Table 2.
Anatomic and Imaging Determinant for LAA occlusion
| Left atrium |
| Dimensions of the LA: for all devices |
| Myocardial thickness: anterior wall and venoatrial junctions may be very thin |
| Distance from the OF to the LAA ostium: for all devices |
| Accessory LAA: mainly anterior wall and mitral isthmus |
| Webs and septa |
| Interatrial septum: should be a low posterior transseptal puncture. OF dimensions, rim thickness, proximity to the aortic root, PFO, |
| patches, occluder devices, and septal aneurysm |
| Left atrial appendage |
| Morphological variants: LAA apex directed behind the pulmonary trunk (exclusion criteria for LARIAT) |
| Ostial diameters/circumference: 17–31 mm (Watchman) and 12.6–28.5 mm (ACP) |
| LAA length: LAA width >40 mm (LARIAT), should exceed the maximal ostial diameter (Watchman) |
| LAA angulation: for all devices, less able to be angled a special concern for the Watchman |
| Maximal length of dominant lobe: for all devices |
| Multilobular LAA: multilobed LAA oriented in different planes >40 mm (exclusion criteria for LARIAT) |
| Distance from the ostium to the first bend of the LAA: landing zone that exceeds the maximal ostial diameter for the Watchman, |
| landing zone ≥10 mm for the ACP |
| Trabeculations (pectinate muscle): should not be mistaken for thrombus |
| Myocardial thickness: thinner posterior wall and risk of cardiac perforation for all devices |
| Extra-appendicular trabeculations: risk of cardiac perforation and periprosthetic leaks |
| Ostial diameters of LSPV |
| Relation LSPV and LAA orifices: usually at the same level |
| Lateral ridge orientation and width: poor definition of the orifice limits in ellipsoid LAA |
| Thrombus: contraindication for ablation |
| Neighbouring structures |
| Left circumflex artery: risk for artery compression between the anchoring lobe and the disc for the ACP |
| Left sinus node artery |
| Great cardiac vein and obtuse marginal vein |
| Persistent left superior vena cava |
| Post-CABG venous grafts |
| Pericardial adhesions: of special concern for the LARIAT |
| Left phrenic nerve: of special concern for the LARIAT |
ACP, Amplatzer Cardiac Plug; CABG, coronary artery bypass graft; LA, left atrium; LAA, left atrial appendage; LSPV, left superior pulmonary vein; OF, oval fossa; PFO, patent foramen ovale.
From Cabrera, Heart Published Online First: March 6, 2014 doi:10.1136/heartjnl-2013-304464