Evaluation Of Regional Myocardial Motion During Isovolumic Contraction With Two-Dimensional Strain Echocardiography

ObjectiveTo evaluate the characteristics of regional left ventricular myocardial strain during isovolumic contraction in normal subjects combined with the strain in ischemic and infarct myocardium in patients with coronary artery disease by two-dimensional strain echocardiography (2DS), in order to explore the clinical value with two-dimensional strain echocardiography for assessment of regional left ventricular dysfunction.MethodsTwenty healthy subjects, sixteen patients with myocardial infarction and eighteen patients with angina pectoris were enrolled in the study.2DS was used to record the longitudinal stain-time curve of each segment of left ventricle wall during isovolumic contraction from the apical four-chamber view, two-chamber view and the left ventricular long-axis view.ε+IVC were measured and theε+IVC segment numbers, the ratio ofε+IVC were calculated among ischemic, infarct and normal myocardium.ε+IVC was rectified by the systolic strain (ε+IVC/|εS|). All the parameters were compared among the ischemic, infarct and normal myocardium. The differences of the ratio ofε+IVC were observed among the normal and ischemic myocardium in different levels and ventricular walls.ResultsThere were two shapes of stain-time curve in isovolumic contraction:gradually increasing negative wave and small positive wave. The gradually increasing negative waves were most popular. In normal myocardium the comparison of the ratios ofε+IVC among the left ventricular levels and walls:the ratio had a tendency of decrement from base to apex and the ratio ofε+IVC among posterior, septerior, inferior walls was higher than that among anterior antsepterior, laterior walls. There were significant differences in each index (P<0.05). Compared with the normal myocardium, the ratio ofε+IVC were more and theε+IVC,ε+IVC/|εS| were significantly larger in the ischemic and infarct myocardium (P<0.01). Compared with the ischemic myocardium, theε+IVC,ε+IVC/|εS | increased more significantly in the infarct one. In ischemic myocardium the difference of the ratio ofε+IVC was not significant between each level (P>0.05), and the ratio ofε+IVC of only posterior wall was higher than that other ventricular walls (P＜0.01).ConclutionsLeft ventricle myocardial deformation can be occured during the isovolumic contraction in normal subject. The change of left ventricle myocardial deformation may help to distinguish the normal myocardium from ischemic and infarct myocardium. 2DS can be used to evaluate the characteristics of regional left ventricular myocardial deformation during isovolumic contraction.