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_min resulted 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.