Abstract 3360: Depressed Left Atrial Function and its Relation to Left Ventricular Filling Pressure in Systolic Heart Failure Patients.

Abstract

Background : In uncomplicated hypertensive patients with preserved left ventricular (LV) function, enhanced left atrial systolic force (LASF) is associated with LV hypertrophy. In contrast, in patients with prevalent cardiovascular disease, reduced LASF has been shown to be associated with incident atrial fibrillation and poor cardiovascular prognosis. To date the relation between LASF and LV filling pressures in patients with systolic heart failure (HF) has not been adequately investigated. Methods : Doppler echocardiographic measurements of LV systolic, diastolic, and Tissue-Doppler longitudinal function, were obtained in 108 patients (66±12 years; 20% women) with systolic HF [NYHA class III; ejection fraction <40% (mean EF%=27.7±7.7%)]. LASF was calculated from mitral orifice area and transmitral peak A velocity. Population study was dichotomized according to the presence or absence of restrictive filling pattern (RF), defined as DT <150 ms. LV end-diastolic pressure (LVEDP) was derived combining transmitral peak E velocity and tissue Doppler E’ (E/E’ ratio). Results : In the overall population, LASF averaged 10.7±5.8 kdynes. LASF was significantly reduced in patients showing RF (n = 43; 39.8% of study population) compared to non-RF patients (8.1±4.8 vs 12.5±5.8 kdynes, p<0.0001). Consistent with this finding, LVEDP was significantly higher in RF patients (p<0.001). In RF patients, LASF was correlated positively with EF% (r=0.23, p<0.05) and TD systolic peak velocity (r=0.39, p<0.0001), and negatively with isovolumic relaxation time (r=0.68, p<0.0001). In additional analysis comparing quartiles of LV end-diastolic pressure, LASF decreased with increasing quartiles of LV end-diastolic pressure (13.7±7 kdynes vs 12±7 kdynes vs 10.6±5 kdynes vs 8±4 kdynes; p for trend <0.01). Conclusions : In systolic HF patients in class NYHA III, left atrial systolic force is reduced in the presence of restrictive filling pattern due in part to increased LV end-diastolic pressure, also associated with reduced LV systolic performance. In CHF patients, increased LVEDP partially blunts LA atrial function, and might be considered as an index of atrial afterload.