 3D in both end-systole and end-diastole. In vitro flow models showed shape-related differences in mid-level flow velocity profiles. Increased LA-CSA was associated with major CE stroke (adjusted relative risk 1.10, 95% CI 1.04 to 1.16; p<0.001), independent of age, gender, atrial fibrillation, left ventricular ejection fraction and CHA₂DS₂-VASc score. Specifically, the inclusion of LA-CSA in a model with traditional risk factors for CE stroke resulted in significant improvement in model performance with the net reclassification improvement of 0.346 (95% CI 0.189 to 0.501; p=0.00001) and the integrated discrimination improvement of 0.013 (95% CI 0.003 to 0.024; p=0.0119).

CONCLUSIONS

LA-CSA is a marker of adverse LA shape associated with CE stroke, reflecting importance of differential LA remodelling, not simply LA size, in the mechanism of CE risk.

Vascular Landmark-Based Method for Highly Reproducible Measurement of Left Atrial Appendage Volume in Computed Tomography

BACKGROUND

Modern computed tomographic scanning can produce 4-dimensional images of the left atrial appendage (LAA). LAA function and morphology can then be measured, to plan interventions such as occlusion and to evaluate LAA flow for thrombogenic risk analysis. A current problem here is defining a reproducible boundary between the LAA and the left atrium.

METHODS

This study used retrospectively gated 4-dimensional computed tomographic data from 25 implantation and coronary artery imaging patients. In each patient, the LAA ostium was defined at multiple time points during the RR interval. To examine the reproducibility of the definition of the LAA ostium, 3 observers analyzed all time frames in each patient 3 times. Five nonconsecutive time frames from each patient were then compared using intraclass correlation coefficients to quantify the precision of the method across patients. The correlation of LAA volumes for each time frame of each patient was determined across the different observers (interobserver) and within each observer's own data sets (intraobserver).

RESULTS

The method was successful in 92% of patients. Two-way random-effect, absolute-agreement, single-measurement intraclass correlation coefficients for interobserver measurements were 0.984, 0.990, and 0.988, with intraobserver intraclass correlation coefficients of 0.989, 0.989, and 0.995. The intraclass correlation coefficient of all observations was 0.988.

CONCLUSIONS

Classification of the LAA ostium using a stepwise procedure identifying the coumadin ridge and 2 vascular landmarks in ECG-gated computed tomography provides a viable method of establishing a highly reproducible boundary between the atrium and LAA needed to obtain LAA metrics useful for procedure planning and measuring LAA function.

Simultaneous Functional and Morphological Assessment of Left Atrial Appendage by 3D Virtual Models

Purpose

The left atrial appendage (LAA) is responsible for thrombus formation in patients with atrial fibrillation. The evaluation of both LAA function and morphology is crucial for the patient characterization and the preprocedural planning of LAA closure intervention. Despite the availability of 3D imaging modalities, the current standard image analysis is based on manual delineation of the LAA contours on 2D views.

Methods

In this study, a comprehensive approach based on a full 3D analysis of the tomographic dataset by surface extraction and processing (3D-S) is presented. The proposed method allows extracting functional and morphologic information in the entire cardiac cycle by minimalizing manual user interaction. The proposed methodology has been validated on ten computer tomography datasets.

Results

The proposed 3D-S method was feasible in all cases. Reproducibility was improved with respect to the reference 2D manual procedure (2D-S) (coefficient of variation 2.9 vs. 4.1% for diastolic ostium area; 3.8 vs. 6.1% for systolic ostium area; 2.4 vs. 5.3% for diastolic LAA volume; 2.7 vs. 5.9% for systolic LAA volume; and 7.7 vs. 17.1% for LAA ejection fraction). No significant differences were found between 2D-S and 3D-S measurements.

Conclusions

In this study, we introduced a fully 3D approach for LAA characterization, allowing the simultaneous assessment of LAA function and geometry. The proposed approach could be used to improve the patient selection and the best sizing of the device for LAA closure and to allow a patient-specific 3D printing.

Anatomy and Physiologic Roles of the Left Atrial Appendage: Implications for Endocardial and Epicardial Device Closure

The left atrial appendage has been implicated as a major nidus for thrombus formation, particularly in atrial fibrillation. This discovery has prompted substantial interest in the development of left atrial appendage exclusion devices aimed at decreasing systemic thromboembolism risk. Its deceptively simple appearance belies the remarkable complexity that characterizes its anatomy and physiology. We highlight the key anatomic features and variations of the left atrial appendage as well as its relationships with surrounding structures. We also summarize crucial anatomic factors that should be taken into account by the interventional cardiologist when planning for or performing left atrial appendage exclusion procedures.

Relation of Left Atrial Appendage Morphology Determined by Computed Tomography to Prior Stroke or to Increased Risk of Stroke in Patients With Atrial Fibrillation

Left atrial appendage (LAA) morphology is considered to be associated with ischemic stroke, non-Chicken Wing LAA morphology increases the risk of thromboembolic events. However, existing classification of LAA morphology remains not well quantifiable and therefore may leave room for substantial subjective interpretation. This study aimed to assess interobserver and intraobserver agreements in LAA morphology and its real value in stroke prediction. A total of 2,264 atrial fibrillation patients who underwent computed tomography to explore the LAA anatomy were enrolled. All computed tomography images were given to 3 reviewers to judge the LAA morphology independently. A consensus between all 3 reviewers was only reached in 655 cases (28.9%). In which, 86 patients had previous stroke. Poor intraobserver consistency was observed between 2 times of reading in all the 3 reviewers (Kappa = 0.368, p = 0.014; Kappa = 0.350, p = 0.014; Kappa = 0.333, p = 0.015). Multivariate analysis showed that persistent atrial fibrillation (odds ratio [OR] 1.679; 95% confidence interval [CI] 1.031 to 2.736; p = 0.037), female gender (OR 1.761; 95% CI 1.037 to 2.994; p = 0.036) and age (OR 1.029; 95% CI 1.004 to 1.056; p = 0.025) were associated with previous stroke. LAA morphology was not associated with previous stroke and non-Chicken Wing LAA morphology did not increase the risk of stroke (OR 1.392; 95% CI 0.847 to 2.288; p = 0.192). In conclusion, high interobserver and intraobserver variabilities suggested that existing classification of LAA morphology was unreliable, the interpretation of the relation between LAA morphology and stroke needs caution.

Impact of low-voltage zones on the left atrial anterior wall on the reduction in the left atrial appendage flow velocity in persistent atrial fibrillation patients

BACKGROUND

The reduction in the left atrial appendage (LAA) flow velocity is related to the presence of emboli in atrial fibrillation (AF) patients. The LAA is located on the left superior side of the left atrial (LA) anterior wall, and we investigated the relationship between the reduction in the LAA flow velocity (LAAFV) and low voltage zones (LVZs < 0.5 mV) on the LA anterior wall.

METHODS

In 146 persistent AF patients, LAAFV measurements, by transesophageal echocardiography, and catheter ablation were performed. LA mapping was performed before ablation during sinus rhythm, and the locations of any anterior-LVZs were documented.

RESULTS

Eighty-one patients had a documented LVZ on the LA anterior wall, and those with an LVZ had a significantly lower LAAFV compared to those without (anterior-LVZ(+) vs. anterior-LVZ(-) = 26 ± 11 vs. 34 ± 10 cm/s, p < 0.001), while no significant difference was observed when compared to the other LVZ regions. A low-LAAFV (≦ 20 cm/s) was observed in 36 patients, and the CHADS₂-vasc score and existence of an anterior-LVZ were associated with a low-LAAFV. In patients with anterior-LVZs, the distance between the anterior-LVZ and LAA orifice correlated with a low LAAFV (r = 0.534, p < 0.001) as compared to the surface area of the anterior-LVZ (r = - 0.288, p = 0.009).

CONCLUSIONS

In persistent AF patients, an LVZ on the LA anterior wall was associated with a low LAAFV. In addition, an anterior-LVZ located near the LAA orifice was further related to a reduction in the LAAFV.

Multimodality imaging for thromboembolic risk assessment in atrial fibrillation

: Atrial fibrillation is the most widely represented sustained arrhythmia in the world. Thromboembolic risk assessment represents the main clinical challenge associated with this condition, requiring enormous medical, social and economical efforts. Several pieces of evidence in literature highlight how clinical risk factors are not enough for a correct thromboembolic risk stratification of patients with atrial fibrillation, since thromboembolic events have been proven to occur even in patients with low clinical risk scores. A comprehensive multimodality imaging approach, with special regard to echocardiography and new technologies seems to be the best method for this purpose. The aim of this review is to propose a hybrid thromboembolic risk stratification system that combinines clinical evaluation with instrumental clues on left atrial remodeling, fibrosis and deformation which, could be useful especially for patients classified at low thromboembolic risk according to clinical scores.

Anticoagulation efficacy of dabigatran etexilate for left atrial appendage thrombus in patients with atrial fibrillation by transthoracic and transesophageal echocardiography

To evaluate the anticoagulation efficacy of dabigatran etexilate for left atrial appendage (LAA) thrombus resolution in patients with atrial fibrillation by transthoracic echocardiography and transesophageal echocardiography, and to investigate the anticoagulation factors.A total of 58 atrial fibrillation patients with LAA thrombus in our hospital were enrolled. After dabigatran etexilate anticoagulation for 3 months, the patients were divided into the effective group and ineffective group according to dissolution of thrombosis. The baseline data and the left atrial diameter (LAD), left atrial ejection fraction (LAEF), left ventricular ejection fraction, LAA flow velocity (LAA-v), and LAA thrombus size before and after anticoagulation treatment were recorded, and the measurement index were statistically analyzed.After the patients received anticoagulation treatment for 3 months, 15 patients had complete dissolution, thrombus in 21 patients reduced significantly, and the complete dissolution rate was 25.9% (15/58), the effective rate of dissolution was 62.1% (36/58). Compared with the ineffective group, the proportion of persistent atrial fibrillation and LAD in effective group were lower than those in the ineffective group, the LAEF and LAA-v in the effective group were higher than those in the ineffective group, and the differences were statistically significant (P < .05). Multivariate logistic regression analysis on the baseline data and each ultrasound index showed that the type of atrial fibrillation, LAD, LAEF, and LAA-v were independently associated with the efficacy of anticoagulation (P < .05).Dabigatran etexilate is effective in dissolution of LAA thrombus in patients with atrial fibrillation, and the atrial fibrillation type, LAD, LAEF, and LAA-v are significantly related with the efficacy of anticoagulation.

Circulating Galectin-3 is Associated With Left Atrial Appendage Remodelling and Thrombus Formation in Patients With Atrial Fibrillation

BACKGROUND

Left atrial appendage (LAA) is gaining increasing attention in patients with atrial fibrillation (AF) in the context of cardioembolic stroke. Galectin-3 (Gal-3) is a mediator of profibrotic pathways and is associated with an increased incidence of heart failure. However, the role of Gal-3 in LAA remodelling and thrombus formation in AF has not been evaluated.

METHODS

This prospective study included 153 consecutive patients with paroxysmal (n=58), persistent (n=55) or permanent (n=40) nonvalvular AF. The serum level of Gal-3 was measured by enzyme-linked immunosorbent assay. The morphology and function of LAA were determined by transoesophageal echocardiography.

RESULTS

Left atrial appendage thrombus was observed in 22 patients (2 in paroxysmal AF, 11 in persistent AF and 9 in permanent AF). Significant differences among patients with different types of AF were found in terms of LAA morphology (orifice diameter and depth) and function (flow velocity and tissue Doppler contracting velocity) as well as serum levels of Gal-3. Furthermore, patients with persistent or permanent AF had higher levels of Gal-3. High Gal-3 level was closely related to LAA flow velocity and occurrence of LAA thrombus. Multivariate logistic regression analysis revealed that Gal-3 was an independent determinant of LAA thrombus in patients with AF. Receiver operating characteristic (ROC) curves related to LAA thrombus formation established a cut-off point for Gal-3 >18.95ng/ml.

CONCLUSIONS

Cardiac rhythm disturbances caused by AF may lead to morphologic and functional remodelling of LAA. The serum level of Gal-3 was significantly correlated with LAA remodelling in patients with AF. High levels of Gal-3 were also a predicator for LAA thrombus formation.

Evaluation of the left atrial appendage by real time three-dimensional transesophageal echocardiography online

OBJECTIVE

The objective of this study was to evaluate the feasibility of online real time three-dimensional transesophageal echocardiography (RT3DTEE) in the measurement of left atrial appendage (LAA) orifice size. We also analyzed the correlation between LAA ejection fraction (EF) and its peak empty velocity (PEV).

METHODS

There were 91 subjects enrolled in this study, with 46 patients with AF and 45 individuals with sinus rhythm (SR). RT3DTEE was performed by four methods including iSlice and iCrop online and QLAB software 3DQ and GI-3DQ off-line which were used to measure LAA orifice area, long diameter, short diameter, depth in the largest LAA, and number of LAA lobes. These LAA parameters achieved by the four methods were compared, respectively. GI-3DQ off-line was used to measure LAA end-diastolic and end-systolic volumes to calculate EF of LAA. Two-dimensional (2D) TEE was applied to measure PEV of LAA. The correlation between EF and PEV was analyzed.

RESULTS

There were no significant differences in all LAA parameters between any two RT3DTEE methods (All P > .05). There was a significant and positive correlation between PEV and EF (r = .423, P = .000). There were statistical differences in LAA EF and PEV between patients with AF and SR individuals (0.38 ± 0.12 vs 0.61 ± 0.07, 35.7 ± 12.1 vs 49.5 ± 10.0 cm/s, P = .000).

CONCLUSION

Using online RT3DTEE for measuring LAA orifice size is feasible, and online RT3DTEE is more convenient than offline RT3DTEE. EF is positively correlated with PEV. LAA function is significantly decreased in patients with AF.