Influence of extreme factors on the ratio of cardiointervals in the structure of the cardiocycle

BACKGROUND: The proportion of the golden section, discovered by Pythagoras, is of great importance in the organization of wildlife. Since the golden proportion is one of the criteria for self-organization in living nature, it is natural to assume that this criterion can also be manifested in the work of the heart. The organization of the cardiac cycle is the result of a long evolution of a living organism in the direction of optimizing the structure and functions, ensuring life with minimal energy consumption. However, in clinical medicine and physiological research, until recently, this approach has hardly been used, and there are only a few reports in the literature on the effectiveness of this method.

AIM: To study the sensitivity of indicators of the symmetry analysis of the cardiocycle in accordance with the methodology of the golden section to physical exertion, hypoxic and temperature effects for an integral assessment of the functional state of the heart. For the geometric analysis of the ECG, the ratios of the main parameters were used to assess their compliance with the criteria of the golden section.

MATERIALS AND METHODS: Geometric analysis of ECG interval intervals according to the principles of the golden section in healthy individuals exposed to debilitating physical activity, hypoxia, combined hyperthermia or low temperatures. In the course of the work, the results of a study of 252 male volunteers aged 20–35 years were analyzed, of which 46 people underwent an exhaustive exercise test, 113 a hypoxic test, 34 a combined hyperthermia tolerance test, and 69 a moderate cooling tolerance test.

RESULTS: the use of a geometric analysis of cardiocycles at rest, during exercise, as well as moderate exposure to typical adverse environmental factors (hypoxia, high or low temperatures) showed the fundamental possibility of assessing the dynamics of the functional state in young practically healthy individuals. The indicators characterizing the activity of the processes of regulation of myocardial work at the extracardiac and intracardiac levels were more dynamic. The indicator of symmetry analysis, which characterizes the level of myocardial homeostasis, energy processes and contractility, to a greater extent reflects unfavorable prognostic characteristics in terms of failure of myocardial adaptation. It has been established that for practically healthy individuals (in the normal state of activity, without external influences), the 1^st class of the functional state occurs in 83% of cases, hemodynamic stress is noted in 16% of the subjects, hemodynamic inadequacy — in 1%.

CONCLUSIONS: The deviations from the ideal proportion of the golden section identified as a result of adverse external influences remained within acceptable fluctuations, which indicated a fairly perfect functioning of the heart and the cardiovascular system as a whole in the surveyed contingent of young, practically healthy individuals. Proposed by N.V. Dmitrieva (1989) the classification of functional states, based on the assessment of the degree of deviation of the calculated coefficients from the optimal value corresponding to the golden section, is not optimal for healthy young men, which include athletes without signs of “sports heart” and other myocardial pathology. It does not take into account the sign of the deviation, as a result, for the state of rest, with the predominance of bradycardia, typical for athletes, there is an overdiagnosis of tense hemodynamics. At the same time, the work of the heart during short-term intense physical exertion, which naturally causes pronounced sympathicotonia, can be unreasonably characterized as a premorbid or pathological condition.