Evaluation of left ventricular torsion by two-dimensional ultrasound speckle tracking imaging in heart transplant patients

Abstract

Objective To evaluate the value of left ventricular (LV) torsion for assessing left ventricular function in adult heart transplant patients using two-dimensional speckle tracking imaging.Methods Basal and apical LV short-axis view and apical LV long-axis view of two-demensional images were acquired in 30 heart transplant patients and 17 healthy volunteers. Using two-dimensional strain software,LV basal and apical rotation versus time profiles were obtained at their short-axis level respectively. LV torsion was defined as apical rotation relative to the base, so the LV torsion versus time profiles could be drawn. LV basal rotation,apical rotation,global torsion and their time to peak were respectively measured,and the rate of LV untwisting was calculated. Statistical analysis was used to find the difference between the two groups and to investigate the relationship between LV torsion or the rate of LV untwisting and echocardiographic parameters. Results LV apical rotation and LV global torsion in heart transplant group were significantly lower than those in normal group. LV global torsion inversely correlated with LV end systolic volume,positively with LV ejection fraction. There was no significant difference between the two groups in the rate of LV untwisting. The rate of LV untwisting didn't correlate with echocardiographic parameters. Conclusions LV torsion can be measured exactly by two-dimensional speckle tracking imaging, it can be used to quantify LV global systolic function in heart transplant patients. Key words: Echocardiography; Heart transplantation; Ventricular function,left; Torsion; Speckle tracking imaging