Informative potential of three-dimensional scattergram for assessment of the sinus node functional activity

Three-dimensional (3-D) scattergram of R-R intervals is a volume geometric figure which in horizontal coordinates depicts relation between current and preceding R-R intervals and in vertical coordinates is a histogram showing probabilistic values of occurrence of each point of scattergram. In the pr esent study 3-D scattergrams of normal R-R intervals of healthy subjects we re compared with those constructed for patients with neurogenic disturbance s of regulation of hemodynamics. Horizontal sections of the lower thirds of 3-D scattergrams were analyzed in both groups. Analogous sections of 3-D s cattergrams were reconstructed with the use of mathematical modeling of hea rt rate variability by sinusoidal (sinusoidal test) and random (random lest ) waves. Horizontal sections of the Tower third of 3-D scattergram obtained from healthy subjects and by sinusoidal test appeared to be ellipsoid holl ow figure with even edges. Similar sections obtained from patients with neu rogenic disturbances of regulation of hemodynamics and by random test looke d like nonhomogeneously filled figures with irregular edges. The results al lowed to conclude that analysis of 3-D scattergrams had high informative po wer for assessment of the sinus node functional activity especially for det ection of disturbed interaction between functional elements of the sinus pa cemaker.