Variability in Left Atrial Volume Index Across Imaging Modalities

Document Type

Conference Proceeding

Publication Date

4-2026

Publication Title

Journal of the American College of Cardiology

Abstract

BACKGROUND An accurate left atrial volume index (LAVI) is essential for managing atrial fibrillation (AF) and estimating success rate of rhythm control. While transthoracic echocardiography (TTE), cardiac computed tomography (CCT), and cardiac magnetic resonance imaging (CMR) can be used to measure LAVI, inter-modality variability remains insufficiently defined.

METHODS We retrospectively analyzed 37 patients who had TTE, CCT and CMR within the same year between 2020 and 2025. LAVI was derived from 2D imaging for ECHO / CMR and 3D imaging for CCT then categorized as normal, mildly, moderately, or severely dilated according to guideline thresholds for each modality. LAVI and classification concordance were compared.

RESULTS LAVI differed between modalities (p < 0.001). Pairwise comparisons showed higher LAVI respectively on CCT, CMR and TTE (p < 0.001) (A). LAVI categorization was different between the 3 modalities (p < 0.001) (B) with CCT tending to assign lower categories than CMR and TTE (B). Pairwise comparison within the normal LAVI and mildly dilated LAVI showed significant difference between the 3 imaging techniques (p < 0.01) (C).

CONCLUSION LAVI and categorization vary between modalities. CCT generates higher values than TTE and CMR due to 3D assessment. TTE significantly overestimates atrial size at normal and mild ranges and trended to overestimate at severe range. Variability in size and severity classification may have important clinical implications in the management of AF.

Volume

87

Issue

13 Suppl

First Page

A878

Last Page

A878

DOI

doi:10.1016/j.jacc.2026.02.2169

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