Figure 6.

Aortic root deformation during ejection. Data from Dagum et al. (1999) expressed as group mean±s.d. per cent change of deformation (longitudinal, circumferential, shear and torsion) during ejection unless specified otherwise. Longitudinal deformation was not observed during ejection (Dagum et al. 1999). Contraction of the base during ejection was not homogeneous: the left and right bases contracted significantly more than the base in the NC sector. In addition, the aortic root underwent non-uniform shearing during ejection that resulted in torsional deformation of the root. The left and NC commissures underwent anticlockwise torsion, while the right commissure underwent clockwise torsion (when looking from the aorta and towards the ventricle). The per cent area change of the base and commissures during ejection was −49±8 and 30±11%, respectively (Dagum et al. 1999). Lansac et al. (2002) observed the following per cent area change at each aortic root level during the last two-thirds of ejection: base, −54±2%; commissures, −67±1%; STJ, −68±3%; ascending aorta, −64±3%.