1. Date of download: 6/3/2016 Copyright © The American College of Cardiology. All rights reserved. From: Imaging the Left Atrial Appendage Prior to, During, and After Occlusion J Am Coll Cardiol Img. 2011;4(3):303-306. doi:10.1016/j.jcmg.2010.09.024 Determination of LAA Size and Anatomy by TEE and MDCT The LAA imaged at 0° and 90° by TEE (A and B) with corresponding MDCT images (C and D). At 0° and 90°, the LAA width is measured in a plane from the left coronary artery (*) to 1 to 2 cm from the tip of the left upper pulmonary vein (LUPV) limbus (¥). Ao = aorta; LA = left atrium; LAA = left atrial appendage; LV = left ventricle; LUPV = left upper pulmonary vein; MDCT = multidetector cardiac computed tomography; RA = right atrium; RVOT = right ventricular outflow tract; TEE = transesophageal echocardiography. Figure Legend:

2. Date of download: 6/3/2016 Copyright © The American College of Cardiology. All rights reserved. From: Imaging the Left Atrial Appendage Prior to, During, and After Occlusion J Am Coll Cardiol Img. 2011;4(3):303-306. doi:10.1016/j.jcmg.2010.09.024 Assessment of Potential Exclusion Criteria (A and B) Demonstrate an LAA with a large dominant lobe (*) and a smaller accessory lobe (**). This anatomy may make successful occluder implantation more challenging as it is imperative that the device occludes the ostia of both lobes. As implantation of the LAA occluder device involves placing a pigtail catheter in the LAA, the presence of thrombus must be excluded prior to the procedure. This patient was not suitable for occluder implantation due to probable LAA thrombus demonstrated on MDCT (failure of contrast to fill the distal LAA) (C) (†) and dense spontaneous echo contrast confirmed on TEE (D) (‡). Abbreviations as in Figure 1. Figure Legend:

3. Date of download: 6/3/2016 Copyright © The American College of Cardiology. All rights reserved. From: Imaging the Left Atrial Appendage Prior to, During, and After Occlusion J Am Coll Cardiol Img. 2011;4(3):303-306. doi:10.1016/j.jcmg.2010.09.024 Access to the LA Via Transseptal Puncture The LAA occluder is implanted percutaneously under general anesthesia via the femoral vein, with fluoroscopic and TEE guidance. Access to the left atrium is via a transseptal puncture, performed under TEE guidance in multiple imaging planes, principally 45° and 90°, ensuring a posterior puncture and avoidance of the aortic root. A posterior puncture site appears to assist in accurate delivery and positioning of the device into the LAA. (A and B) Show simultaneous TEE images demonstrating “tenting” of the atrial septum (arrow) due to pressure from the needle prior to puncture. SVC = superior vena cava; other abbreviations as in Figure 1. Figure Legend:

4. Date of download: 6/3/2016 Copyright © The American College of Cardiology. All rights reserved. From: Imaging the Left Atrial Appendage Prior to, During, and After Occlusion J Am Coll Cardiol Img. 2011;4(3):303-306. doi:10.1016/j.jcmg.2010.09.024 Occluder Deployment and Release The occluder is an umbrella-like device with a fabric covering that is permeable to blood and contrast, but not thrombotic particles. It is designed to be implanted slightly distal to the LAA ostium and has barbs distally to secure its position. The left coronary artery, mitral valve annulus (MVA) and limbus of the LUPV are the anatomic landmarks used to guide correct device positioning. Following deployment and prior to release, the device is assessed by fluoroscopy and TEE through multiple planes for size, position, stability, and seal. (A) (Online Video 1) Demonstrates occluder device deployment in addition to the “stability tug” during which the device moves in unison with the LAA and then returns to its original position. (B) Demonstrates a well-seated 27 mm occluder device, sitting flush with the LAA ostium with appropriate device compression (22 mm) (reduction of original device width by 20%). (C) Demonstrates interrogation of device seal using the X-plane feature and color Doppler. The seal is adequate if all lobes are excluded from communication with the left atrium and any color jets around the device are <5 mm in diameter. (D and E) Demonstrate suboptimal occluder positioning: a device positioned too far into the LAA and failing to occlude an accessory lobe (D, arrow); a suboptimally positioned device with some protrusion into the left atrium (E, arrow). Device repositioning resulted in successful LAA occlusion in both cases. Abbreviations as in Figure 1. Figure Legend:

5. Date of download: 6/3/2016 Copyright © The American College of Cardiology. All rights reserved. From: Imaging the Left Atrial Appendage Prior to, During, and After Occlusion J Am Coll Cardiol Img. 2011;4(3):303-306. doi:10.1016/j.jcmg.2010.09.024 Assessment of Occluder Device 45 Days After Deployment We performed follow-up imaging in our patients with a device at 45 days after the procedure. In the majority of patients, the occluder device is well-seated in the LAA at the time of follow-up (A). (B) Shows a three-dimensional, enface TEE view from the LA. Device seal is assessed at follow-up by TEE color Doppler and dynamic MDCT. (C and D) Are examples of persistent communication (arrow) between the left atrium and LAA as demonstrated by TEE and MDCT in the same patient. In this situation, anticoagulation is continued and imaging repeated in 6 months. The degree of device endothelialization may also be assessed by TEE, however, we believe that MDCT is superior for this purpose. (E) (Online Video 2) Demonstrates incomplete device endothelialization with unrestricted passage of contrast into the LAA. In contrast, (F) demonstrates complete failure of contrast to penetrate the surface of the device at 45 days. PA = pulmonary artery; other abbreviations as in Figure 1. Figure Legend: