Left atrial phasic volumes and function
LA phasic function is demonstrated in table 3. Phasic LA volumes (LA
maximal volume index and LA minimal volume index) were larger in both
DDFx and IndtDFx groups. Interestingly conduit volume index {volume
passing directly from the LA to LV without “filling” the LA ) was not
different among subgroups.
Overall (LA reservoir function), passive (LA passive EF) and active LA
(LA active EF) functions were decreased in both DDFx and IndtDFx groups.
LA reservoir strain and LA passive strain (“E”) were reduced in both
DDFx and IndtDFx groups compared to NDFx. However, LA active strain
(“A”) remained in the normal range. Generally LA function in patients
with IndtDFx was abnormal and similar to DDFx.
Correlates of heart failure symptoms :
HF symptoms were found among 7% of patients with NDFx. Symptoms were
much more common in the DDFx group (38%), and IndtDFx group (18%).
Echocardiographic parameters associated with HF symptoms by univariate
analysis (all cohort) were average E’, average E/E’, pulmonary pressure
and LA volume index (parameters involved in the classification of
diastolic function), and LA reservoir function, phasic LA maximal volume
index, phasic LA minimal volume index. LA conduit volume index, and LA
reservoir strain (parameters of LA phasic function) .
Multivariate logistic regression analysis showed that phasic LA minimal
volume index remained as the only parameter significantly associated
with HF. The area under the curve for LA minimal volume index to predict
HF symptoms on receiver operator curve (ROC) analysis was 0.743 for LA
minimal volume index ≥ 8 ml/m2 (CI=0.615- 0.846,
p=0.0046) (figure 2).