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。     

经食管超声心动图联合增强在诊断老年非瓣膜性心房颤动患者血栓形成中的价值

目的研究经食管超声心动图(TEE)联合增强检出老年非瓣膜性心房颤动(房颤)患者左心耳血栓形成中的价值。方法选取2017年12月～2020年10月内蒙古医科大学附属医院行经TEE检查的老年非瓣膜性房颤患者145例,根据TEE联合增强检查结果分为血栓形成组52例和非血栓组93例。先后行经胸超声心动图(TTE)及TEE检查。并对疑似血栓形成又不能排除的12例患者完成TEE联合增强检查。对比TTE与TEE对左心房及左心耳不同血流状态的检出情况。比较2组一般临床资料,并进行多因素logistic回归分析。结果 TEE联合增强血栓检出率明显高于TTE,差异有统计学意义(35.9%vs 5.5%,P0.01)。与非血栓组比较,血栓形成组左心房内径(LAD)、同型半胱氨酸、C反应蛋白和D-二聚体水平明显升高,左心耳流速和LVEF明显降低,差异有统计学意义(P0.05,P0.01)。多因素logistic回归分析显示,LAD及D-二聚体是老年非瓣膜性房颤患者血栓形成的独立危险因素(OR=1.14,95%CI:1.03～1.25,P=0.027;OR=4.79,95%CI:1.40～16.70,P=0.012),左心耳流速为保护因素(OR=0.84,95%CI:0.78～0.90,P=0.001)。结论 TEE可以直观显示心房及心耳的血流状态,准确测量左心耳流速,联合增强更有助于鉴别诊断。     

64层螺旋CT检测老年心房颤动患者左心耳血栓的价值

目的探讨导管射频消融术前,应用64层螺旋CT检测老年心房颤动患者左心耳血栓的临床价值。方法对102例拟行导管射频消融术的老年心房颤动患者进行心脏64层螺旋CT扫描,并于1周内,经食管超声心动图(TEE)检查。以TEE为参照标准,评价64层螺旋CT诊断患者左心耳血栓的敏感性、特异性、阳性预测值、阴性预测值及准确度,应用κ检验2种方法的一致性。结果 102例患者中,64层螺旋CT检查显示左心耳血栓形成者16例,其中11例经TEE证实,另5例为自发超声显影;64层螺旋CT检查未见血栓征象者86例,其中84例经TEE证实,另2例TEE显示为血栓。64层螺旋CT诊断左心耳血栓的敏感性84.6%,特异性94.4%,阳性预测值68.8%,阴性预测值97.7%,准确度93.1%,2种方法检测左心耳血栓具有较高的一致性(κ=0.724)。结论 64层螺旋CT检测老年心房颤动患者左心耳血栓具有较高的应用价值,未来有可能成为临床上检测左心耳血栓的一种无创、可靠的替代方法。     

阵发性心房颤动患者左心耳血栓形成的相关因素

目的 应用经胸和经食管超声探讨阵发性心房颤动(paroxysmal atrial fibrillation,PAF)患者左心耳血栓形成的相关因素。方法 PAF患者212例,以左心耳内有无血栓将患者分为血栓组（44例）和无血栓组（168例）,详细记录两组患者的一般资料,经胸超声(TTE)参数:左房内径（LAD）、左房舒张末期容积(LAEDV)、左房收缩末期容积(LAESV)、左房射血分数(LAEF),经食管超声(TEE)参数:左心耳内血流速度(LAA-v)、 45°,90°,135°切面左心耳横径(LAA-W)、左心耳深度(LAA-D)。比较两组患者的各项指标差别并进行多因素Logistic回归分析。结果 两组患者中性别、年龄、并发高血压病、糖尿病、高脂血症、 LAA-W及LAA-D差异均无统计学意义;患者的冠心病比例、LAD、LAEDV和LAESV血栓组大于无血栓组,LAEF及LAA-v血栓组小于无血栓组,差异均有统计学意义(均P<0.05);多因素Logistic回归分析显示,LAEF(OR=1.163, 95%CI:1.043~1.296,P<0.01)及LAA-v(OR=29.82,95%CI:7.97~29.82,P<0.05)是血栓形成的独立危险因素。结论 PAF患者左心耳内血栓形成与LAEF及LAA-v密切相关。     

经食管及经胸超声心动图对风湿性心脏病左心房及左心耳血栓的诊断价值

目的　研究多平面经食管超声心动图 (TEE)及经胸超声心动图 (TTE)对风湿性心脏病 (RHD)左心房及左心耳血栓的诊断价值。方法　对同期 TTE检查的 469例和欲行二尖瓣球囊扩张术、闭式分离术、经 TTE检查未发现明确血栓而行 TEE检查的12 6例 RHD病人其左心房血栓 (LAT)及左心耳血栓 (L AAT)的检出情况进行总结分析。结果　 TTE:469例检出血栓者 2 1例。血栓位于左心房内 10例 ,左心房与左心耳并存者 7例 ,单纯左心耳部 4例。 TEE:12 6例中检出血栓者 3 2例 ,其中左心耳部血栓 2 4例 ,与左心房并存者 6例 ,单纯左心房内 1例。结论　 TEE对 L AAT的检出率显著高于 TTE,特别是对左心耳内及左心房周边的小血栓、新鲜血栓及血栓形成前状态优甚于 TTE。心房颤动可促成血栓的形成。对伴有心房颤动的 RHD患者用 TEE检查对 L AT及 L AAT的诊断具有重要价值     

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     

左心耳发育不良临床及影像学分析

目的 分析心房颤动（房颤）患者左心耳发育不良的临床及影像学特点,探讨其预防左心房血栓抗凝方案。方法 回顾性研究2018年7月至2023年10月上海健康医学院附属周浦医院经左心房电子计算机断层扫描造影成像（CTV）和（或）经食管超声心动图（TEE）检查发现左心耳发育不良的房颤患者5例,分析其临床特征、影像学资料、抗凝治疗方案。结果 5例房颤患者,1例完成左心房CTV及TEE检查,1例完成胸部CT平扫及TEE检查,3例完成左心房CTV检查。5例患者均依靠左心房CTV延迟期及肺静脉期多平面重建和（或）TEE结果诊断左心耳发育不良,TEE可见细小的左心耳间隙或不能见到左心耳口。左心耳发育不良均表现为左心耳小,左心耳壁肥厚,无左心耳腔或左心耳腔细小,左心房CTV对比剂难以进入。5例患者均合并心脑血管动脉粥样硬化,1例行冷冻消融术,既有抗血小板方案也有抗凝方案或二者兼有。结论 左心房CTV延迟期及肺静脉期多平面重建可明确诊断特殊类型的发育不良的左心耳,TEE对诊断有一定辅助作用。伴左心耳发育不良的房颤患者抗凝方案有待进一步认识。     

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。     

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...     

房颤时左心耳结构和功能改变与肺静脉血流的关系研究

目的评价房颤时左心耳结构和功能改变与肺静脉血流变化的关系。方法74例房颤患者和16例正常人接受经胸超声心动图(TTE)和经食道超声心动图(TEE)检查,检测左心耳血栓形成、结构、功能和肺静脉血流频谱指标。结果18例房颤患者存在左心耳血栓,血栓组、非血栓组和正常组间左心耳结构、功能和肺静脉血流频谱有显著差异,其中血栓组左心耳扩大,血流速度下降最严重,左心耳结构、功能和肺静脉血流密切相关。结论房颤时左心耳结构改变,功能减退,肺静脉血流和左心耳结构、功能关系密切,能准确反应左心耳功能,在血栓评价中具有重要意义。     

Comparative assessment of left atrial appendage by transesophageal and combined two- and three-dimensional transthoracic echocardiography

Objective: Our objective was to compare the utility of combined two‐dimensional (2D) transthoracic echocardiography (TTE) and three‐dimensional (3D) TTE versus 2D transesophageal echocardiography (TEE) in evaluation of the left atrium (LA) and LA appendage (LAA) for clot. Background: 2DTEE, usually performed to visualize the LAA, is semi‐invasive and not without risks. With improved technology the LAA has been increasingly visualized by 2DTTE and 3DTTE in many patients. Methods: We compared combined 2DTTE and 3DTTE with 2DTEE in evaluating the LA/LAA for a thrombus. Ninety‐two patients underwent 2DTTE, 3DTTE, and 2DTEE. An additional 20 patients, in whom TEE could not be performed, underwent 2DTTE and 3DTTE. Results: LA and LAA could be visualized in all patients. Of 92 patients studied, 74 had no thrombus and 7 had thrombus in the LAA by all modalities. Eleven patients, 9 with atrial fibrillation (AF), had a suspected thrombus by 2DTEE, but 3DTTE cropping clearly showed these to be prominent pectinate muscles which were seen in short axis on 2DTEE as rounded echo dense masses and therefore mimicked thrombi. These 9 patients with AF underwent successful cardioversion without any complications. Of the 20 patients in whom TEE could not be performed, 19 had no thrombus in the LA/LAA and 1 had a clot in the LAA. These 19 patients underwent successful cardioversion without complications. Conclusions: Our preliminary study suggests that combined 2DTTE and 3DTTE has comparable accuracy to TEE in evaluating the LA and LAA for thrombus. In some patients TEE, but not 3DTTE, may misdiagnose pectinate musculature as thrombus.     

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.     

Use of intracardiac echocardiography to guide implantation of a left atrial appendage occlusion device (PLAATO).

BACKGROUND: Over 90% of thrombi in atrial fibrillation (AF) originate from the left atrial appendage (LAA). Patients with contraindications to anticoagulation are potential candidates for LAA occlusion using the Percutaneous Left Atrial Appendage Transcatheter Occlusion system (PLAATO, ev3 Inc., Plymouth, MN). Transesophageal echocardiography (TEE) is typically used to guide implantation. OBJECTIVE: This study sought to examine the utility of intracardiac echocardiography (ICE) in providing adequate imaging guidance as an alternative to TEE during PLAATO implantation. METHODS: The study group consisted of 10 patients who underwent PLAATO implantation with simultaneous TEE and ICE imaging guidance. ICE was used to perform the following tasks typically fulfilled by TEE: (1) verification of the absence of LAA thrombus, (2) identification of the LAA ostial dimension for device sizing, (3) guidance of transseptal puncture, (4) verification of the delivery sheath position, and (5) confirmation of location and stability of device before its irrecoverable release. The ability of ICE to perform these tasks was assessed from three separate positions: the standard right atrial (RA) position, within the coronary sinus (CS), and the right ventricular outflow tract. RESULTS: ICE imaging of the LAA was optimal from within the CS, although imaging from the proximal pulmonary artery provided better visualization of the distal LAA in cross-section. The LAA dimensions, confirmation of the absence of LAA thrombus, proper positioning of the delivery sheath, verification of location and stability of the device obtained by ICE were consistent with findings from TEE. CONCLUSION: Using nonconventional imaging planes, ICE imaging was able to perform the intraprocedural functions provided by TEE during implantation of the PLAATO left atrial appendage occlusion device.     

Direct evidence that sustained dysfunction of left atrial appendage contributes to the occurrence of cardiogenic brain embolism in patients with paroxysmal atrial fibrillation

OBJECTIVE: The goal of this study was to investigate transesophageal echocardiographic (TEE) findings after the termination of atrial fibrillation to clarify the direct evidence for occurrence of acute cardiogenic brain embolism (CBE) in patients with paroxysmal atrial fibrillation (PAF). PATIENTS AND METHODS: Among 98 consecutive patients with CBE, we investigated TEE in 16 patients with PAF (Group CBE, 72 +/- 10 years) within 7 days of the onset and 2 weeks after the first study, in comparison with 15 age-matched PAF patients without CBE (Group N). The duration from reversal to normal sinus rhythm to first TEE was 6 +/- 1 days in both groups. RESULTS: There were no significant differences in left atrial dimension and emptying flow velocity of the left atrial appendage (LAA-eV) between groups. Group CBE had significantly larger LAA area (4.3 +/- 1.3 cm2 vs. 3.1 +/- 1.0 cm2, p < 0.05), smaller LAA fractional area change (LAA-FAC) (43 +/- 25% vs. 80 +/- 22%, p < 0.001), and a higher incidence of left atrial spontaneous echo contrast (LAA-SEC) (25% vs. 7%, p < 0.05) than group N, and those abnormalities in group CBE were significantly improved at the second TEE (LAA area: to 3.2 +/- 0.9 cm2, p < 0.05; LAA-FAC: to 84 +/- 26%, p < 0.001; LAA-SEC: to 0%, p < 0.05), respectively. CONCLUSION: LAA-FAC is a more sensitive marker for LAA dysfunction than the widely used index, LAA-eV, and a sustained deterioration of LAA-FAC may be direct evidence for thrombus formation and occurrence of acute CBE in patients with PAF.     

Is It Time to Move on from Two-Dimensional Transesophageal to Three-Dimensional Transthoracic Echocardiography for Assessment of Left Atrial Appendage? Review of Existing Literature

Left atrial appendage (LAA) has unique anatomical and physiological properties, which make it a common site for thrombus formation in many cardiovascular and systemic diseases. Assessment of LAA for thrombus thus becomes important in many clinical situations and two-dimensional transesophageal echocardiography (2D TEE), which allows excellent quality images of LAA because of its close proximity to esophagus is routinely used for this purpose. However, it is a semiinvasive procedure, requires more time and involves some degree of patient discomfort. With some training and experience, two-dimensional transthoracic echocardiography (2D TTE) can visualize LAA in most patients with good acoustic windows. A disadvantage of both 2D TTE and 2D TEE is that they provide only a thin slice or section of cardiac structures at any given time limiting their utility in comprehensively assessing the LAA for thrombus. On the other hand, live/real time three-dimensional (3D) TTE overcomes this limitation of both 2D TTE and 2D TEE because of its ability to encompass whole of the LAA in three-dimensions in the acquired data set, which can then be cropped and sectioned systematically at any desired angulation to more definitively look for clot. 3D TTE is also useful in differentiating a clot from pectinate muscles in the LAA, which can mimic a thrombus resulting in patient mismanagement. In addition, 3D TTE is helpful in sectioning a clot for lysis, which has implications in clot resolution. We reviewed the existing literature comparing the relative advantages and disadvantages of 3D TTE versus 2D TEE and found that in patients with good acoustic windows 3D TTE had similar efficacy for detecting LAA thrombus. (Echocardiography 2012;29:112-116)     

Left atrial thrombus detection with multiplane transesophageal echocardiography: an echocardiographic study with surgical verification

BACKGROUND AND AIM OF THE STUDY: The detection of left atrial thrombus (LAT) is especially important in patients being evaluated for percutaneous mitral valvuloplasty and elective cardioversion for atrial fibrillation. Transesophageal echocardiography (TEE) is widely used for this indication. This study was undertaken to validate the use of multiplane TEE to detect LAT in the setting of rheumatic mitral valve disease. METHODS: The study population comprised 262 patients (103 men, 159 women, mean age 42.2+/-13.1 years) who underwent open heart surgery for rheumatic mitral valvular disease between January 1994 and October 1997. Of these patients, 178 had mitral stenosis and 84 mitral regurgitation. All patients were examined with multiplane TEE less than three days before valvular surgery. RESULTS: The presence or absence of LAT was confirmed at surgery by direct inspection of the left atrium. Left atrial thrombi were detected by TEE in 34 patients (14 men, 20 women; mean age 51+/-8 years). The presence of all 34 thrombi found by multiplane TEE was confirmed during surgery. Only one thrombus was confirmed surgically among 228 patients shown thrombus-negative by multiplane TEE. The sensitivity, specificity, positive and negative predictive value and diagnostic accuracy for multiplane TEE were 97, 100, 100, 99.6 and 99.6%, respectively. CONCLUSION: Multiplane TEE is exquisitely sensitive for the detection of LAT.     

Left atrial appendage Doppler flow patterns: implications on thrombus formation.

The characteristics and clinical implications of left atrial appendage (LAA) flow have not been clearly analyzed. Thirty-nine consecutive patients underwent a transesophageal echocardiographic (TEE) color Doppler study to correlate the LAA pulsed Doppler flow pattern with echocardiographic variables and the cardiac rhythm of each patient. Three different LAA flow patterns were identified. Type I flow, characterized by a biphasic pattern (waves of filling and emptying), was found in 17 patients, all in sinus rhythm; it was not associated with LAA spontaneous contrast or thrombus. Mean peak velocities of the filling and emptying waves were, respectively: 28 +/- 12 cm/sec and 31 +/- 9 cm/sec. Type II sawtooth active flow (eight patients) (mean peak velocity: 49 +/- 12 cm/sec) was only detected in atrial fibrillation (AF) and dilated LAA (LAA area: 421 +/- 40 mm2) but without thrombus or significant LAA spontaneous echocardiographic contrast. Type III flow pattern was noted in 14 patients with AF and a very dilated LAA (LAA area: 619 +/- 96 mm2). This flow pattern was characterized by the absence of identifiable flow waves and was associated with the presence of LAA spontaneous contrast; the majority (six of seven) had evidence of thrombus. We concluded that the LAA is a dynamic structure in which TEE study identified three flow patterns with different implications. AF is associated with two LAA flow types (II and III) with a larger LAA size as well as a higher incidence of LAA clots in type III flow.     

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.     

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.