Effect of an Increase in Global Left Ventricular Afterload on Myocardial Deformation in Patients with Aortic Stenosis, Comparison with Hypertensive Patients

Abstract

Aims: Left ventricular hypertrophy (LVH) secondary to hypertension and aortic stenosis (AS) are often considered together to be pressure overload hypertrophy. We hypothesized that important differences could exist in the myocardial function with these 2 origins of pressure-overload LVH. Methods: Global LV longitudinal peak strain (GLS), circumferential strain (GCS) and peak left  atrial (LA) longitudinal strain (PALS) were measured using speckle-tracking echocardiography in 38 hypertensive LVH (H-LVH) patients and 36 patients with severe AS and preserved LV ejection fraction. The ratio of E/Ea to PALS was used as an index of LA stiffness. To estimate the global LV afterload, we calculated the valvuloarterial impedance (Zva) as the sum of the systolic arterial pressure and the mean transvalvular pressure gradient divided by the stroke volume index. Results: The patients in the high Zva (n=49, Zva≥3mmHg ml/m2) were divided into two groups: AS group (n=28) and H-LVH group (n=21). GLS and PALS were significantly worsened in the AS group (p<0.0001 and p<0.0001, respectively). However, GCS was not significantly difference between two groups. LA stiffness was greater in the AS group than in the H-LVH group (p<0.0001). Conclusions: Despite of similar global LV afterload and LV hypertrophy, myocardial LV longitudinal systolic function and LA function are impaired in patients with severe AS compared with H-LVH patients.