Left atrial minimum volume and reservoir function as correlates of left ventricular diastolic function: Impact of left ventricular systolic function

Objective: Left atrial (LA) maximum volume (LAV _max) is an indicator of left ventricular (LV) diastolic function. However, LAV _max is also influenced by systolic events, whereas the LA minimum volume (LAV _min) is directly exposed to LV pressure. The authors hypothesised that LAV _min may be a better correlate of LV diastolic function than LAV _max. Design: Cross-sectional. Setting: University hospital. Patients: 357 participants from a community-based cohort study. Methods: LA volumes and reservoir function, measured as total LA emptying volume (LAEV) and LA emptying fraction (LAEF), were assessed by real-time three-dimensional echocardiography. LV diastolic function was assessed by trans-mitral early (E) and late (A) Doppler velocities and mitral early diastolic velocity by tissue-Doppler (e′). LV systolic function was assessed by LV ejection fraction (LVEF) and global longitudinal strain (GLS) by speckle-tracking. Results: LAV _min significantly increased with worsening diastolic dysfunction (p<0.001), whereas the increase in LAV _max was less pronounced (p=0.07). LAEV and LAEF decreased with worsening diastolic dysfunction (both p<0.001). In linear regressions, LAV _min and LAV _max were significant predictors of E/e′, with higher parameter estimates for LAV _min. In multivariate models, LAV _minresulted strongly associated with E/e′ (β=0.45, p<0.001), whereas LAV _max was not (β=-0.16, p=0.08). LA reservoir function was better associated with GLS than LVEF. In multivariate analyses, GLS was significantly associated with LAV _max (β=-0.15, p=0.002), LAEV (β=-0.37, p<0.001) and LAEF (β=-0.28, p<0.001) but not with LAV _min. Conclusions: LAV _min is a better correlate of LV diastolic function than LAV _max. The impact of LV longitudinal systolic function on LA reservoir function might explain the weaker relation between LAV _max and LV diastolic function.