Left atrial appendage flow in nonrheumatic atrial fibrillation : relationship with pulmonary venous flow and ECG fibrillatory wave amplitude

OBJECTIVE: This study was conducted (1) to examine the relationship between left atrial appendage (LAA) flow velocity and pulmonary venous flow (PVF) variables during nonrheumatic atrial fibrillation (AF), and (2) to determine whether a reduction in LAA flow is reflected by the fibrillatory wave amplitude on the surface ECG. BACKGROUND: Although LAA Doppler echocardiographic signals provide information regarding the velocity and direction of flow only for a localized narrow sample, systolic PVF represents in part the global left atrial function, mainly relaxation. Controversy exists about whether the amplitude of fibrillatory waves recorded on the surface ECG correlates with LAA flow velocity during AF. MEASUREMENTS AND RESULTS: Thirty-three patients (20 men, 13 women; mean [+/- SD] age, 61 +/- 11 years) with nonrheumatic AF undergoing transthoracic and transesophageal echocardiography were studied. A correlation between LAA flow velocity and systolic PVF variables (peak systolic velocity, R: = 0.450, p = 0.009; velocity-time integral of systolic flow, R = 0.491, p = 0.004; systolic fraction of PVF, R: = 0.627, p < 0.0001) was observed. Patients with a low LAA flow profile (< 25 cm/s) had a reduced systolic PVF. Longer AF duration and the occurrence of moderate mitral regurgitation were related to reduced LAA flow. AF was subdivided into coarse (peak-to-peak fibrillatory amplitude > or = 1 mm) or fine (< 1 mm) in standard ECG lead V1. There was no association between the coarseness of AF and the LAA flow profile. CONCLUSION: In patients with nonrheumatic AF, a reduction in LAA flow velocity correlates with a reduction in systolic PVF. These hemodynamic changes are not reflected by the ECG fibrillatory wave amplitude.     

Aortic spontaneous echocardiographic contrast and hemostatic markers in patients with nonrheumatic atrial fibrillation

OBJECTIVES: To determine the relationship between spontaneous echocardiographic contrast (SEC) in the descending thoracic aorta and plasma levels of hemostatic markers in patients with nonrheumatic atrial fibrillation (AF). DESIGN AND SETTINGS: A cross-sectional study at a university hospital. PATIENTS AND MEASUREMENTS: In 91 consecutive patients (mean +/- SE age, 70 +/- 1 years; 68 men) with nonrheumatic AF who underwent transesophageal echocardiography, plasma levels of markers for platelet activity (platelet factor 4 [PF4] and beta-thromboglobulin [beta-TG]), thrombotic status (thrombin-antithrombin III complex [TAT]), and fibrinolytic status (D-dimer and plasmin-alpha(2)-plasmin inhibitor complex [PIC]) were determined. RESULTS: Forty-three patients who had aortic SEC (AoSEC) were older (72 years vs 68 years; p < 0.05) and had a higher prevalence of chronic AF (88% vs 52%; p < 0.05) than 48 patients without AoSEC. TAT, PIC, and D-dimer levels were significantly higher in patients with AoSEC than in those without AoSEC, whereas PF4 and beta-TG levels were not different between the two groups. Although the prevalence of cerebral embolism did not differ between the two groups (23% vs 29%), the prevalence of peripheral embolism was higher in patients with AoSEC than in those without AoSEC (10% vs 0%; p < 0.05). Multivariate analysis revealed mitral regurgitation (odds ratio, 7.53; p < 0.02), SEC in the left atrium (odds ratio, 2.14; p < 0.02), and aortic atherosclerosis (odds ratio, 1.87; p < 0.04) emerged as independent predictors of AoSEC. CONCLUSIONS: Patients with nonrheumatic AF who have AoSEC appear to have enhanced coagulation activity but not platelet activity. Intensive anticoagulation treatment might be required for these patients.     

Thoracic aortic plaque enhances hypercoagulability in patients with nonrheumatic atrial fibrillation.

BACKGROUND: Patients with atrial fibrillation (AF) are at risk for thromboembolism, and coexistent cardiovascular diseases could affect their prothrombotic profiles. The relationship between plasma hemostatic markers and aortic atherosclerosis was determined in patients with AF or in sinus rhythm (SR). METHODS AND RESULTS: Sixty patients with nonrheumatic AF and 46 patients in SR who underwent transesophageal echocardiography and did not receive anticoagulant therapy constituted the study group. Markers for platelet activity (platelet factor 4 and beta-thromboglobulin), thrombotic status (thrombin-antithrombin III complex and prothrombin fragment 1+2 (F1+2)) and fibrinolytic status (plasmin-alpha2-plasmin inhibitor complex (PIC) and D-dimer) were determined. Levels of F1+2, PIC and D-dimer were higher in AF patients with severe atheroma than in those without severe atheroma (p<0.05). In patients in SR, hemostatic markers were not significantly increased even if they had severe aortic atherosclerosis. AF (Odds ratio (OR) 4.06, p=0.04) and age>or=75 years (OR 3.98, p=0.02) were independently predictive of elevated D-dimer levels and severe atheroma was predictive of elevated F1+2 levels (OR 5.52, p=0.04). CONCLUSIONS: Elderly patients with AF and severe aortic atherosclerosis might be in a prothrombotic state, and could benefit from intensive antithrombotic therapy.     

血小板激活及内皮损伤血液标志物对心房颤动血栓栓塞危险性的评价

目的:研究心房颤动(Af)患者是否存在血小板激活和内皮损伤,探讨其对评价Af血栓栓塞危险性的价值。方法:Af患者共89例,按是否接受了经食管超声心动图(TEE)检查分为两个亚组:①TEE检查亚组:35例,发现左心房和(或)左心耳有血栓者10例,有明确外周动脉血栓栓塞并发症者8例,无血栓者17例;②未检查亚组:54例。另选33例非Af者为对照组。用ELISA法测定两组的血浆可溶性P选择素(sP选择素)、血管性血友病因子(vWF)、D二聚体(DD)水平,用全自动生化分析仪测定平均血小板体积(MPV),对其结果进行对照分析。结果:Af患者血浆sP选择素、vWF、MPV、DD水平显著升高(P<0.05),其中血浆sP选择素、DD、MPV水平在血栓和无血栓者中差异有统计学意义(P<0.05)。且sP选择素与DD水平呈正相关(r=0.311,P<0.05)。结论:Af患者存在有血小板激活及内皮损伤,与其血栓形成及栓塞并发症有一定关系。     

Clinical implications of left atrial spontaneous echo contrast in nonrheumatic atrial fibrillation.

The prevalence and clinical significance of left atrial (LA) spontaneous echo contrast were investigated in 103 consecutive patients with chronic nonrheumatic atrial fibrillation (AF) using transesophageal echocardiography. LA spontaneous echo contrast was visualized in 25 of 103 patients (24.3%). Age, sex, LA diameter, left ventricular diastolic and systolic dimensions, left ventricular ejection fraction, and the percentage of lone AF were not significantly different between patients with and without LA spontaneous echo contrast; however, those with LA spontaneous echo contrast were less likely to have moderate or severe mitral regurgitation. LA thrombi were observed in 7 patients (6.8%), and all 7 thrombi were found in the atria with spontaneous echo contrast. History of cerebral ischemia or peripheral embolism, or both, was significantly more frequent in patients with than without LA spontaneous echo contrast (84 vs 18%; p less than 0.001). The presence of LA spontaneous echo contrast was highly specific (94%) and predictive for thromboembolic events (positive and negative predictive values of 84 and 82%, respectively). Thus, transesophageal echo-detected LA spontaneous echo contrast is frequently found in patients with chronic nonrheumatic AF. This phenomenon may represent a precursor of thrombus formation, and its presence is associated with an increased thromboembolic risk.     

Diagnostic importance of fibrillatory wave amplitude: a clue to echocardiographic left atrial size and etiology of atrial fibrillation

The electrocardiographic fibrillatory wave amplitude in 148 patients with atrial fibrillation was measured. To assess its diagnostic importance in relation to the left atrial size and underlying etiology, M-mode echocardiography was performed on 89 patients. The patients are classified according to the type of atrial fibrillation (paroxysmal or chronic), the f wave amplitude (coarse or fine), and the underlying etiology (rheumatic or nonrheumatic). The average fibrillatory f wave amplitude and echocardiographic left atrial size in chronic and rheumatic atrial fibrillation are significantly greater than in paroxysmal and chronic nonrheumatic patients. Furthermore, the fibrillatory f wave amplitude correlates strongly with the echocardiographic left atrial size.     

P wave dispersion and left atrial appendage function for predicting recurrence after conversion of atrial fibrillation and relation of p wave dispersion to appendage function

BACKGROUND: We investigated P wave dispersion and left atrial appendage (LAA) function for predicting atrial fibrillation (AF) relapse, and the relationship between P wave dispersion and LAA function. METHODS: Sixty-four consecutive patients with AF lasting /=5 days, LA size >/=45 mm, maximum P wave duration >/=112 ms, P wave dispersion >/=47 ms, spontaneous echo contrast, minimum LAA area >/=166 mm(2), and LAA emptying velocity <36 cm/sec were univariate predictors of recurrence (each P < 0.05). By multivariate analysis, LA size (P = 0.02), P wave dispersion (P < 0.001), and LAA emptying flow (P = 0.01) identified patients with recurrent AF. Their positive predictive values were 91, 97, and 72%, respectively. CONCLUSION: The increased P wave dispersion in addition to the dilated LA and the depressed LAA emptying flow can identify patients at risk of recurrent AF after cardioversion.     

Comparison of diverse platelet activation markers as indicators for left atrial thrombus in atrial fibrillation

Atrial fibrillation (AF) is well known for being a major risk factor of thromboembolic stroke. We could recently demonstrate an association of monocyte–platelet aggregates (MPAs) with the degree of thrombogenicity in patients with AF. This study investigated platelet activation markers, as potential biomarkers for the presence of left atrial (LA) thrombus in patients with AF. One hundred and eight patients with symptomatic AF underwent transesophageal echocardiography (TEE) before scheduled cardioversion or pulmonary vein isolation. In order to determine the content of MPAs by flow-cytometric quantification analyses, blood was drawn on the day of TEE. The soluble CD40 Ligand (sCD40L) and soluble P-selectin (sP-selectin) were obtained by Cytometric Bead Arrays (CBA). D-dimer levels were detected by quantitative immunological determination of fibrin degradation products. Clinical, laboratory, and echocardiographic standard parameters were obtained from all patients, including the determination of the flow in the left atrial appendage (LAA). Patients with detected LA thrombus (n = 28) compared with patients without thrombus (n = 80) showed an increased number of common risk factors, such as age, diabetes, heart failure, and coronary artery disease (CAD). The presence of LA thrombus was associated with significantly increased levels of MPAs (147 ± 12 vs. 304 ± 29 per µl; p < 0.00), sCD40L (106.3 ± 31.0 vs. 33.5 ± 2.1 pg/ml, p = 0.027), and D-dimer (0.13 ± 0.02 vs. 0.69 ± 0.21 mg FEU/l, p = 0.015). In contrast, sP-selectin showed no association with LA thrombus. A multivariate regression analysis showed that MPAs, sCD40L as well as D-dimers were independent indicators for the existence of LA thrombus. MPAs above 170 cells/µl indicated LA thrombus with a high sensitivity of 93% and a specificity of 73% (OR 62, 95% CI. 6.9–557.2, p < 0.001) in patients with AF, whereas the D-dimer lost their quality as independent indicator by using the conventional cut-off of 0.5 mg/l within the regression analysis. MPAs, as well as the D-dimer, correlated significantly negatively with the flow in the LAA measured during TEE. The content of MPAs, sCD40L, and D-dimer, but not sP-selectin showed an increased dependence on LA thrombus in patients with AF. In our study group, MPAs showed the best diagnostic test accuracy of the compared platelet markers. The different results of the examined platelet activation markers could be an indication of diverse mechanisms of LA thrombus in AF. Further studies should evaluate whether determination of MPAs in clinical routine may suffice to indicate the presence of LA thrombus in patients with AF.     

Left atrial appendage function in prediction of paroxysmal atrial fibrilation in patients with untreated hypertension

The onset of AF results in a significant increase in mortality rates and morbidity in hypertensive patients and this rhythm disorder exposes patients to a significantly increased risk of cerebral or peripheral embolisms. Tissue Doppler imaging was found to be useful in early detection of myocardial dysfunction in several diseases. It was shown that tissue Doppler analysis of the walls of the left atrial appendage (LAA) can give accurate information about the function of the LAA in hypertensive patients. In this study, we aimed to investigate and identify the specific predictive parameters for the onset of AF in patients with hypertension with tissue Doppler imaging of LAA. We studied age and sex matched 57 untreated hypertensive patients with paroxysmal atrial fibrillation (PAF) and 27 untreated hypertensive subjects without PAF. With transthoracic echocardiography, diastolic mitral A-velocity and LA maximal volume index which reflects reservoir function of left atrium was measured, with transesophageal echocardiography, LAA emptying velocity (LAA-PW D2) and tissue Doppler contracting velocity of LAA (LAA-TDI-D2) were measured. LA maximal volume index of the groups (22.28?±?3.59?mL/m² in Group 1 versus 20.37?±?3.97?mL/m² in Group 2, p?=?0.07) and diastolic mitral A-velocity [0.93 (0.59–1.84) m/s in patients with PAF versus 0.90 (0.62–1.76) m/s in patients without PAF, p?=?0.26] was not significantly different between study groups, during TEE, LAA-PW D2 (0.31?±?0.04?m/s in Group 1 versus 0.33?±?0.03?m/s in Group 2, p?=?0.034) and LAA-TDI-D2 (0.18?±?0.04?m/s in Group 1 versus 0.21?±?0.05?m/s in Group 2, p?=?0.014) were significantly decreased in Group 1. In this study, we found that in hypertensive PAF patients despite normal global LA functions, LAA contracting function was deteriorated. Tissue Doppler analysis of LAA is clinically usefull approach to detect the risk of developing PAF in hypertensives.     

Plasma brain natriuretic peptide levels indicating thromboembolism in very elderly patients with non-valvular atrial fibrillation.

BACKGROUND: Assessment of left atrial (LA) function by transesophageal echocardiography is useful for detecting patients with a high risk thromboembolism secondary to atrial fibrillation (AF). A recent study showed that the atrium is the main source of brain natriuretic peptide (BNP) in AF patients without overt heart failure. The purpose of this study was to assess the possible relationship between LA function and plasma BNP levels in very elderly patients with non-valvular AF. METHODS AND RESULTS: Seventy-four consecutive patients with chronic non-valvular AF (aged, 82+/-6 years) underwent transthoracic and transesophageal echocardiography and measurement of plasma BNP. Thirteen AF patients who had a history of cerebral embolism or echocardiographic evidence of thrombus (TE+ group) were compared with 61 AF patients who had no such complications (TE- group). The TE+ group demonstrated a lower LA appendage (LAA) velocity and higher plasma BNP level than the TE- group. Assessment of variables by multiple logistic regression analysis revealed that BNP was a significant predictor of thromboembolism. There was a significant negative correlation between the plasma BNP level and the LAA peak flow velocity. CONCLUSIONS: The present findings would suggest the usefulness of measuring plasma BNP to detect very elderly non-valvular AF patients at high risk for thromboembolism.     

Prolonged activation of hemostatic markers following conversion of atrial flutter to sinus rhythm.

BACKGROUND: It remains controversial whether prophylactic anticoagulation for embolism is required in patients with atrial flutter (AFL) prior to and following cardioversion as in patients with atrial fibrillation. To evaluate the potential prothrombotic state following cardioversion of AFL, concentrations of hemostatic markers were determined before and after conversion to sinus rhythm (SR). METHODS AND RESULTS: In 12 patients (mean age 68 years) with AFL who underwent transesophageal echocardiography in the plasma concentrations of markers for platelet activity (platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG)), thrombotic status (thrombin-antithrombin III complex (TAT) and prothrombin fragments 1 and 2 (F1+2)) and fibrinolytic status (D-dimer and plasmin-alpha(2)-plasmin inhibitor complex (PIC)) were determined during AFL, and 3 days and 7 days after restoration of SR. Left atrial appendage (LAA) blood flow velocity was lower immediately after than before restoration of SR (29+/-11 vs 41+/-23 cm/s, p<0.05). Three patients developed left atrial spontaneous echo contrast immediately after restoration of SR. Although the concentrations of the markers of platelet activity did not change after restoration of SR, those of TAT and PIC increased 7 days after restoration of SR as compared with during AFL (p<0.05). CONCLUSIONS: AFL patients have a potential risk for thromboembolism after restoration of SR and therefore anticoagulation might be required in selected patients.     

Hemodynamic impact of percutaneous left atrial appendage closure in patients with paroxysmal atrial fibrillation

Purpose

Percutaneous left atrial appendage (LAA) closure has become a valid alternative to anticoagulation therapy for the prevention of thromboembolic events in patients with atrial fibrillation (AF). However, scarce data exist on the impact of LAA closure on left atrial and ventricular function. We sought to assess the acute hemodynamic changes associated with percutaneous LAA closure in patients with paroxysmal AF.

Methods

The study population consisted of 31 patients (mean age 73?±?10 years; 49% women) with paroxysmal AF who underwent successful percutaneous LAA closure. All patients were in sinus rhythm and underwent 2D transthoracic echocardiography at baseline and the day after the procedure. A subset of 14 patients underwent preprocedural cardiac computed tomography (CT) with 3D LA and LAA reconstruction.

Results

Left ventricular systolic function parameters and LA volumetric indexes remained unchanged after the procedure. No significant changes in left ventricular stroke volume (72.4?±?16.0 vs. 73.3?±?15.7 mL, p?=?0.55) or LA stroke volume (total 15.6?±?4.2 vs. 14.6?±?4.2 mL, p?=?0.21; passive 9.0?±?2.8 vs. 8.3?±?2.6 mL, p?=?0.31; active 10.3?±?5.6 vs. 10.0?±?6.4 mL, p?=?0.72) occurred following LAA closure. Mean ratio of LAA to LA volume by 3D CT was 10.2?±?2.3%. No correlation was found between LAA/LA ratio and changes in LA stroke volume (r?=?0.35, p?=?0.22) or left ventricular stroke volume (r?=?0.28, p?=?0.33).

Conclusions

The LAA accounts for about 10% of the total LA volume, but percutaneous LAA closure did not translate into any significant changes in LA and left ventricular function.

     

Effect of inotropic stimulation on left atrial appendage function in atrial myopathy of chronic atrial fibrillation

Atrial fibrillation (AF) leads to remodeling of the left atrium (LA) and left atrial appendage (LAA), resulting in atrial myopathy. Reduced LA and LAA function in chronic AF leads to thrombus formation and spontaneous echo contrast (SEC). The effect of inotropic stimulation on LAA function in patients with chronic AF is unknown. LAA emptying velocity (LAAEV) and maximal LAA area at baseline and after dobutamine were measured by transesophageal echocardiography in 14 subjects in normal sinus rhythm (NSR) and 6 subjects in AF. SEC in the LA was assessed before and after dobutamine. LAAEV increased significantly in both groups. However, the LAAEV at peak dobutamine in patients with AF remained significantly lower than the baseline LAAEV in patients who were in NSR (P = 0.009). Maximal LAA area decreased significantly with dobutamine in both groups, but LAA area at peak dose of dobutamine in patients with AF remained greater than baseline area in those in NSR (P = 0.01). Despite the increase in LAAEV, SEC improved in only two of five patients. We conclude that during AF, the LAA responds to inotropic stimulation with only a modest improvement in function.     

Growth differentiation factor 15 is associated with left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

Background

There is evidence suggesting that growth differentiation factor 15 (GDF‐15) appears to be associated with stroke in patients with atrial fibrillation (AF). AF‐related thromboembolic stroke is predominantly attributed to the thrombus from the left atrium (LA) or left atrial appendage (LAA).

Hypothesis

GDF‐15 is related to LA/LAA thrombus in nonvalvular AF (NVAF) patients.

Methods

A total of 894 patients with NVAF without anticoagulation therapy were included in this study. All patients routinely underwent transesophageal echocardiography for detection of LA/LAA thrombus. GDF‐15 was measured by enzyme‐linked immunosorbent assay. Logistic regression models were used to test for association.

Results

LA/LAA thrombus was detected by transesophageal echocardiography in 69 (7.72%) patients with AF. The GDF‐15 levels in the patients with LA/LAA thrombus were significantly higher than those without LA/LAA thrombus (log₁₀ GDF‐15: 2.989 ± 0.023 ng/L vs 2.831 ± 0.007 ng/L; P < 0.001). Logistic regression analysis showed that GDF‐15 was an independent risk factor for LA/LAA thrombus (odds ratio [per quarter]: 1.799, 95% confidence interval: 1.381‐2.344, P < 0.001) after adjusting for potential clinical risk factors. The optimal cutoff point for GDF‐15 predicting LA/LAA thrombus was 809.9 ng/L (sensitivity, 75.3%; specificity, 61.5%), determined by ROC curve. The area under the curve was 0.709 (95% confidence interval: 0.644‐0.770, P < 0.001).

Conclusions

Elevated GDF‐15 indicated a significantly increased risk for LA/LAA thrombus in NVAF patients. Thus, GDF‐15 might be a potentially useful adjunct in discriminating LA/LAA thrombus in NVAF patients.     

Left atrial appendage function and abnormal hypercoagulability in patients with atrial flutter

STUDY OBJECTIVES: The prevalence of thromboembolism might be higher than previously recognized in patients with atrial flutter (AFL) based on findings of transesophageal echocardiography (TEE). To evaluate the potential prothrombotic state in patients with AFL, TEE findings and hemostatic markers were compared among patient groups with AFL, normal sinus rhythm (NSR) and chronic nonvalvular atrial fibrillation (AF). DESIGN AND SETTINGS: Cross-sectional study at a university hospital. METHODS: In 28 patients (mean age, 63 years) with AFL, 58 patients (mean age, 66 years) with AF, and 27 patients (mean age, 61 years) with NSR who underwent TEE, plasma levels of markers for platelet activity (platelet factor 4 and beta-thromboglobulin [beta-TG]), thrombotic status (thrombin-antithrombin III complex and prothrombin fragments 1 and 2) and fibrinolytic status (d-dimer and plasmin-alpha(2)-plasmin inhibitor complex) were determined. RESULTS: Left atrial appendage (LAA) blood flow velocity in patients with AFL was higher (p < 0.05) than that in patients with AF, but was lower (p < 0.05) than that in patients with NSR (AF, 25 +/- 2; AFL, 44 +/- 4; NSR, 60 +/- 4 cm/s). Dense left atrial spontaneous echo contrast (SEC) was found in 4 patients (14%) with AFL and 16 patients (28%) with AF. There was no significant difference in plasma levels of hemostatic markers between the AFL group and the NSR group. AFL patients with impaired LAA function (LAA flow < 30cm/s, dense SEC, or both), however, showed higher level of d-dimer and beta-TG than those without impaired LAA function (d-dimer, 1.9 +/- 0.6 microg/mL vs 0.4 +/- 0.1 microg/mL; beta-TG, 73 +/- 17 ng/mL vs 33 +/- 5 ng/mL, p < 0.05). CONCLUSIONS: Patients with AFL as a whole are not in the prothrombotic state as compared with those with AF. However, patients with AFL and impaired LAA function are at potentially high risk for thromboembolism and might require anticoagulation.     

Relationship between flow dynamics in the left atrium and hemostatic abnormalities in patients with nonvalvular atrial fibrillation

To investigate the relationship between left atrial (LA) flow dynamics and hemostatic markers in nonvalvular atrial fibrillation (AF), 45 patients with nonvalvular AF who had not received anticoagulants were evaluated by transesophageal echocardiography. We determined the LA appendage flow and the presence of LA spontaneous echo contrast (SEC) or thrombus. We measured plasma levels of thrombin-antithrombin III complex (TAT), fibrinopeptide A, D-dimer, beta-thromboglobulin, and platelet factor 4 in peripheral blood as hemostatic markers. The patients were divided into a low-velocity group (n = 19; sum of peak emptying and filling LA appendage flow velocities < 40 cm/s) and a high-velocity group (n = 26; > or = 40 cm/s). The maximum LA diameter was significantly greater and the LA expansion fraction was significantly smaller in the low-velocity group than in the high-velocity group. LA SEC or thrombus was observed in 11 patients (58%) in the low-velocity group, but not in any patients in the high-velocity group (p < 0.001). The plasma levels of TAT, fibrinopeptide A, D-dimer, beta-thromboglobulin, and platelet factor 4 were significantly higher in the low-velocity group than in the high-velocity group. The plasma levels of TAT, fibrinopeptide A, beta-thromboglobulin, and platelet factor 4 were significantly higher in 8 patients without LA SEC or thrombus in the low-velocity group than in 26 patients in the high-velocity group. Patients with nonvalvular AF accompanied by an enlarged and dysfunctioning LA and a decreased LA appendage flow velocity had increased intravascular coagulation-fibrinolysis activity and platelet activation. These abnormalities may be closely related to the thrombogenetic state in patients with nonvalvular AF.     

Clinical value of fibrillatory wave amplitude on surface ECG in patients with persistent atrial fibrillation

Purpose

We postulated that amplitude of fibrillatory (F)-wave in patients with persistent AF would correlate with clinical characteristics and outcome in patients undergoing catheter ablation for AF.

Method

Maximal and mean amplitude of F-waves were measured in V1 and lead II in 90 patients prior to ablation for persistent AF. F-wave amplitudes were correlated to clinical, echocardiographic variables, and outcome.

Results

F-wave?≥?0.1 mV in lead II and V1was correlated with younger age and shorter AF history, and in lead II only was correlated with a smaller left atrium. Higher F-wave amplitude at baseline predicted AF termination during ablation. Maximal amplitude of?≥?0.07 mV predicted AF termination by ablation with 82%/79% sensitivity and 68%/73% specificity in V1/lead II respectively. An association between F-wave amplitude and AF recurrence was observed. Forty-three percent of patients with mean f wave amplitude <0.05 in lead V1 had AF recurrence compared to 12% of those with F-wave?≥?0.05 (p?=?0.004).

Conclusion

Longer AF duration, older age and larger LA size are associated with fine AF amplitude. High F-wave amplitude predicts procedural termination of arrhyhmia in patients with persistent AF and freedom from AF upon follow-up.     

Left atrial dysfunction in patients with atrial fibrillation after successful rhythm control for > 3 months

BACKGROUND: Large-scale clinical trials have demonstrated that patients with atrial fibrillation (AF), when treated with a rhythm-control strategy, are still at risk for embolic events. We hypothesized that left atrial (LA) dysfunction persisted even after successful maintenance of sinus rhythm for > 3 months. METHODS: A total of 93 patients with AF and satisfactory rhythm control for > 3 months were included. Satisfactory rhythm control was defined as being free of AF based on patient-reported symptoms, monthly ECG follow-up, and ambulatory Holter ECG if needed. Among the 93 patients, 25 patients had sustained AF that was terminated by electrical or pharmacologic cardioversion, while 68 patients had paroxysmal AF under good medical control. Clinical data were obtained, and transthoracic and transesophageal echocardiography were performed after satisfactory rhythm control for > 3 months. RESULTS: Among the 93 patients, 34 patients (37%) had LA dysfunction, defined as LA appendage (LAA) peak emptying velocity < 40 cm/s or spontaneous echo contrast and/or thrombus in the LA or LAA. When compared to the other 59 patients without LA dysfunction, they had larger LA dimension (40 +/- 6 mm vs 36 +/- 8 mm [+/- SD], p = 0.018) but did not differ significantly regarding the left ventricular (LV) chamber size, LV ejection fraction, mitral or tricuspid inflow, and ratio of the amplitude of the waves created by early diastolic filling and atrial contraction. We also analyzed the relationship between LA function and clinical risk factors for stroke, including hypertension, diabetes mellitus, coronary artery disease, age > 65 years, and prior cerebral vascular accident. LA dysfunction was found in 10 of 17 patients (59%) with three or more risk factors. The odds ratio for having LA dysfunction was 3.1 (p = 0.04; 95% confidence interval, 1.1 to 9.1) when compared with patients with less than three risk factors. CONCLUSIONS: LA dysfunction was present in more than one third of AF patients after satisfactory rhythm control for > 3 months. Patients with higher burden (three or more) of clinical risk factors were more likely to have impaired LA function.     

Cardiac computed tomography angiography‐derived analysis of left atrial appendage morphology and left atrial dimensions for the prediction of atrial fibrillation recurrence after pulmonary vein isolation

BackgroundLeft atrial appendage (LAA) is a potential source of atrial fibrillation (AF) triggers.HypothesisLAA morphology and dimensions are associated with AF recurrence after pulmonary vein isolation (PVI).MethodsFrom cardiac computed tomography angiography (CCTA), left atrial (LA), pulmonary vein (PV), and LAA anatomy were assessed in cryoballoon ablation (CBA) patients.ResultsAmong 1103 patients undergoing second‐generation CBA, 725 (65.7%) received CCTA with 473 (42.9%) qualifying for detailed LAA analysis (66.3 ± 9.5 years). Symptomatic AF reoccurred in 166 (35.1%) patients during a median follow‐up of 19 months. Independent predictors of recurrence were LA volume, female sex, and mitral regurgitation ≥°II. LAA volume and AF‐type were dependent predictors of recurrence due to their strong correlations with LA volume. LA volumes ≥122.7 ml (sensitivity 0.53, specificity 0.69, area under the curve [AUC] 0.63) and LAA volumes ≥11.25 ml (sensitivity 0.39, specificity 0.79, AUC 0.59) were associated with recurrence. LA volume was significantly smaller in females. LAA volumes showed no sex‐specific difference. LAA morphology, classified as windsock (51.4%), chicken‐wing (20.7%), cactus (12.5%), and cauliflower‐type (15.2%), did not predict successful PVI (log‐rank; p = 0.596).ConclusionsLAA volume was strongly correlated to LA volume and was a dependent predictor of recurrence after CBA. Main independent predictors were LA volume, female sex, and mitral regurgitation ≥°II. Gender differences in LA volumes were observed. Individual LAA morphology was not associated with AF recurrence after cryo‐PVI. Our results indicate that preprocedural CCTA might be a useful imaging modality to evaluate ablation strategies for patients with recurrences despite successful PVI.     

Left atrial appendage obliteration in atrial fibrillation patients undergoing bioprosthetic mitral valve replacement

Background

Left atrial appendage (LAA) obliteration is a proven stroke-preventive measure for patients with nonvalvular atrial fibrillation (AF). However, the efficacy of LAA obliteration for patients with AF after bioprosthetic mitral valve replacement (MVR) remains unclear.

Aim

This study aimed to estimate the efficacy of LAA obliteration in preventing embolism and to investigate the predictors of thromboembolism after bioprosthetic MVR.

Methods

We retrospectively studied 173 AF subjects with bioprosthetic MVR; among them, 81 subjects underwent LAA obliteration using an endocardial running suture method. The main outcome measure was the occurrence of thrombosis events (TEs). The mean follow-up time was 40?±?17 months.

Results

AF rhythm was observed in 136 patients postoperatively. The incidence rate of TEs was 13.97?% for postoperative AF subjects; a dilated left atrium (LA; >?49.5 mm) was identified as an independent risk factor of TEs (OR?=?10.619, 95?% CI?=?2.754–40.94, p?=?0.001). For postoperative AF patients with or without LAA, the incidence rate of TEs was 15.8?% (9/57) and 12.7?% (10/79; p?=?0.603), respectively. The incidence rate of TEs was 2.7?% (1/36) and 4.2?% (2/48) for the subgroup patients with a left atrial diameter of <?49.5 mm, and 38.1?% (8/21) and 25.8?% (8/31) for those with a left atrial diameter of >?49.5 mm (p?=?0.346).

Conclusion

Surgical LAA obliteration in patients with valvular AF undergoing bioprosthetic MVR did not reduce TEs, even when the CHA₂DS₂-VASc score (a score for estimating the risk of stroke in AF) was ≥?2 points.