Assessment of fetal left atrial volume and function using a novel left atrial volume tracking method

BACKGROUND: Several fetal cardiovascular structural defects may alter the hemodynamics of the cardiac chambers resulting in changes in chamber sizes. Quantitative measurements of the sizes of cardiac chambers can augment the diagnostic power of fetal echocardiography. AIMS: Using a new left atrial volume tracking (LAVT) method, time-left atrial volume curves (TLAVCs) can be automatically obtained. The goal of this study was to examine whether this method can be used to evaluate left atrial volume (LAV) and provide reference values for LAV and indices of left atrial function in normal human fetuses. METHODS: Two hundred and four normal human fetuses were enrolled. Using LAVT, the maximal left atrial volume (LAVmax) and minimal left atrial volume (LAVmin) were measured from TLAVCs. Left atrial ejection fraction (EF) was calculated. The maximal left atrial area (LAAmax) and minimal left atrial area (LAAmin) were measured using manual method tracing. RESULTS: Between 21 and 40 weeks, mean LAVmax increased from 0.27 ml to 4.15 ml, and mean LAVmin increased from 0.13 ml to 2.26 ml, respectively, while the EF remained stable at around 0.43. From 21 to 40 weeks, mean LAAmax increased from 0.61 cm2 to 2.64 cm2, and mean LAAmin increased from 0.34 cm2 to 1.53 cm2. CONCLUSIONS: This study establishes reference values for fetal LAV during the second half of gestation. The LAVT method appears to be feasible in estimating fetal LAV and shows potential for assessing left atrial function.