Left atrial function and maximum volume as determined by MDCT are independently associated with atrial fibrillation.

Rationale And Objectives: To assess whether left atrial (LA) volume, function, and diameter as determined by multidetector computed tomography (MDCT) are associated with the presence and chronicity of atrial fibrillation (AF).

Materials And Methods: A total of 232 subjects, 156 with AF (43 with chronic and 113 with paroxysmal) and 76 normal subjects, formed the study population. AF subjects underwent MDCT of the pulmonary veins and LA, and normal subjects underwent coronary computed tomography (CT), on which LA volume, function, and diameter were measured. Associations between each MDCT LA parameter and presence and chronicity of AF were assessed using logistic regression analysis.

Results: The indexed LA maximum volume (odds ratio [OR]=2.42; 95% confidence interval [CI], 1.43-4.08; P=.0009) was significantly associated with chronicity and presence of AF (OR=1.06; 95% CI, 1.03-1.10; P=.0003) after adjustment for traditional risk factors. The LA function was associated with presence of AF (OR=0.93; 95% CI, 0.89-0.97; P=.0005), but not with AF chronicity (OR=1.12; 95% CI, 0.93-1.33; P=.21).

Conclusions: Decreased LA function is associated with presence of AF, and increased LA maximum volume is associated with presence and chronicity of AF, independent of traditional risk factors.