Left Atrial Appendage Ejection Fraction Research Articles

Morphometrical features of left atrial appendage in the atrial fibrillation patients subjected to left atrial appendage closure.

This study aimed to evaluate the morphometrical features of left atrial appendage (LAA) in patients with atrial fibrillation, subjected to LAA percutaneous closure (LARIAT) for stroke prevention. Computed tomography (CT) scans of 51 patients with atrial fibrillation subjected to LARIAT procedure were comparatively evaluated with 50 patients with sinus rhythm (control group). Three-dimensional reconstructions were created using volume-rendering for evaluation. No differences were found in LAA types of distribution (cauliflower: 25.5 vs. 34.0%, chicken wing: 45.1 vs. 46.0%, arrowhead: 29.4 vs. 20.0%, all p > 0.05) between groups. However, the study group was characterized by LAAs with a lower number of lobes. The LAA orifice anteroposterior and transverse diameters (19.3 ± 4.12 vs. 17.2 ± 4.0 mm, p = 0.01 and 25.1 ± 5.1 vs. 20.5 ± ± 4.4 mm, p = 0.001), orifice area (387.2 ± 133.9 vs. 327.1 ± 128.3 mm2, p = 0.02) and orifice perimeter (70.2 ± 12.5 vs. 61.2 ± 11.6 mm, p = 0.04) was significantly larger in atrial fibrillation patients. More oval LAA orifices was found in atrial fibrillation group (94.0 vs. 70.4%, p = 0.001). No statistically significant differences were found in LAA body length (47.4 ± 15.4 vs. 43.7 ± 10.9 mm, p = 0.17), body width (24.7 ± 5.6 vs. 24.4 ± 5.8 mm, p = 0.81), and chamber depth (17.7 ± 3.5 vs. 16.5 ± 3.8 mm, p = 0.11). Calculated LAA ejection fraction was significantly lower in study group compared to healthy patients (16.4 ± 14.9 vs. 48.2 ± 12.9%, p = 0.001). Important morphometrical differences in LAA orifice have been found, which was significantly larger and more oval in patients with atrial fibrillation compared to healthy controls. Although no difference in LAA body type and size was observed; the LAA ejection fraction was significantly lower in atrial fibrillation rhythm patients.

Invasively diagnosed HFpEF in AF associated with functional remodelling of the left atrial appendage: implications for stroke risk

Abstract Background HFpEF commonly coexists with atrial fibrillation (AF). The influence of coexisting HFpEF on function of the left atrial appendage (LAA) and risk of stroke remains unknown. Objective To use invasive hemodynamic assessment and multi-modality imaging to evaluate the influence of underlying HFpEF on LAA function in patients with symptomatic AF. Methods Patients with AF and preserved ejection fraction undergoing AF ablation were prospectively recruited. All participants underwent invasive diagnosis of HFpEF using established hemodynamic criteria. Participants were classified as ‘HFpEF’ when mean left atrial pressure (mLAP) was >15mmHg and ‘early HFpEF’ when mLAP rose to above 15mmHG after infusion of 500mls saline. For LAA assessment, participants underwent 1) contrast-enhanced cardiac CT to evaluate LAA volume, 2) transesophageal echocardiography to investigate emptying velocities (LAAEV), filling velocities (LAAFV) and LAA ejection fraction (LAAEF) and 3) high-density electroanatomic mapping to assess LAA bipolar voltages. Results Of 115 participants recruited, 55 had ‘HFpEF’, whilst 29 had ‘early HFpEF’ and 31 had ‘no HFpEF’. Table 1 demonstrates the baseline characteristics and LAA structural and functional parameters across the three groups. The HFpEF group was characterized by higher BMI (p=0.008) and higher prevalence of hypertension (p=0.023) but there was no significant difference in age (p=0.194) or gender (p=0.376). LAA volume was not significantly different across the three groups (p=0.509). However, the HFpEF group demonstrated reduced LAAEV (p=0.021) and LAAFV (p=0.015) compared to early HFpEF and no HFpEF. HFpEF was also associated with reduced LAAEF (p=0.015) and reduced LAA bipolar voltages in sinus rhythm (p=0.028) compared to no HFpEF. In a multivariable analysis HFpEF group was the only independent predictor of reduced LAAEV (p=0.015). Conclusions Invasively diagnosed HFpEF in AF is common and associated with significantly reduced LAA function. The coexistence of HFpEF may therefore be a determinant of future stroke risk in patients with AF.

Abstract 15625: Left Atrial Appendage Volumetric and Functional Assessment Using Cardiac CT-Derived Three-Dimensional Models

Introduction: The left atrial appendage (LAA) is the most common site of thrombus formation in atrial fibrillation (AF) patients who develop strokes, yet its dynamic volumetric parameters remain uncharacterized. We present a quantitative analysis of cardiac phase-specific LAA volumes and function using cardiac CT-derived three-dimensional (3D) models of 920 LAA segmentations. Methods: We measured LAA volumes at 10% increments of the cardiac cycle (R-R interval) in patients with AF and controls with sinus rhythm (SR). After identifying the LAA orifice using anatomical landmarks on multiplanar CT images, we performed computational LAA segmentation using specialized software. For precise mapping, we used iterative active region-growing and cutting tools to separate the LAA from surrounding structures. We used the resulting 3D model for volumetric assessment of the LAA during the cardiac cycle. Results: We analysed 580 LAA segmentations in patients with AF and 340 segmentations in patients with SR. Both groups displayed LAA volume increase from 0 to 40% of the cardiac cycle followed by a gradual decrease during diastole. LAA volumes were significantly higher in AF at 0%, 10%, 70%, 80%, and 90% of the cardiac cycle (p =0.01, 0.021, 0.047, 0.025 and 0.011, respectively). LAA volumetric variance within the AF group was significantly greater (p<0.001). LAA ejection fraction was significantly lower in AF compared to SR (40.8±16.1% vs 49.7±12.6%, p=0.003). Polynomial plots of incremental volume changes showed an accelerated rate of LAA filling in early systole in the SR, which was significantly dampened in AF. Conclusions: We present the first comparative analysis of LAA volumetric and functional assessment in patients with AF and SR. We conclude that impaired LAA filling and emptying in AF can contribute to blood stasis and thrombogenicity. Further investigations into the utility of LAA metrics as prognostic and risk-stratification tools in patients with AF are warranted.

Left atrial appendage angiography for stroke risk prediction in patients with atrial fibrillation.

The current risk stratification schemes for stroke in patients with atrial fibrillation (AF) are insufficient for an accurate assessment of stroke risk. This study evaluates the association between the mechanical function of the left atrial appendage (LAA), as assessed by angiography, and the risk of stroke. We conducted a cross-sectional study to assess the mechanical function of the LAA by measuring the left atrial appendage ejection fraction (LAAEF) and grading the contrast retention (CR) using angiography. A total of 746 patients referred for a left atrial appendage occlusion (LAAO) procedure with (n=151; stroke group) or without (n=595; control group) a history of stroke were included in the analysis. LAAEF was significantly lower (14% [9-19] vs 20% [12-33]; p<0.001) and grade 3 CR was more common (66.9% vs 33.9%; p<0.001) in patients with a history of stroke. Multivariable analysis showed that CR was independently associated with stroke in patients with AF (grade 2 vs grade 1=7.29; 95% confidence interval [CI]: 2.84-21.65; p<0.001; grade 3 vs grade 1=16.45; 95% CI: 6.16-51.02; p<0.001). The receiver operating characteristics curve demonstrated that CR identified patients with stroke more accurately than the CHA2D-VASc score (C-statistic 0.712 vs 0.512; p<0.001), and the combination of CR and the CHA2DS2-VASc score provided the best performance (C-statistic 0.871 vs 0.829 [CHA2DS2-VASc score alone]; p=0.048) Conclusions: Impaired mechanical function of the LAA, indicated by a low LAAEF and CR, is associated with a history of stroke in patients with AF. Assessment of CR using LAA angiography helps improve the stratification scheme for stroke risk prediction.

Evaluation of Left Atrium/Left Atrial Appendage Function in Cases with Systemic Embolization in the Setting of Normal Transthoracic Echocardiography and Normal Sinus Rhythm.

Various left atrium (LA) and left atrial appendage (LAA) anatomies and functions could be associated with embolic events. We aimed to investigate the impact of variation in LAA and LA functions on the occurrence of systemic embolization in normal sinus rhythm and normal echocardiography findings. This cross-sectional study was performed on 22 patients with documented peripheral emboli versus 32 control subjects. LA area, LAA area, ejection fraction (EF) of LA/LAA, LAA velocity and tissue Doppler imaging (TDI) of LA walls, left ventricular diastolic function, and EF were determined. There were statistically significant differences between LAA area, LAA EF, TDI of lateral LA wall, and TDI of anterior LA wall in cases versus controls. Echocardiography findings in LAA and LA functions could help to identify high-risk patients for embolic events in normal sinus rhythm cases.

Left ventricular longitudinal contraction impacts the left atrial appendage function and the occurrence of thromboembolic events in patients with atrial fibrillation

Abstract Introduction Previous research has revealed a relationship between left ventricular (LV) function and incidence of stroke in atrial fibrillation (AF) but the mechanism remains unknown. Purpose Given that the left atrial appendage (LAA) is located in the vicinity of the LV base we hypothesized that the LV longitudinal contraction has an impact on the LAA function, LAA thrombus (LAAT) formation, and occurrence of ischemic stroke (Figure 1A). The aim of this study was to investigate this phenomenon using transesophageal echocardiography (TEE). Material and methods We included in our study 105 consecutive patients (age 59±11; 55 men) undergoing TEE-guided cardioversion for AF. LV longitudinal function was assessed using the mitral annulus plane systolic excursion (MAPSE). LAA function was evaluated using the LAA emptying velocity (LAAEV) and LAA ejection fraction (LAAEF) (Figure 1B). The presence LAAT and spontaneous echo contrast (SEC) were evaluated as well. Results Our patients had a median CHADS2vasc score = 3 (IQR 2–4), LVEF=50±11%, and MAPSE=7.3±1.7mm. MAPSE showed a positive significant correlation with both LAAEV (r=0.34; p&amp;lt;0.01) and LAAEF (r=0.23; p&amp;lt;0.05) (Figure 2). LVEF correlated significantly with LAAEV (r=0.42, p&amp;lt;0.01), and LAA area (r=−0.34; p&amp;lt;0.05), respectively. Additionally, patients who exhibited SEC had significantly lower LAAEF as well as LAAEV when compared with patients without SEC: 31±12% vs 38±12% P=0.022 and 35±18cm/s vs 49±21cm/s P=0.005. Patients who displayed both SEC and LAAT had wider LAA neck when compared to the rest of the group (21.46±3.96mm vs. 18.23±3.78mm; P=0.021). Logistic regression analysis revealed that MAPSE independently predicted the occurrence of ischemic stroke both in univariate and multivariate models that also included the CHADSvasc2 score. Conclusions LV longitudinal contraction appears to influence LAA function. This relationship could potentially have an impact on occurrence of thromboembolic events in patients with atrial fibrillation. Funding Acknowledgement Type of funding sources: None.

Altered left atrial appendage function associated with cardioembolic stroke in patients with rheumatic heart disease

Background: Left atrial appendage (LAA) is usually the first site for thrombus formation in rheumatic heart disease (RHD). LAA function is altered in RHD which may predispose it to thrombus formation. The aim of this study was to determine an association between function of LAA and cardioembolic stroke.Methods:Total 132 patients with RHD were studied by means of transthoracic echocardiography and/or transesophageal echocardiography and left atrial (LA) size, LAA ejection fraction (EF) and peak flow velocities were measured. These patients were followed up for 18 months with reference to development of cardioembolic stroke.Results: Seventy nine patients had atrial fibrillation (AF), of which 34 had thrombus in LAA. Out of 53 patients with sinus rhythm, 5 had LAA thrombus. Mean LAA EF was significantly lower in patients with thrombus in LAA, so was the peak flow velocity (both variables p&lt;0.0001). Saw tooth LAA outflow velocity pattern was visible in 30 (80%) patients with LAA thrombus versus 20 (28%) patients without LAA thrombus. Total 14 patients experienced cardioembolic stroke. Patients with cardioembolic stroke had lower mean LAA EF and peak flow velocity as compared to patients without cardioembolic stroke.Conclusions:Increased LAA size, reduced LAA EF and reduced peak flow velocity are associated with increased risk of cardioembolic stroke. LAA evaluation should be mandatory in deciding treatment strategies in patients with RHD and AF.

Three-Dimensional Echocardiographic Left Atrial Appendage Volumetric Analysis

Left atrial appendage (LAA) echocardiographic assessment is difficult because of the complex shape and relatively small size of the LAA. Three-dimensional (3D) echocardiographic imaging can overcome the limitations of two-dimensional imaging. Pulsed-wave Doppler is the only currently standard LAA functional parameter. The aim of this study was to test a new approach for 3D echocardiographic volumetric analysis to obtain LAA ejection fraction (EF), its size and shape. Transesophageal two-dimensional and 3D LAA images were prospectively obtained in 159 consecutive patients. LAA volumes were measured from 3D echocardiographic images using available software. Pulsed-wave Doppler was considered the reference value for LAA function and was used for comparison with LAA EF. Comparison with cardiac computed tomography was performed in a subgroup of 32 patients. Comparisons included linear regression and Bland-Altman analyses. Repeated measurements were performed to assess measurement variability. Nine patients were excluded because of suboptimal image quality (94% feasibility). Three-dimensional LAA calculated EF was in good agreement with LAA pulsed-wave measurements. Three-dimensional morphologic evaluation showed that 43% of the patients had "chicken wing," 33% "cactus," 19% "windsock," and 5% cauliflower shapes. At the time of data acquisition, patients with atrial fibrillation had nonsignificantly larger LAA end-systolic and end-diastolic volumes, leading to lower calculated EFs. Three-dimensional echocardiographic LAA end-systolic volumes were in good agreement with cardiac computed tomography (r=0.75), with small biases (mean, -2.5±3.9ml). Reproducibility was better for larger LAA volumes. A novel 3D echocardiographic approach can determine the geometry, size, and function of the LAA. A new parameter, LAA EF, provides functional quantitation.

Association of Structure and Function of left atrial Appendage with Left atrial appendage Thrombus formation in patients with Rheumatic Heart Disease: ASFALT-RHD study

Context: In patients with rheumatic heart disease (RHD), left atrial appendage (LAA) dilation and thrombus formation is widely known. LAA thrombus formation is a risk factor for stroke even in patients with sinus rhythm. The aim of this study was to determine an association between LAA structure and function with respect to thrombus formation and differences in LAA size and velocity between patients with sinus rhythm and those with atrial fibrillation (AF). Materials and Methods: We prospectively studied LAA structure and function in 120 patients with RHD by transthoracic echocardiography and/or transesophageal echocardiography by measuring left atrial (LA) dimension, LA area, LAAmax/min, LAA ejection fraction (EF), and LAA emptying velocity. Results: Four out of 48 patients with sinus rhythm had LAA thrombus. In 72 patients with AF, 32 had LAA thrombus. Patients with LAA thrombus had lower mean LAA EF and emptying velocity both variables P-value is same (P Conclusions: We conclude that LAA contractility is reduced in RHD with LAA thrombus, and loss of both contractility and LAA dilation is associated with increased risk of thrombus formation and hence the risk of stroke.

Abstract 14676: Landmark-based Functional Computed Tomography Reveals Diminished Left Atrial Appendage Contraction During Atrial Fibrillation

Introduction: The formation of thrombus in the left atrial appendage (LAA) and risk for systemic embolization may result in part from stasis and poor blood volume emptying during atrial fibrillation (AF). Functional 4-dimensional computed tomography (4DCT) is a promising technique to measure LAA ejection fraction and blood volume emptying. Hypothesis: We hypothesize that the LAA ejection fraction measured by 4DCT is decreased during AF compared to sinus rhythm. Methods: 256-slice 4DCT scans obtained in patients for coronary artery imaging or pre-procedurally for AF, VT or SVT ablation procedures were analyzed retrospectively. In each patient, LAA volumes were measured at multiple phases during one cardiac cycle using segmentation software (ITK-SNAP and Osirix MD). LAA ejection fraction was calculated as the difference between minimum and maximum volumes and was analyzed using Wilcoxon rank sum. Results: Out of 54 patients, 37 patients were in sinus rhythm and 17 patients were in AF. Between NSR vs. AF, mean age was 69.1±12.8 vs 73.2±11.5 years (p=0.13), 28% vs 36% female (p=0.54), LVEF was 58±11% vs 60±9% (p=0.95), and echo-derived left atrial volume index was 29.5±6.1 ml/m2 vs 41.7±12.8 ml/m2 (p=0.06). Patients who were in sinus rhythm during their CT scan had a higher LAA ejection fraction than those who were in AF (58±13% vs. 29±9%, p&lt;0.0001). For patients who were in AF during their CT scan, there was no difference in LAA ejection fraction between patients with a history of paroxysmal AF compared to patients with a history of persistent AF (30±10% vs. 28±10%, p=0.75). Conclusions: Analysis of the LAA volumes using functional cardiac CT is a feasible method to quantify blood volume emptying from the LAA. Patients in AF were observed to have significantly decreased LAA ejection fraction and blood volume emptying compared to patients in sinus rhythm. Further studies are needed to determine whether this technique may improve personalized risk stratification for stroke.

P1056Left atrial and left atrial appendage ejection fraction assessed by preprocedural cardiac CT are useful parameters for predicting the outcome of pulmonary vein isolation

Abstract Introduction Pulmonary vein isolation (PVI) is an effective but complex treatment option for atrial fibrillation (AF). Therefore preprocedural outcome prediction is of special interest. Left atrial volume (LAVmax) is a commonly used predictor for recurring arrhythmia. Several studies have investigated different parameters for the prediction of sustained rhythm control. We hypothesized that left atrial and left atrial appendage ejection fraction (LAEF &amp; LAAEF) assessed by high-resolution CT-imaging are even more sensitive predictors of the outcome of PVI than LAVmax. Methods All patients who underwent PVI between 2015 and 2018 with available preinterventional cardiac CT were included in this retrospective study and separated into 2 groups: Group A comprises all patients with sinus rhythm (SR) at follow-up and group B all patients in whom recurrence of AF was observed. Volumetric analysis of the left atrium was performed in ventricular systole (30%-Phase of the cardiac cycle) and diastole (0%-Phase). Obtained data were used to calculate left atrial and left appendage ejection fractions (LAEF &amp; LAAEF). Success of pulmonary vein isolation was defined as clinical freedom of symptomatic AF together with sinus rhythm on the available Holter-ECG recordings during follow-up examinations. Uni- and multivariate logistic regression models and NAMS RMLE tests were used to compare LAVmax to these functional parameters. Results In total 152 patients with symptomatic paroxsymal or persistent AF underwent PVI at our hospital from 2015 to 2018. Due to inconsistencies in archiving in our PACS-system, 98 patients had to be excluded from analysis. Four patients were excluded due to motion artifacts. 50 patients were included in the final study (41 patients without and 9 patients with recurring AF on average 254 days after ablation). Significant differences in means were found for all assessed parameters. LAEF (accuracy 94%, sensitivity 67%) and LAAEF (accuracy 90%, sensitivity 67%) had a higher sensitivity than LAVmax (accuracy 86%, sensitivity 33%), though not significant in this study population (p = 0.18). LAVmax and LAEF in combination improved sensitivity significantly from 33% to 78% (p = 0.046). Measurements on cardiac-CT showed an excellent interobserver-reliability. Conclusion Reduced LAEF and LAAEF were found to be significant predictors of the outcome of PVI. Furthermore we found a trend that these functional parameters might be more sensitive than LAVmax. Thus we propose that left atrial function, assessed with preprocedural cardiac CT, offers important prognostic information for successful PVI. Abstract Figure. Surface rendering of LA and LAA

Role of 2D speckle-tracking echocardiography in the assessment of left atrial function and its relation to the presence of left atrial appendage thrombus in patients with non-valvular paroxysmal atrial fibrillation

Introduction The study aimed to evaluate the role of speckle-tracking echocardiography (STE) in the assessment of left atrial (LA) function and its relation to the presence of left atrial appendage thrombus (LAAT) compared with the gold standard transesophageal echocardiography (TEE) among patients with nonvalvular paroxysmal atrial fibrillation (AF). Patients and methods Forty five patients with nonvalvular paroxysmal AF were included in the study. All patients underwent transthoracic echocardiography (TTE) immediately prior to or following clinically indicated TEE. LA deformation parameters such as left atrial global longitudinal strain-reservoir (LAGLS-RES), left atrial global longitudinal strain pump (LAGLS-pump), left atrial strain rate systolic (LA SR S), left atrial strain rate emptying (LA SR E), and left atrial strain rate atrial (LA SR A) were measured using 2D-STE. Through TEE, we assessed the presence of LAAT, left atrial appendage ejection fraction (LAA EF), left atrial appendage emptying (LAA E), and left atrial appendage filling (LAA F) velocities. Patients were divided into two groups according to the presence of LAAT. Results LAAT was detected in 14 (31%) patients of our study population. STE-derived LAGLS-RES, LAGLS-pump, and LA SR A values were found to be significantly lower in patients with LAAT. There was positive correlation between LAA E velocity and LAGLS-RES, LAGLS-pump, LA SR S, and LA SR A (r=0.358, P Conclusion 2-D STE can be used for the assessment of LA mechanical function and discriminate patients with LAAT from those without LAAT compared with the gold standard TEE among patients with non-valvular paroxysmal AF.

Inverse Correlation Between Left Atrial Appendage Function and CHA2DS2-VASc Score in Patients with Atrial Flutter

Impaired left atrial appendage ejection fraction (LAA-EF) and peak LAA flow velocity (LAA-FV) are associated with high thromboembolic risks in patients with atrial fibrillation (AF). Herein, we examined LAA function among patients with atrial flutter (AFL) stratified by the CHA2DS2-VASc score using transesophageal echocardiography (TEE). Of 231 consecutive patients with typical AFL, 84 who fulfilled the inclusion criteria were enrolled. Among them, 57 had ongoing AFL and were divided into the isolated AFL (n = 38) and AFL with paroxysmal AF (PAF) (n = 19) groups, depending on whether they had sporadic AF before TEE. The remaining 27 patients with spontaneous sinus rhythm during TEE were designated as controls. Both the LAA-FV (31.9 cm/s vs. 51.5 cm/s, P = 0.004) and LAA-EF (28.4% vs. 36.5%, P = 0.024) measured during AFL were significantly lower in the AFL + PAF group than in the isolated AFL group. Significant inverse correlations between the CHA2DS2-VASc score and LAA-EF were identified in the AFL (P = 0.008) and AFL + PAF (P = 0.032) groups. We observed progressive LAA dysfunction in patients with AFL + PAF compared with that in patients with isolated AFL, and the LAA-EF was inversely correlated with the CHA2DS2-VASc score in these patients. Our findings may have implications on the application of thromboprophylactic therapy in patients with AFL.

Sacubitril/Valsartan Improves Left Atrial and Left Atrial Appendage Function in Patients With Atrial Fibrillation and in Pressure Overload-Induced Mice.

LCZ696 (sacubitril/valsartan) is an angiotensin receptor-neprilysin inhibitor and has shown beneficial effects in patients with heart failure. However, whether LCZ696 protects against left atrial (LA) and LA appendage (LAA) dysfunction is still unclear. The present study aimed to assess the efficacy of LCZ696 for improving the function of LA and LAA. We performed both a retrospective study comparing LCZ696 with angiotensin receptor blockers (ARBs) to assess the efficacy of LCZ696 in patients with atrial fibrillation and an animal study in a mouse model with pressure overload. LA peak systolic strain, LAA emptying flow velocity, and LAA ejection fraction (LAAEF) were significantly increased in patients with LCZ696 as compared with ARBs (p = 0.024, p = 0.036, p = 0.026, respectively). Users of LCZ696 had a lower incidence of spontaneous echocardiography contrast (p = 0.040). Next, patients were divided into two groups (LAAEF ≤ 20% and > 20%). Administration of LCZ696 in patients with LAAEF > 20% was more frequent than LAAEF ≤ 20% (p = 0.032). Even after controlling for LAA dysfunction-related risk factors (age, atrial fibrillation type, old myocardial infarction, hypertension, congestive heart failure, and prior stroke or transient ischemic attack), use of LCZ696 remained significantly associated with reduced probability of LAAEF ≤ 20% [odds ratio = 0.011; 95% confidence interval (0.000–0.533), p = 0.023]. To further confirmed effect of LCZ696 in LA function, we constructed a post-transverse aortic constriction model in mice. Mice with LCZ696 treatment showed lower LA dimension and higher left ventricular ejection fraction and LAA emptying flow velocity as compared with mice with vehicle or valsartan treatment. Meanwhile, as compared with vehicle or valsartan, LCZ696 significantly decreased LA fibrosis in mice. In summary, we provide evidence that LCZ696 may be more effective in improving LA and LAA function than ARBs in both humans and mice, which suggests that LCZ696 might be evaluated as a direct therapeutic for atrial remodeling and AF.

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.

Morphologic and functional features of left atrial appendage in Iranian population: an echocardiographic study.

Introduction: Cardioembolic events are accompanied by left atrial appendage (LAA) in patients suffering from atrial fibrillation (AF); therefore, the LAA closure is implemented as a preventive strategy. The detection of LAA morphologies and function is a paramount step before establishing the LAA closure. Herein, we sought to determine the morphologic features of the LAA in an Iranian population using echocardiographic evaluation. Methods: Seventy-two near-normal heart patients were investigated by conducting a cross-sectional study. All patients were examined using the 2-dimensional and 3-dimensional transesophageal echocardiography (2D- and 3D-TEE) method. The anatomical features and functions of LAA were examined. All images were stored and analyzed offline. Results: The patients’ mean age was 39 ± 15.5 year and 33 (45.8%) were female. The most frequent shape of LAA was wind sock . More LAA lobes was observed in patients with AF compared to those with NSR. In comparison with AF group, the NSR had higher LAA flow velocity (P < 0.01). The paroxysmal AF had greater LAA flow velocity and LAA ejection fraction in comparison with the chronic AF (39 ± 19 vs. 75 ± 22, P < 0.01; and 49±4 vs. 72±14, P < 0.003; respectively). The paroxysmal AF had smaller systolic LAA orifice area in comparison with the chronic AF (P < 0.02). Conclusion: The morphologic features of LAA in Iranian population were within the range of other studies and LAA length and orifice diameters in 2D- and 3D-TEE were consistent. In addition, AF influenced the morphologies and functions of LAA compared to sinus rhythm.

Evaluation of the volume and function of left atrial appendage and left atrium in patients with atrial fibrillation by three-dimensional transesophageal echocardiography and transthoracic echocardiography

To evaluate the volume and function of left atrium and left atrial appendage in patients with atrial fibrillation by three-dimensional transesophageal echocardiography and transthoracic echocardiography. Methods: A total of 112 patients with atrial fibrillation were divided into two groups: a paroxysmal atrial fibrillation (ParAF) group (n=80) and a persistent atrial fibrillation (PerAF) group (n=32). Control group was people without atrial fibrillation (n=40). Clinical data of the participants were collected. Left atrial dimension (LAD), left atrial volume (LAV), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) were measured by transthoracic echocardiography, while left atrial appendage peak emptying flow velocity (LAAeV), left atrial appendage peak filling flow velocity (LAAfV), left atrial appendage maximum volume (LAAVmax) and left atrial appendage minimum volume (LAAVmin) were measured by three-dimensional transesophageal echocardiography. Left atrial volume index (LAVI), left ventricular ejection fraction (LVEF) and left atrial appendage ejection fraction (LAAEF) were calculated. Results: Compared with the control group, LAAEF, LAAeV and LAAfV in the ParAF group were decreased obviously, while LAD, LAV, LAVI, LAAVmax and LAAVmin in the ParAF group were increased obviously (P<0.05). Compared with the ParAF group, LAAEF, LAAeV and LAAfV in the PerAF group were also decreased obviously, and LAD, LAV, LAVI, LAAVmax and LAAVmin in the ParAF group were also increased obviously (P<0.05). There was no statistically significant difference in LVEDV, LVESV, LVEF between the ParAF group and the PerAF group (P<0.05). Conclusion: Left atrium and left atrial appendage were enlarged and the function of left atrial appendage was declined in patients with AF, and the changes were more obvious in patients with PerAF compared with patients with ParAF by three-dimensional transesophageal echocardiography and transthoracic echocardiography.

Transesophageal echocardiography measures left atrial appendage volume and function and predicts recurrence of paroxysmal atrial fibrillation after radiofrequency catheter ablation.

Paroxysmal atrial fibrillation (PAF) commonly recurs after radiofrequency catheter ablation (RFCA). This study aimed to assess left atrial appendage (LAA) volume and function by transesophageal echocardiography (TEE) and to explore its value in predicting PAF recurrence after RFCA. Eighty patients with PAF were recruited. The left atrial (LA) and LAA volume and function were measured by transthoracic echocardiography (TTE) and TEE before ablation. Patients were followed up for 12months after RFCA, and recurrence was recorded. Odds ratios of candidate risk indicators were determined by logistic regression analysis. Prediction model was constructed using logistic regression with backward selection. Receiver operating characteristic (ROC) curve with area under curve (AUC) was performed to evaluate the prediction efficiency. Twenty-four (30%) PAF patients had recurrence (R group), and 56 (70%) patients had no recurrence (NR group). Compared to NR group, LA dimension (LAD), LA volume index (LAVI), LAA maximum volume (LAAVmax), and LAA minimum volume (LAAVmin) were significantly higher in R group, while LAA peak emptying flow velocity (LAAeV), LAA peak filling flow velocity (LAAfV), and LAA ejection fraction (LAAEF) significantly declined in R group. According to multivariate analysis and backward selection, LAVI, LAAEF, and LAAeV were significant risk factors for PAF recurrence. The LAVI+LAAEF+LAAeV joint model could effectively predict PAF recurrence with AUC of 0.893 (95% confidence interval=0.816, 0.970), sensitivity of 0.75, and specificity of 0.929. This study demonstrated that LAVI, LAAEF, and LAAeV were significant predictors of PAF recurrence after RFCA.

Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures.

ObjectiveTo investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures.Materials and MethodsA total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis.ResultsSeven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P<0.05) present in women (8.0%) than in men (4.2%). LAA orifice was oval in 81.5%, triangular in 7.3%, semicircular in 4%, water drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (P<0.01) major axis in men (24.79±3.81) than in women (22.68±4.07). The LAA orifice long axis was significantly (P<0.05) positively correlated with the height, weight and surface area of the patient. The LAA morphology parameters displayed strong positive correlation with the left atrium volume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (P<0.05) greater distance from its orifice to the mitral ring in women than in men. The LAA had two filling and two emptying processes with the greatest volume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (P<0.05) positively correlated with the body height, weight and surface area, whereas the LAA ejection fraction had an inverse correlation with the LAA minimal volume but no correlation with the maximal volume.ConclusionThe LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation procedures.

The Effects of Percutaneous Mitral Balloon Valvuloplasty on the Left Atrial Appendage Function in Patients With Sinus Rhythm and Atrial Fibrillation

Introduction: Mitral stenosis (MS) causes structural and functional abnormalities of the left atrium (LA) and left atrial appendage (LAA), and studies show that LAA performance improves within a short time after percutaneous transvenous mitral commissurotomy (PTMC). This study aimed to investigate the effects of PTMC on left atrial function by transesophageal echocardiography (TEE). Methods: We enrolled 56 patients with severe mitral stenosis (valve area less than 1.5 CM2). All participants underwent mitral valvuloplasty; they also underwent transesophageal echocardiography before and at least one month after PTMC. Results: Underlying heart rhythm was sinus rhythm (SR) in 28 patients and atrial fibrillation (AF) in remainder 28 cases. There was no significant change in the left ventricular ejection fraction (LVEF), left ventricular end diastolic dimension (LVEDD), or the left ventricular end systolic dimension (LVESD) before and after PTMC in both groups. However, both groups showed a significant decrease in the left atrial volume index (LAVI) following PTMC (P=0.032 in SR and P=0.015 in AF group). LAA ejection fraction (LAAEF) and the LAA emptying velocity (LAAEV) were improved significantly after PTMC in both groups with SR and AF (P<0.001 for both). Conclusion: Percutaneous transvenous mitral commissurotomy improves left atrial appendage function in patients with mitral stenosis irrespective of the underlying heart rhythm.