Left atrial volumes changes are associated with changes in mitral annular dimensions and functional properties in healthy adults – a three-dimensional speckle-tracking echocardiographic study
Authors: Nemes A , Kormanyos A , Ambrus N , Lengyel C 
Published: October 2021

Abstract

Introduction
Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) is a novel echocardiographic method with capability of 3D assessment of heart chambers and valvular annuli making an opportunity to compare cyclic changes of left atrial (LA) volumes and mitral annular (MA) dimensions in physiological healthy circumstances. The present study was designed to examine correlations between LA volume changes and MA dimensions and functional properties in healthy adult subjects by 3DSTE.

Methods
The study population consisted of 199 healthy adults (mean age: 33.5±12.7 years, 104 males), who had no symptoms, conditions or diseases, which could affect results. None of subjects received any medication. The group of subjects was divided according to their maximum LA volume (Vmax) into three groups using 30 ml and 50 ml as cut-off values. All subjects underwent complete two-dimensional Doppler echocardiography extended with 3DSTE.

Results
All LA volumes and stroke volumes increased with end-systolic Vmax. Early diastolic passive atrial emptying fraction (PAEF) was significantly reduced in patients with Vmax&gt;50 ml. End-systolic total atrial emptying fraction (TAEF) and late diastolic active atrial emptying fraction (AAEF) was not accompanied with increased end-systolic Vmax. Both end-diastolic and end-systolic MA dimensions were dilated in subjects with increased Vmax, which was accompanied with reduction of MA function. Only end-systolic MA dimensions showed further increase, when end-systolic Vmax was larger than 50 ml compared to cases with Vmax between 30 ml and 50 ml. When prognostic value of MA dimensions and functional properties were analyzed, several MA dimensions and MA fractional area change (MAFAC) were found to have prognostic value to predict Vmax&gt;50 ml. The cut-off values for end-diastolic MA diameter (MAD-D), end-systolic MA diameter (MAD-S) and area, end-diastolic and end-systolic MA perimeter and MAFAC to predict Vmax&gt;50 ml proved to be 2.3 cm, 1.5 cm, 3.4 cm2, 10.2 cm, 7.4 cm and 50.93%, respectively. While increased LA volumes were associated with both dilated MAD-D and MAD-S, only increased diastolic LA volumes were associated with reduced MAFAC. While dilated MAD-D was associated with increased total and active atrial stroke volumes, similar relationship with MAD-S could not be detected. Increased passive atrial stroke volume was associated with augmented MAFAC. While dilated MAD-D was associated with increased AAEF, dilated MAD-S was found to be related to reduced TAEF and PAEF. Increased MAFAC was associated with increased values regarding all emptying fractions. End-diastolic MA dimensions increased with dilation of end-systolic MA dimensions and vice versa. Increased MAFAC was associated with dilated MAD-D and reduced MAD-S.

Conclusions
Strong relationship exists between LA volumes and MA dimensions and functional properties in healthy subjects.

Funding Acknowledgement
Type of funding sources: None.