Biomedical subjects
Publications and source records attributed to A N Matlashov.
We describe a method of identifying the distributed sources associated with biomagnetic data sets. The technique is based on Tikhonov regularisation. An algorithm has been implemented in FORTRAN on a PC/AT computer. Its predictions are stable with respect to measurement noise.
Late ventricular potentials (LVP) were detected with an ECG signal-averaging installation developed at the Institute of Radio Engineering and Electronics, USSR Academy of Sciences. A total of 103 patients were examined: 33 with sustained ventricular tachycardia (VT), 30 with unsustained VT and high-grade ventricular premature contraction, 20 with coronary heart disease, postinfarction cardiosclerosis without arrhythmias and 20 apparently healthy subjects (controls). LVPs are the most susceptible to sustained VT in the presence of postinfarction cardiosclerosis (77%), their specificity is lower (70%). LVPs are a low sensitive marker (35%) for sustained idiopathic VT. In unsustained VT and high-grade premature ventricular contraction, LVPs were recorded infrequently in 1 (3%) of the 30 patients.
Late potentials (high-frequency oscillation of the initial part of ST-segment) reflect decelerated ventricular depolarization and predispose onset of reentry arrhythmias. Investigators are keenly interested in their possible exact registration. The article describes the experience of realization of late potentials registration method based on the method of Simson et al, with the use of a USSR-produced electronic apparatus. The first experience of clinical application of the late potentials registration method in patients with IHD is analysed. Presence of late potentials is correlated with spontaneous ventricular arrhythmias and possible disturbances of left ventricular contractility. The obtained data as well as analysis of technical possibilities of the developed system allow evaluation of the proposed technique as acceptable for late potentials registration.
Dynamic magnetic maps have been constructed with the help of a magnetocardiograph, based on a superconductive quantum interferometric transducer, for 19 normal subjects, 12 patients with postinfarction cardiosclerosis, 5 patients with ventricular extrasystoles, and 1 patient with left-ventricular hypertrophy. A correlation between general patterns and ventricular depolarization phases of normal subjects' maps was demonstrated, using a biophysical myocardial excitation wave model as an even layer of current dipoles. Methods are proposed for the localization of ectopic pacemaker, postinfarction scars and hypertrophic myocardial areas within the same model.
Explore the source record for details and available documents.
One of the methods of recording late ventricular potentials, markers of decelerated depolarization of the heart ventricles, is depicted. The complex suggested by the authors consists of an interface connected to the personal computer, a block for cardiosignal processing, and an analog-to-digital converter. The averaging is realized after preliminary signal processing, which results in the computation of the mean period of the QRS. The mode of automatic amplification is provided as are alterations of the lower frequency of the section of the band-pass filters as well as the switching on of the rejection filter.
Explore the source record for details and available documents.