Background: Rotation of the left ventricular (LV) apex to the base, or LV torsion, is related to myocardial contractility and structure and has recently been recognized as a sensitive indicator of cardiac performance, but it has been difficult to measure. The recent development of 2-dimensional (2D) speckle tracking imaging (STI) may provide a powerful means of assessing LV torsion. This study was conducted to evaluate the global and regional LV twist in patients with anterior wall myocardial infarction (AMI) disease before and after revascularization by STI.
Methods: 2D STI was performed in 35 AMI patients before and one month after revascularization, as well as in 32 normal controls. Left ventricular global and regional rotations were obtained at basal and apical short-axis levels; LV torsion was defined as apical rotation relative to the base. The time sequences were normalized to the percentage of systolic and diastolic duration.
Results: Before revascularization, LV peak regional and global torsion in patients with AMI were significantly reduced as the result of reduced apical and basal rotation relative to those of normal control group (all P < 0.001); most significantly in the anterior and anterior-septal regions (P < 0.001); one month after revascularization, there were significant changes in peak rotation at either the base or apex relative to pre-revascularization values (all P < 0.001). Similarly, peak regional and global LV torsion were increased significantly (all P < 0.001). Global torsion inversely correlated with EDV (r = -0.605, P = 0.028) and ESV (r = -0.638, P = 0.019); and positively correlated with LVEF (r = 0.630, P = 0.021). Tight relations were also found between torsion and LV longitudinal and short axis function.
Conclusions: Systolic torsion was decreased in AMI patients. Revascularization therapy can improve the LV function of the AMI patients. STI has a potential to quantify left ventricular global and segment torsion in patients with AMI, and may make the assessment more available in clinical and research cardiology.