Left Atrial Appendage Closure

Stroke prevention is the primary goal in atrial fibrillation (AF) given its clinical and socioeconomic impact. With AF, the prevalence of thromboembolic stroke continues to rise and there is an urgent need to develop better strategies of stroke prevention. Warfarin, although effective when used appropriately, is burdened by underutilization, narrow therapeutic windows, and life-threatening bleeding complications. Novel pharmacologic agents have been plagued by off-target toxicity and only modest improvement in bleeding complications over warfarin. Because most thromboemboli arise from the left atrial appendage (LAA), surgical exclusion of the LAA is often used in AF patients undergoing cardiac surgery. Percutaneous device LAA closure has now been developed as an adjunct and as an alternative to pharmacotherapy in patients with AF. Promising randomized data are available with the WATCHMAN device, while several other devices are in various stages of clinical and preclinical development.     

Left Atrial Appendage Stenosis

We describe an unusual case with an anatomic narrowing at the opening of the left atrial appendage demonstrated by two-dimensional color Doppler and continuous-wave Doppler transesophageal echocardiography.     

Changes in Left Atrial Appendage Dimensions Following Volume Loading During Percutaneous Left Atrial Appendage Closure

ObjectivesThis study sought to determine whether volume loading alters the left atrial appendage (LAA) dimensions in patients undergoing percutaneous LAA closure.BackgroundPercutaneous LAA closure is increasingly performed in patients with atrial fibrillation and contraindications to anticoagulation, to lower their stroke and systemic embolism risk. The safety and efficacy of LAA closure relies on accurate device sizing, which necessitates accurate measurement of LAA dimensions. LAA size may change with volume status, and because patients are fasting for these procedures, intraprocedural measurements may not be representative of true LAA size.MethodsThirty-one consecutive patients undergoing percutaneous LAA closure who received volume loading during the procedure were included in this study. After an overnight fast and induction of general anesthesia, patients had their LAA dimensions (orifice and depth) measured by transesophageal echocardiography before and after 500 to 1,000 ml of intravenous normal saline, aiming for a left atrial pressure >12 mm Hg.ResultsSuccessful implantation of LAA closure device was achieved in all patients. The average orifice size of the LAA at baseline was 20.5 mm at 90°, and 22.5 mm at 135°. Following volume loading, the average orifice size of the LAA increased to 22.5 mm at 90°, and 23.5 mm at 135°. The average increase in orifice was 1.9 mm (p < 0.0001). The depth of the LAA also increased by an average of 2.5 mm after volume loading (p < 0.0001).ConclusionsIntraprocedural volume loading with saline increased the LAA orifice and depth dimensions during LAA closure. Operators should consider optimizing the left atrial pressure with volume loading before final device sizing.     

Conformal Left Atrial Appendage Seal Device for Left Atrial Appendage Closure: First Clinical Use

ObjectivesThe authors report the first clinical experience with the Conformal Left Atrial Appendage Seal (CLAAS) device.BackgroundThe CLAAS device was designed to address the limitations of first-generation left atrial appendage closure (LAAC) devices by providing an implant that is minimally traumatic, can be deployed in a noncoaxial fashion, and does not require postprocedural oral anticoagulation.MethodsPatients with atrial fibrillation at high stroke risk (CHA₂DS₂-VASc score ≥2) were recruited using standard selection criteria. The LAAC procedure was guided by transesophageal echocardiography with patients under general anesthesia. The CLAAS device is composed of a foam cup, with a Nitinol endoskeleton with an expanded polytetrafluoroethylene cover, delivered with a standard delivery system using a tether for full recapture. All patients received dual-antiplatelet therapy for 6 months, followed by aspirin alone. Transesophageal echocardiographic follow-up was scheduled for 45 days and 1 year.ResultsTwenty-two patients (63.7% with CHA₂DS₂-VASc scores ≥3, 76.2% with HAS-BLED scores ≥3) were enrolled. The device was successfully implanted in 18 patients and unsuccessfully in 4 patients. There were no serious procedural complications. On transesophageal echocardiography performed at 45 days, 1 significant leak (≥5 mm) was seen, which was due to a large posterior lobe not appreciated at the time of implantation, and 1 device-related thrombus was noted, which resolved on oral anticoagulation. There were no periprocedural strokes, major pericardial effusions, or systemic or device embolization.ConclusionsThis first-in-human study demonstrates the clinical feasibility of the CLAAS device for LAAC.     

左心耳结构复杂性与非瓣膜性心房颤动患者左心耳血栓形成的关系

目的:探讨左心耳结构复杂性与非瓣膜性心房颤动(NVAF)患者左心耳血栓形成的关系。方法:连续入选拟行射频消融术治疗的NVAF患者295例,记录病史资料和化验指标,进行CHA2DS2-VASc评分。行经食道超声心动图和计算机断层扫描血管造影(CTA)检查了解左心耳有、无血栓形成,以此将患者分为血栓组(n=42)和无血栓组(n=253)。应用CT影像后处理系统对左心房CTA影像进行三维重建,获取每例患者的左心耳形态,将左心耳形态分为单纯型和复杂型两类。分析左心耳血栓形成与各项潜在危险因素的关系。结果:血栓组非阵发性心房颤动(76.2%vs 18.2%)、复杂型左心耳比例(66.7%vs 45.1%)显著高于无血栓组(P均<0.01)。此外,血栓组患者的年龄、心房颤动病程、左心房前后径、B型利钠肽、血尿酸、CHA2DS2-VASc评分均大于无血栓组(P均<0.05)。相对于无血栓组,血栓组患者的高血压、糖尿病、冠心病、慢性心力衰竭、脑卒中/短暂性脑缺血发作/血栓栓塞以及血管疾病的患病率更高(P均<0.05)。多因素Logistic回归分析显示,复杂型左心耳(OR=4.129,95%CI:1.413~12.069)、心房颤动病程(OR=1.021,95%CI:1.006~1.036)、非阵发性心房颤动(OR=13.910,95%CI:4.563~42.406)与CHA2DS2-VASc评分(OR=2.580,95%CI:1.115~5.966)均是左心耳血栓形成的独立危险因素(P均<0.05)。结论:复杂型左心耳为NVAF患者左心耳血栓形成的独立危险因素。     

Atrial Tachycardia Confined Within the Left Atrial Appendage

AT Confined Within the LAA. Left atrial tachycardias are often seen following catheter ablation of persistent atrial fibrillation (AF). We report here an unusual case where AF was converted to sinus rhythm following catheter ablation, but ongoing atrial tachycardia confined within the left atrial appendage (LAA) was observed. Although the LAA tachycardia was dissociated from the atrium in sinus rhythm, bidirectional conduction between the left atrium and the LAA was, however, demonstrated after tachycardia termination. (J Cardiovasc Electrophysiol, Vol. 21, pp. 933‐935, August 2010)     

Inverted Left Atrial Appendage Bonded to Atrial Septum

Inverted left atrial appendage (LAA) is a rare surgical complication. Our patient, a boy aged 2 years, was diagnosed with a partial atrioventricular defect with mild regurgitation of the left atrioventricular valve and a large primum atrial septal defect. Direct postoperative transesophageal echocardiography revealed a new left atrial mass attached to the atrial septum, without left ventricle inflow obstruction. Out of concern about the nature of this mass, we chose surgical direct examination. Intraoperatively, we diagnosed it as an inverted LAA accidentally attached to the atrial septum suture line. Awareness of this condition can avoid unnecessary diagnostic and therapeutic procedures.