Impact of global left ventricular afterload on left ventricular function in asymptomatic severe aortic stenosis: a two-dimensional speckle-tracking study.

Aims: The present study sought to assess the effect of global left ventricular (LV) afterload on LV myocardial systolic function in patients with aortic stenosis (AS) and preserved LV ejection fraction.
<br />Methods and results: We prospectively examined the LV myocardial deformation (i.e. longitudinal, radial, and circumferential) by two-dimensional speckle tracking in 173 patients with asymptomatic severe AS. Thirty-eight patients (22%) had lowflow as determined by a low stroke volume index (􏰀35 mL/m2). By multivariable analysis, four variables emerged as independently associated with low-flow AS: peak Ea velocity (P 1⁄4 0.01), left atrial area index (P 1⁄4 0.017), global LV afterload (P 1⁄4 0.024), and circumferential myocardial deformation (P 1⁄4 0.04). Forty-nine patients (28%) had an increased global LV afterload (􏰁5 mmHg mL/m2). Systemic arterial compliance (P 1⁄4 0.001), circumferential myocardial deformation (P 1⁄4 0.024), and left atrial area index (P 1⁄4 0.04) were independently associated with increased global LV load in multivariable analysis.
<br />Conclusion: In asymptomatic patients with severe AS, LV ejection fraction markedly underestimates the extent of myocardial sys- tolic impairment. Intrinsic myocardial dysfunction is particularly common in patients with increased global LV after- load, and especially in the subset of patients with low-flow AS.