心脏CT在左心耳封堵术中的应用价值

相比经食管心脏超声和术中造影,心脏CT由于其高分辨率、多层面性和非侵入性,能更准确地评估左心耳封堵术的难度,减少术后并发症的发生率和改善患者预后。基于CT的3D打印模型可能在未来具有更广阔的应用前景。现就心脏CT在左心耳封堵术中的应用价值做一综述。     

Left Atrial Appendage Studied by Computed Tomography to Help Planning for Appendage Closure Device Placement

Left Atrial Appendage Studied by Computed Tomography . Objective: To quantitatively study various morphologic parameters of the left atrial appendage (LAA) by computed tomography (CT) to aid the preoperative planning and implantation of left atrial appendage closure devices. Methods: In 612 cases of patients with or without atrial fibrillation (AF), a cardiac CT study was performed. Results: The classification of general LAA morphology included ChickenWing type (18.3%), WindSock (46.7%), Cauliflower type (29.1%), and Cactus type (5.9%). Anatomical relationship of the LAA to the left superior pulmonary vein (LSPV) were classified as high type (superior to LSPV, 30.2%), mid type (parallel to LSPV, 58.1%), and low type (inferior to LSPV, 11.7%). LAA ostium could be classified into 5 types including oval (68.9%), foot‐like (10%), triangular (7.7%), water drop‐like (7.7%), and round (5.7%). Two‐dimensional (2D) orthogonal method was obviously not accurate for determining the LAA orifice because the measurement was often unparallel to the LAA orifice. Two‐dimensional oblique method was better than 3‐dimensional method in reproducibility to determine the size of LAA ostium. The diameter calculated from the perimeter of the LAA ostium was superior to the diameter from direct measurement of the LAA ostium for selecting the occluder. Conclusion: The morphology of the LAA and the LA ostium are extremely complex and heterogeneous. Sixty‐four‐channel cardiac CT could assist preoperative planning of LAA closure device placement. The diameter of the LAA ostium calculated from the perimeter is the best parameter for sizing the LAA occluder. (J Cardiovasc Electrophysiol, Vol. 21, pp. 973‐982, September 2010)     

Incomplete Endothelialization of Left Atrial Appendage Occlusion Device 10 Months After Implantation

Incomplete Endothelialization of Left Atrial Appendage . We describe the case of a 74‐year‐old man with Rendu Osler Weber syndrome affected by permanent atrial fibrillation, who underwent percutaneous placement of a 24‐mm Watchman left atrial appendage system. After anticoagulation therapy dismissal, he had a transient ischemic attack (TIA). Therefore he underwent surgical removal of the device, ablation of atrial fibrillation with Maze IV procedure and biatrial reduction. Very interestingly, no significant endothelialization of the device was observed 10 months after implantation. In conclusion, this case is important because, to our knowledge, it is the first finding of Watchman device with lack of endothelialization. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1384‐1385, December 2012)     

Evaluation of Left Atrial Appendage Functions in Patients with Thrombus and Spontaneous Echo Contrast in Left Atrial Appendage by Using Color Doppler Tissue Imaging

Objective: Thrombus and spontaneous echo contrast (SEC) develops in the left atrial appendage (LAA) when LAA function is disturbed. Decrease of left atrial appendage emptying velocity shows LAA dysfunction. The purpose of this study is to examine the incidence of SEC and/or thrombus in LAA in patients with acute myocardial infarction and to assess the LAA function using color Doppler tissue imaging (CDTI) of the patients with detected SEC and/or thrombus. Method and Results: Eighty‐four patients with acute myocardial infarction were included in the study. Spontaneous echo contrast and/or thrombus were observed in 24 (29%) of the 84 patients who were categorized as group 1 (mean age 59 ± 12 years). Sixty patients (71%) without thrombus and/or SEC in LAA were categorized as group 2 (mean age 58 ± 8 years). Left atrial diameters and left ventricular ejection fraction were measured by using transthoracic echocardiography. Left atrial appendage emptying and LAA filling velocity were measured by transesophageal Doppler echocardiography. Systolic appendage tissue velocities (SaV cm/s) were measured at the basal, mid, and tip of medial wall of LAA by transesophageal CDTI. Group 1 had significantly decreased LAA emptying velocities, mid SaVs, and left ventricular ejection fractions compared to group 2 (37 ± 9 cm/s vs 55 ± 22 cm/s, 3.1 ± 1.6 cm/s vs 3.7 ± 1.2 cm/s, and 47 ± 13% vs 58 ± 10%, respectively, P = 0.002, P = 0.04, P = 0.03). Group 1 had significantly increased left atrial diameters compared to group 2 (40 ± 5 mm vs 36 ± 6 mm P = 0.001). Left atrial appendage‐filling velocities, basal SaVs and tip SaVs in group 1 were lower than those in group 2 but not significantly. Conclusions: Mid‐SaV of LAA medial wall and LAA emptying velocity decrease in patients with thrombus and/or SEC were an indication of functional disorder of LAA. Color Doppler tissue imaging appears to be a clinically applicable and reliable imaging technique that allows quantitative assessment of regional LAA systolic function.     

Left atrial appendage closure with the Amplatzer™ Cardiac Plug: Impact of shape and device sizing on follow-up leaks

Background

The Amplatzer Cardiac Plug (ACP) is a relatively new system for left atrial appendage (LAA) closure. In general, the particular design of the device and the variability of the LAA anatomy make the sizing process challenging. The objective of our study was to analyze the impact of the shape and sizing of the device on the presence of follow-up leaks.

Methods

The shape was evaluated by angiography and classified as “strawberry-like”, “square-like” and “tire-like”. The presence of peri-device leaks was assessed by transesophageal echocardiography (TEE) and graded as: 1) severe, 2) major, 3) moderate, 4) minor and 5) absent.

Results

Twenty five patients were included. Overall, the device was oversized by 3.38 ± 2.26 mm and 1.58 ± 2.75 mm in relation to the largest angiographic and TEE diameter respectively. None of the patients presented any intra-procedural complication. After discharge, one patient was admitted for cardiac tamponade and another for stroke. In both, the device was optimally deployed. Follow-up TEE was done after a mean time of 7.9 ± 5.9 months. The presence of a leak was associated with a lower degree of device over-sizing by TEE (0.06 ± 3.31 mm if leak vs. 2.73 ± 1.85 mm if no leak; p = 0.04) and a trend towards by angiography (2.39 ± 3.06 mm if leak vs. 3.98 ± 1.57 mm if no leak; p = 0.16). The shape of the device was not associated with the presence of TEE leaks. Neither the shape nor the presence of leaks was associated with worse clinical outcomes.

Conclusions

Although the shape and sizing of the device were not linked to any particular clinical outcome, we found an association between a lower degree of over-sizing and the presence of follow-up leaks.     

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.     

Evaluation of Left Atrial Appendage Functions According to Different Etiologies of Atrial Fibrillation with a Tissue Doppler Imaging Technique by Using Transesophageal Echocardiography

Background: Atrial fibrillation (AF) occurs due to various etiologies that carry different risks for thromboembolism. However, the effect of different etiologies on left atrial appendage (LAA) function has not been investigated. This study aimed to examine the LAA function in AF that occurred under various etiologies and to compare the findings with a novel tissue Doppler imaging (TDI) technique by using transesophageal echocardiography (TEE). Methods: LAA function was assessed in 84 patients with permanent AF according to various etiologies [mitral stenosis in 20 (24%), hypertension in 44 (52%), and hyperthyroidism in 20 (24%) patients] and in 23 controls with sinus rhythm. LAA area change, PW-Doppler and tissue velocities of LAA were measured. The presence of SEC or thrombus and their relation to LAA function was evaluated. Results: LAA velocities were lowest in mitral stenosis and highest in hyperthyroidism. Moderate–severe LAA SEC was detected in 61 and thrombi in 23 patients. Factors associated with the severity of SEC were the percentage of the LAA area change, PW-Doppler peak emptying velocity, and TDI septal wall downward velocity. The percent of the LAA area change and PW-Doppler peak emptying velocity were the significantly related factors for the presence of thrombi (OR = 0.84, 95% CI = 0.74–0.95, P = 0.005 and OR = 0.85, 95% CI = 0.74–0.98, P = 0.02, respectively). Conclusion: LAA function deteriorated most severely in mitral stenosis and least in hyperthyroidism. The LAA area change and PW-Doppler emptying velocity were important predictors for SEC or thrombi. Although TDI was not superior to classical methods, it provided complementary data to PW-Doppler velocities for predicting SEC and thrombi.     

CT定量评价左心耳解剖结构与心房颤动射频消融术后复发的相关性研究

目的:采用256层螺旋CT定量评价左心耳解剖结构与心房颤动(房颤)射频消融术后复发的关系。方法:研究纳入83例首次进行射频消融术的房颤患者,平均年龄(60.36±10.11)岁,男性49例(59.04%)。所有患者术前均行256层螺旋CT检查,测量左心房体积、左心耳体积、左心耳开口周长、短径、长径、深径并收集患者临床资料。83例房颤患者行射频消融术后中位随访时间19(4~24)个月,27例(32.53%)患者复发。根据有无复发分为复发组(n=27例)和未复发组(n=56例)。结果:对83例患者的临床资料进行分析,复发组持续性房颤患者及心力衰竭(心衰)患者较未复发组比例更高,CHA2DS2-VASc评分更高(P均<0.05);对左心耳解剖结构分析,左心房体积、左心耳体积、左心耳开口周长、短径、长径、深径,复发组均大于未复发组(P均<0.05);多因素Cox比例风险回归分析显示较大的左心耳体积是房颤复发的独立预测因子(HR=1.160,95%CI:1.095~1.229,P<0.001);左心耳体积>9.25 ml对射频消融术后复发具有一定预测价值,敏感度85.2%、特异度67.9%、AUC 0.82,房颤复发率较高(P<0.00l)。结论:房颤会造成心脏结构重构,左心耳各解剖径线明显增大可能是房颤射频消融术后复发的原因,并且发现左心耳体积增大是房颤射频消融术后复发的独立预测因子。     

Comparative Expression of Proteins in Left and Right Atrial Appendages From Patients With Mitral Valve Disease at Sinus Rhythm and Atrial Fibrillation

Proteomics and Atrial Appendages. Introduction: The objective was to compare by proteomics the expression of proteins associated with the cytoskeleton, energetic metabolism, and cardiac cytoprotection between left atrial appendages (LAA) and right atrial appendages (RAA) obtained from patients with mitral valve disease both in sinus rhythm (SR, n = 6) and in permanent atrial fibrillation (AF, n = 11). Methods and Results: Samples from RAA and LAA were obtained from the same patient. Proteins were separated in 2‐dimensional electrophoresis and identified by mass spectrometry. LAA from SR patients upexpressed α‐actin isotype 1 and desmin isotypes 3 and 5 with respect to RAA. In LAA from AF patients were upexpressed cardiac α‐actin isotypes 1 and 2, tropomyosin α‐ and β‐chains, and myosin light chain embryonic muscle/atrial isoform with respect to LAA from SR patients. In RAA from AF patients also upexpressed different cytoskeleton associated proteins with respect to RAA from SR patients. Different energetic metabolism‐associated proteins were upexpressed in LAA and RAA from AF with respect those from SR patients. In AF patients, the expression of proteins associated with cardiac cytoprotection such as gluthatione‐S‐transferase, heat shock protein (Hsp) 27, and different Hsp60 isotypes, were higher in RAA but not in LAA with respect to the corresponding appendages in SR patients. Conclusions: For each individual patient RAA and LAA showed a similar level of proteins expressed associated with cytoskeleton, energetic metabolism, and cardiac cytoprotection. There were more differences in the level of proteins associated with the above‐mentioned mechanisms between the atrial appendages from AF with respect to SR patients, which may open new targets for drugs. (J Cardiovasc Electrophysiol, Vol. 21, pp. 859‐868, August 2010)     

应用Amplatzer封堵器封堵小儿房间隔缺损的并发症分析

目的　总结Amplatzer封堵器 (ASO)封堵小儿房间隔缺损 (ASD)后出现并发症的种类及其防治方法。方法　应用Amplatzer封堵器封堵的 2 11例ASD患儿中 ,9例在术中或术后随访中出现并发症。其中体循环系统空气栓塞 2例、肺空气栓塞 1例、心包填塞 1例、封堵器脱落 1例、房性早搏1例、测量球囊碎片残留体内 1例、封堵器部分移位 1例、二尖瓣穿孔并返流 1例。分别给予内科、外科积极治疗及随诊观察等处理。结果　冠状动脉气栓及早搏病例自行缓解。封堵器部分移位及二尖瓣穿孔病例仍在随访观察中 ,其余病例均经治疗痊愈。结论　空气栓塞是应用ASO治疗时较易发生的并发症 ,且其发生多数与手术操作有关。并发症一旦发生大多需采取包括外科手术在内的积极处理。加强对ASO治疗病例的随访工作非常重要。     

Association Between Ischemic Stroke and Left Atrial Appendage Morphology in Patients With Atrial Fibrillation and Low CHA2DS2-VASc Scores

BackgroundPatients with atrial fibrillation are at risk for ischemic stroke, even with low CHA₂DS₂-VASc scores. The left atrial appendage is a known site of thrombus formation in individuals with atrial fibrillation.MethodsWe conducted a prospective study, enrolling patients with nonvalvular atrial fibrillation and CHA₂DS₂-VASc scores of 0 or 1. Patients were divided into groups based on left atrial appendage morphology (determined by computed tomography): the “chicken wing” group and the non–chicken wing group. We followed patients for more than 1 year to observe the incidence of stroke.ResultsOf 509 patients with a mean (SD) age of 48.9 (11.6) years; 332 (65.2%) were men. The chicken wing group had fewer left atrial appendage lobes, a lower left atrial appendage depth, and a smaller left atrial appendage orifice area (all P < .001). During the follow-up period, 5 of the 133 patients (3.8%) in the chicken wing group and 56 of the 376 patients (14.9%) in the non–chicken wing group experienced ischemic stroke (P < .001). The following findings were significantly associated with the incidence of stroke: left atrial appendage depth (hazard ratio [HR], 1.98; 95% CI, 1.67-3.12; P = .03), left atrial appendage orifice area (HR, 2.16; 95% CI, 1.59–3.13; P < .001), and non–chicken wing left atrial appendage morphology (HR, 1.16; 95% CI, 1.10–1.23; P < .001).ConclusionFor patients with atrial fibrillation and a low CHA₂DS₂-VASc score, the non–chicken wing left atrial appendage morphology type is independently associated with ischemic stroke.     

Influence of Cardiac Pacing Mode on Left Atrial Appendage Flow Velocity: Implication to Systemic Embolism During VVI Pacing

Previous studies have shown that the incidence of thromboembolism is higher in patients with single-chamber ventricular demand (VVI) pacemakers than in patients with dual-chamber (DDD) pacemakers. However, data on left atrial appendage flow velocity in pacing patients are limited. To investigate the influence of the pacing mode on the left atrial appendage flow velocity, we studied 19 patients with permanent DDD pacemakers and measured the left atrial appendage flow velocity by transesophageal echocardiography at baseline (during DDD pacing) and after switching to VVI pacing. The indications for pacemaker implantation were second- and third-degree atrioventricular block (AVB group, n = 11) and sick sinus syndrome (SSS group, n = 8). Compared with the DDD pacing mode, there was a significant decrease in the left atrial appendage flow velocity during VVI pacing in both the SSS group (43 ± 14 vs 23 ± 7 cm / sec, P < 0.05) and the AVB group (59 ± 18 vs 41 ± 18 cm / sec, P < 0.05). In eight patients with persistent retrograde ventriculoatrial conduction during VVI pacing, the left atrial appendage flow velocity was markedly decreased (from 43 ± 16 to 25 ± 9 cm / sec, P < 0.05). In five (63%) of the eight patients, left atrial appendage flow velocity was less than 25 cm/sec. A reduction in left atrial appendage flow velocity when switching from DDD to VVI pacing may account for an increased risk of thrombus formation in the left atrial appendage (an increased thromboembolic risk in patients in sinus rhythm with VVI pacemakers).     

Peridevice Leak Following Amplatzer Left Atrial Appendage Occlusion: Cardiac Computed Tomography Classification and Clinical Outcomes

ObjectivesThis study aimed to investigate cardiac computed tomography (CT) and transesophageal echocardiography (TEE) peridevice leak (PDL) assessments, and the clinical relevance of PDL.BackgroundPDL assessment is integral during follow-up after left atrial appendage (LAA) occlusion. Comparative studies of TEE and cardiac CT are sparse, and the clinical relevance of PDL is uncertain.MethodsThis was a single-center observational study of consecutive patients undergoing LAA occlusion with Amplatzer devices (Amplatzer Cardiac Plug/Amulet) between 2010 and 2018 (N = 415). Patients with both 8-week CT and TEE were included for analysis (n = 346). Images were analyzed by blinded investigators (K.K. and A.S.). PDL on cardiac CT was classified from grade 1 to 3, based on PDL at the device disc, device lobe, and LAA contrast patency. Primary clinical outcome was a composite of ischemic stroke, transient ischemic attack, systemic embolism, or all-cause death.ResultsPDL was present in 110 patients (32%) by TEE, with 29 (8%) >3 mm. By cardiac CT, 210 patients (61%) had PDL at the disc, with contrast patency in 204 patients (59%). A grade 3 PDL (gap at disc, lobe, and LAA contrast patency) was present in 63 patients (18%). Bland-Altman analysis showed poor agreement between CT and TEE for leak sizing. CT and TEE detected PDL was not significantly associated with worse outcome, hazard ratio: 1.82 (95 % confidence interval: 0.95 to 3.50); p = 0.07 and hazard ratio: 1.43 (95% confidence interval: 0.74 to 2.76); p = 0.28, respectively.ConclusionsPDL occurrence is substantially higher with CT compared with TEE, with a large discrepancy between modalities in leak quantification. A novel CT-based classification is proposed, yet PDL was not associated with worse clinical outcome.