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).