New Insight Into the Evaluation of Abnormal Left Ventricular Wall Motion

Abstract

BackgroundEvaluation of mechanical dyssynchrony using echocardiography has failed to improve refractory heart failure in patients treated with cardiac resynchronization therapy. Previous predictors may not accurately reflect cardiac dyssynchrony. It was hypothesized that the spatially and temporary continuous information of the whole endocardium is required when the mechanical dyssynchrony is assessed using echocardiography. This study aimed to examine differences in the locus of the centroid of the left ventricle between abnormal and normal wall motion. MethodsTwenty-seven patients with dilated cardiomyopathy (left ventricular ejection fraction [LVEF]: 43±7%) and 45 old myocardial infarction patients with aneurysm (LVEF: 38±11%) were compared with 188 individuals with normal wall motions (LVEF: 61±5%). In an off-line system, the border of the endocardium was defined for each coordinate via the two-dimensional speckle tracking method. The centroid of the three-dimensional left ventricle was defined as the central point between both centroids calculated from four- and two-chamber images using an original application. ResultsThe locus of the centroid of the left ventricle in the normal wall motion group showed a horizontally inverted β shape, whereas this shape was absent in the other groups. When corrected by left ventricular end-systolic volume, the total and each directional length of the locus of the centroid of the left ventricle in the abnormal wall motion groups were clearly reduced compared with those recorded in the normal wall motion group. The acceleration of the centroid was also reduced in the abnormal wall motion groups. Multiple regression analysis with a stepwise method revealed a corrected antero-posterior shift of the centroid of left ventricle by left ventricular end-systolic volume and N-terminal pro-brain natriuretic peptide, which strongly correlated with the LVEF (adjusted R2: 0.6818, p≤2.2e-16).ConclusionUse of the locus of the centroid of the left ventricle provides novel insight into the evaluation of abnormal left ventricular contractions. Trial registrationretrospectively registered