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

Abstract

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.

Figure 1

Left atrial (LA) phasic volumes by real-time three-dimensional echocardiography. Arrows indicate LAV_max and LAV_min.

Figure 2

Left ventricular (LV) systolic function assessment by speckle-tracking echocardiography. LV longitudinal strain was measured from the apical four-chamber (A) and two-chamber (B) views and averaged over 12 segments.

Figure 3

Scatter plot illustrating the relationship between left atrial volumes and the ratio of peak early phase mitral inflow velocity to the peak early phase diastolic velocity (E/e′).

Figure 4

Left ventricular (LV) systolic function and left atrial (LA) three-dimensional volumes. The relationships of LV ejection fraction (LVEF) with LA phasic volumes are shown in a, b and c. The relationships of global longitudinal strain (GLS) with LA phasic volumes are shown in d, e, and f. LAEV, LA total emptying volume LAEF, LA total emptying fraction.