[Age-related transfer coefficients of the basic indices of cardiac variance]. / Vuzrastovi prevodni koefitsienti na osnovni pokazateli na surdechnata variativnost.

This study was concerned with the relationship of changes in cardiac variance to age. A total of 518 subjects were involved. The following indicators of ACV (analysis of cardiac variance) were investigated: mean--mean value of successive cardiac intervals, SD--standard deviation of mean value of cardiac intervals (R-R), AMo--amplitude of the mode, HI--homeostatic index, Pt--spectral power of R-R related to thermoregulation, Pr--spectral power of R-R related to respiration, IBO--index of centralization. For each one of these ACV indicators, a mathematical expression of its relationship to age was specified. The coefficients obtained from the indicated expressions of the relationship "age-to-ACV indicators" represent transfer coefficients for the particular measured quantities. Their methodological importance lies in the fact that through them it becomes possible to make age corrections of ACV indicator figures for the purpose of comparing individual subjects or groups of subjects. These coefficients help to establish nomograms for the particular age ranges.

[The correlations between psychological indices and cardiac variance]. / Korelativni zavisimosti mezhdu niakoi psikhologichni pokazateli i surdechnata variativnost.

Correlative links between psychologic and psychologic indicators were studied in subjects occupied either in airline transportation or in the chemical industry. Investigations covered three groups of persons: managers of airline traffic (57 subjects); workers at "Vratsa" Chemical plant (14 subjects); and operators at "Vratsa" Chemical plant (14 subjects). The psychologic parameters measured included indicators of cardiac variance: mean--mean value of successive cardiac intervals, SD--standard deviation of mean value of cardiac intervals (R-R), AMo--amplitude of the mode, HI--homeostatic index, Pt--spectral power of R-R related to thermoregulation, Pp--spectral power of R-R related to respiration, IBO--index of centralization; psychologic parameters included: extrovertiveness, introvertiveness, neuroticism, psychoticism, interpersonality conflicts, self-control, social support, self-confidence, work satisfaction, psychosomatic complaints. There was evidence of significant and highly significant correlative links between indicators of cardiac variance and psychologic indicators. There thus appeared to exist certain relationships between the psychologic and psychologic levels during lengthy stressful occupational exposure.