Impact of aortic valve stenosis on left atrial phasic function.

The aim of this study was to determine the impact of aortic stenosis (AS) on the different components of left atrial (LA) function. The study consisted of a total of 52 consecutive patients with severe AS (aortic valve area < 1 cm(2)) and 20 normal subjects matched for gender, heart rate, body surface area, and baseline systolic blood pressure. Phasic LA longitudinal function was assessed using tissue Doppler imaging. LA peak systolic (reservoir function), early diastolic (conduit function), and late diastolic (active function) strain rates were measured. During late diastole, LA peak strain (active function) was also measured. Mitral annular systolic, early diastolic (Ea), and late diastolic (Aa) velocities were also measured. Compared with controls, all strain values were significantly reduced in patients with AS. By multivariate regression analysis, mitral E-wave deceleration time (p = 0.033) and E/Ea ratio (p = 0.02, R(2) = 0.43) emerged as independently associated with LA peak systolic strain rate. Ea was the sole determinant of LA early diastolic strain rate (p < 0.0001, R(2) = 0.42), whereas LA late diastolic strain rate was independently related to aortic valve area (p = 0.031) and Aa (p = 0.022, R(2) = 0.51). In conclusion, in patients with severe AS, the 3 components of LA function are reduced. LA reservoir dysfunction is related to left ventricular filling pressures, whereas LA conduit dysfunction depends on left ventricular relaxation. Active LA dysfunction is related to the severity of AS and late left ventricular diastolic function.