Novel Method for Displaying Left Ventricular Function and Dyssynchrony Using Tissue Doppler Imaging: Evaluation of Its Applicability in Dilated Cardiomyopathy With Wide and Narrow QRS Complexes

A Display of Combined Left Ventricular Function and Dyssynchrony Using Doppler Tissue Imaging: Its Application in Acute Response to Cardiac Resynchronization Therapy

“…This method, based on the vector analysis for the six basal LV segments, provides combined measures of global LV contractile function and mechanical dyssynchrony; determination of the most delayed segment was also possible. Among patients with nonischemic dilated cardiomyopathy, the prevalence of LV mechanical dyssynchrony, as assessed by the new method, was 68% in those with wide QRS complexes and 39% in those with narrow QRS complexes 1 . These percentages were equivalent to those obtained with conventional DTI methods.…”

“…1, right): (1) percentage area of the hexagon, the area divided by the overall graph area, reflecting global LV systolic function; (2) net‐delay magnitude of mechanical contraction (ms), the length of the composite vector for the six vectors, a dyssynchrony index; (3) delayed contraction site (°), the graphical position of the composite vector. Reproducibility of the parameters was described in our recently published report, which showed acceptable results 1 …”

“…We recently proposed a method for displaying LV function and dyssynchrony using DTI 1 . This method provides three major parameters related to LV mechanical dyssynchrony: (1) percentage area of the hexagon; (2) net‐delay magnitude; and (3) delayed contraction site.…”

“…This method provides three major parameters related to LV mechanical dyssynchrony: (1) percentage area of the hexagon; (2) net‐delay magnitude; and (3) delayed contraction site. These parameters are obtained using the custom‐made software program, which provides at‐a‐glance information regarding LV function and mechanical dyssynchrony on a hexagonal graph with an arrow 1 . We applied this method in patients with nonischemic dilated cardiomyopathy and wide or narrow QRS complexes, and found similar incidence of LV mechanical dyssynchrony when compared with the conventional dyssynchrony indexes; however, its validation in the setting of CRT has not ever been investigated.…”

“…We have recently proposed a novel method of displaying left ventricular (LV) function and dyssynchrony using Doppler tissue imaging (DTI) 1 . This method, based on the vector analysis for the six basal LV segments, provides combined measures of global LV contractile function and mechanical dyssynchrony; determination of the most delayed segment was also possible.…”