Background: Measurement of left atrial appendage (LAA) dimensions has become a key guiding stage before introducing a percutaneous LAA closure device. Currently, 2-Dimensional Transesophageal Echocardiography (2DTEE) at a cut plane angulation of 135° is the recommended method to size maximal LAA orifice diameter.
We compare Real-Time-3-Dimensional Transesophageal Echocardiography (RT3DTEE) and 2DTEE for measuring LAA dimensions versus computed tomography (CT) as gold standard.
Methods: We prospectively studied 30 consecutive patients who underwent a routine TEE exam, using the QLAB 10 Application on EPIQ7 IE33 3D-Echo machine (BORTHEL Phillips) between 12/2012 and 12/2013. All patients underwent 64-slice CT as well before pulmonary vein isolation or for workup of pulmonary embolism. LAA measurements (area of orifice, depth, maximal diameter, number of lobes, and volume) were compared between 2DTEE at 135° cut plane angulation and RT3DTEE. Results were compared with CT measurements.
Results: Using the RT3DTEE, larger LAA diameters were measured compared to the measurements at 135° 2DTEE (23.5±3.9 vs. 24.5±4.7 mm). In seven patients (23.3%) the measurements in 135° 2DTEE were smaller than the cut plane angulation with maximal orifice diameter. RT3DTEE measurements were not different from CT measurements regarding number of LAA lobes, area of LAA orifice, maximal LAA diameter, and LAA depth. LAA volume could not be measured directly using RT3DTEE. No difference was found between the LAA depth using RT3DTEE (19.5±2.3 mm) vs. CT (19.6±2.3, p=NS) and 2DTEE (19.4±2.2 mm) vs. CT (p=NS). However, RT3DTEE (24.5±4.7 mm) vs. CT (24.6±5, p=NS) was more accurate in measuring maximal LAA diameter compared to 2DTEE (23.5±3.9 mm) vs. CT (p<.01).
Conclusion: RT3DTEE method is more accurate than 2DTEE for assessment of maximal LAA orifice diameter. Bedside RT3DTEE LAA measurements are not statistically different compared to CT. Thus, RT3DTEE may facilitate LAA closure procedure by choosing the appropriate closing device size.
