Abstract 14240: Different Impairment Patterns of Left Atrial Strain and Strain Rate with Advancing Left Atrial Enlargement

Abstract

Left atrial strain (S-LA) and strain rate (SR-LA) measured by two-dimensional speckle tracking are promising parameters to evaluate LA function. It was reported S-LA and SR-LA in peak systole (s), early diastole (e) and late diastole (a) reflect LA reservoir, conduit and booster function, respectively. However, the impact of LA enlargement on each LA function remains to be determined. The purpose of this study was to investigate the relationship between S-LA and SR-LA in each phase and LA volume index (LAVI) in patients with or without chronic heart failure (CHF). Transthoracic echocardiography was performed in 122 subjects with sinus rhythm including 39 patients with chronic heart failure, 17 patients with diastolic dysfunction without heart failure and 66 normal subjects. We measured longitudinal S-LA and peak longitudinal SR-LA at each LA segment (septum, lateral, inferior, anterior, and posterior) and averaged them. The study subjects were divided into 3 groups according to tertile for LAVI (45 ml/m²).S-LAs, SR-LAs and S-LAe, were decreased and SR-LAe was increased with advancing of LAVI tertiles. However, there were no differences in S-LAa and SR-LAa between first and second tertile of LAVI, while they were impaired in third tertile (Figure). The Receiver operating characteristic (ROC) curve for respective strain and strain rate as a predictor of CHF could be constructed. For example, the AUC for S-LAs was 0.965. S-LAs < 25 had a sensitivity of 87% and a specificity of 92% for CHF. In conclusions, LA reservoir and conduit function may gradually deteriorate with LA enlargement. Meanwhile, LA booster function may be preserved until moderate LA enlargement. LA strain and LA strain rate measured by 2DST may be useful markers for LA dysfunction and development of heart failure.