Evaluation of left ventricular twist function by speckle tracking echocardiography in aortic stenosis patients with preserved ejection fraction before and after aortic valve replacement

Objective To assess the effect of aortic valve replacement (AVR) on left ventricular (LV) twist function in severe aortic stenosis (AS) patients with preserved LV ejection fraction (LVEF) by speckle tracking imaging (STI).Methods Twenty-eight severe aortic stenosis (AS) patients (17 male,age 64.1 ± 10.4 years) with normal LVEF (≥50％) were examined by STI before and six months after AVR.The standard mitral valve and apical short-axis views were obtained to analyze LV basal and apical peak systolic rotation.LV peak systolic twist was calculated as the different between apical rotation and basal rotation.LV fractional shortening (LVFS) was calculated as the percentage fall of LV systolic dimension with respect to diastolic dimension.The data were compared with 28 age and sex-matched normal controls.Results In patients,LVEF remained unchanged after AVR.LV twist increased before (19.7° ± 5.7° vs 12.9° ± 3.2°,P ＜0.001) because of increased apical rotation (13.0° ± 5.8° vs 7.6° ± 2.6°,P ＜0.001),and normalized after AVR (14.4°± 5.2°,P ＜0.001).In controls,LV twist correlated with LVFS (r =0.81,P ＜ 0.001),this relationship was reversed in patients before (r =0.52,P ＜0.01) and after AVR (r =0.34,P ＞0.05).Conclusions In patients with severe AS and normal LVEF,LV twist is exaggerated suggesting potential compensation for reduced long axis function.These disturbances normalize within six months of AVR but lose their relationship with basal LV function. Key words: Echocardiography; Aortic valve stenosis; Heart valve prosthesis implantation; Ventricular function, left ;  Speckle tracking imaging