Kinetic energy as a factor in assessing the work of the heart in patients with aortic stenosis

Goal. To analyze the evolution of the myocardial contraction force through the assessment of kinetic energy in patients with aortic stenosis based on intraventricular blood flows

Material and methods. According to the selection criteria, 21 healthy volunteers (age 34 ± 3) and 105 patients with aortic stenosis (age 62 ± 4) were examined before and after surgery for 7–10 days. Transthoracic echocardiography was performed on a Vivid E9 device in 2, 3 and 4 chamber positions with registration of intraventricular blood flows, calculation of the rate of change in volume and kinetic energy depending on the left ventricular EDV, pressure gradient (ΔP) on the aortic valve with an assessment of the displacement of the left ventricular endocardium contour, based on technologies for tracking speckles of ultrasonic images in the MultiVox program.

Results. Our goal was to quantify kinetic energy (KE) during the entire cardiac cycle of the left ventricle (LV) using echocardiography. One of the main strengths identified in these studies is the high reproducibility of the assessment of LV blood flow and hemodynamics the average coefficient of variability 7 ± 2% for assessing LV function. Studies have shown increased diagnostic reliability without spending additional time. In systole, the KE before the LV operation was higher than normal values (0.62–0.78 J) after the operation, the KE approached the norm, averaging 0.55 J.

Conclusion. Changes in intraventricular blood flow in patients with pressure overload of the heart demonstrate higher systolic energy compared to the control group. Different time values of energy in systole and diastole, observed in patients before surgery, represent an objective approach to assessing the work of the heart. The energy analysis reflects earlier signs of mechanical myocardial disorders, compared with the ejection fraction and, possibly, predict the development of cardiac remodeling. Adequate correction of the defect normalizes the work of the heart already in the early postoperative period.

1. Vallelonga F., Airale G., Pedrizzetti G. et al. Introduction in hemodynamic forces analysis moving into the new frontier of cardiac deformation analysis. J. Am. Heart Assoc. 2021; 10 (24): e023417. http://doi.org/10.1161/JAHA.121.023417

2. Zajac J., Eriksson J., Dyverfeldt P. et al. Turbulent kinetic energy in normal and myopathic left ventricles. J. Magn. Reson. Imaging. 2015; 41 (4): 1021–1029. http://doi.org/10.1002/jmri.24633

3. Eriksson J., Dyverfeldt P., Engvall J. et al. Quantification of presystolic blood flow organization and energetics in the human left ventricle. Am. J. Physiol. Heart Circ. Physiol. 2011 Jun; 300 (6): H2135–2141. http://doi.org/10.1152/ajpheart.00993.2010

4. Dweck M.R., Joshi S., Murigu T. et al. Left ventricular remodeling and hypertrophy in patients with aortic stenosis: insights from cardiovascular magnetic resonance. J. Cardiovasc. Magn. Reson. 2012; 14 (1): 50. http://doi.org/10.1186/1532-429X-14-50

5. Sandrikov V.A., Kulagina T.Yu. Echocardiography in cardiac surgery. Vector analysis and intraventricular blood flows. Moscow: Our World, 2022. 607 p. ISBN: 978-5-907549-17-3 (In Russian)

6. Pedrizzetti G., La Canna G., Alfieri O., Tonti G. The vortex – an early predictor of cardiovascular outcome? Nat. Rev. Cardiol. 2014; 11 (9): 545–553. http://doi.org/10.1038/nrcardio.2014.75

7. Crandon S., Westenberg J.J.M., Swoboda P.P. et al. Impact of Age and Diastolic Function on Novel, 4D flow CMR Biomarkers of Left Ventricular Blood Flow Kinetic Energy. Sci. Rep. 2018; 8 (1): 14436. http://doi.org/10.1038/s41598-018-32707-5

8. Dweck M.R., Joshi S., Murigu T. et al. Left ventricular remodeling and hypertrophy in patients with aortic stenosis: insights from cardiovascular magnetic resonance. J. Cardiovasc. Magn. Reson. 2012; 14 (1): 50. http://doi.org/10.1186/1532-429X-14-50

9. Arvidsson P.M., Töger J., Pedrizzetti G. et al. Hemodynamic forces using four-dimensional flow MRI: an independent biomarker of cardiac function in heart failure with left ventricular dyssynchrony? Am. J. Physiol. Heart Circ. Physiol. 2018; 315 (6): H1627–H1639. http://doi.org/10.1152/ajpheart.00112.2018

10. Eriksson J., Dyverfeldt P., Engvall J. et al. Quantification of presystolic blood flow organization and energetics in the human left ventricle. Am. J. Physiol. Heart Circ. Physiol. 2011; 300 (6): H2135–2141. http://doi.org/10.1152/ajpheart.00993.2010

11. Lund O., Flø C., Jensen F.T. et al. Left ventricular systolic and diastolic function in aortic stenosis. Prognostic value after valve replacement and underlying mechanisms. Eur. Heart J. 1997; 18 (12): 1977–1987. https://doi.org/10.1093/oxfordjournals.eurheartj.a015209