|SEC||Low blood flow velocities.|
Composed of activated platelets and leukocytes or aggregated red blood cells.
|Swirling echodensity within the atrium.||Anticoagulation does not reduce SEC but reduces the development of LAA thrombus.|
Cardioversion is acceptable. SEC can initially increase, but eventually decreases after cardioversion.
|Sludge||Low blood flow velocities.||Viscous, gelatinous morphology, not well formed. Represents an intermediate stage between SEC and formed thrombus.||Anticoagulation. Cardioversion in the setting of sludge is controversial and associated with a higher risk of thrombus being present.||5D|
|Thrombus||Low blood flow velocities.||Organized formed thrombus.||Anticoagulation. Cardioversion contraindicated with this finding.||5E, F|
|Pectinate muscle||Part of the normal LAA morphology.||No treatments, normal finding.||5A, B|
LAA = left atrial appendage; SEC = spontaneous echocardiographic contrast.