Left atrial volume assessed by ECG-gated computed tomography: Variations according to age, gender and time during the cardiac cycle

Abstract Purpose The purpose of this study was to retrospectively assess the accuracy of the maximal left atrial volume (LAV max ) measured at 75% of the cardiac cycle compared to the 40% measurements and to evaluate this volume according to age and gender. Patients and method A total of 150 patients with a mean age of 50 ± 17 (SD) years (range: 21–79 years) were analyzed. There were 78 men and 72 women. LAV max were measured from retrospective triphasic cardiac-gated multi-detector computed tomography (MDCT) data at the 40% (LAV 40 ) and 75% (LAV 75 ) of the RR cycle phases by a semi-automatic method. Results LAV 40 was 50.7 ± 14 mL/m 2 and LAV 75 was 42.5 ± 13 mL/m 2 . The difference was statistically significant. Considering the reference range of LAV max reported in the literature, 33% of the patients had enlarged LA with LAV 40 and only 17% with LAV 75 . These volumes were positively influenced by age but not by gender. The relationship between LAV 75 and LAV 40 was: LAV 75  = 0.908 LAV 40  – 3.486 ( r 2  = 0.92) or LAV 40  = 1.1 × LAV 75  + 3.8 ( r 2  = 0.92). Conclusion LAV max measured at the 75% of the cardiac cycle phase significantly underestimates actual LAV leading to reconsider normal values. LAV 40 can be computed from the measured value of LAV 75 obtained on prospective ECG-gated MDCT.