Left Atrial Appendage Spontaneous Echo Contrast Research Articles

Refining the prognosis of patients with AF using 3D transesophageal echocardiography of the left atrial appendage

Abstract Background Left atrial (LA) volume is considered an echocardiographic marker of thrombosis risk and prognosis in atrial fibrillation (AF). Limited data is available on the prognostic value of left atrial appendage (LAA) volume in AF as evaluated with three-dimensional (3D) transoesophageal echocardiography (TEE). Purpose We hypothesized that 3D LAA volume is associated with prognosis in patients hospitalized with AF. Methods We prospectively evaluated 206 patients hospitalized for AF with two-dimensional transthoracic echocardiography (TTE) and 3D TEE of the LAA within 24 hours of admission. 3D parameters were analysed off-line using Tomtec software (4D Cardio-View, Generic Volume, Philips). The primary composite outcome was all-cause death during at 2 years follow up. Results The median age of the study group was 66.3 ± 11.5 years with 129 (62.6%) men. In the global population, at admission, the median 3D LAAV was 9.02 (6.96-12.15) ml. Patients were divided into two groups according to the median 3D LAAV: Group 1: LAAV < 9ml (103 patients) and Group 2: LAAV ≥ 9ml (103 patients). Patients with LAAV ≥ 9ml had more frequently a history of heart failure and chronic obstructive pulmonary disease. There were no significant intergroup differences in CHA2DS2-VASc score. Patients with LAAV ≥ 9ml had higher values of BNP and CRP and lower LVEF, higher LA volumes, higher E/e’, lower LAA emptying flow velocity, and higher 3D ES LAA ostium area. There were no statistical differences in LAA spontaneous echo contrast and LAA morphology between groups (Table 1). Kaplan–Meier curves demonstrated a significant difference in survival according to the 3D ES LAAV: 3 deaths occurred in the group with 3D ES LAA volume < 9mL and 11 in the group with 3D ES LAA Volume≥9mL (p=0.0315) (Figure 1). Conclusion Among LAA parameters, 3D LAA end-systolic volume is significantly associated with a worse outcome in patients with AF. Further investigations are needed to evaluate this unique parameter against usual geometric and functional LA/LAA parameters.

Risk factors associated with left atrial appendage thrombosis in patients with non-valvular atrial fibrillation by transesophageal echocardiography

Purpose: This study investigated possible mechanism of left atrial appendage (LAA) thrombosis and constructed a model to evaluate the future risk of LAA thrombosis and spontaneous echo contrast (SEC) in non-valvular atrial fibrillation (NVAF) patients. Methods: This retrospective study included 2591 patients diagnosed with NVAF. Patients were divided based on the presence of transesophageal echocardiography (TEE) into a thrombus group, SEC group, and control group. General, biochemical, and echocardiography data of the three groups were analyzed. The variables independently associated with LAA thrombosis and SEC were determined by the logistic regression analysis. A nomogram was constituted based on the regression analysis and the discriminatory ability was analyzed by receiver operating characteristic (ROC) curve. Results: LAA thrombosis and SEC were present in 110 (4.2%) patients and 103 (3.9%) patients, respectively. AF type (OR = 1.857), previous stroke (OR = 1.924), fibrinogen (OR = 1.636), diameters of the left atria (OR = 1.094), left ventricular ejection fraction (OR = 0.938), and LAA maximum caliber (OR = 1.238) resulted as independent risk factors for LAA thrombosis and SEC. The area under curve of the nomogram established by multivariate logistic regression was 0.824. Conclusions; Through the study, 6 independent risk factors related to the LAA thrombosis and SEC were found, and an effective nomogram was constructed to predict the LAA thrombosis and SEC in NVAF patients.

The value of left atrial longitudinal strain in evaluating left atrial appendage spontaneous echo contrast in non-valvular atrial fibrillation.

Spontaneous echo contrast (SEC) observed in transesophageal echocardiography (TEE) is a reliable predictor of the risk of future ischemic stroke in patients with non-valvular atrial fibrillation (NVAF). Left atrial strain globally reflects atrial function, remodeling and distensibility. The left atrial appendage (LAA) is a myogenic remnant of the left atrium, which can actively relax and contract. The left atrial appendage (LAA) is an important part of releasing the pressure of the left atrium. The key role of the left atrium is to regulate the left ventricular filling pressure, act as a reservoir for pulmonary venous return during ventricular contraction, and act as a conduit, transferring blood to the Left ventricle during early ventricular diastole. The purpose of this study was to explore the relationship between left atrial function and left atrial appendage spontaneous echo contrast (LAASEC). A retrospective study of 338 patients with non-valvular AF was conducted. Two-dimensional speckle-tracking echocardiography provided the following metrics of LA strain: LA strain during the reservoir phase (LASr), LA strain during the conduit phase (LAScd). LA or LAA has the dense SEC of more than grade 3, which is defined as mud like change or pre thrombosis. Patients with level 3 SEC (n = 81) has lower LASr than those with lower grades of SEC (n = 257) (7.20 ± 3.70 vs. 17.48 ± 8.67, P < 0.001). Multivariate logistic regression model showed that the type of atrial fibrillation (persistent∼), increased heart rate, decreased LASr were independently associated with the dense LAASEC (OR (CI 95%), 5.558 (1.618-19.09), 1.016 (1.006-1.026) 0.002, 1.224 (1.085-1.381), both P < 0.01). Venn Diagram showed that lower CHADVASC2 score groups had dense SEC cases. Receiver operating characteristic (ROC) curve was used for analyzing results and selecting cut off values. The cut off point for LASr < 8.85% and CHADVASC2 score was >2 scores with sensitivity and specificity were 79% and 85%. Lower LASr is independently associated with the dense LAASEC in NVAF and has incremental values superior to clinical scores. The decrease of LASr may be a potential non-invasive parameter for evaluating the higher risk of LAA thrombosis.

Risk of left atrial appendage thrombus in patients with atrial fibrillation and chronic kidney disease.

BackgroundAtrial fibrillation (AF) and chronic kidney disease (CKD) are associated with an increased risk of ischemic stroke. The aim of this study was to compare the clinical characteristics, the incidence of left atrial appendage (LAA) thrombus and its predictors, and spontaneous echo contrast (SEC) in a population of patients with AF depending on estimated glomerular filtration rate (eGFR) values.MethodsThis study included 1962 patients who underwent transesophageal echocardiographic examination prior to cardioversion or ablation in the years 2014–2018 in three cardiac centers.ResultsMore than a quarter of AF patients had decreased eGFR (< 60 mL/min/1.73 m2) and were characterized as a high-risk population, with more comorbidities, higher thromboembolic and bleeding risk compared to those with normal renal function. Oral anticoagulation (OAC) was prescribed in 97% and 93% of patients with decreased and normal eGFR, respectively, with a higher prevalence of prescribed non-vitamin K antagonist oral anticoagulants (NOACs). The incidence of LAA thrombus (24%, 9% and 4%) and SEC (25%, 25% and 19%) increases simultaneously with a decrease in eGFR (< 30, 30–59 and ≥ 60 mL/min/1.73 m2, respectively). Among patients prescribed reduced doses of NOAC, those with decreased eGFR were more often observed with LAA thrombus (10% vs. 2.5%). Non-paroxysmal AF, heart failure and previous bleeding were predictors of LAA thrombus, irrespective of eGFR value. CKD was the predictor of LAA thrombus in all patients including those with non-paroxysmal AF, males, without diabetes, without hypertension and with CHA2DS2-VASc < 2.ConclusionsDespite OAC, patients with concomitant AF and CKD remain at high risk for LAA thrombus formation.

Left atrial appendage structure predicts thromboembolic risk in 185 patients with crytogenic stroke/TIA without history of AF

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Akerhus University Hospital Dept. of Cardiology Background Cryptogenic stroke/TIA (CS) is supposed to be associated with intracardiac thrombus formation and left atrial (LA) structure, in particular thrombus formation in left atrial appendage (LAA). However, there is little evidence if thromboembolic risk is associated with LAA morphology in patients with CS. Purpose We aimed to investigate, if different LAA morphology types may predict thromboembolic risk in patients with CS. Methods In this prospective study (mean follow-up 859 ± 226 days), 185 patients with CS (mean age 68 ±13 years, 33% female) without history of AF were included. All patients underwent complete transesophageal echocardiography in sinus rhythm after index CS (mean 5 ± 3days). Occurrence of LAA thrombus, sludge or spontaneous echo contrast (SEC) were defined as thromboembolic risk and LAA structure was evaluated by 2D and 3D transesophageal echocardiography. Multilobate LAA was defined as LAA with &amp;gt; 1 lobes. Results Of the 185 included patients, LAA type chicken wing was found in 79 (43%), type windsock in 64 (35%), type cactus in 35 (19%) and type cauliflower in 7 (4%). Thrombus formation occurred in 29/185 (16%), LAA sludge in 112/185 (61%), and LAA SEC in 74/185 (40%), which is increased compared to data in the general population. We found SEC in sludge in 65/112 (58%), SEC in thrombus in 18/29 (62%) and sludge in thrombus in 27/29 (93%). SEC and sludge were significantly associated with thrombus formation, (p &amp;lt; 0.001 and p &amp;lt; 0.01, respectively). Finally, thromboembolic risk occurred in 123 (67%) of all patients with CS. Moreover, LAA type chicken wing was significantly associated with thromboembolic risk (p &amp;lt; 0.01), while all other LAA types were not. Multilobate LAA occurred in 115 (62%) of all patients and predicted thromboembolic risk vs. non-lobated LAA (p= 0.04). In a multivariate analysis LAA type chicken wing and multilobate LAA were independently predictors of thromboembolic risk, figure 1. Conclusions Patients with cryptogenic stroke/TIA without history of AF showed increased thromboembolic risk, and SEC and sludge were significantly associated with LAA thrombus formation. Only LAA type chicken wing and multilobate LAA predicted independently thromboembolic risk in this study. Abstract Figure.

Porphyromonas gingivalis and left atrial appendage spontaneous echo contrast in atrial fibrillation ablation candidates.

Atrial fibrillation (AF) is associated with a fivefold risk of stroke and thrombotic embolism, which are usually derived from the left atrial appendage (LAA). Spontaneous echo contrast (SEC) is known as a risk factor for thrombosis. Porphyromonas gingivalis (P. gingivalis) has some prothrombotic effects and plays a key role in periodontitis and oral-systemic disease connection. We aimed to clarify the relationship between P. gingivalis and LAA SEC among AF patients. A total of 569 AF ablation candidates were enrolled in the present study. LAA SEC was categorized into nondense SEC and dense SEC based on transesophageal echocardiography. Serum immunoglobulin G antibody titers of P. gingivalis fimA subtypes (types I-IV) were measured with an enzyme-linked immunosorbent assay. The levels of antibody titers were categorized into high (> mean + 3 standard deviation) and low values. A total of 513 (90%) patients were included in the nondense SEC group, and 56 (10%) were included in the dense SEC group. Multivariate regression analysis revealed that the high-value serum antibody titers of P. gingivalis types II and IV were independently associated with dense SEC [type II: adjusted odds ratio (OR) 2.220; 95% confidence interval (CI) 1.062-4.643; P = 0.02; and type IV: adjusted OR 3.169; 95% CI 1.058-6.657; P = 0.002]. The results revealed that P. gingivalis types II and IV are related to LAA SEC severity among AF patients who receive appropriate anticoagulation therapy.

Predictors of spontaneous echo contrast and left atrial appendage thrombosis in nonvalvular atrial fibrillation

Aim. To identify predictors of spontaneous echo contrast (SEC) and/or left atrial appendage (LAA) thrombosis in patients with nonvalvular atrial fibrillation (AF) who are referred for elective cardioversion or catheter ablation (CA).Material and methods. A retrospective analysis of data from 638 patients with nonvalvular AF who were hospitalized from 2014 to 2017 for cardioversion or CA was performed. All patients underwent diagnostic tests, including transthoracic and transesophageal echocardiography (TEE).Results. According to the TEE results, two groups of patients were formed: group 1 — 95 patients (14,9%) with signs of SEC and/or thrombosis in LAA; group 2 — 543 patients (85,1%) without SEC or thrombosis in LAA. Patients with the phenomenon of SEC and/or LAA thrombosis were older, had a higher risk on the CHA2DS2-VASc score. These patients were more likely to have coronary heart disease (CAD), hypertension, stage IIA chronic heart failure, obese class &gt;II, persistent or permanent AF Patients in both groups did not differ in anticoagulant therapy. Patients in group 1 had a larger size of the left and right atria, right ventricle, left ventricular (LV) end-systolic and end-diastolic diameters, higher LV mass index, lower values of LV ejection fraction and blood flow velocity in LAA. Logistic regression revealed following independent predictors of SEC and/or LAA thrombosis: CAD (odds ratio (OR) 2,289; 95% confidence interval (CI) 1,313-3,990; p=0,003), persistent or permanent AF (OR 2,071; 95% CI 1,222-3,510; p=0,007), LA diameter &gt;43 mm (OR 3,569; 95% CI 2,0822-6,117; p&lt;0,001), concentric or eccentric LV hypertrophy (OR 2,230; 95% CI 1,302-3,819; p=0,003).Conclusion. As the result, all patients referring for CA or cardioversion, regardless of the CHA2DS2-VASc score, should underwent LAA. According to this study, the presence of CAD, persistent or permanent AF, LA diameter &gt;43 mm, concentric or eccentric LV hypertrophy are independent predictors of SEC and/or LAA thrombosis.

Predictors of Spontaneous Echo Contrast in Left Heart Chambers in Patients with Dilated Cardiomyopathy: Slowing Down Might not Always Mean Enjoying Life.

Introduction:Spontaneous echo contrast(SEC) is usually detected in heart chambers as a result of reduced flow velocity in the cavity. The clinical importance of SEC lies in its association with embolic events. The aim of our study was to determine the frequency of SEC in left heart chambers in sinus rhythm patients with dilated cardiomyopathy and predictors for its emergence.Materials and Methods:This was a prospective cross-sectional transesophageal echocardiography study conducted in 101 sinus rhythm patients with dilated heart and mild-to-moderate systolic dysfunction.Results:Moderate-degree SEC was found in the left ventricle(LV) in around 9% of patients, in the left atrium(LA) in 12% and in left atrial appendage(LAA) in 40%. Multiple regression analysis showed that lower heart rate(95% confidence interval[CI]: 0.845–0.978; P = 0.011) and larger LV end-systolic diameter(LVESD)(95% CI: 1.034–1.394; P = 0.017) were independent predictors for LV SEC presence. Lower LV ejection fraction(LVEF) (95% CI: [−0.079]–[−0.037]; P = 0.0001) was the only independent predictor for SEC in the LA. Whereas, independent predictors for SEC in LAA were lower heart rate(95% CI:[−0.030]–[−0.003]; P = 0.018), greater LA indexed diameter (95% CI: 0.016–0.116; P = 0.010), and higher value of C-reactive protein(CRP)(95% CI: 0.0026–0.031; P = 0.027).Conclusions:SEC in left heart chambers is a frequent finding in patients with dilated cardiomyopathy in sinus rhythm. Lower heart rate and LVEF, larger LVESD and LA, as well as higher CRP, predict the presence of SEC in left heart chambers. Lower heart rate might be an essential predictor for SEC presence and severity in these patients.

The value of left atrial strain and strain rate in predicting left atrial appendage stasis in patients with nonvalvular atrial fibrillation.

This study aimed to investigate the value of left atrial (LA) strain and strain rate (S/SR) by transthoracic echocardiography (TTE) in predicting left atrial appendage (LAA) stasis, in order to find a way for LAA stasis screening which is easily performed in patients with nonvalvular atrial fibrillation (NVAF). One hundred and thirty NVAF patients prepared for AF ablation were enrolled. TTE and transesophageal echocardiography (TEE) were performed in all patients. LA S/SR in each phase was analyzed off-line. LAA blood flow state and LAA function were assessed by using TEE. LA S/SRs during atrial reservoir phase (LA Sres/SRres) were significantly negatively cor-related with LAA spontaneous echo contrast (SEC) grade (r = -0.567 and -0.520, respectively; all p < 0.01), and positively correlated with LAA emptying fraction (r = 0.602 and 0.619, respectively; all p < 0.01) and with LAA peak emptying flow velocity (r = 0.623 and 0.642, respectively; all p < 0.01). The multivariate logistic regression analysis showed LA Sres to be the strongest independent predictor of LAA stasis, followed by LA volume index. LA Sres < 13% was recommended to predict LAA stasis with sensitivity of 90% and specificity of 74%. LA Sres by TTE can noninvasively predict LAA stasis and may be used as a screening tool to assist in the detection of LAA stasis in patients with NVAF. (Cardiol J 2018; 25, 1: 87-96).

Clinical study on influencing factors for left atrial appendage spontaneous echo contrast or thrombosis in patients with non-valvular atrial fibrillation

Objective To investigate the influencing factors for left atrial appendage(LAA) spontaneous echo contrast (SEC) or thrombosis in patients with non-valvular atrial fibrillation(NVAF) and normal left ventricular ejection fraction(LVEF). Methods This study prospectively enrolled 255 patients with NVAF [paroxysmal atrial fibrillation(PaAF) 196 cases and persistent atrial fibrillation(PeAF) 59 cases]. Patients were divided into two groups according to the findings on transesophageal echocardiography(TEE): positive group with the presence of the LAA SEC or thrombosis (group Ⅰ) and negative group(group Ⅱ) without this two presences. The clinical and echocardiographic data were compared between the two groups. The multivariate logistic regression analysis was used to explore the independent risk factors for development of LAA SEC or thrombosis. Receiver operating characteristic (ROC) curve was performed to determine the predictive value of the factors. Results A total of 255 patients were enrolled. There were 26 cases(10.2%) in group Ⅰ, and 229 cases (89.8%) in group Ⅱ. The age, NT-proBNP, occurrence rate of PeAF, left atrial volume index(LAVI), and LAA orifice long diameter and depth were higher in group Ⅰ than those in group Ⅱ(all P<0.01). The left atrial appendage emptying velocity(LAAV), global left atrial longitudinal strain(GLALS) and LVEF were lower in group Ⅰ compared with those in group Ⅱ (all P<0.01). Multivariate logistic regression analysis and ROC curve showed that GLALS<12.2% and LAAV<31.2 cm/s were independent risk factors of LAA SEC or thrombosis in patients with NVAF and perserved LVEF. Conclusions The impairment of left atrial and LAA function are potential risk factors for cardiogenic embolism. GLALS and LAAV can be used as useful referenced parameters for prediction of stroke in patients with NVAF. Key words: Echocardiography, transesophageal; Atrial fibrillation; Atrial function, left; Left atrial appendage; Spontaneous echo contrast; Strain

Evaluation of transesophageal echocardiography on the morphology and function of the left atrial appendage in nonvalvular atrial fibrillation

Objective To investigate the application value of the transesophageal echocardiography (TEE) in patients with nonvalvular atrial fibrillation about the size, lobes, morphology and function of left atrial appendage (LAA). Methods One hundred and forty-two patients underwent TEE were divided into nonvalvular atrial fibrillation group (98 cases) and non atrial fibrillation group (44 cases). The orifice diameter, depth, volume, peak emptying velocity (PEV) of the LAA and the 1eft atrial dimension (LAD) were measured. The form and lobes of LAA, thrombus and spontaneous echo contrast (SEC) in LAA were observed. Results The LAA orifice diameter, depth, volume and LAD of patients with atrial fibrillation were significantly higher than those in the group without atrial fibrillation, which showed statistical significance (P<0.05). Forty-one cases in atrial fibrillation group were found with the SEC, and the number with thrombus in LAA was 22. The differences of PEV between chicken wings and non-chicken wings were statistically significant (P<0.05). The SEC in LAA and the lobe number of LAA had no relevance. Conclusions It was reliable to analyze the size, morphologies, lobes and hemodynamic parameters of LAA in patients with atrial fibrillation by TEE, which provided reference for percutaneous LAA occlusion and anticoagulation therapy for the patients with atrial fibrillation. Key words: Echocardiography, transesophageal; Atrial fibrillation; Left atrial appendage

Decreased left atrial peak systolic strain evaluated by two-dimensional speckle tracking reflects left atrial appendage dysfunction in sinus rhythm patients with acute ischemic stroke

It is well known that transesophageal echocardiography (TEE) is useful for evaluating left atrial appendage (LAA) function, but TEE is a semi-invasive procedure. Many clinical studies have shown a close relationship between LAA thrombus formation and left atrial (LA) mechanical remodeling. Left atrial (LA) strain assessed by two-dimensional speckle tracking echocardiography is a new tool to evaluate LA function. However, the association of LA strain and LAA function remains to be fully determined. We performed transthoracic and transesophageal echocardiography in 58 consecutive patients with acute ischemic stroke within 7 days of onset and sinus rhythm at TEE performed (40 males, mean age 71±11 years). Longitudinal LA strain was obtained using two-dimensional speckle tracking imaging at each LA segment, and peak systolic strain (S-LAs) was calculated by averaging the results for each segment. Eight patients had LAA thrombus and/or severe LAA spontaneous echo contrast (LAA-SEC). S-LAs was significantly lower in patients with LAA dysfunction than in those without (34.5±12.5 vs. 15.9±7.2%, P<0.01). S-LAs was significantly correlated with LAA eV (r=0.466, p<0.01). The optimal cut off value of S-LAs for predicting LAA dysfunction was determined for 21% (Figure). In patients with LAA dysfunction, 7 patients had low S-LAs. In those 6 patients (86%) had history of paroxysmal atrial fibrillation before stroke onset. Multivariate logistic regression analysis showed that S-LAs was an independent predictor of LAA thrombus and/or LAA-SEC (odds ratio 1.758, p<0.01). In conclusion, decreased S-LAs was independently associated with LAA dysfunction and thrombus formation in patients with acute ischemic stroke and sinus rhythm at echocardiography ![Figure][1] Figure 1. Receiver operating characteristics (ROC) curve analysis of LA peak systolic strain for predicting LAA dysfunction. [1]: pending:yes

Abstract 9903: Left Atrial Appendage Contractility Assessed by Speckle Tracking Transesophageal Echocardiography as a Determinant of Thrombus Formation in Patients Receiving Warfarin for Chronic Atrial Fibrillation: beyond CHADS2 and CHA2DS2-VASc Score

Background: Establishment of optimal risk stratification is the best hope for decreasing the burden of atrial fibrillation (AF)-related thromboembolism. Left atrial appendage (LAA) thrombus is a high risk factor of embolism even in AF with warfarin. LAA contractility evaluated by LAA emptying function (EF), strain and radial velocity (RV) of LAA wall motion could contribute to blood stasis and be an important determinant of thrombus in chronic AF, especially in patients with low CHADS2 or CHA2DS2-VASc score. Methods: Consecutive 260 chronic AF patients with warfarin were examined and divided into 2 groups according to the presence of thrombus; AF with thrombus (n=43, 69±10) and AF without thrombus (n=217, age 66±11). Each group was divided into subgroup according to CHADS2 or CHA2DS2-VASc score≤2 (low CHADS2 or CHA2DS2-VASc subgroup). LAA EF, peak strain and peak RV of LAA wall were measured using speckle tracking echocardiography. LAA volume, spontaneous echo contrast (SEC) and LAA flow velocity were measured. Results: Seventy one % of patients with thrombus and 61% without thrombus met the target INR recommended by Japanese Circulation Society. AF with thrombus had more increased CHADS2 and CHA2DS2-VASc score and reduced LAA EF and strain compared to AF without thrombus (Table). LAA EF and strain were also reduced in low CHADS2 and CHA2DS2-VASc subgroup with thrombus. In multivariate analysis, LAA EF and strain were independent determinants of LAA thrombus. Using 20% of LAA EF as a cutoff, sensitivity and specificity for thrombus were 84% and 90%, using 5 of LAA peak strain, those values were 88% and 76%. Conclusion: LAA EF and peak strain were more useful predictors of thrombus in chronic AF than LAA flow velocity, SEC and CHADS2 and CHA2DS2-VASc score. LAA thrombus formation may depend on LAA contractility. Thus, AF patients with reduced LAA contractility should have a strict anticoagulant therapy regardless of CHADS2 or CHA2DS2-VASc score.

Comprehensive Left Atrial Appendage Optimization of Thrombus Using Surface Echocardiography: The CLOTS Multicenter Pilot Trial

The aim of this study was to determine the ability to identify thrombus within the left atrial appendage (LAA) in the setting of atrial fibrillation (AF) using transthoracic echocardiography (TTE). In AF, the structure and function of the LAA has historically been evaluated using transesophageal echocardiography (TEE). The role of TTE remains undefined. The Comprehensive Left Atrial Appendage Optimization of Thrombus (CLOTS) multicenter study enrolled 118 patients (85 men; mean age, 67 +/- 13 years) with AF of >2 days in duration undergoing clinically indicated TEE. On TEE, the LAA was evaluated for mild spontaneous echo contrast (SEC), severe SEC, sludge, or thrombus. Doppler Tissue imaging (DTI) peak S-wave and E-wave velocities of the LAA walls (anterior, posterior, and apical) were acquired on TTE. Transthoracic echocardiographic harmonic imaging (with and without intravenous contrast) was examined to determine its ability to identify LAA SEC, sludge, or thrombus. Among the 118 patients, TEE identified 6 (5%) with LAA sludge and 2 (2%) with LAA thrombi. Both LAA thrombi were identified on TTE using harmonic imaging with contrast. Anterior, posterior, and apical LAA wall DTI velocities on TTE varied significantly among the 3 groups examined (no SEC, mild SEC, severe SEC, sludge or thrombus). An apical E velocity < or = 9.7 cm/s on TTE best identified the group of patients with severe SEC, sludge, or thrombus. An anterior S velocity < or = 5.2 cm/s on TTE best identified the group of patients with sludge or thrombus. The CLOTS multicenter pilot trial determined that TTE is useful in the detection of thrombus using harmonic imaging combined with intravenous contrast (Optison; GE Healthcare, Milwaukee, WI). Additionally, LAA wall DTI velocities on TTE are useful in determining the severity of LAA SEC and detecting sludge or thrombus.

Contrast-enhanced tissue Doppler imaging of the left atrial appendage is a new quantitative measure of spontaneous echocardiographic contrast in atrial fibrillation

Although left atrial appendage spontaneous echo contrast (LAASEC) is a marker of increased thromboembolic risk in atrial fibrillation, it has previously only been evaluated qualitatively. We sought to determine if an intravenous contrast echocardiographic agent combined with tissue Doppler imaging (TDI) of the LAA could accurately quantify LAA-SEC in patients with atrial fibrillation. We prospectively identified 55 patients with persistent atrial arrhythmias (mean age 63+/-13 years) undergoing a transesophageal echocardiography (TEE), with LAA-SEC prior to direct current cardioversion. In addition to off-line calculation of backscatter index and shear rate, quantification of the velocity in a color TDI region of interest was performed in the LAA cavity following a 0.5-mL intravenous bolus of Optison. LAA-SEC was qualitatively graded by a blindedreader as mild (n = 29) or severe (n = 26), and was compared off-line to TEE-derived quantitative variables. Compared to patients with mild LAA-SEC, those with severe LAA-SEC had significantly decreased LAA emptying velocity, LAA TDI mean velocities and shear rate. Over the whole group, the mean maximal velocity of the LAA using TDI correlated with LAA emptying velocity (r = 0.59; P < 0.0001), shear rate (r = 0.55; P < 0.0001) and LAA area (r = 0.34; P = 0.014). Severe LAA-SEC was found with 72% sensitivity and 82% specificity if TDI mean velocity was <6.13 cm/s. On logistic regression analysis, LAA-TDI was the only predictor of qualitative LAA-SEC grade. Contrast-enhanced TDI is an original new tool that provides a quantification of the mean velocity of LAA-SEC that might improve our decision making in patients with atrial fibrillation.

Transthoracic Echocardiographic Predictors of the Left Atrial Appendage Contraction Velocity in Stroke Patients with Sinus Rhythm

Systemic embolization is a potential complication in patients with thrombi situated in the left atrium and particularly, in the left atrial appendage (LAA). Reduced LAA contraction velocities, determined by the transesophageal echocardiography (TEE), are associated with increased risk of LAA spontaneous echocontrast and thrombus formation, and a history of systemic embolism. However, TEE remains a semi-invasive procedure, limiting its serial application as a screening tool. Therefore, it is desirable to obtain information regarding LAA function by transthoracic echocardiography in patients having cardioembolic stroke. The present study was designed to investigate various echocardiographic variables for patients with stroke to predict LAA dysfunction, reflected as reduced LAA contraction velocity. We studied a total of 61 patients with newly diagnosed acute embolic stroke (42 patients) and transient ischemic attack (19 patients). Computerized tomographic scanning was performed for the diagnosis of embolic stroke. Left atrial functional parameters determined by transthoracic echocardiography, such as left atrial active emptying fraction and acceleration slope of mitral inflow A wave, had significant correlations with the LAA contraction velocity (r = 0.57, p < 0.001; r = 0.54, p < 0.001, respectively). Left atrial volume index, left atrial active emptying volume and left atrial fractional shortening were also correlated with LAA contraction velocity (r = -0.44, p < 0.001; r = 0.38, p = 0.003; r = 0.37, p = 0.004, respectively). In conclusion, transthoracic echocardiography can provide valuable and reliable information about the LAA contraction velocity in stroke patients with sinus rhythm. This finding gives new insights for the appropriate strategy in the evaluation of an acute ischemic stroke.

Echocardiographic Predictors of Left Atrial Appendage Spontaneous Echocontrast in Patients with Stroke and Atrial Fibrillation

The presence of spontaneous echocontrast (SEC) in the left atrium (LA) or LA appendage (LAA) has been associated with a higher risk of thromboembolism and cerebrovascular accidents. The purpose of this study was to define the new transesophageal echocardiographic predictors of SEC for patients with stroke and atrial fibrillation. We studied 47 patients with stroke and atrial fibrillation who were undergoing transesophageal echocardiography for the evaluation of source of cardiac emboli. Patients were divided into two groups based on the absence (group 1) or presence (group 2) of SEC in the LAA. Compared with group 1, group 2 had larger LA, larger LAA minimum and maximum areas, and decreased LAA flow velocity, LAA wall velocity, LAA tissue intensity, and intensity ratio. In the stepwise discriminate analysis tissue intensity of LAA, minimum LAA area, LAA flow velocity, and LAA wall velocity were found as independent predictors of LAA SEC. LAA wall velocity had the greatest area under the receiver operating characteristic curve, indicating that the most powerful parameter for SEC is LAA wall velocity. Decreased LAA flow velocity and LA wall velocity, increased LAA size, and less negative LAA tissue intensity are associated with SEC in patients with nonvalvular atrial fibrillation. Strain and strain measurements of LAA give no more benefit.

Evaluation of left atrial appendage functions in patients with thrombus and spontaneous echo contrast in left atrial appendage by using color Doppler tissue imaging.

Thrombus and spontaneous echo contrast (SEC) develops in the left atrial appendage (LAA) when LAA function is disturbed. Decrease of left atrial appendage emptying velocity shows LAA dysfunction. The purpose of this study is to examine the incidence of SEC and/or thrombus in LAA in patients with acute myocardial infarction and to assess the LAA function using color Doppler tissue imaging (CDTI) of the patients with detected SEC and/or thrombus. Eighty-four patients with acute myocardial infarction were included in the study. Spontaneous echo contrast and/or thrombus were observed in 24 (29%) of the 84 patients who were categorized as group 1 (mean age 59 +/- 12 years). Sixty patients (71%) without thrombus and/or SEC in LAA were categorized as group 2 (mean age 58 +/- 8 years). Left atrial diameters and left ventricular ejection fraction were measured by using transthoracic echocardiography. Left atrial appendage emptying and LAA filling velocity were measured by transesophageal Doppler echocardiography. Systolic appendage tissue velocities (SaV cm/s) were measured at the basal, mid, and tip of medial wall of LAA by transesophageal CDTI. Group 1 had significantly decreased LAA emptying velocities, mid SaVs, and left ventricular ejection fractions compared to group 2 (37 +/- 9 cm/s vs 55 +/- 22 cm/s, 3.1 +/- 1.6 cm/s vs 3.7 +/- 1.2 cm/s, and 47 +/- 13% vs 58 +/- 10%, respectively, P = 0.002, P = 0.04, P = 0.03). Group 1 had significantly increased left atrial diameters compared to group 2 (40 +/- 5 mm vs 36 +/- 6 mm P = 0.001). Left atrial appendage-filling velocities, basal SaVs and tip SaVs in group 1 were lower than those in group 2 but not significantly. Mid-SaV of LAA medial wall and LAA emptying velocity decrease in patients with thrombus and/or SEC were an indication of functional disorder of LAA. Color Doppler tissue imaging appears to be a clinically applicable and reliable imaging technique that allows quantitative assessment of regional LAA systolic function.

Assessment of left atrial appendage filling pattern by using intravenous administration of microbubbles: Comparison between mitral stenosis and mitral regurgitation

Mitral stenosis (MS) and mitral regurgitation (MR) are the most frequent conditions that cause a dilation and dysfunction of the left atrial appendage (LAA). Despite similarly dilated LAA in patients with MS and MR, the incidence of LAA thrombi and the risk of thromboembolism is different between these patients. The purpose of this study was to characterize the filling pattern of LAA by using intravenous administration of perfluorocarbon-exposed dextrose albumin (PESDA) during transesophageal echocardiographic examination in patients with MS and MR. Twenty-four patients with moderate to severe MS, 12 patients with severe MR, and a control group including 30 patients with conditions other than mitral valve disease underwent transesophageal echocardiographic examination with an intravenous bolus injection of PESDA. LAA emptying and filling velocities and maximal and minimal areas of LAA and LAA ejection fraction were measured. Digital gray-scale intensity (GSI) of the left atrial (LA) and LAA cavity after PESDA injection was measured by off-line analysis. Compared with control patients, patients with MS or MR had larger maximal and minimal areas of LAA and reduced LAA ejection fraction. LAA peak emptying flow velocity was significantly lower in patients with MS compared with those of MR or control patients. LAA peak filling velocity was significantly lower in patients with MS compared with that of control patients. However, there was no significant difference of LAA peak filling velocity between the patients with MS and MR. There was no significant difference of GSI ratio of LAA and LA between patients with MR and control patients; however, GSI ratio of LAA and LA was significantly lower in patients with MS compared with that of MR. The incidence of LAA spontaneous echo contrast and LAA thrombi in patients with MS was significantly higher than that of the patients with MR and control subjects (P <.005). Despite similarly dilated LAA area and depressed contractile function of LAA in patients with MS and MR compared with control patients, profoundly impaired LAA filling with resultant flow stasis was demonstrated by contrast echocardiography in patients with MS. These findings may explain the higher incidence of LAA spontaneous echo contrast and thrombus in patients with MS.

Transthoracic and Transesophageal Echocardiographic Indices Predictive of Sinus Rhythm Maintenance After Cardioversion of Atrial Fibrillation: An Echocardiographic Study During Direct Current Shock

Up to 57% of atrial fibrillation (AF) recurrences after cardioversion take place during the first 30 days following direct current shock (DCS) delivery. Previous echocardiographic studies on sinus rhythm (SR) maintenance after cardioversion have focused mainly on parameters recorded before DCS, while other studies have reported on the indices recorded soon after delivery of the shock. Therefore, we investigated 18 patients with nonrheumatic AF, selected to undergo DCS, by both transthoracic (TTE) and transesophageal (TEE) echocardiography performed within 10 minutes before and after the electrical shock delivery. TTE was utilized for the evaluation of left atrium and left ventricle shape as well as for mitral Doppler flow sampling, while TEE was used to evaluate left atrial appendage (LAA) morphology and function, to score the LAA spontaneous echo contrast, and to evaluate the flow of left superior pulmonary vein; the transesophageal probe was left in situ during the electrical procedure. Thirty days after cardioversion, 10 (55%) patients maintained SR (Group 1) while 8 (45%) reverted to AF (Group 2). We compared the mean values of the parameters recorded in the two groups both before and after DCS. Although many parameters of pre- and postcardioversion analysis proved to be significantly different between the two groups, the most marked differences were exhibited by the following postcardioversion indices: Peak Doppler flow velocity of the end-diastolic mitral flow (30.10 +/- 5.24 vs. 20.50 +/- 6.32 cm/sec, P = 0.003); sum of peak velocities of the end-diastolic contraction (A) and relaxation (A(1)) of LAA (A + A(1) = 58.20 +/- 17.02 vs. 31.25 +/- 9.27 cm/sec, P = 0.001); duration of A + A(1) (162.70 +/- 27.01 vs. 133.75 +/- 5.31 msec, P = 0.002); and sum of durations of the early diastolic forward (E) and reverse (E(1)) flow of LAA (101.90 +/- 35.15 vs. 53.33 +/- 16.33 msec, P = 0.006). Using a single echocardiographic examination during DCS and after induction of anesthesia, without further discomfort to patients, we were able to identify useful parameters for the prediction of future electrical activity of the heart before as well as soon after DCS. Postcardioversion indices, derived by both TTE and TEE, were even more predictive of SR maintenance after 1 month than precardioversion parameters.