Background: Two-dimensional (2D) speckle tracking imaging (STI) is a non-invasive method used to assess subtle changes in left ventricular (LV) function such as strain and rotational dynamics. However, 2D methodology is complicated by issues such as the out-of-plane problem inherent in short-axis imaging. In addition, circumferential rotation contributes to three-dimensional (3D) wall deformations and affects tracking accuracy. By using 3D-STI technique, we evaluated LV global longitudinal strain (GLS) and apical rotation in severe aortic stenosis (AS) patients with preserved LV ejection fraction (EF).
Methods: LV GLS and apical rotation were evaluated using 3D-STI in 20 severe AS patients (79 ± 8 years old; aortic valve area 0.7 ± 0.2 cm2) with preserved LVEF (68 ± 7%). Data were compared with those of 11 hypertensive LV hypertrophy (LVH) patients (75 ± 10 years old, EF = 66 ± 4%) and 12 controls (healthy individuals: 30 ± 14 years old, EF = 63 ± 6%).
Results: Compared with LVH patients, severe AS patients had significantly decreased values of GLS (-13.0 ± 2.4 vs. -10.4 ± 2.0%, p = 0.008). In contrast, LV rotation was significantly higher in AS than LVH patients (13.9 ± 3.0° vs. 10.8 ± 2.5°, p = 0.007). There was no significant difference in stroke volume index among three groups. In these three groups, severe AS patients had significantly decreased values of GLS [analysis of variance (ANOVA), p < 0.001] and increased LV rotation (ANOVA, p < 0.001).
Conclusions: In severe AS patients, impaired GLS existed although LVEF was preserved. However, LV rotation was increased in patients with severe AS probably to maintain the LV stroke volume.
Keywords: Aortic stenosis; Speckle tracking; Strain; Three-dimensional echocardiography.