PubMed Health⌕ Search

Biomedical subjects

L I Titomir

Publications and source records attributed to L I Titomir.

41 records · Page 3Linked to original sources
PubMedDate not supplied

[Non-invasive mapping of cardiac electric potential of a specific quasi-epicardium].

A procedure was proposed for non-invasive mapping of the cardiac electrical potential or a spherical quasiepicardium from its synchronous multichannel measurement on the surface of the chest, i.e. routine electrocardiodraphic mapping. Mathematical simulation was used to demonstrate that the quasiepicardial potential can be calculated with the accuracy sufficient for clinical diagnosis by applying the multipole electric field resolution method with allowance made for three lowest resolution terms. Due to the fact that the spherical quasiepicardium is more approximate to the heart and more concentric as to its center than the chest surface, the maps of the quasiepicardial potential permit recognition of some features of the pattern of a cardiac electric process, which do not manifest themselves in the distribution of the potential on the body's surface. The examples showing that the assessment of a cardiac abnormality can be made more accurate by using this method are given in the paper.

Body Surface Potential Mapping↗
PubMedDate not supplied

[Integral characteristics of the eletrical generator of the human heart].

Integral characteristics of the cardiac electrical generator, namely the dipole moment vector, position of the moving electrical center and the complexity parameter (relative quadrupolar potential), are presented for a group of healthy middle-aged men. The characteristics are determined as a result of mathematical processing of electrical potential distribution on the torso surface and geometrical parameters of this surface in a digital computer. The values of the surface potentials and coordinates were obtained by means of experimental measurements using a special automatized measuring system for investigating the cardiac electrical field. Main qualitative properties of the integral characteristics and their possible diagnostic significance are discussed.

Computers↗
PubMedDate not supplied

[A model of spherical quasi-epicardium for mapping of the electrical potential of the heart].

Possibility of determination of the heart electric potential maps on the spherical quasiepicardium from the body surface potentials measured by means of multiple leads, is estimated. The simplified models of ventricular depolarization electric generator considered in this study, consist of sets of uniform double layers representing basic configurations of the true electric generator of the heart, while allowing an analytical calculation of the multipole components, as well as potential of the generator. The contribution of the generator multipole components to the potential on the spherical quasiepicardium is evaluated. The results of the study show that it is reasonable to use the multipole components up to the 3rd order for noninvasive mapping of the potential on the spherical quasiepicardium with the radius which provides tangential touching of the quasiepicardium with the precordium surface. Because of bringing the potential observation region nearer to the generator and improving concentricity of this region with respect to the generator, the quasiepicardium mapping technique allows revealing much more complicated generator configurations than those found out by straightforward estimation of the potential measured on the chest surface, thereby facilitating more accurate noninvasive recognition of the heart electrophysiological state.

Body Surface Potential Mapping↗