Analysis Of Left Atrial Appendage By Multislice Computed Tomography In Patients With And Without Paroxysmal Atrial Fibrillation

Objective: The aim was to assess the left atrial appendage (LAA) anatomic variations in patients with and without atrial fibrillation(AF) by multislice spiral computed tomography (MSCT), and describe the value of MSCT in the detection of LAA anatomy.Methods: Forty-four patients( 32male and 12 female, age 56.4±13.6years) with paroxysmal AF candidated for catheter ablation and 42 controls cases( 25male and 17 female, age 54.5±9.9 years) without AF were enrolled in this study. Cardiac MSCT was used to analyze volume and ostium dimensions of LAA, relationship between LAA and left circumflex (LCX) coronary artery, and the length and width of LAA crista as well.Results: In patients with AF, the volume of LA (119.8±33.4 )ml, the volume of LAA (10.1±4.8) ml, the area of LAA ostium(293.2±113.7) mm2, and the long and short diameter (24.3±5.3) mm, (15.6±4.4) mm of LAA ostium were all significantly greater than those in control group [ (89.6±29.2) ml,(7.5±3.1) ml, (221.5±87.6) mm2, (20.8±3.8) mm and (13.0±3.3) mm ; all P < 0.005 ]. There was a great heterogeneity of LAA area from 54.0 to 502.4 mm2 in AF patients, whereas that in control group was from 111.0 to 566.6 mm2. For the length and width of the LAA crista no significant difference was found between the two groups[ (24.21±4.3) mm vs(19.6±3.2) mm,(3.8±1.0) mm vs (4.0±1.2) mm; all P > 0.05 ]. The distance between the LAA base and LCX in AF patients was similar to that of the controls[ (3.6±0.8) mm vs (3.4±1.4) mm ;P > 0.05 ], with the variation from 1.3 to 6.7 mm, similar to that of the control [ (3.6±0.8) mm vs (3.4±1.4) mm; P > 0.05 ].Conclusion: Besides the enlargement of LA, the volume of LAA and the area of LAA ostium were significantly increased in AF patients. Preprocedural assessment of LAA ostium should be helpful for the selection of occlusion devices. Because LAA is be very close to LCX, the selection of AF ablation strategies should be carefully taken to avoid possible damage of LCX.