|| Checking for direct PDF access through Ovid
3D Echo assessment of left ventricular dyssynchrony is based on the time to minimum volume of regional wall segments by automated border tracking using endocardial detection. Speckle tracking (ST) can directly quantify left ventricular mechanics and provides an alternative method to calculate regional volumes. We evaluated the reproducibility of new parameters based on 3D ST and compared it to current methodology.Methods: 40 analyses of adequate quality 3D datasets from patients with DCM and LBBB were independently performed by experienced observers in 2 institutions. Current LV analysis (2.7) and prototype (3.0) TomTec software was used to analyse datasets. A Matlab tool was used to exclude segments that were poorly visualised from the analysis. Systolic dyssynchrony index (SDI) was calculated using current and new ST software. Novel parameters including a modified SDI incorporating apical rocking (SDI-II) and SDI for 3D strain (SDI-strain) were also calculated.Results: Intra-class correlation coefficients (ICC) and Bland-Altman plots were calculated. The ICC for SDI using new software, current software, SDI-II and SDI-ST were 0.915, 0.897, 0.753 and 0.489 respectively. The mean difference for the same parameters was 0.18, -0.52, 1.38 and -0.42 respectively.Conclusions: SDI based upon new ST based algorithms and current methodology had excellent and very good reproducibility respectively. However, reproducibility of novel parameters (SDI-II & SDI-strain) less so good. Further work is necessary to define the parameters that affect the reproducibility of 3D strain assessments.