64排螺旋CT与经食道超声对房颤患者左房血栓的检测

目的探讨64排螺旋CT(64SCT)扫描对房颤患者左房血栓的检测价值。方法选择2009年1月至2015年2月就诊于我院心脏诊疗中心拟行房颤射频消融术的房颤病例,行64SCT肺静脉检查及经食道超声心动图检查(TEE),并将64SCT与TEE检测左房或左心耳血栓的结果进行比较分析。结果共计入选资料完整的房颤患者89例,以TEE作为"金标准",其中75例64SCT扫描与TEE诊断相符,诊断符合率为84.27%(75/89)。64SCT检测左房或左心耳血栓的诊断特异度为98.48%(65/66),诊断灵敏度为43.48%(10/23),阳性预测值为90.91%(10/11),阴性预测值为83.33%(65/78),阳性似然比为28.70,阴性似然比为0.57。两者进行配对设计Mc Nemarχ2检验,P=0.014,统计学上尚不能认为两者的检测效果相同。结论 64SCT扫描对房颤患者左房或左心耳血栓检测的特异度高,对左房或左心耳血栓诊断具有重要价值。但64SCT检查左房或左心耳血栓的敏感性不够,在房颤射频消融术前不能完全代替经食道心脏超声预测左房或左心耳血栓。     

双源256排CT和食管超声的联合应用对心房颤动患者左心房/左心耳血栓的检测价值

目的：比较双源256排CT(MDCT)和食管超声(TEE)对左心房/左心耳血栓检出的准确性比较。方法：拟行导管消融术的房颤患者1178例,术前48小时内同一天行MDCT和TEE检查,必要时复查TEE,及再次MDCT阅片。评价MDCT和TEE的准确性。结果：经TEE检测出有血栓者为186例,其中假阳性2例。经MDCT检测出有血栓者176例,无假阳性,假阴性8例（1%占）,MDC的敏感性94.6%,特异性100%,阳性预测值100%,阴性预测值99%。两种检测方法的Kappa值为0.961（P＜0.05）。结论：MDCT不能完全取代食管超声作为检测左心房/左心耳血栓的手段。术前常规同时行MDCT和TEE,能提高左心房/左心耳血栓诊断的准确性。     

多层螺旋CT与经食管超声心动图检测心房颤动患者左心房血栓对比

目的 :探讨多层螺旋CT(MSCT)与经食管超声心动图(TEE)在检测心房颤动(房颤)患者左心房血栓的价值。方法:收集我院心内科2014年1月1日至2015年6月30日住院拟行房颤射频消融手术病例,在同一次住院期间均行MSCT与TEE检查,搜集2种检查方法检测血栓的结果,比较2种方法的敏感度和特异度。结果:MSCT与TEE诊断符合的为190例,其中6例2种方法均诊断为血栓,余184例均未发现血栓,诊断符合率为94.1%。MSCT检测血栓阳性或可疑阳性的8例患者,TEE则提示左心房及左心耳内淤血表现、云雾状影、絮状回声或未见明显血栓。另外4例TEE诊断为血栓者中1例为左心房前上壁附壁血栓、3例为左心耳少量血栓,而MSCT诊断未见血栓。以TEE为"金标准",MSCT检测血栓灵敏度60.0%,特异度95.8%,阳性预测值42.9%,阴性预测值97.9%,阳性似然比14.4,阴性似然比0.42。经过四格表配对χ~2检验,χ~2=45.936,P     

双源256排CT联合食管超声对心房颤动患者左心房/左心耳血栓的检测价值

目的:比较双源256排CT(MDCT)和食管超声(TEE)对左心房/左心耳血栓检出的准确性。方法:拟行导管消融术的房颤患者1 178例,术前48 h内同1天行MDCT和TEE检查,必要时复查TEE,并再次MDCT阅片。评价MDCT和TEE的准确性。结果:经TEE检测出有血栓者186例,其中假阳性2例。经MDCT检测出有血栓者176例,无假阳性,假阴性8例(4. 3%),MDCT的敏感性95. 7%,特异性100%,阳性预测值100%,阴性预测值99%。2种检测方法的Kappa值为0. 974(P 0. 05)。结论:MDCT不能完全取代食管超声作为检测左心房/左心耳血栓的手段。术前常规同时行MDCT和TEE,能提高左心房/左心耳血栓诊断的准确性。     

64层螺旋CT检测非瓣膜性心房颤动患者左房血栓的临床价值

目的:探讨64层螺旋CT检测非瓣膜性心房颤动(NVAf)患者左房血栓的临床价值.方法:32例NVAf患者均行64层螺旋CT检查,其中有13例患者同时行经食管超声心动图(TEE)检查,对2种检测结果进行比较.结果:64层螺旋CT发现6例患者有左房血栓, 其中2例同时行TEE检查,也发现有左房血栓;6例患者于64层螺旋CT显示"血栓前状态",其中3例同时行TEE检查示左房均存在左房自发超声对比现象(Ⅱ～Ⅳ级);20例患者64层螺旋CT检测中无血栓,8例同时行TEE检查,也排除了血栓的存在.结论:64层螺旋CT可以成为检测NVAf患者左房血栓的一种安全可靠的替代方法.     

左心房肺静脉CT双期增强扫描对心房颤动病人左心耳血栓的评估价值

目的探讨宝石能谱CT左心房肺静脉双期增强扫描诊断心房颤动病人左心耳血栓的价值及左心耳口径大小与左心耳血栓形成的关系。方法收集我院2018年1月—2018年12月临床怀疑有左心耳血栓的心房颤动病人90例,行左心房肺静脉双期增强扫描,第1期采用小剂量法确定扫描时间,第2期延迟时间为40 s。在AW4.6工作站以横断面图像为基础,结合冠状位、矢状位图像观察左心耳内有无血栓,采用后处理软件测量左心耳开口的长径、短径,比较血栓组与无血栓组左心耳开口的大小。结果 3例病人无法耐受经食道超声(TEE),87例病人纳入研究。第1期CT扫描发现左心耳内低密度充盈缺损25例,第2期CT扫描仍呈现充盈缺损,诊断左心耳血栓20例(其中19例经TEE确诊为血栓)。以TEE为金标准,第1期CT诊断左心耳血栓的符合率、特异度、灵敏度、阳性预测值、阴性预测值分别为91.95%、91.04%、95.00%、76.00%、98.39%;第2期CT诊断左心耳血栓的符合率、特异度、灵敏度、阳性预测值、阴性预测值分别为97.70%、98.51%、95.00%、95.00%、98.51%,第2期诊断左心耳血栓的符合率、特异度、阳性预测值、阴性预测值均较第1期提高。血栓组与无血栓组左心耳口长径、短径比较,差异有统计学意义(t值分别为6.683、7.876,P0.001)。结论左心房肺静脉CT双期增强扫描能鉴别左心耳血栓及血流瘀滞状态,减少单期增强造成的假阳性结果,为临床提供一种安全无创、客观精确的检测左心耳血栓的方法。心房颤动病人左心耳口增大可能是血栓形成的危险因素。     

经食管超声心动图在房颤介入治疗前左心耳血栓检查中的应用价值

目的探讨经食管超声心动图（TEE）在房颤介入治疗前左心耳血栓检查中的应用价值。方法对48例拟行射频消融、经皮穿刺二尖瓣球囊成形术（PBMV）的房颤患者应用经胸超声心动图（TTE）筛查,对未发现左房血栓或可疑左心耳血栓者进一步行TEE检查,以确定左心耳有无血栓。结果 48例房颤患者常规TTE检查42例未发现左心耳血栓,2例可疑左心耳血栓。TEE检查在48例中发现9例左心耳血栓,占18.7%（7/48）,发现左心耳＂自发性显影＂8例。结论 TEE在房颤介入治疗前左心耳血栓检查中具有重要的临床应用价值。     

64层螺旋CT对老年冠状动脉疾病患者的诊断价值评价

目的探讨64层螺旋CT对老年冠状动脉疾病患者的诊断价值。方法对61例疑为冠心病的老年患者进行冠状动脉64层螺旋CT扫描,并于1周之内进行冠状动脉造影检查。以冠状动脉造影为“金标准”,评价冠状动脉64层螺旋CT诊断老年冠状动脉疾病患者的敏感性、特异性、阳性预测值、阴性预测值及准确度。结果61例患者总计915个冠状动脉节段,64层螺旋CT能够评价其中882个节段(96．4％),其检测中度以上冠状动脉狭窄的敏感性75．6％,特异性88．1％,阳性预测值64．0％,阴性预测值92．8％,准确度85．4％。结论64层螺旋CT对老年冠状动脉疾病患者具有较高的诊断价值,有可能成为筛查老年人冠心病的一个较为可靠的无创检测手段     

双源CT联合食管超声心动图检测房颤左心耳血栓

目的 探讨双源CT与食管超声心动图（TEE）联合检测对心房颤动（简称房颤）患者是否发生左心耳血栓的诊断价值,为临床早期筛查诊断、针对性制定治疗方案提供参考依据。方法 选取平顶山市精神病医院2021年7月至2023年7月收治的74例房颤患者作为研究对象,入院后均行双源CT检查及食管超声检查。以最终临床诊断结果为“金标准”,比较房颤患者中有左心耳血栓与左心耳血栓双源CT定量参数[左心房最大容积（LAVmax）、左心房最小容积（LAVmin）、左心耳最大容积（LAVVmax）、左心耳最小容积（LAVVmin）、左心房射血分数（LAEF）、左心耳射血分数（LAAEF）],比较双源CT与TEE单独及联合检测对左心耳血栓的诊断效能。结果 最终临床诊断结果显示,74例房颤患者中,有左心耳血栓28例,无左心耳血栓46例。有左心耳血栓患者LAVmax、LAVmin、LAAVmax、LAAVmin高于无左心耳血栓患者,LAFF、LAAEF低于无左心耳血栓患者（P<0.05）;双源CT检测结果显示,有左心耳血栓患者20例,无左心耳血栓患者54例;TEE检测结果显示,有左心耳血栓患者21例,无左心耳血栓...     

经食道超声心动图在二尖瓣球囊扩张术前对左心房血栓检出的研究

目的 :探讨经食道超声心动图 (TEE)对风湿性心脏病中重度二尖瓣狭窄 (二尖瓣口面积为 0 92± 0 2 1cm2 )患者左心房和 (或 )左心耳血栓的诊断价值。方法 :2 41例准备经皮二尖瓣球囊扩张的患者术前检查 ,所有病例经胸超声心动图 (TTE)未发现或可疑左心房和(或 )左心耳血栓 ,并至少禁食 4小时后进行TEE。结果 :76 ( 32 % )例经TEE显示左心耳和 (或 )左心房内附壁血栓。以TEE为标准 ,TTE诊断左心耳血栓的敏感性和特异性分别为 2 5 %和 94%。结论 :大多数二尖瓣狭窄病例左心房血栓发生在左心耳内 ,TTE探查左心耳血栓敏感性低 ,应该使用TEE探查     

Comparison of contrast enhanced 64-slice computed tomography and transesophageal echocardiography in detection of left atrial thrombus in patients with atrial fibrillation

BACKGROUND AND OBJECTIVE: Recent advances in multi-slice computed tomography (MSCT) have allowed an improved analysis of left atrial (LA) and left atrial appendage (LAA) anatomy prior to catheter ablation of atrial fibrillation (AF). However, data regarding the ability of MSCT to identify LA/LAA thrombus are limited. This prospective study compared the efficacy of 64-slice contrast-enhanced computed tomography (64CCT) with transesophageal echocardiography (TEE) of the heart in the identification of LA/LAA thrombus. MATERIALS AND METHODS: One-hundred and seventy consecutive patients scheduled for first-time catheter ablation of paroxysmal (n = 120) or persistent (n = 50) AF were enrolled for study. Each patient underwent non-gated 64CCT and TEE of the heart for exclusion of LA/LAA thrombus prior to ablation procedure. RESULTS: Fourteen cases (8.2%) of LA/LAA thrombi were interpreted by 64CCT (ten false-positive, four true positive), whereas 11 actual thrombi (6.5%) were detected by TEE (seven false-negative by 64CCT) in the same population. Maximal dimension of TEE identified thrombi did not differ between the false-negative by 64CCT group and the true-positive group (17 +/- 6 vs. 18 +/- 5 mm P = 0.677). Results indicated 64CCT sensitivity = 36.4%, specificity = 93.7%, positive predictive value = 28.6%, and negative predictive value = 95.5% in the detection of LA/LAA thrombus. The Kappa value in evaluating the agreement between 64CCT and TEE for detection of LA/LAA thrombus was 0.267. CONCLUSION: Compared to gold standard TEE, 64CCT was shown to be less reliable in the detection of LA/LAA thrombus prior to catheter ablation in patients with AF.     

Low incidence of left atrial or left atrial appendage thrombus in patients with paroxysmal atrial fibrillation and normal EF who present for pulmonary vein antrum isolation procedure

Introduction: The incidence of left atrial appendage (LAA) thrombus in patients with paroxysmal atrial fibrillation (PAF) who present for pulmonary vein antrum isolation procedure (PVAI) is unknown.
Methods and Results: All consecutive patients from January 2000 to June 2004 who underwent a PVAI received a computed tomography (CT) to evaluate LAA thrombus before the procedure and 3 months post-PVAI. All patients were followed prospectively. One thousand two hundred twenty-one patients received a PVAI during the study dates. All patients received a CT pre-PVAI at 3 months, and 601 (49%) received a transesophageal echocardiography (TEE) pre-PVAI. Per protocol, all patients who had CT scans that were positive for LAA thrombus received a TEE. There were 9 patients who had LAA thrombus on CT scan, but only 3 had LAA thrombus on TEE. Using TEE as the gold standard, only 3 patients had an LAA thrombus before PVAI; of these patients, 2 had chronic AF with average ejection fraction (EF) of 48% and 1 patient had PAF with EF 25%. No patients with PAF and normal EF had LAA thrombus. Patients with LAA thrombus pre-PVAI had lower EF than patients without LAA thrombus (40% vs. 53%, P = 0.007) but had similar LA size (5.0 vs. 4.5 cm, P = 0.77). No other differences in baseline characteristics were noted.
Conclusions: In this registry of 1,221 patients, we did not observe LA thrombus in PAF patients with normal EF who present for PVAI. Prescreening CT alone is likely to be sufficient in paroxysmal AF patients with normal EF, and the use of TEE may not be needed.     

A comparison of intracardiac and transesophageal echocardiography to detect left atrial appendage thrombus in a swine model

Purpose

Transesophageal echocardiography (TEE) is the gold standard in the evaluation for left atrial appendage (LAA) thrombus in patients with atrial fibrillation (AF) and is often performed prior to AF ablation. We routinely use intracardiac echocardiography (ICE) to assist in AF ablation; however, standard right atrial views do not provide adequate visualization of the LAA. As the incidence of thrombus in this population is relatively low, TEE incurs additional risk, cost, and patient discomfort. Novel views of the LAA with ICE may obviate the need for TEE in this population. We tested the hypothesis that due to their proximity, imaging the LAA from the pulmonary artery (PA) would provide equivalent sensitivity and specificity to TEE in detecting LAA thrombus in a swine model.

Methods

Five domestic swine were utilized. Baseline images of the LAA with TEE were obtained. An 8Fr ICE catheter was placed in the left main PA, and imaging of the LAA was repeated. After transseptal puncture, an admixture of 2 cm³ blood and 1,000 IU of thrombin was injected into the LAA, and imaging of the LAA was repeated. Two blinded, independent reviewers experienced in ICE assessed the images and adjudicated both the presence of thrombus and the subjective image quality.

Results

The presence or absence of thrombus was correctly identified in all cases by both reviewers. Both reviewers rated the subjective quality of ICE images superior to TEE.

Conclusions

ICE is equivalent to TEE in imaging LAA thrombus in a porcine model. Whether ICE can provide similar diagnostic accuracy and safety for detecting LAA thrombus in humans remains unproven.     

64排螺旋CT在诊断房颤患者左房血栓中的作用

目的：评价64排螺旋CT行左房及肺静脉计算机断层血管摄影术（CTA）诊断左房血栓的可行性及有效性。方法：51例需行房颤射频消融术或二尖瓣狭窄伴房颤患者拟行球囊扩张术前常规行左房及肺静脉CTA检查,有左房血栓的病例作为实验组,未提示左房血栓的病例作为对照组.所有病例均行经食道超声检查（TEE）,且在行左房及肺静脉CTA检查时测量左房容积（LAV）。检查前均抽取静脉血检查脑钠肽（BNP）水平。结果：51例房颤患者CTA检测出左房血栓11例,无左房血栓40例,均经TEE检测证实;与房颤无血栓组比较,房颤伴左房血栓组BNP水平明显升高[（168.10±50.68）pg/ml比（253.03±150.88）pg/ml],LAV明显增大[（150.55±47.44）cm2比（229.10±104.96）cm2],P均〈0.05。结论：房颤患者行左房及肺静脉CTA检查可以发现是否存在左房血栓,是检测房颤患者是否存在左房血栓的一种无创性方法。     

Diagnostic accuracy of arterial phase 64-slice multidetector CT angiography for left atrial appendage thrombus in patients undergoing atrial fibrillation ablation

Introduction: Multidetector CT (MDCT) is used prior to atrial fibrillation ablation (AFA) to anatomically guide ablation procedures. Whether 64-slice MDCT also can be used to diagnose left atrial thrombus is not known.
Methods: We sought to determine the accuracy and interobserver variability of MDCT in the evaluation of left atrial thrombus prior to AFA. We enrolled 50 patients scheduled for AFA who underwent 64-slice MDCT scan and transesophageal echocardiography prior to the procedure. Three experienced observers reviewed all the MDCT images for the presence of a left atrial thrombus, and two different readers interpreted the transesophageal echocardiograms (TEE), which were used as the gold standard. All observers were blinded to clinical data and each other.
Results: Interobserver variability between the three MDCT readers was poor (highest kappa statistic 0.43, P = 0.001). Diagnostic accuracy was highly variable, with sensitivities ranging from 100% to 50% and specificities ranging from 85% to 44%. TEE reader agreement was 98%.
Conclusion: MDCT demonstrates high interobserver variability and has only modest diagnostic accuracy for the detection of left atrial thrombus in patients undergoing AFA procedure. Potential factors affecting the accuracy of MDCT include image quality and the difficulty of distinguishing clot from pectinate muscle. MDCT likely is not the optimal method to detect left atrial thrombus using current techniques and standards of interpretation.     

Filling defects of the left atrial appendage on multidetector computed tomography: their disappearance following catheter ablation of atrial fibrillation and the detection of LAA thrombi by MDCT

Filling defects of the left atrial appendage (LAA) on multidetector computed tomography (MDCT) are known to occur, not only due to LAA thrombi formation, but also due to the disturbance of blood flow in the LAA of patients with atrial fibrillation (AF). The purpose of this study was to evaluate the impact of the maintenance of sinus rhythm via ablation on the incidence of LAA filling defects on MDCT in patients with AF. A total of 459 consecutive patients were included in the present study. Prior to ablation, MDCT and transesophageal echocardiography (TEE) were performed. AF ablation was performed in patients without LAA thrombi confirmed on TEE. The LAA filling defects were evaluated on MDCT at 3 months after ablation. LAA filling defects were detected on MDCT in 51 patients (11.1 %), among whom the absence of LAA thrombi was confirmed in 42 patients using TEE. The LAA Doppler velocity in patients with LAA filling defects was lower than that of patients without filling defects (0.61 ± 0.19 vs. 0.47 ± 0.21 m/s; P < 0.0001). The sensitivity, specificity and negative predictive value of MDCT in the detection of thrombi were 100, 91 and 100 %, respectively. No LAA filling defects were observed on MDCT at 3 months after ablation in any of the patients, including the patients in whom filling defects were noted prior to the procedure. MDCT is useful for evaluating the presence of LAA thrombi and the blood flow of the LAA. The catheter ablation of AF not only suppresses AF, but also eliminates LAA filling defect on MDCT suggesting the improvement of LAA blood flow.     

Multidetector row computed tomography for identification of left atrial appendage filling defects in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation: Comparison with transesophageal echocardiography

BACKGROUND: Advances in multidetector computed tomography (MDCT) technology now permit three-dimensional cardiac imaging with high spatial and temporal resolution. Historically, transesophageal echocardiography (TEE) has been the gold standard for assessment of the left atrial appendage (LAA) in patients with atrial fibrillation and other atrial arrhythmias. Findings on TEE, including demonstration of LAA thrombus and dense nonclearing spontaneous echocardiographic contrast (SEC), predict future fatal and nonfatal thromboembolic events. OBJECTIVE: The purpose of this study was to compare the diagnostic performance of 64-detector row MDCT in detecting LAA thrombus and dense nonclearing SEC as identified by TEE in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation. METHODS: A total of 72 consecutive patients (69.4% male; mean age 56.1 +/- 10.3 years) underwent both MDCT and TEE for evaluation of the LAA (median intertest interval 0 days, interquartile range 0-5 days). MDCT assessment of the LAA was performed by two methods: (1) comparison of Hounsfield unit (HU) densities in the LAA apex to the ascending aorta (AscAo) in the same axial plane and (2) nonquantitative visual identification of a filling defect in the LAA. TEE evaluation of the LAA included identification of echodense intracavitary masses in the LAA as well as pulsed-wave Doppler interrogation of the LAA ostium. RESULTS: Patients with LAA thrombus or dense nonclearing SEC by TEE exhibited significantly lower LAA/AscAo HU ratios than patients who did not (0.82 +/- 0.22 vs 0.39 +/- 0.19, P <.001). LAA/AscAo HU cutoff ratios < or = 0.75 correlated to LAA thrombus or dense nonclearing SEC by TEE, with 100% sensitivity, 72.2% specificity, 28.6% positive predictive value, and 100% negative predictive value. HU ratios < or = 0.75 were associated with pulsed-wave Doppler velocities <50 cm/s of the LAA ostium (P <.001). In multivariable analysis, LAA/AscAo HU ratio < or = 0.75 remained a robust predictor of LAA thrombus or dense nonclearing SEC by TEE (P <.001). In contrast, MDCT identification of TEE-identified LAA thrombus or dense nonclearing SEC by visual detection of LAA filling defects resulted in lower sensitivity (50%) and negative predictive value (95.1%). CONCLUSION: Current-generation MDCT successfully identifies LAA thrombus and dense nonclearing SEC with high sensitivity and moderate specificity. Importantly, LAA/AscAo HU ratios >0.75 demonstrate 100% negative predictive value for exclusion of LAA thrombus or dense nonclearing SEC. These results suggest that in patients undergoing pulmonary vein isolation procedures, MDCT examinations that demonstrate LAA/AscAo HU ratios >0.75 may preclude the need for preprocedural TEE.     

ECG-gated dual-source CT for detection of left atrial appendage thrombus in patients undergoing catheter ablation for atrial fibrillation

Purpose  

Left atrial ablation is increasingly used to treat patients with symptomatic atrial fibrillation (AF). Prior to ablation, exclusion of left atrial appendage (LAA) thrombus is important. Whether ECG-gated dual-source computed tomography (DSCT) provides a sensitive means of detecting LAA thrombus in patients undergoing percutaneous AF ablation is unknown. Thus, we sought to determine the utility of ECG-gated DSCT in detecting LAA thrombus in patients with AF.     

Prevalence and Clinical Characteristics Associated With Left Atrial Appendage Thrombus in Fully Anticoagulated Patients Undergoing Catheter‐Directed Atrial Fibrillation Ablation

LAA Thrombus Among Anticoagulated AF Patients. Introduction: Catheter‐directed atrial fibrillation (AF) ablation is contraindicated among patients with left atrial appendage (LAA) thrombus. The prevalence of LAA thrombus among fully anticoagulated patients undergoing AF ablation is unknown. Methods and Results: We retrospectively evaluated the prevalence of LAA thrombus among 192 consecutive patients undergoing AF ablation between July 2006 and January 2009. Seven of 192 patients (3.6%) had evidence of thrombus on transesophageal echocardiogram (TEE) despite being fully anticoagulated on warfarin (international normalized ratio [INR] 2–3) for 4 consecutive weeks prior to echocardiogram. Univariate analysis demonstrated that structural heart disease, large left atrial dimension, and number of AF ablations were associated with thrombus. Three patients with thrombus had paroxysmal AF with normal LV function. Conclusion: Despite full anticoagulation, 3.6% of patients undergoing AF ablation had LAA thrombus. We recommend that all patients, regardless of LV function or left atrial size, should undergo preprocedural TEE to exclude the presence of LAA thrombus. (J Cardiovasc Electrophysiol, Vol. 21, pp. 849‐852, August 2010)     

Role of transesophageal echocardiography in the prediction of thromboembolism in patients with chronic nonvalvular atrial fibrillation

The purpose of this study was to determine whether parameters derived from transesophageal echocardiography (TEE) could predict thromboembolism in patients with chronic nonvalvular atrial fibrillation (AF). Eighty-nine patients, mean age 66+/-9 years, who underwent TEE in 1996 to 1999 were studied. The clinical endpoint was a thromboembolic event, including transient ischemic attack (TIA). Sixty-seven patients (75%) were anticoagulated with warfarin after TEE. After a follow-up period of 29+/-10 months, 1 patient died suddenly, 4 had a thromboembolism, and 3 had a TIA; the annual embolic event rate was 3.3%. Left atrial appendage (LAA) thrombus (86% vs 17%, p<0.001), LAA dysfunction (LAA velocity <20 cm/s; 71% vs 25%, p=0.009), and severe LA spontaneous echo contrast (29% vs 2%, p=0.002) were more prevalent in patients with an embolic event than in those without. In patients with LAA thrombus, the annual event rate was 11% as compared with 1.2% in those without (p=0.004). On the Cox proportional hazards model analysis, LAA thrombus (chi-square 7.0, p=0.008), severe LA spontaneous echo contrast (chi-square 7.0, p=0.008), and LAA dysfunction (chi-square 5.9, p=0.015) were significantly related to thromboembolism. Multivariate analysis revealed that LAA thrombus (chi-square 5.5, p=0.019) and LAA dysfunction (chi-square 4.0, p=0.045) were the independent predictors. In conclusion, TEE parameters, particularly the presence of LAA thrombus, can be used to assess thromboembolic potential in patients with chronic nonvalvular AF.