Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 12 3 2025 07 01 627 634 Parvaneh Aliakbarzadeh Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Naser Khezerlouy Aghdam Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Mehrnoosh Toufan Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran 2024 02 18 2024 03 04 Background: Three-dimensional echocardiography (3DE) allows simultaneous evaluation of the entire left ventricular (LV) volume, motion, and mechanical dyssynchrony. This study aimed to provide valuable data on the feasibility and reliability of 3DE in assessing LV dyssynchrony in healthy individuals. Methods: One hundred healthy volunteers, including both genders, with mean age, weight, and BMI of 39.64±10.21 years, 76.57±14.65 kg, and 27.59±4.3 kg.m-2, respectively, without evidence of structural heart or chronic disease, were included. 3DE examinations were conducted using a 4-chamber view and the full-volume method for all volunteers. Dyssynchrony was automatically quantified as the systolic dyssynchrony index (SDI) for selected LV segments using Q-lab software. The standard deviation (SD) of the time to attain minimum systolic volume was considered as SDI. This time length was expressed as % R-R to compensate for the variability of heart rate and increase reproducibility. Consequently, a single SDI (global SDI) was available for quantifying the degree of LV dyssynchrony by comparing all segments. Results: According to echocardiographic findings, the mean global LV-SDI, apical SDI, basal SDI, and mid SDI were 28.68±15.48 msec, 26.16±27.47 msec, 24.41±14.35 msec, and 22.07±18.24 msec, respectively. After correction for RR duration, the mean global LV-SDI was 3.49±1.97%, apical SDI: 3.21±3.58%, basal SDI: 2.97±1.82%, and mid SDI: 2.68±2.19%. Conclusion: 3DE proves to be a useful tool for evaluating LV dyssynchrony. The data provided include age- and sex-related changes in total and regional SDI in healthy volunteers, serving as a suitable reference for further investigations into LV dyssynchrony changes. https://fbt.tums.ac.ir/index.php/fbt/article/view/942 https://fbt.tums.ac.ir/index.php/fbt/article/download/942/396