Evaluation of left ventricular rotation and untwist by speckle tracking echocardiography in normal subjects

Objective To assess the characteristics of left ventricular(LV)rotation and untwist in normal subjects by speckle tracking echocardiography (STE).Methods Thirty healthy adults were enrolled in this study.Then the parasternal basal and apical short-axis views were scanned and the angle of LV rotation during isovolumic contraction phase,ejection phase and isovolumic relaxation phase was measured by STE,LV untwisting rate during isovolumic relaxation phase was calculated.The correlation between the indexes and the ages was analyzed.Results LV performed contradictory motion with a counterclockwise rotation at the apex and a clockwise rotation at the base.After end systole,rapid untwisting was developed.LV rotations had positive correlation with age during ejection phase(P0.05),while negative correlation with age during isovolumic contraction phase.There was significant difference at basal level(P0.05),while no significant difference at apical level (P0.05).Untwisting rate had negative correlation with age during isovolumic relaxation phase(P0.05).Conclusion STE can evaluate LV rotation and untwist noninvasively.