ABC | Volume 114, Nº3, March 2020

Original Article Sousa et al. Software: analysis of strain curves Arq Bras Cardiol. 2020; 114(3):496-506 Figure 3 – Simultaneous visualization of strain longitudinal curves of the left (18 segments) and the right (six segments) on the right. Time of the onset of the phases and parameters calculated in the terminal on the left. Other configurations can be accessed through the options available; MVC: mitral valve closure; AVO: aortic valve opening; AVC: aortic valve closure; MVO: mitral valve opening. Figure 4 – EchoPAC selection criterion of the peak systolic strain. EchoPAC selection criterion for the peak systolic strain For P > –0.75*N: the positive peak is selected For P < –0.75*N: the negative peak is selected P – Positive Peak N – Negative Peak a) Normality test The analysis using the Q-Q plot is visual and hence subjective. If data are normally distributed, the points lie on a straight line constructed with data analyzed. The assumption of normality (Shapiro-Wilk test) was accepted if p-value was > α (level of significance = 5%). b) Spearman correlation coefficient ≥0.95. c) Hypothesis testing: p-value>0.05 (equivalence between the measurements) Ho: mean difference (EchoPAC - D-Station) = 0 Ha: mean difference ≠ 0 d) Bland-Altman • Systematic error (bias) ≤ 1% • scattering of the data ≤ 2% (*) Please note that the unit of measurement of GLS is % and therefore these values refer to absolute variation. Results Simultaneous visualization of the curves in different cardiac chambers The D-Station software provides the simultaneous display of all strain curves and SR of different cardiac chambers, allowing the study of the interaction between them. Additional options 499