The left ventricular strain-volume loop in a healthy Dutch population: age- and sex related differences

Abstract

Abstract Introduction By combining left ventricular (LV) global longitudinal strain (GLS) with LV volume during the cardiac cycle, LV strain-volume loops can be generated. LV SV-loop derived parameters provide new insights into the interaction between cardiac contraction and volume in a variety of cardiac diseases (1,2) and may even have prognostic value. (3,4) Reference values for healthy individuals with attention to sex- and age-related differences have not been established yet. Therefore, the aim of this study is to provide reference ranges in a healthy adult population and investigate potential sex- and age-related differences of LV SV-loop characteristics. Methods In 125 healthy volunteers aged 18-72 years, apical 2-, 3- and 4-chamber views were acquired to measure GLS. Custom software was used to combine strain and volume data to construct SV-loops. Different parameters were derived: (i)linear slope of systolic strain-volume relation (S-Slope); (ii) early linear slope of systolic strain-volume relation (ES-Slope); (iii) early linear slope of diastolic strain-volume relation (ED-Slope); and (iv) uncoupling between systolic and diastolic strain-volume relation (UNCOUP). Results For the systolic strain-volume relation higher values were observed in females as compared with males with S-Slope values of 0.19 [0.17-0.22] %/mL m-² and 0.13 [0.11-0.15] %/mL m-² respectively. ED-Slope was higher in females as compared with males with values of 0.18 [0.09-0.28] %/mL m-² and 0.12 [0.06-0.18] %/mL m-² respectively. Relative coupling of the systolic and diastolic strain-volume relation was observed with a mean value of 0.34 ± 1.1. UNCOUP was correlated with age with a value for r of 0.4. Conclusion Higher values for the systolic and early-diastolic strain-volume relation in females can be reflective of different cardiomechanics as LV contraction is not only comprised of longitudinal but also circumferential and radial deformation. In line with current literature our custom software found relative coupling of the systolic and diastolic strain-volume relation in our cohort of healthy subjects. Towards older age relative uncoupling of the systolic and diastolic strain-volume relation was found.Figure 1.Strain-volume loop