Echocardiographic evaluation of left ventricle mechanical parameters in infants of the first year of life

Aim. The study focused on the analysis of the measurement range of left ventricle mechanics (strain, strain rate, rotation, rotation rate, twisting, untwisting, torsion) in healthy infants of the first year of life to obtain their baseline values. Methods. The study included 125 healthy infants aged 5 days to 12 months (average 5.9±3.9 months. The Аcuson S 2000 machine (Siemens Medical Systems, Mountain View, CA, USA) was used to perform echocardiography. The indicators of left ventricle longitudinal strain (%) and strain rate (s-1), radial strain and strain rate (% and s-1), circumferential strain and strain rate (% and s-1), basal and apical rotation in systole and diastole (°) and rotation rate (°/s), twisting (°), untwisting (°), twisting and unwinding rate (°/s) and torsion (°/cm) were measured and analyzed. Results. It was found out that the values of the longitudinal strain and strain rate inversely correlate with the pumping function (stroke volume index) and diastolic function (filling pressures and the untwisting rate). The parameters of the circular and radial strain tended to depend on the left ventricle mass index, interventricular septum/left ventricle posterior wall thicknesses. Left ventricle twisting and untwisting would increase in healthy infants from the newborn period to the first year of life. Left ventricle torsion range was determined by the twist values and not by left ventricular geometry. Conclusion. The obtained data on the values of longitudinal, circumferential and radial left ventricle strain and strain rate can be used as reference ranges to evaluate the mechanical left ventricular function in infants of the first year of life.