Assessment of left ventricular twisting and untwisting in anterior wall acute myocardial infarction using speckle tracking imaging

Abstract

Objective To examine left ventricular(LV)twisting and untwisting in patients with anterior wall acute myocardial infarction by speckle tracking imaging(STI).Methods Basal and apical LV short-axis images were acquired in 38 patients with anterior wall myocardial infarction and 20 healthy subjects.Patients were divided into two groups according to global LV systolic function [normal LV ejection fraction(LVEF)group(LVEF≥45%)and abnormal LVEF group(LVEF<45%)].The value of LV rotation at basal and apical levels of each plane were obtained and recorded.Peak twist(Ptw),twist at aortic valve closure(AVCtw),twist at mitral valve opening(MVOtw),untwisting rate(UntwR),peak twist velocity(PTV),time to peak twist velocity(TPTV),peak untwisting velocity(PUV),time to peak untwisting velocity(TPUV)were separately measured.Results Although PTV,PUV and TPTV were not different among the three groups,UntwR were significantly reduced in abnormal LVEF group(P<0.01),and Ptw,AVCtw,MVOtw were also significantly depressed(P<0.05,respectively).Significant correlation was noted between untwisting rate and LVEF(r=0.63.P<0.001)and LV end-systolic volume(r=0.52,P<0.001).Conclusions Left ventricular twisting and untwisting could be measured by STl.Systolic twisting and diastolic untwisting rate were decreased in accordance with LV systolic dysfunction in anterior wall AMI. Key words: Echocardiography; Myocardial infarction; Ventricular function; left; Torsion; Speckle tracking imaging