LA volume assessment : A critical parameter with a time trouble !

LA dimension and volume have become vital parameters in recent times, especially, with the entity of HFpEF is becoming so common. LA not only acts as a live barometer, reflecting all that happens in LV, but it is also a chronic marker of LV diastolic function. (Funnily referred to as HBA1c of diastolic dysfunction)  What is normal LA dimension & volume ?  Normal left atrial diameter < 4.1 cm in men or < 3.9 cm in women Normal left atrial volume indexed for body surface area (BSA) is 34 ml/m2 for both women and men  Which part of the cardiac cycle do we measure?  Ever since Wiggers introduced the overwhelming concept of LV systole and diastole, most of us ignored the fact that atria do have a separate contraction relaxation cycle, independent of what happens in the ventricle. Of course, atria and ventricles act as a single chamber in diastole. In reality, atria lack true boundaries when it acts as a conduit. The LA dimension varies considerably during the atrial cardiac cycle. Look at the  LA pressure-volume loop, which can frighten anyone, with its horizontally lying figure of 8 pattern. During every cardiac cycle, the volume reaches atleast two troughs and one peak. Don’t get frightened with this graph, spend some time, and you will get it right, Begin at  “3” o clock position with the onset of diastole with a downsloping green loop, that continues as the red line of atrial contraction to end up in systole. The entir...
Source: Dr.S.Venkatesan MD - Category: Cardiology Authors: Tags: Cardiology Illustrations cardiology physiology Left atrial enlargement Uncategorized LA end diastolic dimension la end diastolic vs end systolic dimension LA end systolic dimension la pressure volume loop LA volume by mri normal LA dimen Source Type: blogs