Echocardiographic Evaluation of Left Atrial Mechanics: Function, History, Novel Techniques, Advantages, and Pitfalls
Table 1
(a) Two-dimensional echocardiographic of LA volume and function in healthy volunteers () Saraiva et al. [16]. Data are expressed as the means ± SD. (b) According to Todaro et al. [18].
(a)
Variable
Value
Maximum LA volume index (mL/m²)
21.9 ± 5.1
Minimum LA volume index (mL/m²)
7.3 ± 5.0
Precontraction LA volume index (mL/m²)
12.1 ± 4.4
Total LA stroke volume (mL)
28.0 ± 7.7
Total LA emptying fraction (%)
70.3 ± 9.2
Active LA stroke volume (mL)
10.6 ± 5.0
Active LA emptying fraction (%)
46.6 ± 11.7
Passive LA stroke volume (mL)
17.5 ± 6.0
Passive LA emptying fraction (%)
44.3 ± 12.1
LA expansion index (%)
271.5 ± 126.4
Total LA stroke volume: maximum LA volume − minimum LA volume. Active LA stroke volume: precontraction LA volume − minimum LA volume. Passive LA stroke volume: maximum LA volume − precontraction LA volume. The total LA emptying fraction: (total LA stroke volume/maximum LA volume) × 100. The active LA emptying fraction: (active LA stroke volume/precontraction LA volume) × 100. The passive LA emptying fraction: (passive LA stroke volume/maximum LA volume) × 100. LA expansion index: (total LA stroke volume/minimum LA volume) × 100.
(b)
LA passive volumes
(i) Preatrial contraction volume (), measured at the onset of the P-wave using an electrocardiogram (ECG).
(ii) Minimal LA volume (), measured at the closure of the mitral valve and end-diastole.
(iii) Maximal LA volume (), measured just before the opening of the mitral valve in end-systole.
LA active volumes
(i) LA reservoir volume ()
(ii) LA conduit volume (LV total stroke volume − LA reservoir volume)
