Evaluation of relation between left ventricular torsion and cardiac cycle phase using two-dimensional ultrasonic speckle tracking imaging in normal volunteers

AIM: To investigate the relation between left ventricular torsion(LVtor)/ rotation and cardiac cycle in normal persons by speckle tracking imaging(STI).METHODS: Thirty-two normal volunteers were included in the study.At the standardized time,the rotations of apical and basal rotation were measured from short-axis images by two-dimension strain software,and then LVtor was calculated.The phase relations between rotations of short-axis and LVtor were observed.Peak rotation at the end of systole,LVtor and time of peak were measured.RESULTS: During isovolumic contraction period,the normal LV performed a wringing motion with a counterclockwise rotation at the base and clockwise rotation at the apex.During ejection period,the normal LV performed a clockwise rotation at the base and counterclockwise rotation at the apex.The LVtor showed a systolic counterclockwise twist followed by a diastolic clockwise twist.Immediately after end systole,rapid untwisting developed.CONCLUSION: STI can be used as a new method to assess LV torsion deformation and may have a potential ability to evaluate the relation betweenLVtor/rotation and cardiac cycle phase.