Abstract and Introduction
Abstract
Background: Left atrial (LA) sizing in patients with atrial fibrillation (AF) is crucial for follow-up and outcome. Recently, the automated quantification of LA using the novel three-beat averaging real-time three dimensional echocardiography (3BA-RT3DE) is introduced. The aim of this study was to assess the feasibility and accuracy of 3BA-RT3DE in patients with atrial fibrillation (AF).
Methods: Thirty-one patients with AF (62.8 ± 11.7 years, 67.7 % male) were prospectively recruited to have two dimensional echocardiography (2DE) and 3BA-RT3DE (SC 2000, ACUSON, USA). The maximal left atrial (LA) volume was measured by the conventional prolate-ellipse (PE) and area-length (AL) method using three-beat averaging 2D transthoracic echocardiography and automated software analysis (eSie volume analysis, Siemens Medical Solution, Mountain view, USA); measurements were compared with those obtained by computed tomography (CT).
Results: Maximal LA volume by 3BA-RT3DE was feasible for all patients. LA volume was 68.4 ± 28.2 by PE-2DE, 89.2 ± 33.1 by AL-2DE, 100.6 ± 31.8 by 3BA-RT3DE, and 131.2 ± 42.2 mL by CT. LA volume from PE-2DE (R = 0.48, p < 0.001, ICC = 0.64, p < 0.001), AL-2DE (R = 0.47, p < 0.001, ICC = 0.67, p < 0.001), and 3BA-RT3DE (R = 0.50, p = 0.001, ICC = 0.65, p < 0.001) showed significant correlations with CT. However, 3BA-RT3DE demonstrated a small degree of underestimation (30.5 mL) of LA volume compared to 2DE-based measurements. Good-quality images from 3BA-RT3DE (n = 16) showed a significantly tighter correlation with images from CT scanning (R = 0.60, p = 0.0004, ICC = 0.76, p < 0.001) compared to those of fair quality.
Conclusion: Automated quantification of LA volume using 3BA-RT3DE is feasible and accurate in patients with AF. An image of good quality is essential for maximizing the value of this method in clinical practice.
Introduction
Left atrial (LA) size has been demonstrated as an important factor in atrial fibrillation (AF) development. In patients with a diagnosed AF, LA enlargement is related with a cerebrovascular outcome, a risk of AF relapse after electrical cardioversion or catheter ablation.
Therefore, accurate assessment of LA size is critical for making prognostic and treatment decisions in patients with AF. Transthoracic echocardiography (TTE) is the most common method for assessing LA volume. However, data obtained from 2D echocardiography (2DE) are limited due to geometric assumptions and foreshortening of the LA cavity. LA remodeling is frequently asymmetrical, rendering standard geometric assumptions even more inadequate. Therefore, three-dimensional assessment of LA might help to solve this issue. In addition, current recommendations suggest multi-beat measurements of LA volume in AF patients, which further increases the potential variability of 2DE images.
Three-dimensional echocardiography (3DE) exhibits accurate assessment of LA volume and better intra-observer and inter-observer agreement when compared to those obtained with magnetic resonance imaging (MRI) or computed tomography (CT). However, previous studies often excluded AF patients. Recently, a novel automated three-beat averaging real-time three-dimensional echocardiography (3BA-RT3DE) method was introduced. In this study, we examined the feasibility and accuracy of the 3BA-RT3DE to measure LA volume in patients with stable AF compared to that of 2DE and CT.