Diagnosis of a bilobed left atrial appendage and pectinate muscles mimicking thrombi on real-time 3-dimensional transesophageal echocardiography

3D transesophageal echocardiography assists in evaluating the morphology, function, and presence of thrombi of left atrial appendage in patients with atrial fibrillation

Background

Left atrial appendage (LAA) is significantly more likely to form thrombi in patients with atrial fibrillation (AFib). Two-dimensional transesophageal echocardiography (2D TEE) is considered the gold standard for assessing and studying LAA morphology and anatomy. However, 2D TEE can only visualize one plane at any given time. Real-time three-dimensional echocardiography (RT-3D TEE) imaging can preserve spatial and temporal resolution, which is a safe, accurate, and reproducible imaging modality. There are few reports of the usage of RT-3D TEE to study LAA in AFib patients. In our research, RT-3D TEE helps to provide detailed LAA information and identifying the presence or absence of thrombi from pectinate muscles in paroxysmal and long-standing AFib patients.

Methods

LAA morphology was analyzed in detail by 2D TEE and RT-3D TEE in 320 patients with paroxysmal or long-standing AFib. The LAA flow pattern, as maximal LAA emptying flow velocity (LAAeV), was retrieved from 2D and 3D TEE imaging. LAA morphological parameters, spontaneous echo contrast (SEC), and thrombi were also detected by 2D and 3D TEE in all patients. In addition, LAA lobes and types were classified according to the morphology by 3D TEE, and the relationship between LAA types and the incidence of thrombi was evaluated.

Results

Long-standing AFib had greater enlargement of LAAs (orifice diameters and area), significantly more severe SEC, and a higher thrombi clot incidence rate by 3D-TEE compared with paroxysmal AFib patients (P<0.05). In addition, cauliflower morphology in long-standing AFib patients was associated with a higher LAA thrombus (OR 2.1, 95% CI: 1.1–8.5, P=0.031) and increased prevalence of SEC. Moreover, the uncertainty of thrombi detection was significantly decreased by 3D TEE compared with 2D TEE (P<0.001), and the certainty of thrombi detection by 3D TEE also decreased slightly (P=0.06).

Conclusions

RT-3D TEE is a safe and real-time option for the evaluation of LAA morphology and function. Long-standing AFib has greater LAA and SEC, as well as a higher incidence of thrombi than the paroxysmal group. Cauliflower LAA type was associated with a higher prevalence of SEC and thrombi.

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.

Transverse sinus fat pad may masquerade as left atrial appendage thrombus

Transesophageal echocardiography (TEE) is a commonly utilized investigation in patients with atrial fibrillation to study the left atrial appendage (LAA) and exclude an appendage thrombus before proceeding with cardioversion. Although TEE is considered the procedure of choice for this purpose, it may sometimes offer a limited specificity due to common anatomical variations associated with either the LAA or the adjoining cardiac structures. We herewith present a patient with atrial fibrillation who underwent TEE and was found to have an echodensity in the vicinity of left atrial appendage that mimicked a thrombus. A careful further evaluation however confirmed that the echodensity actually was consistent with a dense epicardial fat pad. TEE imaging evaluation in different planes and angulations is thus paramount in establishing a correct diagnosis. Supplemental information from other imaging modalities such as cardiac computed tomography may sometimes offer an additional value, especially if the diagnosis remains unclear.

Transesophageal echocardiography for the assessment of left atrial appendage thrombus: Study of the additional value of systematic real time 3D imaging after regular 2D evaluation

BACKGROUND

Two-dimensional transesophageal echocardiography (2DTEE) is currently validated for left atrial appendage (LAA) thrombus assessment but has some limitations.

AIMS

To evaluate the performance and interest of systematic real time three-dimensional transesophageal echocardiography (3DTEE) for LAA thrombus assessment, when performed after 2DTEE.

METHODS AND RESULTS

Consecutive patients undergoing TEE were prospectively included. LAA was first evaluated using 2DTEE, and patients were classified as "2D-NT" if no thrombus was found, "2D-T" in case of clear thrombus, or "2D-EQ" if equivocal. Then, 3DTEE of the LAA was performed and patients were similarly classified as "3D-NT," "3D-T," or "3D-EQ." Additional LAA CT scan was only performed if LAA thrombus was not clearly ruled out or confirmed by TEE. Additional value of 3DTEE after 2DTEE LAA evaluation was then assessed. We included 104 patients undergoing TEE. Agreement between 2DTEE and 3DTEE was very good for thrombus diagnosis (k = 0.936), but moderate for vacant LAA (k = 0.562) due to more frequent 2D-EQ than 3D-EQ (11.5% vs 2.9%; P = .016). 3DTEE allowed to refine the LAA status in 11 of 12 (91.7%) 2D-EQ patients: 10 3D-NT, 1 3D-T, and 1 3D-EQ. Coupling 3DTEE to 2DTEE permitted a definite LAA diagnosis in 103 of 104 (99%) vs 92 of 104 (88.5%) patients when 2DTEE was used alone (P = .002). Nine (8.7%) LAA thrombi were diagnosed, and 3 CT scan were performed.

CONCLUSION

3DTEE of the LAA is more effective for thrombus assessment than 2DTEE. 3DTEE should be particularly considered in case of equivocal 2DTEE, as it allows to reach a definite LAA diagnosis in almost all of the patients.

Left atrial appendage closure: beyond the artifact

: Transesophageal echocardiography (TEE) represents the gold standard technique to detect left atrial appendage (LAA) thrombosis. Several conditions may be erroneously interpreted as LAA thrombus at TEE, including artifacts mimicking thrombi. We report a case of a 78-year-old man with atrial fibrillation and contraindication to anticoagulation who was referred to our institution for percutaneous left appendage closure with a transcatheter trans-septal approach. Intraoperative transesophageal echocardiography revealed a thrombus-mimicking image, related to reverberations of left upper pulmonary vein ridge, located at twice the distance of the ridge from the transducer.

Evaluation of left atrial appendage function and thrombi in patients with atrial fibrillation: from transthoracic to real time 3D transesophageal echocardiography

The detection of embolic sources in patients with atrial fibrillation (AF) is important to guide anticoagulant therapy. Two-dimensional transesophageal echocardiography (TEE) is the gold standard to study left atrial appendage (LAA) anatomy and morphology, despite some false-positive diagnosis. We hypothesized that real time 3D TEE (RT3DTEE) is superior to 2DTEE in detecting and/or excluding LAA thrombi. We studied 93 patients with non-valvular AF (60 males, age = 67.1 ± 14.2 years) referred for electric cardioversion with transthoracic, 2DTEE and RT3DTEE. Before cardioversion, TTE allowed a confident measurement of emptying velocity of LAA (LAAeV) only in 59/93 patients (63%). On the contrary a good quality TEE LAAeV was obtained in all patients with 49/93 (53%) dysfunctional LAA (LAAeV < 40 cm/s). A subgroup of 5 patients (7.2% of the 69 effective cardioversion) presented a persistent dysfunction after cardioversion (with LAAeV values of <40 cm/s on the TEE post-CV). TEE allowed to observe a bilobed shape in 45 patients (48.4%) and three lobes in 22 patients (23.7%). In addition, besides to several additional findings, 2DTEE managed to detect thrombi with certainty in 8/93 patients (8.6%). In other 5 cases with diagnostic doubts for thrombi with 2DTEE (5/93 patients: 5.4%), the addition of the RT3DTEE mode allowed to discriminate with certainty the presence of just pectinate muscles in 4 patients RT3DTEE in patients with AF at risk of embolism is feasible, accurate and showed an additional diagnostic capability in the differential diagnosis of selected cases with suspected LAA thrombi.

Role of Transesophageal Echocardiography in Left Atrial Appendage Device Closure

Left atrial appendage (LAA) occlusion or ligation by percutaneously implanted devices is increasingly an alternative management option for atrial fibrillation, particularly for patients who are intolerant or have contraindications for anticoagulation. Echocardiography plays an important part in screening, guidance of implantation, and after-device assessment. Assessment of LAA anatomy suitable for device implantation, thrombus exclusion, guidance of transseptal puncture, localization of catheter, guidance of device deployment, and after-device assessment are all important functions of echocardiography. This article reviews the role of echocardiography in device-based LAA occlusion or ligation.

Transcatheter left atrial appendage occlusion

Occlusion of the left atrial appendage (LAA) may reduce the risk of stroke in patients with atrial fibrillation (AF). Trials comparing LAA occlusion to warfarin anticoagulation in patients with nonvalvular AF showed a reduction in hemorrhagic stroke, although an increase in safety events due to procedural complications. Long-term follow-up suggests possible superiority of LAA occlusion due to fewer strokes and bleeding events. The superior dosing and safety profiles of the novel oral anticoagulants raise the accepted threshold for safety and efficacy of LAA occlusion procedures, and underscore the need for randomized studies comparing LAA occlusion with these newer anticoagulants.