Periprocedural Intracardiac Echocardiography for Left Atrial Appendage Closure: A Dual-Center Experience

ObjectivesThis dual-center study sought to demonstrate the utility and safety of intracardiac echocardiography (ICE) in providing adequate imaging guidance as an alternative to transesophageal echocardiography (TEE) during Amplatzer Cardiac Plug device implantation.BackgroundOver 90% of intracardiac thrombi in atrial fibrillation originate from the left atrial appendage (LAA). Patients with contraindications to anticoagulation are potential candidates for LAA percutaneous occlusion. TEE is typically used to guide implantation.MethodsICE-guided percutaneous LAA closure was performed in 121 patients to evaluate the following tasks typically achieved by TEE: assessment of the LAA dimension for device sizing; guidance of transseptal puncture; verification of the delivery sheath position; confirmation of location and stability of the device before and after release and continuous monitoring to detect procedural complications. In 51 consecutive patients, we compared the measurements obtained by ICE and fluoroscopy to choose the size of the device.ResultsThe device was successfully implanted in 117 patients, yielding a technical success rate of 96.7%. Procedural success was achieved in 113 cases (93.4%). Four major adverse events (3 cardiac tamponades and 1 in-hospital transient ischemic attack) occurred. There was significant correlation in the measurements for device sizing assessed by angiography and ICE (r = 0.94, p < 0.0001).ConclusionsICE imaging was able to perform the tasks typically provided by TEE during implantation of the Amplatzer Cardiac Plug device for LAA occlusion. Therefore, we provide evidence that the use of ICE offered accurate measurements of LAA dimension in order to select the correct device sizes.     

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.     

Transesophageal Echocardiography during Pulmonary Vein Cryoballoon Ablation for Atrial Fibrillation

We describe our first 20 cases of cryoablation of atrial fibrillation (AF) using transesophageal echocardiography (TEE). Continuous procedural monitoring with TEE by a cardiologist and senior sonographer assists the electrophysiologist in performance of the cryoballoon procedure of AF. Previously using intracardiac echocardiography (ICE) we have found TEE to have better overall procedural imaging, and monitoring for pericardial effusion or thrombus formation. We have found TEE monitoring to be helpful with positioning for interatrial septal (IAS) puncture, catheter tip avoidance of the left atrial appendage (LAA), and guidance of the balloon catheter into each pulmonary vein (PV), with proper positioning within each PV orifice, and documentation of PV occlusion for the cryoballoon procedure. Procedural equipment and the cryoballoon protocol used are presented in detail. The role of TEE imaging during the procedure and in preventing potential dangers is illustrated. It is the goal of this study to demonstrate how the electrophysiology and echocardiography laboratories work together in this cryoablation procedure.     

Implantation of left atrial appendage occlusion devices and complex appendage anatomy: the importance of transesophageal echocardiography

Percutaneous delivery of left atrial appendage (LAA) occluding devices represents a novel approach for stroke prevention in patients with atrial fibrillation. Transesophageal echocardiography (TEE) has a pivotal role throughout these procedures, facilitating device size selection and ensuring optimal deployment of the device. We report a case of an LAA occluding device implantation in which apparent proper positioning on fluoroscopy was determined by TEE to be malpositioning with a nonocclusive, perpendicular orientation to the plane of the LAA ostium. This problem appeared to be related to a complex, multilobed LAA anatomy and was readily resolved by repositioning of the device under TEE guidance.     

A novel approach to the diagnosis of left atrial appendage thrombus using contrast echocardiography and power Doppler imaging

Background: Transesophageal echocardiography is performed routinely amongpatients with atrial fibrillation (AF) in order to exclude leftatrial appendage (LAA) thrombus prior to cardioversion. Becauseassessment for LAA thrombus is dependent upon the experienceof the operator and is therefore subjective, there remains asubset of patients in whom the diagnosis may not be definitive.The purpose of this report is to present a novel technique whichmay aid in the confirmation and/or exclusion of LAA thrombususing contrast echocardiography (CE) and power Doppler (PD)imaging. Methods: TEE imaging of the LAA appendage was performed in 3 patients.By visual inspection, the presence of the thrombus was absent(patient one), equivocal (patient two) and definite (patientthree). Contrast echocardiography with Definity^® and powerDoppler imaging was performed to aid in the confirmation and/orexclusion of thrombus in these 3 patients. Results: CE alone was useful in confirming the absence and presence ofLA thrombus determined by visual inspection in patients oneand three, respectively. CE in conjunction with PD imaging wasuseful in identifying the presence of LAA thrombus (by showinga filling defect and the absence of flow in the tip) in thepatient with equivocal results by visual inspection Conclusion: Contrast echocardiography alone may be useful in confirmingand/or excluding the presence of LAA thrombus among patientswith AF. CE with PD imaging provides incremental informationin aiding in the diagnosis when the conventional images areequivocal.     

Intracardiac echocardiography with ultrasound probe placed in the upper left pulmonary vein to guide left atrial appendage closure: First description

Intracardiac echocardiography (ICE) has become an effective alternative to trans‐esophageal echocardiography (TEE) as a guidance during interventional procedures for structural heart diseases, allowing to proceed under conscious sedation. To guide percutaneous left atrial appendage (LAA) closure, the ICE probe is usually placed in the right atrium, in the pulmonary artery or in the left atrium (LA); however, the views from the right atrium or the pulmonary artery are often suboptimal, debarring a complete visualization of the LAA and the surrounding structures, whereas the LA location requires trans‐septal puncture, may provoke LA wall mechanical stimulation and is often associated with unstable position of the ICE probe. In our case, after a second trans‐septal puncture, the ICE probe was placed in the upper left pulmonary vein; this was safely performed and provided an optimal imaging of the LAA, comparable to that obtained by TEE, thus warranting an adequate guide during all procedural steps.     

Use of Intracardiac Compared With Transesophageal Echocardiography for Left Atrial Appendage Occlusion in the Amulet Observational Study

ObjectivesThe aim of this study was to compare patient and procedural characteristics, clinical events, and left atrial appendage (LAA) occlusion rates among implantation procedures guided either by intracardiac echocardiography (ICE) or by transesophageal echocardiography (TEE) in the Amulet Observational Study.BackgroundTEE is standard for intraprocedural imaging during LAA occlusion. ICE is an alternative enabling local rather than general anesthesia.MethodsThe Amulet Observational Study is a prospective, multicenter, post-market study of the Amulet device in patients with atrial fibrillation at risk for thromboembolism from the LAA. Procedures were guided by ICE in the left atrium or TEE. A clinical events committee adjudicated serious adverse events. LAA closure was assessed by a core laboratory 1 to 3 months post-implantation.ResultsNine hundred fifty-five procedures were TEE guided and 130 (12%) were ICE guided. Local anesthesia was used in 93% of ICE-guided cases. Implantation success was >99% in both groups (p = 1.00). The procedure was longer (40 ± 31 min vs. 33 ± 21 min; p = 0.01) and contrast use higher (145 ± 157 ml vs. 98 ± 76 ml; p < 0.01) for ICE cases. LAA closure rate was 100% using ICE and 98% using TEE. Vascular access serious adverse events occurred in 0.8% of ICE patients and 1.5% of TEE patients (p = 0.52). Pericardial effusions or tamponade was observed at rates of 2.5% per year and 1.7% per year in ICE and TEE patients, respectively (p = 0.57). Rates of ischemic stroke (4.1% per year vs. 2.6% per year; p = 0.37) and major bleeding (8.2% per year vs. 10.6% per year; p = 0.44) did not differ significantly between ICE and TEE patients.ConclusionsAmulet LAA occlusion procedures guided by ICE and TEE resulted in comparable clinical event and LAA closure rates, without differences in procedural or vascular complications despite longer procedures and more contrast use.     

Incomplete occlusion of the left atrial appendage with the percutaneous left atrial appendage transcatheter occlusion device is not associated with increased risk of stroke

Background  

Percutaneous approaches to left atrial appendage (LAA) closure are being developed for stroke prophylaxis in atrial fibrillation patients as an alternative to warfarin. Non-randomized clinical trials suggested that the first of these devices, the percutaneous left atrial appendage transcatheter occlusion (PLAATO) device, is safe and reduces stroke risk. Percutaneous closure has the potential limitation of incomplete exclusion of LAA from the systemic circulation, which could potentially lead to thrombus formation and stroke. This study investigated the interaction between residual blood flow in the LAA after percutaneous closure with PLAATO and risk of stroke.     

房颤患者左心耳功能评估和血栓识别超声学进展

左心耳（LAA）是房颤患者最常见心源性血栓来源。持续性房颤（AF）患者左心房血栓可能会因为形态变异而导致诊断困难,由多普勒超声衍生而来的新型成像模式,如组织多普勒成像（TDI）和斑点跟踪超声心动图（STE）,以及由组织速度显像(TVI)得出的新技术-应变成像（SI）和应变速率成像（SRI）分析可能会对识别这些血栓有帮助。LAA游离壁较薄,现有的技术很难从视觉上评估它的机械功能,而LAA基底部的肌小梁如左脊（LLR）和基底内侧二尖瓣前庭BMAS,在某种程度上能反应LAA的机械活动,从而通过TEE进行LAA功能评估。本文综述了这方面的进展。     

Left atrial appendage septae not visualized with transesophageal echocardiography.

Left atrial appendage (LAA) filter implantation was attempted in an 89 year old male. The LAA size was estimated by transesophageal echocardiography (TEE). Complete LAA obliteration was not achieved. LAA angiography suggested that the LAA was multilobed, likely separated by a thin septae not seen with TEE. MRI or CT may be more appropriate imaging modalities to define LAA anatomy.     

Role of echocardiography in percutaneous occlusion of the left atrial appendage

Percutaneous occlusion of the left atrial appendage (LAA) is a modern alternative for the treatment of patients with atrial fibrillation (AF) and with a high risk of stroke who are not eligible for long-term anticoagulation therapy. Echocardiography plays a significant role in selecting patients, guiding the procedure, and in the post-procedural follow-up. OBJECTIVES AND METHODS: To test the role of transesophageal echocardiography (TEE) and intracardiac echocardiography (ICE) in facilitating and shortening the procedure. RESULTS: ICE represents a more convenient approach in patients who are not under generally anesthesia and helps to facilitate transseptal puncture. On the other hand, TEE, having the ability to rotate the image plane, helps to better determine the position of the occluder. CONCLUSIONS: Echocardiographic guidance of this procedure is essential. Which approach will be preferred will depend on the development of these two methods.     

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。     

多平面经食管超声心动图在鉴别左心耳内血栓与梳状肌的作用

目的;了解多平面经食管超声心动图（TEE）在鉴别左心耳内血栓与梳状肌的作用。方法：采用多平面TEE观察54例风湿性心脏病二尖瓣狭窄患者左心耳结构。结果：54例患者中,30例在0～90°扫描切面左心耳尖部或侧壁出现直径0．30～0．78cm大小回声,类似血栓形成,但当扫描切面转至110～135°时,左心耳底部可见2～4个平行排列、清晰的点状或条索状回声,为梳状肌,其中12例为手术证实;24例在0～90°C以及110～135°时左心耳和（或）左心房体部可见直径1．0～3．4cm大小边缘清楚、致密的回声光团,为血栓形成,其中18例为手术证实。结论：多平面TEE能清晰观察左心耳内发达的梳状肌,并能与血栓作出可靠的鉴别诊断。     

Associations between use of prasugrel vs clopidogrel and outcomes by type of acute coronary syndrome: an analysis from the PROMETHEUS registry

Journal of Thrombosis and Thrombolysis - Left atrial contrast computed tomography (LA-CT) as well as transesophageal echocardiography (TEE) can exclude left atrial appendage (LAA) thrombus, but is...     

Sudden floating thrombus formation on the delivery cable before Amplatzer‐Amulet device deployment during left atrial appendage occlusion: The need for a standardized anticoagulation

Anticoagulation is of paramount importance during left atrial appendage occlusion procedure (LAAOP) to prevent periprocedural stroke. We present the case of a 66‐year‐old male patient who was scheduled to undergo LAAOP because of a prior intracranial bleeding. After transesophageal echocardiography‐guided transseptal puncture, intravenous heparin 5,000 IUs were administered obtaining an ACT greater than 300 s. We planned to implant an Amplatzer‐Amulet 25 mm LAA occluder through the dedicated 12F delivery sheath. After starting the tug test, TEE suddenly showed a floating thrombus whose proximal part was connected to the delivery cable. Because transesophageal echocardiography showed a good position of the device, we decided to release it and to quickly retrieve as a unit into the right atrium both the delivery cable with attached thrombus and the delivery sheath. We discuss about periprocedural anticoagulation dosing and monitoring and the importance to have specific studies in the setting of LAAOP.     

Intracardiac echocardiography for guidance of transcatheter left atrial appendage occlusion: An expert consensus document

Transcatheter left atrial appendage occlusion (LAAO) is an increasingly used alternative to oral anticoagulation in selected patients with atrial fibrillation. Intraprocedural imaging is a crucial for a successful intervention, with transesophageal echocardiography (TEE) as the current gold standard. Since some important limitations may affect TEE use, intracardiac echocardiography (ICE) is increasingly used as an alternative to TEE for guiding LAAO. The lack of a standardized imaging protocol has slowed the adoption of ICE into clinical practice. On the basis of current research and expert consensus, this paper provides a protocol for ICE support of left atrial appendage occlusion.     

Left atrial appendage occlusion using a Watchman device in a transplanted heart with biatrial anastomosis

A percutaneous left atrial appendage (LAA) occlusion using a Watchman device was performed in a patient with prior biatrial anastomosis orthotopic heart transplant (OHT). Due to the anatomical changes following biatrial anastomosis, transesophageal echocardiography (TEE) imaging and transseptal puncture become technically challenging. We describe how the standard LAA views on TEE were obtained for device sizing, and how the transseptal puncture was modified to cross the scarred septum. This case demonstrates that LAA occlusion using a Watchman device in biatrial anastomosis OHT is safe and can successfully be done.     

Intracardiac echocardiography off piste? Closure of the left atrial appendage using ICE and local anesthesia

Left atrial appendage (LAA) occlusion is increasingly accepted to reduce the risk of stroke in patients with atrial arrhythmia who are unsuitable for routine anticoagulation. It is generally performed under general anesthesia, guided by transoesophageal echocardiography with accurate imaging being essential for correct deployment of the device. We present a case where LAA occlusion was done under local anesthesia in a high‐anesthetic risk patient, using novel placement of an intracardiac echo probe via a Mullins sheath in the right ventricular outflow tract and pulmonary artery. This allowed accurate visualization of device deployment in the LAA. This technique may increase the spectrum of patients who may benefit from the procedure and decrease procedure time, fluoroscopy, and procedure‐related morbidity. © 2010 Wiley‐Liss, Inc.     

Left atrial appendage closure with Amplatzer cardiac plug for stroke prevention in atrial fibrillation: Initial Asia‐Pacific experience

Background : Left atrial appendage (LAA) is the main source of left atrial thrombus that causes stroke in patients with non‐valvular atrial fibrillation (NVAF). This study reported the initial safety, feasibility, and 1‐yr clinical outcomes following AMPLATZER cardiac plug (ACP) implantation in Asia‐Pacific region.Methods : Twenty NVAF patients (16 males, age 68 ± 9 yr) with high risk for developing cardioembolic stroke (CHADS₂ score: 2.3 ± 1.3) and contraindications to warfarin received ACP implants from June 2009 to May 2010. Patients received general anesthesia (n = 9) or controlled propofol sedation (n = 11) and the procedures were guided by fluoroscopy and transesophageal echocardiography (TEE). Clinical follow‐up was arranged at 1 month and then every 3 months after implantation, whereas, a TEE was scheduled at 1 month upon completion of dual anti‐platelet therapy.Results : The LAA was successfully occluded in 19/20 patients (95%) at two Asian centers. One procedure was abandoned because of catheter‐related thrombus formation. Other complications included coronary artery air embolism (n = 1) and TEE‐attributed esophageal injury (n = 1). The median procedural and fluoroscopic times were 79 (IQR: 59–100) and 18 (IQR 12–27) minutes, respectively. The mean size of implant was 23.6 ± 3.1 mm. The average hospital stay was 1.8 ± 1.1 days. Follow‐up TEE showed all the LAA orifices were sealed without device‐related thrombus formation. No stroke or death occurred at a mean follow‐up of 12.7 ± 3.1 months. Conclusions : Our preliminary data suggested LAA closure with ACP is safe, feasible with encouraging 1‐yr clinical outcomes. Further large‐scaled trials are needed to confirm the efficacy of this device. © 2011 Wiley Periodicals, Inc.     

Usefulness of phased-array intracardiac echocardiography for the assessment of left atrial mechanical "stunning" in atrial flutter and comparison with multiplane transesophageal echocardiography(*)

We compared transesophageal and phased-array intracardiac echocardiography (TEE/ICE) for the 2-dimensional and spectral Doppler assessment of left atrial (LA) mechanical function. TEE is commonly used to assess LA body and LA appendage mechanical function in patients who are undergoing radiofrequency ablation of typical atrial flutter. Fifteen patients underwent TEE and ICE imaging before and after ablation of typical atrial flutter. The following parameters were measured: (1) LA appendage emptying velocity and fractional area change, (2) severity of LA spontaneous echo contrast (graded 0 to 4), (3) maximal inflow velocity of the left and right upper pulmonary veins, and (5) maximal mitral valve E- and A-wave inflow velocities in sinus rhythm. Diagnostic quality imaging was achieved in all patients with TEE and ICE. Comparing TEE and ICE, the following absolute values and linear correlation coefficient (R) were obtained: preablation LA appendage emptying velocity: 0.45 +/- 0.21 versus 0.44 +/- 0.21 m/s (r = 0.95, p = <0.001); postablation LA appendage velocity: 0.33 +/- 0.24 versus 0.34 +/- 0.24 m/s (r = 0.97, p <0.001); LA appendage fractional area change: 35.3 +/- 13.7 versus 35.9 +/- 17.1% (r = 0.81, p <0.001); left upper/right upper pulmonary vein inflow velocity: 0.50 +/- 0.17/0.49 +/- 0.18 versus 0.51 +/- 0.17/0.47 +/- 0.20 m/s (r = 0.93/0.90, p <0.001); mitral valve E/A wave: 0.66 +/- 0.14/0.31 +/- 0.14 versus 0.69 +/- 0.17/0.35 +/- 0.23 (r = 0.84/0.97, p <0.002); LA spontaneous echo contrast (pre- and postablation): 1.1 +/- 1.2/1.3 +/- 1.2 versus 1.2 +/- 1.3/1.4 +/- 1.3 (r = 0.92/0.90, p <0.001). No patients were identified with LA appendage thrombus. Thus, TEE and phased-array ICE provided equivalent imaging data with high statistical correlation. ICE may be an imaging alternative to TEE in the evaluation of a "stunned" left atrium.