Abstract 11745: Left Atrial Stiffness and Reserve Dysfunction in Heart Failure with Preserved Ejection Fraction
Purpose: Causative mechanisms for heart failure with preserved ejection fraction (HFpEF) are characterized by depressed reserve capacity involving multiple domains of cardiovascular function. However, little is known about left atrial (LA) reserve capacity in them. It is now possible to examine LA function by using speckle tracking echocardiography (STE). Thus, the aim of this study was to examine LA function in HFpEF patients.
Methods: Patients with HFpEF (HFpEF: n=20) and subjects with hypertension (HT) without history of heart failure (HT: n=14) were studied at rest and during leg lift by STE. Peak atrial longitudinal strain during ventricular systole (LAs) was measured using an 8-segment model for the left atrium, and global LAs was obtained by averaging 8 segments. Then, the ratio of E/e’ to global LAs strain was used as an index of LA stiffness, and left ventricular end-diastolic stiffness (EED) was estimated by dividing the E/e’ ratio by left ventricular end-diastolic volume (EDV).
Results: Inter and intra-observer variability for global LAs at rest was 0.93 and 0.90 with an intraclass correlation coefficient. And, inter and intra-observer variability for global LAs during leg lift was 0.93 and 0.93, respectively. HFpEF patients had significantly higher EED, larger maximum LA volume index (LAVI maximum) and higher LA stiffness compared with HT controls at rest (all p<0.05 HFpEF vs. HT controls). During leg lift, HT controls had an upward trend in global LAs and LAVI maximum significantly increased. On the other hand, global LAs significantly decreased and LAVI maximum failed to increase normally, and the E/e’ ratio consequently rose in HFpEF patients during leg lift. As a result, the difference in the E/e’ ratio between two groups became highly significant. In multivariable regression analysis, only EED was independently correlates with LA stiffness in HFpEF patients (β=0.84, p<0.001).
Conclusions: LA stiffness and EED were both higher in patients with HFpEF compared with HT controls. The stiff left atrium is characterized by reduced LA distensibility. EED is an only independent determinant of LA stiffness in patients with HFpEF. HFpEF patients have depressed reserve dysfunction involving the left atrium.
- © 2011 by American Heart Association, Inc.