Ces radiol. 2020, 74(1):37-42 | DOI: 10.55095/CesRadiol2020/007

Noninvasive measurement of left atrial volume using echocardiography and computed tomographyOriginal article

Zbyněk Tüdös¹, Jan Macek¹, Martin Hutyra², Tomáš Skála²

¹ Radiologická klinika LF UP a FN Olomouc

² I. interní klinika - kardiologická LF UP a FN Olomouc

Aim: Non-invasive imaging of the left atrium is a routine part of management before catheter radiofrequency ablation in patients suffering from atrial fibrillation. The aim of the study was to verify the degree of agreement in left atrial volume (LAV) calculated from echocardiography and computed tomography (CT) images. Further, we tried to verify whether the use of electrocardiography (ECG) gated CT protocol affects the degree of agreement between echocardiographic and CT volumetry.

Methods: Totally, 62 patients with atrial fibrillation met the inclusion criteria. They all underwent routine transthoracic echocardiography. Furthermore, the group was prospectively randomized into two groups. Group A underwent a contrast-enhanced CT scan of the pulmonary veins and left atrium using ECG-gated protocol. For group B, a helical CT protocol without ECG synchronization was used. Left atrial volumetry was performed using CT data. Left atrial volume was calculated using Simpson's biplane discs summation method based on 2D echocardiographic images. In both imaging methods, the resulting volume was indexed to the body surface area. The indexed left atrial volume (LAVi) in echocardiography and CT scan between group A and group B was statistically compared. We also calculated correlation between echo LAVi and CT LAVi in both subgroups and in the whole study group.

Results: LAVi measured by echocardiography was statistically significantly lower by 31.8-36.6% (p < 0.001). The CT LAVi value did not differ significantly between groups A and B (50.71 vs. 54.57 ml/m²; p = 0.34). Similarly, the echo LAVi value did not differ significantly between groups A and B (34.58 vs. 34.60 ml/m²; p = 0.94). The correlation coefficient rho between echo LAVi and CT LAVi in group A reached 0.429, in group B 0.527 and in the whole group 0.482.

Conclusion: The estimation of left atrium volume in a routine transthoracic echocardiography was significantly underestimated and achieved only moderate correlation in comparison with CT volumetry, therefore this estimation should be interpreted with caution. The use of ECG-gated protocol during the CT data acquisition did not affect the degree of agreement between echocardiographic and CT volumetry.

Keywords: atrial fibrillation, computed tomography, echocardiography, left atrial volume

Grants and funding:

Práce byla podpořena vnitřním grantem Univerzity Palackého: IGA_LF_2020_012.

Accepted: January 30, 2020; Published: March 1, 2020  Show citation