Left Atrial Appendage Dysfunction Research Articles

Abstract WMP72: High Risk Left Atrial Appendage Morphology (LAA-H) is Associated With Cardioembolic and Embolic Stroke of Unknown Source Subtypes

Background: The left atrial appendage (LAA) is the main source of thrombus in atrial fibrillation (AF); biomarkers of LAA dysfunction are associated with ischemic stroke (IS) risk in patients with AF. We hypothesized that high risk LAA features [High risk morphology (LAA-H), LAA volume (LAAV), and LAA orifice surface area (LAAOSA)] would be more prevalent among patients with cardioembolic (CE) stroke and embolic stroke of undetermined source (ESUS) than among those with non-cardioembolic stroke (NCS). Methods: Consecutive patients with IS from a prospective comprehensive stroke center registry who previously underwent a clinically-indicated qualifying chest CT were included. Patients underwent inpatient diagnostic evaluation for ischemic stroke, and stroke subtype was determined based on ESUS criteria. LAA morphology [Low risk morphology was defined as two lobes with an acute angle between them or chicken wing morphology and LAA-H defined as all others], LAAOSA (measured in a plane parallel to the left atrium), and LAAV (measured using a volumetric analysis software) were determined using contrast enhanced thin-slice chest CT (≤2.5 mm thickness) by investigators blinded to stroke subtype. Results: Of 1234 patients with ischemic stroke, 329 (26.7%) patients had a qualifying chest CT performed (126 CE, 116 ESUS, and 87 NCS). The baseline characteristics of patients with and without chest CT were similar. When compared to NCS, LAA-H was more prevalent in ESUS (86.4% vs. 70.1%, p=0.018) and CE stroke (82.5% vs. 70.1%, p=0.042). The LAAOSA and volume did not significantly differ between the 3 groups (Table). Conclusion: LAA characteristics associated with cardioembolic stroke are also more prevalent in patients with ESUS. Larger studies are needed to confirm that LAA features are a risk factor for stroke among patients without AF, and whether anticoagulation is effective in patients with high-risk LAA features.

Left atrial appendage dysfunction in acute embolic stroke young patients with sinus rhythm: Correlation with Tissue Doppler mitral annular systolic velocity

BackgroundTrans-esophageal echocardiogram (TEE) is a gold standard test for diagnosis of left atrial (LA) appendage function. AimTo evaluate left atrial appendage (LAA) dysfunction using mitral annular systolic velocity measured by tissue Doppler imaging “Sm” in acute embolic stroke young patients with sinus rhythm. MethodsTransthoracic (TTE) and transesophageal echocardiography (TEE) were performed in 70 consecutive patients with sinus rhythm without obvious left ventricular dysfunction within 2 weeks after embolic stroke. Two groups were identified: LAA dysfunction [LAA emptying peak flow velocity (LAA-eV) <0.55 m/s, n = 28, age 52 ± 11 years] and without LAA dysfunction (LAA-eV ≥ 0.55 m/s, n = 42, age 54 ± 10 years) on TEE. Tissue Doppler mitral annular systolic velocity “Sm” was obtained in apical four chambers view on TTE and D-dimer level estimated for all patients. ResultsSm was significantly lower in patients with than in those without LAA dysfunction (P < 0.0001). There was a significant correlation between Sm, LAVI, LAEF%, E/A ratio and LAA-eV in all selected patients groups. The optimum cut-off value of Sm for predicting LAA dysfunction was below or equal 8 cm/s (sensitivity 89.6% and specificity 94.2%). ConclusionTissue Doppler mitral annular systolic velocity is an independent non-invasive easy predictor of LAA dysfunction and significantly correlated with LAA-eV (p < 0.0001) in acute embolic stroke young patients with sinus rhythm.

Association between the N-terminal plasma brain natriuretic peptide levels or elevated left ventricular filling pressure and thromboembolic risk in patients with non-valvular atrial fibrillation

BackgroundWe aimed to investigate the role of brain natriuretic peptide (BNP) levels and left ventricular (LV) filling pressures in thromboembolic risk in patients with non-valvular atrial fibrillation (AF). MethodsAmong 327 patients with non-valvular AF, the ratio of peak early filling velocity to mitral annulus velocity (E/Ea) and N-terminal proBNP (NT-proBNP) was compared according to the presence of left atrial appendage (LAA) dysfunction [presence of spontaneous echo contrast (SEC)≥grade 3 and/or reduced LAA emptying flow velocity <20cm/s]. ResultsCompared to patients without LAA dysfunction, patients with LAA dysfunction presented with significantly higher CHADS2 scores (1.24±1.14 vs. 1.68±1.31, p=0.005), high-sensitivity C-reactive protein (0.36±1.18mg/dl vs. 0.66±1.32mg/dl, p=0.043), and NT-proBNP (765.3±2534.8pg/ml vs. 2266.9±6117.4pg/ml, p=0.002). Furthermore, patients with LAA dysfunction showed significantly higher left atrial volume index (LAVI, 25.1±10.9 vs. 43.1±22.1, p<0.001) and E/Ea (10.8±7.27 vs. 7.97±2.50mg/dl, p<0.001). Plasma logNT-proBNP levels were significantly correlated with the presence of SEC (r=0.276, p<0.001), LAA emptying flow velocity (r=−0.492, p<0.001), LAVI (r=0.405, p<0.001), and E/Ea (r=0.353, p<0.001). Binary logistic regression analysis showed that high NT-proBNP level >249.7pg/ml (odds ratio, OR 6.79, 95% confidence interval, CI 3.16–15.55, p<0.001) and E/Ea >10 (OR 4.41, 95% CI 2.39–8.15, p<0.001) were independent predictors of LAA dysfunction after adjustment of known thromboembolic risk factors. ConclusionElevated plasma NT-proBNP concentrations and LV filling pressures represented by LAA dysfunction may be reliable surrogate markers for predicting thromboembolic risk in patients with AF.

Lower Body Weight in Men, an Epidemiological Predictor of Enlarged Left Atrium in Sinus Rhythm Patients with Dilated Heart.

Background/Aims:The source of thrombi in patients with dilated cardiomyopathy is not necessarily from the dilated left ventricle. Left atrium (LA) and left atrial appendage (LAA) might be in charge for relatively high rate of systemic embolizations in these patients. The main aim of our study was to identify epidemiological predictors in sinus rhythm patients with dilated heart for LA and LAA dilation and/or dysfunction.Patients and Methods:This was a prospective cross-sectional study conducted from 2009 to 2014 in 101 sinus rhythm patients with dilated heart. We excluded patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flutter, severe systolic dysfunction, mechanical valves, oral anticoagulation therapy, and/or patients with a history of stroke/systemic thromboembolic event.Results:Mean patient age was 58.13 ± 12.66 years and 69.3% were men. Hypertension was encountered in 51% of our patients, 56% of them had a history of coronary artery disease, 30% had diabetes, 25% had dyslipidemia, 30% were smokers, whereas 10% were alcoholics. Mean LA dimensions resulted higher than reference values, whereas 86% of our patients had LAA dysfunction. Male gender was an independent predictor for LA diameter dilation (95% confidence interval [CI]: 1.765–9.078, P = 0.005), while lower body weight was a predictor for enlargement of LA area (95% CI: 0.044–0.351, P = 0.014) and LA volume (95% CI: 0.160–2.067, P = 0.024).Conclusion:Male patients with dilated cardiomyopathy at sinus rhythm with lower body weight tend to have larger LA and consequently might be at higher risk of developing atrial thrombus and its subsequent consequences.

Abstract 12030: The Process of Left Atrial Appendage Dysfunction Evaluated by 3D Transesophageal Echocardiography

Introduction: Left atrial appendage (LAA) dysfunction progressively evolves in atrial fibrillation (AF) patients. LAA transesophageal echocardiographic (TEE) parameters can predict thrombotic tendencies and AF treatment outcomes. However, the process of LAA dysfunction remains to be elucidated. Methods: Eighty-four persistent AF patients (64men, age 68±10) that underwent TEE were enrolled. We obtained three-dimensional full-volume LAA data from these patients and reconstructed two-dimensional LAA cross sectional images at the orifice and mid-portion level of the LAA. The maximum and minimum cross-sectional LAA areas were measured at each position and the area change ratio at the orifice (ACR-O) and mid-portion (ACR-M) were calculated. We defined low contractility as a decreasing area change ratio (ACR) of &lt;30% at each position and evaluated the associations between the ACR-O, ACR-M, and continuous AF duration. Results: The patients were categorized into three groups based on the ACR-O and ACR-M: those that maintained both ACR-Os and ACR-Ms (n=48, Group 1), those with reduced ACR-Os and maintained ACR-Ms (n=17, Group 2), and those with both reduced ACR-Os and ACR-Ms (n=19, Group 3). There were no patients with maintained ACR-Os and reduced ACR-Ms. The mean continuous AF durations of each group were 29±42, 54±40, and 88±87 months, respectively. In Group 3, the LAA emptying flow velocity was significantly decreased compared to that in Group 1 and Group 2 (38±19, 31±14, 22±11,cm/s) and LAA thrombi were detected more frequently (0%, 12%, 58%). Conclusions: This study suggested that LAA dysfunction occurred from the orifice and progressed toward the mid-portion. When LAA dysfunction extended over the mid-portion, the LAA flow velocity decreased and LAA thrombi were detected more frequently. Even though anticoagulant drugs were administrated in all patients, 58% of patients had thrombi in Group 3. These patients should be considered for additional therapeutic approaches.

Left Atrial Appendage Function and Stroke Risk.

About 30% to 40% of ischemic stroke is of unknown cause.1,2 Recently, biomarkers of atrial dysfunction, or atrial cardiopathy, have been associated with embolic stroke risk even in the absence of atrial fibrillation (AF), suggesting that the presence of AF is not required for left atrial thromboembolism to occur.3 Most left atrial thrombi occur in the left atrial appendage (LAA), but there is limited use of LAA dysfunction parameters, such as LAA flow velocity and morphology, to predict ischemic stroke risk. Here we review the literature on the association between LAA pathology and dysfunction and ischemic stroke, with a focus on patients with unexplained, or cryptogenic, stroke. Each year, at least 200000 people in the United States experience a cryptogenic stroke.1,2 The classification of cryptogenic stroke, a subgroup of stroke of undetermined cause, was conventionally made when the initial stroke evaluation was unrevealing, regardless of whether the evaluation was exhaustive, routine, or incomplete.4 More recently, investigators have used the term embolic stroke of undetermined source in reference to a nonlacunar infarction occurring in the absence of a specific identifiable high-risk stroke mechanism, such as AF, valvular heart disease, or large artery stenosis.5 The idea that such infarctions are caused by a distant source of embolus is supported by findings from the National Institute of Neurological Disorders and Stroke Databank, indicating that undocumented cardiac or aortic sources of embolism were found in about two thirds of patients with cryptogenic stroke on follow-up testing.2 One of the most common mechanisms often found in a delayed fashion after cryptogenic stroke is paroxysmal AF, which is detected in ≤30% of patients with cryptogenic stroke on outpatient heart-rhythm monitoring.6,7 However, more than half of cryptogenic strokes remain a mystery even after long-term …

Assessment of left atrial appendage function during sinus rhythm in patients with obstructive sleep apnea.

Objective:Obstructive sleep apnea (OSA) is associated with thromboembolic events. Compromised left atrial appendage (LAA) function due to left ventricular (LV) performance abnormality, often present in patients with OSA, may play an important role. The purpose of this study is to evaluate LV and LAA mechanical functions during sinus rhythm (SR) in patients with OSA.Methods:LV and LAA functions were assessed in 43 OSA patients and compared with that of 20 control patients in SR. Tissue Doppler velocities of the LAA apex and emptying velocities (EV) of LAA were obtained on parasternal short-axis view.Results:The baseline clinical characteristics were similar except for AHI (apnea-hypopnea index), minimal SaO2, mean SaO2, hypertension, and body-surface area. Most of the LV echocardiographic parameters significantly deteriorated in OSA patients in comparison with those in the control group. LAA EV, LAA systolic relaxation velocity (SM), LAA early-diastolic velocity (EM), LAA contraction velocity (AM), left atrial (LA) minimum volume index, LA ejection fraction, LA conduit volume index, and LA reservoir volume index were lower in OSA patients compared with those in the control group (p<0.05). LAA AM was negatively correlated with AHI and the ratio of peak early diastolic flow velocity (E) to early-diastolic (E’) and positively correlated with LA conduit volume (p<0.05). Multiple predictors for LAA AM were AHI, presence of diastolic dysfunction, and E/E’ values (p<0.05).Conclusion:LAA mechanical function is significantly depressed in patients with OSA and SR. LAA dysfunction may predispose these patients to thromboembolic events. The evaluation of LAA mechanical function by tissue Doppler study using transthoracic echocardiography (TTE) may become an alternative for routine work-up in OSA patients.

Abstract 18516: Regional Dysfunction of Left Atrial Appendage and its Association with Stroke in Atrial Fibrillation

Background: Atrial Fibrillation (AF) is associated with an increased risk of cardioembolic stroke. Previous studies demonstrate that the Left atrial appendage (LAA) is the most common site of intracardiac thrombus, and the LAA morphology alone may determine the risk of stroke. We aimed to determine the association between LAA regional dysfunction using novel, noninvasive, image-based motion-estimation CT (iME) and prior history of stroke in patients with AF. Methods: Among the patients with history of AF referred for ablation who underwent pre-ablation CT with retrospective ECG gating, we identified 18 patients with a prior history of stroke or TIA, and 18 age- and gender-matched controls. The patients in AF at the time of CT were excluded. Four-dimensional motion vector field was estimated from reconstructed CT images using iME at every 5% RR interval. To assess myocardial deformation, area change ratio and area change rate were calculated over the endocardial surface of the LA and LAA. Univariate and multivariate comparisons were made by using binary logistic regression model. Results: A total of 36 patients (mean age 67.6 ± 8.1 years, 66.7% male, 16.7% persistent AF) were included in the study. Univariate analysis showed that the LA pre-atrial contraction area change ratio and LAA maximum area change ratio were significantly lower (P= 0.02 and 0.04, respectively) in the stroke/TIA group compared to the control group. These changes remained statistically significant in multivariate analysis (P=0.03 and 0.04, respectively) after adjusting for age, sex, body mass index, LV ejection fraction, type of AF, and CHADS score. Conclusions: LAA regional dysfunction is associated with stroke/TIA in patients with AF. LAA regional dysfunction detected by iME could represent a marker for stroke and a possible therapeutic target.

Left atrial strain as evaluated by two-dimensional speckle tracking predicts left atrial appendage dysfunction in patients with acute ischemic stroke

BackgroundLeft atrial appendage (LAA) dysfunction predisposes patients with atrial fibrillation (AF) to cardioembolic stroke. Two-dimensional (2D) speckle tracking was reported to be useful for evaluating left atrial (LA) regional function, as well as left ventricular function. However, it remains unclear whether 2D speckle tracking is useful for evaluating LAA dysfunction. Therefore, we investigated whether decreased LA strain may predict LAA dysfunction and thrombus formation in patients with acute ischemic stroke. MethodsWe performed transthoracic and transesophageal echocardiography in 120 patients (83 males, mean age 72±11years) within 7days of onset of an acute ischemic stroke. Longitudinal LA strain was evaluated using 2D speckle tracking imaging at each LA segment, and peak systolic strain was calculated by averaging the results for each segment. ResultsForty-eight patients had LAA dysfunction as defined by the presence of LAA thrombus and/or severe spontaneous echo contrast. LA peak systolic strain was significantly decreased in patients with LAA dysfunction compared to those without (32.3±13.7% vs. 12.1±7.2%, p<0.0001). LA peak systolic strain was significantly correlated with LAA emptying flow velocity (r=0.693, p<0.0001). The optimum LA peak systolic strain cut-off value for predicting LAA dysfunction was 19%. Multivariate logistic regression analysis showed that LA peak systolic strain was an independent predictor of LAA dysfunction (odds ratio 0.059, 95% confidence interval 0.018–0.146; p<0.0001). ConclusionDecreased LA peak systolic strain was independently associated with LAA dysfunction in patients with acute ischemic stroke.

Prediction of high risk of thrombus by haemodynamics changes in left atrial appendage using transesophageal echocardiography

Objective To study the left atrial appendage (LAA) function and haemodynamics by transesophageal echocardiography,and predict high risk of thrombosis.Methods Eighty-nine consecutive patients were studied using transesophageal echocardiography.According to with spontaneous echo contrast (SEC) or not,all patients were divided into SEC group (n =17) and non-SEC group (n-=72).LAA emptying peak flow velocity (LAA-EV),filling peak flow velocity (LAA-FV) were measured by pulsed Doppler.The middle segment of the LAA medial wall systolic peak velocity (LAA-TSV) and diastolic peak velocity (LAA-TDV) were obtained by tissue Doppler imaging.LAA color Doppler and M-mode color Doppler images were acquired and derived the LAA emptying flow propagation velocity (LAA-EPV).Results LAA-EV,LAA-FV,LAA-TSV,LAA-TDV,LAA-EPV of SEC group were lower than those of non-SEC group (P ＜0.05).LAA M-mode color Doppler had four characteristic patterns,N pattern (normal pattern) which flow eject from LAA apical to LAA orifice,R pattern (reverse pattern) which flow eject from LAA orifice to LAA apical,V pattern (vertical pattern) vertical signals seen in systole and without efficient flow,S pattern (stasis pattern) almost no flow signal.V,R and S patterns may indicate high risk of SEC and thrombosis.LAA-EPV had strong correlation with LAA-EV (r =0.742,P ＜0.001),and moderate correlation with LAA-TSV (r =0.462,P ＜0.01),LAA-EV had strong correlation with LAA-TSV (r =0.600,P ＜0.01).Conclusions LAA dysfunction would result in hypokinetic LAA wall motion and reduced blood flow velocity.Emptying abnormalities of LAA might be the important reasons for blood stasis and thrombus formation.Emptying characteristic low patterns of V,R and S might be novel methods to predict high risk of thrombus. Key words: Echocardiography,transesphageal; Atrial appendage; Hemodynamics

Left atrial appendage dysfunction in acute cerebral embolism patients with sinus rhythm: correlation with pulse wave tissue Doppler imaging.

To evaluate left atrial appendage (LAA) dysfunction using left atrial pulse-wave tissue Doppler imaging (PW-TDI) in acute cerebral embolism (ACE) patients with sinus rhythm (SR), transthoracic (TTE) and transesophageal echocardiograhy (TEE) were performed in 60 consecutive patients with SR without obvious left ventricular dysfunction within 2 weeks after ACE. Two groups were identified: LAA dysfunction [LAA emptying peak flow velocity (LAA-eV) <0.55 m/s, n = 20, age 65 ± 10 years] and without LAA dysfunction (LAA-eV ≥ 0.55 m/s, n = 40, age 64 ± 10 years) on TEE. Left atrial wall motion velocity (WMV) was obtained from PW-TDI, with the sample volume placed at the left atrial anterior wall adjacent to ascending aortic inferior wall from the long axis view on TTE. WMVs showed triphasic waves: after the P wave (La') during systole (Ls'), and during early diastole. La' and Ls' were significantly lower in the group with versus without LAA dysfunction (4.9 ± 1.4 vs. 7.7 ± 1.8 cm/s, p < 0.0001; 5.3 ± 2.0 vs. 6.7 ± 1.9 cm/s, p < 0.001, respectively) and prevalence of paroxysmal atrial fibrillation, left atrial volume index, and serum levels of brain natriuretic peptide were significantly higher (60 vs. 15 %, p < 0.001; 32 ± 13 vs. 24 ± 13 ml/m(2), p < 0.05; 174 ± 279 vs. 48 ± 68 pg/ml, p < 0.01, respectively). La' was an independent predictor of LAA dysfunction (OR 0.380, 95 % CI 0.156-0.925, p < 0.05), and was significantly correlated with LAA-eV (r = 0.594, p < 0.0001) and LAA fractional area change (r = 0.682, p < 0.0001). The optimal cut-off value for LAA-eV < 0.55 m/s was 5.5 cm/s (sensitivity 83 %, specificity 88 %). La' is a useful and convenient strong predictor of LAA dysfunction in ACE patients with SR.

Echocardiographic Predictors of Left Atrial Thrombus in Patients With Severe Rheumatismal Mitral Stenosis

Background: Rheumatismal mitral stenosis is less common today than it was several decades ago, but it is a common cause of mitral stenosis (MS) in the developing world. Mitral valve stenosis symptoms include fatigue, palpitations, and Shortness of breath especially with exertion. Objectives: The purpose of this prospective study was to determine the incidence of left atrial (LA) thrombus and the predisposing factors predicting its developments in patients with symptomatic rheumatismal mitral stenosis who underwent transesophageal echocardiography (TEE) planed for percutaneous transvenous mitral commissurotomy (PTMC). Patients and Methods: Patients who were referred to perform TEE before mitral balloon valvuloplasty enrolled the study. Data were analyzed by SPSS. Results: Out of 92 patients, females were 68 (73.91%). Mean age was 43.35 ± 13.94. They were classified into two groups based on the presence or absence of LA thrombus. Group A consisted of 21 patients (seven men and 14 women) with LA thrombus (mean age of 53.00 ± 15.70 years). Group B consisted of 71 patients (17 men and 54 women) without LA thrombus. There were no statistically significant differences between the two groups regarding age, sex, LA diameter, LA area, LA smoke, Trans-mitral mean pressure gradient, systolic pulmonary artery pressure, left ventricular ejection fraction and right ventricular function, but patients with LA clot had more LA appendage dysfunction, more frequent atrial fibrillation rhythm, and smaller mitral valve area (P = 0.020, 0.005 and 0.020 respectively) and the prevalence of MR was also lower in this group (P = 0.049). In our evaluation there was no statistically significant difference regarding the LA diameter or LA area in patients with or without LA smoke. Conclusions: The frequency of left atrial clots increased with the presence of LAA dysfunction, atrial fibrillation rhythm, and smaller mitral valve area. Presence of MR had protective effects against LA clots.

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

Association between Paroxysmal Atrial Fibrillation and the Left Atrial Appendage Ejection Fraction during Sinus Rhythm in the Acute Stage of Stroke: A Transesophageal Echocardiographic Study

This study aimed to investigate whether left atrial appendage (LAA) dysfunction evaluated by transesophageal echocardiography (TEE) during sinus rhythm is predictable of paroxysmal atrial fibrillation (PAF) as an embolic source in the acute stage of stroke. We measured and analyzed LAA flow velocity (LAA-FV) and LAA ejection fraction (LAA-EF) in 300 acute ischemic stroke patients by TEE. We divided the acute ischemic stroke patients into 3 groups. The atrial fibrillation (AF) group (n=58) comprised patients whose TEE was performed during AF rhythm. The PAF group (n=42) comprised patients with a history of AF but with normal sinus rhythm when TEE was performed. The normal sinus (sinus) group (n=200) did not have any history of AF. We found that mean LAA-FV and LAA-EF values in the PAF group were significantly lower than those in the sinus group (P<.001). The diagnostic accuracy of LAA-FV for the diagnosis of PAF calculated as the area under receiver operating characteristic curves was low (.582, 95% confidence interval [CI]=.498-.665) but that of LAA-EF was modest (.721, 95% CI=.653-.789), with an optimal cutoff point of 49.1%. LAA dysfunction as determined by TEE (LAA-EF<49.1%) in the acute stage of stroke is predictive of PAF with moderate accuracy. Long-term electrocardiographic monitoring is recommended for cryptogenic stroke patients with LAA dysfunction.

EComment. Left atrial appendage: an underestimated component of surgery for atrial fibrillation

We have read with great interest the manuscript by Bakker et al. [1], in which they share their surgical experience with the modified maze procedure as concomitant surgery and define risk factors for recurrent atrial fibrillation. It is a well-designed retrospective cohort study, but a few issues have to be discussed. 66.9% of patients had a left atrial appendage (LAA) amputation and 10.7% of patients had a bi-auricular amputation in the study cohort. There were 2 patients, who had a stroke even in early postoperative course (<30 days). It is well established that LAA amputation is an important component of the Cox-maze procedure. The role of LAA has been increasingly recognized in the initiation and maintenance of AF. Moreover, LAA amputation not only lowers the risk of embolic events postoperatively, but also lowers risk of recurrent atrial fibrillation. Recent papers have shown that LAA is an underrecognized trigger site of AF and may be an important area causing recurrent AF after ablation [2]. For that reason, it would be wise to perform LAA amputation as an integral part of Cox-maze procedure. One obstacle for this may be the physiological role of LAA. It is known that LAA has role in supporting cardiac output and regulation of blood pressure, and modulating thirst and hypercoagulability. In humans, it has been shown that atrial natriuretic peptide (ANP) and brain natriuretic peptide concentrations, levels of von Willebrand factor, D-dimer, and thrombin-antithrombin III complex increase with LAA dysfunction. However, there were no alterations in haemodynamics and coagulation in patients with amputated LAAs [3]. In terms of the right atrial appendage (RAA), there is currently no strong evidence for performing an RAA amputation during arrhythmia surgery except in patients with thrombi in the RAA (rare, when compared to LAA) [4]. Moreover, it is suggested that preservation of the RAA attenuated the reduction in plasma ANP levels after the maze procedure. So, the increased plasma ANP levels may have protective role in detrimental haemodynamic consequences after surgery [5]. As a result, surgeons must amputate LAA routinely in the surgical treatment of AF, whereas RAA amputation must be amputated occasionally with strict indications. Conflict of interest: none declared

Comparison of left and right atrial appendages anatomy and function in patients with mitral stenosis and sinus rhythm

Abstract Background The left atrial appendage (LAA) has been considered a relatively significant portion of the cardiac anatomy. Transesophageal echocardiography (TEE) is a technique that makes clear imaging of the LAA possible, so that its shape and function can be assessed. Tissue Doppler imaging (TDI) was used recently for the assessment of the contractile function of the left atrial appendage (LAA) and right atrial appendage (RAA). Patients and methods Forty-three patients with pure mitral stenosis (MS) in sinus rhythm were compared to 12 normal individuals only patients with mild and severe mitral stenosis were included. Patients with moderate mitral stenosis were excluded. A transthoracic and a transesophageal echo were performed in all patients. We assessed the LAA anatomy (neck width, length, area). Assessment of LAA function was done by the recording of LAA emptying velocity. Pulsed-wave tissue Doppler imaging (TDI) was positioned at the tip of the LAA and the tip of the RAA to obtain atrial peak systolic (Sm) and diastolic myocardial velocities. Results Patients with MS (severe and mild) had a larger left atrial diameter and area than the control {50.5 ± 3.8 & 46.2 ± 4.5 vs 35.4 ± 1.8, and 31.2 ± 3.3 & 26 ± 2.3 vs 19.9 ± 1.4} P-value 0.0001 & 0.0001, respectively and patients with MS (severe and mild) had a higher PASP than the control {50.9 ± 10.5 & 30 ± 7 vs 25.2 ± 1.6} P-value 0.0001. TEE data of patients with MS (severe and mild) had a larger left atrial appendage length, base, and area than the control {(49.8 ± 6.38 & 42 ± 2.5 vs 37.8 ± 2.2), (27.7 ± 3.8 & 23.2 ± 3.1 vs 18 ± 2.5), and (7.6 ± 0.6 & 6.5 ± 0.5 vs 4.6 ± 0.7} P-value 0.0001. Patients with MS (severe and mild) had a significant decrease in atrial peak systolic flow velocities (S wave) than the control (16.1 ± 3.7 & 26.5 ± 0.7 vs 70 ± 13), P-value 0.0001.Also patients with MS (severe and mild) had significant decrease in atrial peak systolic myocardial velocities (Sm wave) of the LAA compared with the control (6.1 ± 1.7 & 12.6 ± 0.3 vs 18.8 ± 1.9), P-value 0.0001. (TDI) flow of the RAA myocardial velocity, patients with mitral stenosis (severe and mild) had a significant decrease in atrial peak systolic myocardial velocities (Sm wave) of the RAA compared with the control (16.5 ± 2.9 & 17.7 ± 1.6 vs 20.1 ± 2.6), P-value 0.0001. SEC was detected in the LAA in 17 patients of the 43 patients with mitral stenosis which represents 39.5% of the patients. All patients with SEC were with severe MS. Patients with SEC had a significant increase in Fc, mean transmitral gradient, PASP, Sm LAA, Sm RAA, LAA area and peak S velocity LAA than patients without SEC. No patient had SEC in the RAA cavity. Conclusion LAA and RAA dysfunction occurred in patients with MS and sinus rhythm due to increase of atrial afterload presented by a decrease in atrial myocardial velocities.

Elevated plasma brain natriuretic peptide levels predict left atrial appendage dysfunction in patients with acute ischemic stroke

It is well known that left atrial appendage (LAA) dysfunction plays an important role in the occurrence of cardioembolic stroke. The atrium is the main source of brain natriuretic peptide (BNP) in patients with atrial fibrillation (AF). We hypothesized that the plasma BNP level would be a sensitive predictor of LAA dysfunction in patients with acute ischemic stroke. Transesophageal echocardiography was performed and plasma BNP levels were measured in 223 patients (145 males, age 69 ± 14 years), within 7 days after the onset of acute ischemic stroke. None of the patients had a history of congestive heart failure. LAA thrombus was detected in 23 of 77 (30%) patients with AF. Plasma BNP levels were markedly higher in patients with cardioembolic stroke compared to those without (144 pg/ml vs. 35 pg/ml, p<0.05). Plasma BNP levels were significantly correlated with LAA emptying flow velocity regardless of sinus rhythm (R=-0.352) or AF (R=-0.436). Furthermore, among patients with cardioembolic stroke, plasma BNP levels were markedly higher in patients with cardiogenic stroke, as diagnosed by transesophageal echocardiography, than in those with cryptogenic stroke (193 pg/ml vs. 14 pg/ml, p<0.05). Multivariate logistic regression analysis showed that a BNP concentration >90 pg/ml was an independent predictor of cardiogenic stroke (odds ratio 41.39, 95% confidence interval 1.28-138; p=0.0358). Elevated plasma BNP concentrations may be a reliable surrogate marker for the prediction of LAA dysfunction and cardiogenic stroke in patients with acute ischemic stroke.

Comparison of the Left Atrial Appendage Flow Velocities between Patients with Dipper versus Nondipper Hypertension

In this study, left atrial appendage (LAA) flow velocities of dipper and nondipper hypertensive patients were compared with normal subjects. Twenty-three patients with nondipper hypertension (NDH), 25 patients with dipper hypertension (DH), and 25 control subjects with comparable age, gender, and body mass indices were enrolled in the study. A detailed history, physical examination, and routine laboratory tests were obtained on all participants. Standard transthoracic echocardiographic examinations were performed on each subject. In addition, LAAs of all patients were visualized using transesophageal echocardiography. LAA filling and ejection velocities were measured using pulsed-wave Doppler with the sample volume placed in proximal third of the LAA. The mean LAA ejection velocity in patients with NDH (47.7 + 13.0 cm/sec) was found to be significantly lower relative to the DH (66.3 + 12.9 cm/sec) and the control group (81.7 + 8.0 cm/sec) (P < 0.001). The mean LAA filling velocity in patients with NDH (41.7 + 14.7 cm/sec) was also significantly lower relative to those observed in the DH 58.8 + 9.2 cm/sec) and the control group (67.2 + 7.9 cm/sec) (P<0.001). In NDH patients, LAA filling and ejection flow rates are decreased relative to DH patients and the control group. For patients with NDH detected using ambulatory blood pressure monitoring, more aggressive treatment approach should be considered. Maintenance of LAA function may prevent potential complications secondary to left atrial appendage dysfunction.

Prognostic Value of Low Left Atrial Appendage Wall Velocity in Patients with Ischemic Stroke and Atrial Fibrillation

It is important to evaluate left atrial appendage (LAA) dysfunction for primary and secondary prevention of stroke in patients with atrial fibrillation (AF). LAA dysfunction can reportedly be evaluated by LAA wall velocity (LAWV) measured by transthoracic echocardiographic (TTE) imaging. The aim of this study was to examine whether TTE-LAWV can predict long-term cerebrovascular events in patients with ischemic stroke with AF. TTE imaging and transesophageal echocardiographic imaging were performed <7 days after onset in 179 consecutive patients with stroke with AF. TTE-LAWV was measured using Doppler tissue imaging at the LAA tip from the parasternal short-axis view on TTE imaging, as previously reported. All patients were followed up prospectively. Cerebrovascular events were defined as cerebrovascular death and/or recurrent ischemic stroke requiring hospitalization. There were 32 cerebrovascular events during a median follow-up period of 397 days. TTE-LAWV was significantly lower in patients with cerebrovascular events than in patients without (8.3 ± 2.8 vs 11.3 ± 4.0 cm/sec, P < .01). Cox multivariate hazard analysis showed that low TTE-LAWV (<8.7 cm/sec) was an independent predictor of cerebrovascular events (hazard ratio, 3.460; P < .05). Kaplan-Meier analysis showed that cerebrovascular event rates were significantly higher in patients with low TTE-LAWV (<8.7 cm/sec) compared with those with high TTE-LAWV (34% vs 7%, P < .01). Impaired LAA function was associated with long-term cerebrovascular events in patients with stroke with AF. TTE-LAWV may be a feasible parameter for risk stratification in patients with AF.

Comparison of Tissue Doppler Dynamics with Doppler Flow in Evaluating Left Atrial Appendage Function by Transesophageal Echocardiography in Prehypertensive and Hypertensive Patients

Increased blood pressure (BP) is associated with an increase in cardiovascular mortality and morbidity. We aimed to analyze the effect of increased BP onto the function of left atrial appendage (LAA) in early stages of hypertension. Transesophageal echocardiography (TEE) was prospectively performed to assess LAA functions in 120 patients with increased BP, and in 58 normotensive subjects without cardiovascular disease. Patients with increased BP were divided according to Joint National Committee VII (JNC VII) report: prehypertensive, stage-1 hypertensive and stage-2 hypertensive patients. During TEE, LAA late-emptying velocities (LAAEV) were significantly reduced only in stage-2 hypertensives as compared with control group (P < 0.001). In contrast, LAA late-contracting velocity (LAA TDI-D2) was significantly reduced in prehypertensive,stage-1 hypertensive and stage-2 hypertensive patients, when compared with control group (P < 0.05, P < 0.001, and P < 0.001, respectively). The LAA maximal areas were increased significantly only in stage-2 hypertensive patients when compared with control group (P < 0.05). During TEE, left atrial spontaneous echocardiographic contrast was found in 2 of 36 patients in prehypertension group, in 7 of 40 patients in stage-1 hypertension group, and in 10 of 44 patients in stage-2 hypertension group. Left atrial thrombi were observed in 3 (6.8%) patients of stage-2 hypertension group. In conclusion, in patients with untreated prehypertension and hypertension, elevation of afterload imposed on left atrium involved both left atrium and LAA, resulting in impairment of the LAA function. Tissue Doppler imaging (TDI) enables the detection of this functional impairment in early stages of hypertension, even in prehypertensive phase, when compared with conventional Doppler flow measurement of the LAA. Even in prehypertensive phase, BP should be decreased to normal levels to prevent the LAA dysfunction.