Left atrial appendage function in mitral stenosis: is a group in sinus rhythm at risk of thromboembolism?

Prevalence and predictors of left atrial appendage inactivity in patients of rheumatic mitral stenosis in sinus rhythm: An observational study

BACKGROUND

Systemic thromboembolism is a known complication of rheumatic mitral stenosis (RMS) in sinus rhythm (SR). Left atrial appendage (LAA), the commonest site of thrombus formation is usually hypocontractile (inactive) in such patients. We aimed to study the prevalence of LAA inactivity (LAAI) in severe RMS and assess its independent predictors.

METHODS

The study population consisted of 100 patients of severe RMS in SR. Transthoracic and transesophageal echocardiography were done to assess LAA contractile function. Patients with LAA-peak emptying velocity < 25 cm/seconds were defined as having LAAI.

RESULTS

The mean age of study subjects was 31.66±8.69 years and 56% were females. 73% patients had LAAI (Group A), while remaining 27% had normal LAA function (Group B). Mitral-valve area (MVA) and lateral annulus systolic velocity (Sa-wave) were significantly lower while mitral valve mean gradient (MVMG) and serum fibrinogen were significantly higher (all p-values < 0.001) in group A patients. On multivariate binary logistic regression analysis, MVMG (p < 0.001), Sa-wave (p = 0.02), and serum fibrinogen (p = 0.005) were independent predictors of LAAI. Optimal cut-off values of MVMG, Sa-wave and serum fibrinogen for predicting LAAI were 11.5 mm Hg, 6.8 cm/seconds and 300 mg/dl, respectively. Sixty-Seven (90.55%) patients in group A compared to 13(48.1%) in group B had LA/LAA smoke. LAAI was the only independent predictor of left atrium (LA)/LAA smoke with or without associated thrombus.

CONCLUSION

There is high prevalence of LAAI in patients of severe MS in SR. MVMG, Sa-wave, and serum fibrinogen levels are independent predictors of LAAI. LAAI is an independent predictor of LA/LAA smoke with or without associated thrombus.

Differentiation of left atrial appendage thrombus from circulatory stasis using cardiac CT radiomics in patients with valvular heart disease

OBJECTIVES

To determine whether quantitative radiomic features from cardiac CT could differentiate the left atrial appendage (LAA) thrombus from circulatory stasis in patients with valvular heart disease.

METHODS

Ninety-five consecutive patients with valvular heart disease and filling defects in LAA on two-phase cardiac CT from March 2016 to August 2018 were retrospectively enrolled and classified as having thrombus or stasis by transesophageal echocardiography or cardiac surgery. The ratio of Hounsfield units in the filling defects to those in the ascending aorta (AA) was calculated on early- and late-phase CT (LAA/AA_E and LAA/AA_L, respectively). Radiomic features were extracted from semi-automated three-dimensional segmentation of the filling defect on early-phase CT. The diagnostic ability of radiomic features for differentiating thrombus from stasis was assessed and compared to LAA/AA_E and LAA/AA_L by comparing the AUC of ROC curves. Diagnostic performances of CT attenuation ratios and radiomic features were validated with an independent validation set.

RESULTS

Thrombus was diagnosed in 25 cases and stasis in 70. Sixty-eight radiomic features were extracted. Values of 8 wavelet-transformed features were lower in thrombus than in stasis (p < 0.001). The AUC value of a radiomic feature, wavelet_LHL, for diagnosing thrombus was 0.78, which was higher than that of LAA/AA_E (AUC = 0.54, p = 0.025) and similar to that of LAA/AA_L (AUC = 0.76, p = 0.773). In the validation set, the AUC of wavelet_LHL was 0.71, which was higher than that of LAA/AA_E (AUC = 0.57, p = 0.391) and similar to that of LAA/AA_L (AUC = 0.75, p = 0.707).

CONCLUSIONS

Quantitative radiomic features from the early phase of cardiac CT may help diagnose LAA thrombus in patients with valvular heart disease.

KEY POINTS

• Wavelet-transformed grey-level non-uniformity values from radiomic analysis are significantly lower for LAA thrombus than for circulatory stasis. • Radiomic features may have an additional value for differentiating LAA thrombus from circulatory stasis when interpreting single-phase cardiac CT. • Radiomic features extracted from single-phase images may show similar diagnostic ability as conventional quantitative analysis from two-phase images.

Study of immediate and late effects of successful PTMC on left atrial appendage function in patients with severe rheumatic mitral stenosis IN SINUS rhythm

INTRODUCTION

Since its introduction in 1984, Percutaneous Transvenous Mitral Commissurotomy (PTMC) has become established as a safe and effective treatment for rheumatic Mitral Stenosis (MS).( Ben Farhat et al., 1998) 1 Chronic pressure and volume overload imposed by MS causes left atrial (LA) and Left Atrial Appendage (LAA) dysfunction. Risk of cerebrovascular accident (CVA) is increased approximately 17-fold in patients of MS in Atrial Fibrillation (AF) and is present even in patients of MS in sinus rhythm (SR). This study was undertaken to evaluate the effect of PTMC on LAA function by Trans-esophageal echocardiography (TEE) Doppler and Doppler Tissue Imaging (DTI).

METHODS

Total 70 cases were enrolled in this study. Patients with symptomatic severe MS (Mitral Valve Area <1.5cm2), in SR, who underwent a successful PTMC during the period from May 2016 to May 2019 were selected. All the patients underwent Clinical examination, ECG, detailed TTE and TEE before, immediately after (within 24 h) & after 6 months of PTMC.

RESULTS

There was non significant improvement in Left Atrial appendage fractional area change {LAAAC (%)} immediately Post PTMC but there was significant improvement at 6 months Post PTMC. There was significant increase in LAA PW Doppler velocities (LAAEDE, LAALDE and LAAF velocity) immediately Post PTMC which got further improved significantly at 6 months of follow up. There was significant increase in LAA DTI velocities (E_LAA, A_LAA and S_LAA velocity) immediately Post PTMC which got further improved significantly at 6 months of follow up.

CONCLUSION

PTMC improves left atrial appendage function in patients with mitral stenosis.

Spontaneous left atrial echo contrast, mitral annular systolic velocity, and left atrial appendage late emptying velocity in predicting improvement of left atrial function after percutaneous balloon mitral valvuloplasty

BACKGROUND

Thromboembolic events are the major cause of morbidity and mortality in patients with mitral stenosis (MS). This study aims to investigate left atrial spontaneous echo contrast (LA SEC), mitral annular systolic velocity (Sa-wave), left atrial appendage (LAA) late emptying velocity (LAAEV), LAA filling velocity (LAAFV) pre- and postpercutaneous balloon mitral valvuloplasty (PBMV) for MS. This also aims to study the association of LA SEC with inflammatory marker, high-sensitivity C-reactive protein (hs-CRP) in MS.

METHODS

The study population consisted of 100 patients with symptomatic MS with sinus rhythm who underwent PBMV. Transthoracic echo (TTE), tissue Doppler imaging (TDI), and transesophageal echo (TEE) examinations were carried out before and 14 days following PBMV. High-sensitivity C-reactive protein (hs-CRP) was measured at the time of admission.

RESULTS

The mean age was 33.2 ± 10.3 years with female preponderance (71%). There was a decrease in SEC grading, (pre-PBMV 2.8 ± 0.9 and post-PBMV 0.4 ± 0.1; P < .01), increase in LAAEV (pre-PBMV 23.0 ± 7.9 cm/s and post-PBMV 40.9 ± 8.4 cm/s; P < .01), and LAAFV (pre-PBMV 31.8 ± 9.3 cm/s and post-PBMV 51.2 ± 8.7 cm/s; P < .01).A significant positive correlation was present between LAAEV and Sa-wave (r = .52, P < .01). Correlation between hs-CRP and SEC was positive and significant (r = .33, P < .01). Optimal cutoff value of hs-CRP for prediction of moderate to dense SEC was >2.3 mg/dL, the cutoff value of Sa-wave was≤ 5.5 cm/s for prediction of the presence of inactive LAA (LAAEV < 25 cm/s).

CONCLUSION

Mitral annular systolic velocity (Sa-wave) is an independent predictor of inactive LAA and a useful parameter in estimating inactive LAA in MS. Sa-wave and hs-CRP are independent predictors for SEC. PBMV improves LAA function in patients with MS.

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.

Effect of percutaneous mitral balloon valvuloplasty on left atrial appendage function: transesophageal echo study

BACKGROUND

To compare left atrial appendage (LAA) function by Doppler and Doppler tissue imaging (DTI) before and after percutaneous balloon mitral valvuloplasty (PBMV).

MATERIALS AND METHODS

Fifty-nine patients with symptomatic rheumatic mitral stenosis who underwent PBMV were included in this study. LAA function was measured before and after PBMV. To study LAA function, LAA late emptying (LAALE) velocity, LAA late filling (LAALF) velocity, and LAA area change percentage (LAAAC %) were measured. In the DTI study, tissue Doppler velocities of the LAA, including peak early diastolic (E(LAA)), peak late diastolic (A(LAA)), and peak systolic (S(LAA)), were measured.

RESULTS

There was significant increase in LAALE velocity, LAALF velocity, E(LAA), A(LAA), S(LAA) waves measured by Doppler and DTI after PBMV compared with baseline (p < 0.001) but there was no significant change in LAAAC% (p = not significant). Spontaneous echo contrast was present in 10 of the 59 patients before the procedure. It completely disappeared (6 patients) or decreased (4 patients) after PBMV.

CONCLUSIONS

Our results suggest that PBMV improves LAA function and, thereby, may have a favorable influence on future thromboembolic complications.

Dual-enhanced cardiac CT for detection of left atrial appendage thrombus in patients with stroke: a prospective comparison study with transesophageal echocardiography

BACKGROUND AND PURPOSE

A noninvasive method with high reliability and accuracy comparable to transesophageal echocardiography for identification of left atrial appendage thrombus would be of significant clinical value. The aim of this study was to assess the diagnostic performance of a dual-enhanced cardiac CT protocol for detection of left atrial appendage thrombi and for differentiation between thrombus and circulatory stasis in patients with stroke.

METHODS

We studied 83 consecutive patients with stroke (56 men and 27 women; mean age, 62.6 years) who had high risk factors for thrombus formation and had undergone both dual-source CT and transesophageal echocardiography within a 3-day period. CT was performed with prospective electrocardiographic gating, and scanning began 180 seconds after the test bolus.

RESULTS

Among the 83 patients, a total of 13 thrombi combined with spontaneous echo contrast and 14 spontaneous echo contrasts were detected by transesophageal echocardiography. All 13 thrombi combined with spontaneous echo contrast were correctly diagnosed on CT. Using transesophageal echocardiography as the reference standard, the overall sensitivity and specificity of CT for the detection of thrombi and circulatory stasis in the left atrial appendage were 96% (95% CI, 78% to 99%), and 100% (95% CI, 92% to 100%), respectively. On CT, the mean left atrial appendage/ascending aorta Hounsfield unit ratios were significantly different between thrombus and circulatory stasis (0.15 Hounsfield unit versus 0.27 Hounsfield unit, P=0.001). The mean effective radiation dose was 3.11 mSv.

CONCLUSIONS

Dual-enhanced cardiac CT with prospective electrocardiographic gating is a noninvasive and sensitive modality for detecting left atrial appendage thrombus with an acceptable radiation dose.

Usefulness of left atrial volume versus diameter to assess thromboembolic risk in mitral stenosis

In patients with mitral stenosis (MS) in sinus rhythm (SR), guidelines recommend anticoagulation if the left atrium is enlarged based on diameter measurements. We sought to compare the association of left atrial (LA) diameter and LA volume with markers of thromboembolic risk (peak LA appendage emptying velocity [LAAv] and LA spontaneous contrast density) measured during transesophageal echocardiography in 152 patients with moderate to severe MS. High thromboembolic risk was defined by a peak LAAv < 25 cm/s and/or dense spontaneous contrast. Mean LA diameter (50 ± 7 mm, 32 to 77) and LA volume (152 ± 70 ml, 67 to 720) were significantly correlated (r = 0.71, p < 0.0001), but the relation was curvilinear and the 95% confidence interval increased with LA diameter. In the subset of 80 patients in SR who underwent clinically indicated transesophageal echocardiography, body surface area (BSA)-indexed LA volume but not LA diameter differentiated patients with normal from those with low LAAv (86 ± 17 vs 71 ± 17 ml/m(2), p < 0.01, and 50 ± 6 vs 48 ± 6 mm, p = 0.13, respectively) and patients with dense spontaneous contrast from those with no or mild spontaneous contrast (81 ± 16 vs 63 ± 15 ml/m(2), p < 0.01, and 49 ± 6 vs 46 ± 5 mm, p = 0.11, respectively). BSA-indexed LA volume provided the highest area under the curve (0.85) for high thromboembolic risk and LA diameter the lowest (0.65). A BSA-indexed LA volume > 60 ml/m(2) provided an excellent 90% sensitivity despite 44% specificity, 76% positive predictive value, and 70% negative predictive value. Use of this threshold instead of 50 or 55 mm would have changed the indication for anticoagulation in 51% to 77% of patients. In conclusion, LA volume was more strongly associated with markers of thromboembolic risk than LA diameter, which poorly reflected LA size. Our results support the use of BSA-indexed LA volume to guide the decision for anticoagulation in patients with MS in SR, which may lead to significant change in the management of those patients. We suggest a threshold of 60 ml/m(2), which has good sensitivity, albeit with low specificity.

Systolic Tissue Velocity Is a Useful Echocardiographic Parameter in Assessment of Left Atrial Appendage Function in Patients with Mitral Stenosis

BACKGROUND

The incidence of thromboembolism remains high in patients with mitral stenosis (MS). The left atrial appendage (LAA) is a potential site for development of thrombus and LAA dysfunction is an independent predictor of thromboembolism. The LAA dysfunction is represented by reduced LAA late emptying velocity. But the magnitude of LAA flow velocities is dependent on acute changes in loading conditions.

AIM

To investigate the value of the LAA tissue velocities obtained by tissue Doppler imaging (TDI) in assessment of LAA function in MS patients with and without thromboembolic events.

METHODS

The study population consisted of 98 isolated MS patients of 32 age and sex-matched healthy controls. All subjects underwent transesophageal echocardiography (TEE). LAA late peak emptying (LAAEV) and filling (LAAFV) flow velocities were recorded. LAA peak late tissue systolic (LSV) and diastolic (LDV) tissue velocities by TDI were measured. The patients were divided into three groups as Group I (n = 38, sinus rhythm and LAAEV > or = 25 cm/s), Group II (n = 26, sinus rhythm and LAAEV < 25 cm/s), and Group III (n = 34, atrial fibrillation).

RESULTS

Twenty-one patients had thromboembolic events. LAAEV, LAAFV, LSV, and LDV were significantly reduced in patients with embolic events. Spontaneous echo contrast (SEC) density was strongly negative correlated with LSV, whereas weakly negative correlated with LAAEV. Multivariate regression analysis showed that LSV and the presence of SEC were independently associated with embolic events.

CONCLUSION

LSV seems more reliable and useful parameter in evaluating LAA function. LAA function is more depressed among patients with embolic events.

Mitral Annular Systolic Velocity Reflects the Left Atrial Appendage Function in Mitral Stenosis

BACKGROUND

Left atrial appendage (LAA) dysfunction is an independent predictor of thromboembolism in mitral stenosis (MS).

OBJECTIVES

To investigate whether there is a relation between annular velocities obtained by tissue Doppler imaging and LAA function and to determine if the annular velocities can predict the presence of the inactive LAA in MS.

METHODS

Eighty-five MS patients and 80 healthy controls were evaluated by transthoracic echocardiography and all patients underwent transesophageal echocardiography. The annular systolic (S-wave) and diastolic (E- and A-waves) velocities were recorded. Inactive LAA was defined as LAA emptying velocity <25 cm/sec. Patients were divided into three groups; group I (n = 43): sinus rhythm (SR) and LAA emptying velocity > or =25 cm/sec, group II (n = 15): SR and LAA emptying velocity <25 cm/sec and group III (n = 27): atrial fibrillation.

RESULTS

Thrombus was detected in 12 patients and spontaneous echo contrast (SEC) was detected in 48 patients. Both S-wave and peak LAA emptying velocities were decreasing, while SEC frequency and density were increasing from group I to group III. There was a positive correlation between LAA emptying and S-wave velocities (P < 0.001, r = 0.682). Multivariate regression analysis showed that only S-wave is the independent predictor of inactive LAA (P = 0.001, odds ratio = 0.143, 95% CI = 0.047-0.434). In patients with SR, the cutoff value of S-wave was 13.5 cm/sec for the prediction of the presence of inactive LAA (sensitivity: 95.3%, specificity: 93.3%).

CONCLUSIONS

S-wave is an independent predictor of inactive LAA and a useful parameter in estimating inactive LAA in MS with SR.

Effect of Percutaneous Mitral Balloon Valvuloplasty on Left Atrial Appendage Function: A Doppler Tissue Study

The aim of this study was to compare left atrial appendage (LAA) functions by Doppler tissue imaging (DTI) before and after percutaneous balloon mitral valvuloplasty (PBMV). Twenty patients with symptomatic rheumatic mitral stenosis who underwent PBMV were included in this study. LAA functions were measured before and after PBMV. To determine LAA functions, LAA late filling (LAALF) velocity, LAA late emptying (LAALE) velocity, and area change of LAA percent were measured. In the DTI records, the first positive wave identical to the LAALE wave after the P wave was accepted as LAA late systolic wave, and the second negative wave identical to the LAALF flow was accepted as late diastolic wave. There was no difference in LAALF velocity and area change of LAA percent after PBMV. LAALE velocity increased after PBMV compared with baseline (P = .005). Late emptying, systolic, and diastolic wave values measured by DTI were found to be increased after PBMV compared with baseline (P = .023, P = .002, and P = .002, respectively). LAALE velocity measured by standard Doppler was increased after PBMV compared with baseline (P = .005), but there was no change in area change of LAA percent or LAALF. Spontaneous echocontrast was present in 7 of the 20 patients before procedure. It completely disappeared (4 patients) or decreased (3 patients) after procedure. In patients with spontaneous echocontrast, LAALE and late emptying, systolic, and diastolic wave values measured by DTI were found to be increased after PBMV compared with baseline. Our results suggest that PBMV improves LAA functions and, thereby, may have a favorable influence on future thromboembolic complications.

Clinical and echocardiographic predictors of left atrial appendage dysfunction in patients with mitral stenosis in sinus rhythm

BACKGROUND

Mitral stenosis (MS) causes left atrial (LA) appendage (LAA) dysfunction resulting in reduced LAA flow velocities. Low LAA peak emptying velocity (PEV), determined by transesophageal echocardiography, is a risk for thrombus formation and systemic embolism.

OBJECTIVE

We sought to investigate various clinical and echocardiographic predictors of low LAA blood flow velocities.

METHODS

A total of 44 patients with newly diagnosed MS were classified into two groups on the basis of the presence of high (PEV > or = 46 cm/s) or low (PEV < 46 cm/s) LAA flow profile on Doppler transesophageal echocardiography. LAA flow velocities were measured to be 27.38 +/- 8.17 cm/s in patients with LAA dysfunction and 70.75 +/- 16.71 cm/s in high-flow profile (P <.0001). Simultaneous 12-lead electrocardiogram was used to measure P waves.

RESULTS

P maximum, P dispersion, and LA diameter were significantly higher in patients with low LAA PEV (n = 32) than in those with high LAA PEV (111.87 +/- 16.93 vs 96.66 +/- 14.97, P =.0084; 73.12 +/- 20.7 vs 49.16 +/- 9.96, P <.0001; 46.06 +/- 4.384 vs 38.08 +/- 7.42 mm, P =.004; respectively). Patients with MS and low LAA blood flow had smaller mitral valve area compared with those with high LAA blood flow velocity (1.48 +/- 0.431 vs 1.85 +/- 0.442 cm(2), P =.02). Male sex, spontaneous echocontrast, and thrombus were more frequent in patients with low LAA PEV [7 [21.87%] vs 5 [41.66%], P =.026; 21 [65.62%] vs 4 [33.3%], P =.088; 4 [12.5%] vs none; respectively]. Mild MS was more frequent in patients with high blood flow velocity [6 [27.2%] vs 14 [63.6%], P =.03].

CONCLUSION

At linear regression analysis, only P-wave dispersion and LA diameter predicted the LAA mechanical dysfunction reflected as low LAA PEVs.

Color Doppler Tissue Imaging to Evaluate Left Atrial Appendage Function in Patients With Mitral Stenosis in Sinus Rhythm

Two-dimensional color Doppler tissue imaging (CDTI) has so far been used, in general, to evaluate ventricular function. In this study, the left atrial appendage (LAA) tissue velocity was measured by CDTI. LAA function in 38 patients with mitral stenosis in sinus rhythm (SR) and 19 healthy subjects undergoing transesophageal echocardiography were examined by CDTI. Systolic tissue appendage velocity (SaV, m/s) was measured at the tip of the LAA in the basal short-axis view. LAA emptying (LAAEV) and filling (LAAFV) velocities (m/s) were also recorded 1 cm below the orifice of the appendage. LAA ejection fraction was also measured. In addition, two-dimensional imaging was used to determine the presence of thrombus and/or spontaneous echo contrast (SEC). Patients with mitral stenosis in SR had significantly decreased LAAEV, LAAFV, SaV, and LAA ejection fraction compared to controls (0.34 +/- 0.15 vs 0.72 +/- 0.17, 0.37 +/- 0.13 vs 0.63 +/- 0.19, 0.050 +/- 0.015 vs 0.071 +/- 0.093, and 39 +/- 14% vs 69 +/- 13%, respectively, P < 0.001, P < 0.001, P < 0.001, and P < 0.001). Among the patients with mitral stenosis in SR, 10 patients had SEC and one had LAA thrombus. Compared with patients without SEC, patients with SEC had decreased LAAEV, LAAFV, SaV, and LAA ejection fraction (0.24 +/- 0.05 vs 0.37 +/- 0.16, 0.29 +/- 0.05 vs 0.39 +/- 0.14, 0.039 +/- 0.087 vs 0.055 +/- 0.015, and 28 +/- 14% vs 43 +/- 12%, respectively, P = 0.01, P = 0.02, P = 0.01, and P = 0.006). In conclusion, these results suggest that the LAA dysfunction may occur in patients with mitral stenosis in SR and CDTI can successfully be used for the quantification of contraction at the tip of the LAA.

Role of monocytes in atherogenesis

This review focuses on the role of monocytes in the early phase of atherogenesis, before foam cell formation. An emerging consensus underscores the importance of the cellular inflammatory system in atherogenesis. Initiation of the process apparently hinges on accumulating low-density lipoproteins (LDL) undergoing oxidation and glycation, providing stimuli for the release of monocyte attracting chemokines and for the upregulation of endothelial adhesive molecules. These conditions favor monocyte transmigration to the intima, where chemically modified, aggregated, or proteoglycan- or antibody-complexed LDL may be endocytotically internalized via scavenger receptors present on the emergent macrophage surface. The differentiating monocytes in concert with T lymphocytes exert a modulating effect on lipoproteins. These events propagate a series of reactions entailing generation of lipid peroxides and expression of chemokines, adhesion molecules, cytokines, and growth factors, thereby sustaining an ongoing inflammatory process leading ultimately to lesion formation. New data emerging from studies using transgenic animals, notably mice, have provided novel insights into many of the cellular interactions and signaling mechanisms involving monocytes/macrophages in the atherogenic processes. A number of these studies, focusing on mechanisms for monocyte activation and the roles of adhesive molecules, chemokines, cytokines and growth factors, are addressed in this review.

Clinical and echocardiographic characteristics of patients with left atrial thrombus and sinus rhythm: experience in 20 643 consecutive transesophageal echocardiographic examinations

BACKGROUND

Left atrial (LA) thrombus is infrequently detected in the presence of sinus rhythm (SR) and, in these cases, is usually associated with additional cardiac pathologies. We sought to determine the clinical and echocardiographic characteristics of patients with LA thrombus and SR to define a high-risk group of patients prone to this uncommon clinical presentation.

METHODS AND RESULTS

The institution's echocardiographic laboratory database was searched to identify patients with LA thrombus, diagnosed by transesophageal echocardiography (TEE), who were in SR during the TEE examination. Of 20 643 consecutive TEE examinations performed during an 11-year period, LA thrombus was detected in 314 patients in 380 TEE examinations. Of these, SR was present in 20 patients (age 69+/-13 years; 40% men) in 23 examinations (0.1% of all TEE examinations; 6.1% of TEE examinations with LA thrombus). High-risk structural heart disease (severe left ventricular dysfunction or significant left-sided valve disease [predominantly mitral valve disease]), previous documented episodes of atrial fibrillation, or both (structural heart disease and previous atrial fibrillation) were present in 10, 4, and 5 of the 20 patients, respectively. Only 1 patient with LA thrombus and SR did not have high-risk features.

CONCLUSIONS

LA thrombus is very infrequently detected in the presence of SR. Patients with LA thrombus and SR constitute a high-risk group characterized by specific structural cardiac abnormalities or previous atrial fibrillation, abnormalities that are potentially detectable before TEE.