RESUMO
Electric and dynamic properties of intracardiac blood are not taken into account considering questions of surface electrocardiogram genesis. Therefore assumptions of the lack of electric processes reflecting on the body surface are made. However in 7 male patients (mean age 38 +/- 2) suffering from aortic insufficiency by means of signal-averaged body surface mapping in diastole low amplitude negative potentials in regard to central terminal of Wilson are discovered. The potentials localize in the left anterior thoracic region, the amplitude of minimum varies in relation to the patient's clinical status and equals to hundreds of microvolts. As the phenomenon is sufficiently remote from the moment of the possible U wave appearance and precedes for tens of milliseconds to the beginning of atrial depolarization we suggested that it is caused exclusively by hemodynamic factors. For the experimental proof of the hypothesis the potentials difference between parts of aqueous 0.9% sodium chloride solution on the moment of flow generation within it are detected by means of differential amplifier with input impedance of 1 G omega to constant current. The registered signal has the form of a decremental harmonic oscillation. The mathematical model of the process in the form of differential equation connecting the volume density of charges in the electrolyte, its viscosity and the acceleration of the flow within the electrolyte has been constructed. Thus, the intracavitary blood as an electrolyte with different ions movability which moves with acceleration possesses the electrogenic properties and their contribution must be taken into account in the consideration of mechanisms of the surface electrocardiogram generation.
