[Localization of accessory atrioventricular pathways in patients with manifest premature ventricular excitation syndrome by three-dimensional vector electrocardiography].

Distribution of excitation via ventricular myocardium in patients with accessory atrioventricular pathways (AAVP) was studied using three-dimensional vector ECG. Analysis of the ECGs obtained during the study formed new views on the excitation process in the myocardium in the presence of AAVP, and made it possible to formulate vector ECG (VECG) criteria of AAVP localization. In 30 cases out of 33 it was possible to correctly localize AAVP. Information obtained as a result of VECG analysis made it possible to localize AAVP preoperatively within the limits of 1/14th atrioventricular sulcus with 97.1% accuracy, which is substantially higher than the accuracy of conventional electrocardiographic algorithms. Thus, the study found that in some cases three-dimensional vector ECG allows for substantial increase in the validity of AAVP localization, while in others it is the only sensitive non-invasive method of topical diagnostics of manifest premature ventricular excitation syndrome. Knowledge of the character of intervector interaction during ventricular electric systole makes it possible to predict the character of changes in the trajectory of QRS vector loop in any AAVP localization, i.e. to model the vector loop.

[Additional diagnostical ECG parameters in particular cardial pathology].

The authors offer additional diagnostic ECG parameters including temporal dependences of the angular (phase) rotation speed of the integral electric heart vector relative to the pinning point of the vector origin, the linear speed of the transference of the terminus along the loop trajectory, as well as a new parameter, the product of vector angular speed magnitude and the magnitude of its value at each moment of time. Reference values are adduced; their changes in post-infarction patients and in Wolff Parkinson White syndrome and their sensitivity to these diseases have been analyzed.

[Spatial vector electrocardiography: technique, perspectives of use]. / Prostranstvennaia vektorélektrokardiografiia.

Potentials of the use of computer synthesis of integral electrical vector of the heart D0 are described. Calculation of spatial angular vector velocity and linear velocity of its movement along trajectory can be carried out in a framework of biophysical dipole model. Spatial presentation of vector is realized and its behavior in accordance with established pathologies discussed. Possible diagnostic value of obtained results and utility of their introduction into clinical practice are stressed.

[Evaluation of the vascular wall by the spectra of Korotkov's tones]. / Otsenka sostoianiia sosudistoi stenki po spektram tonov Korotkova.

A method has been proposed for the registration and frequency analysis of Korotkov's tones. For interpretation of spectra, the authors accept the theory which interprets the tones as an acoustic result of hydrodynamic flutter in the partially ligated arterial portion. A unit based on a multifunctional recorder with variable frequency characteristics, an analog-to-digital converter, and a computer is used to record the tones. Computer-assisted Fourier analysis of tones is made. Three basic types of frequency spectra for brachial artery have been obtained in patients of different age. The signs used to evaluate the vascular wall at different stages of development of vascular pathology have been established.