Abstract 3142: The Assessment of Left Ventricular Twist Behavior in Anterior Wall Myocardial Infarction Using Two-Dimensional Speckle Tracking Imaging
The aim of this study was to investigate whether left ventricular (LV) twist would be depressed in anterior wall myocardial infarction (AMI) by 2D speckle tracking imaging. Methods: Basal and apical LV short-axis views were acquired in 30 patients with AMI and 15 age-matched healthy volunteers. Using commercially available 2D strain software, regional LV strain, rotation and radial displacement was obtained. LV twist was defined as apical LV rotation relative to the base. By plotting twist-displacement (TD) data during one cardiac cycle, TD loop was created in each subject. To adjust for inter-subject differences in heart rate, the time sequence was normalized to the percentage of systolic and diastolic duration. Patients were divided into 2 groups according to the global LV systolic function (LVEF < 45%, n = 14, LVEF≥45%, n = 16). Results: Circumferential strain in the apex was significantly reduced in patients with LVEF < 45% than in those with LVEF≥45% (−7.3 ± 2.6 versus −13.5 ± 4.1, p < 0.001). Peak LV twist was significantly reduced in patients with LVEF < 45% (5.6 ± 2.6 versus 9.8 ± 4.0 degree, p < 0.005) mainly due to reduced apical rotation (Figure A, B⇓). Peak positive and negative twist velocity was also significantly depressed. The morphology of the TD loop was distorted in AMI patients with LVEF < 45%, characterizing reduced and prolonged untwisting (Figure C, D⇓). Conclusion: Systolic twist was decreased and diastolic untwisting was delayed and depressed in accordance with LV systolic dysfunction in AMI. Anterior wall MI has a significant impact on TD loops. 2D speckle tracking imaging has the potential for the quantitative evaluation of regional LV function in patients with AMI.