Functional geometry of the left ventricle in dilated cardiomyopathy before and after resynchronization therapy
Aim. To analyse quantitative parameters of functional geometry of the left ventricle (LV) in patients with dilated cardiomyopathy (DCMP), to assess the changes in cardiac resynchronization therapy (CRT) and to reveal the relation of functional geometry of LV and its contractility. Material and methods. In DCMP patients group, who were directed to CRT according to the Guidelines of Russian Arhythmologists Society 2013, echocardiographic study was performed before and after CRT (at 5th day). Based on two-dimensional LV pictures the parameters were assessed in the cycle, as segmented kinetics of wall contraction, LV shape dynamics: sphericity index, Hibson, conicity of apical zone, Fourier shape complexity. Results. In DCMP patients the decrease of global ejection fraction <35% was followed with a decrease of systolic change of all sectoral squares of LV and enhancement of dimensional heterogeneity and asynchronicity of regional wall motion during cardiac cycle comparing to controls. There was negative correlation revealed between the proposed index of non-homogeneity and global ejection fraction. All shape indexes point to more spherical shape of LV in DCMP. However, opposite to controls, DCMP patients lack dynamical changes of shape indexes during cardiac cycle, that witnesses on significant disorders of wall motion coordination in cycle. After CRT there is significant re-coordination of LV wall motion, followed by restoration of non-homogeneity pattern of segmental kinetics, decrease of nonhomogeneity indexes and of asynchronicity and appearance of the dynamics of shape indexes changes during cardiac cycle. It was shown that end-systolic indexes of sphericity shape complexity of Fourier make it to separate patients who respond or does not on therapy, by clinical parameters. Changes of sphericity index between end diastole and end systole <3,5% selects patients with the highest prognostic significance comparing with other parameters. Conclusion. Disorders of functional geometry of the LV, particularly an increase of non-homogeneity and asynchronicity parameters of the regional motion of the wall, decrease of dynamical changes of LV sphericity indexes, might influence contractility and pumping function of the heart, and have diagnostic significance in selection of patients responding to CRT.