PhD, Associate Professor E.N. Minina¹
Dr.Med., Professor A.G. Lastovetsky²
Dr.Med., Professor Y.V. Bobrik¹
PhD, Associate Professor V.V. Minin¹
Post-graduate student Z.R. Kurbetdinova^1
1V.I. Vernadsky Crimean Federal University, Simferopol,
²Scientific Research Institute of Health Organization and Informatization of the Ministry of Health of the Russian Federation, Moscow

Keywords: cardiovascular system, PHASOGRAP® test system, T-peak symmetry, ECG signal phasometry.

Introduction. Excessive physical loads and psycho-emotional stress caused by sports training and strive for sports achievements, as well as extreme competitive activity combined with other risk factors, lead to disruption of myocardial activity and, sometimes, cardiovascular disorders [1, 2].

The formation of adaptive reserves in the process of training depends on physical and emotional stresses, especially in young people, and often conceals the premonitory symptoms of cardiovascular diseases, which prevents from timely diagnosis of pathological processes and their correction at the off-clinical stages. This implies the formation of integral informative off-clinical markers of cardiovascular disorders associated with regular sports activities, which makes it possible to adequate dose individual training loads and detect myocardial responses at early stages. Timely differentiation of the T-peak symmetry of the single-channel ECG and its correlation with the established individual norm allows reducing the risk of pathological conditions in terms of sports competitions.

Objective of the study was to argue in favor of the relevance of the prognostic ratings of cardiac activity in modern football using the cardiac activity phase measurement tools.

Methods and structure of the study. We applied a computerized PHASOGRAP® test system to read and analyze the ECG data, with the single-channel ECG data being processed in the phased space with application of the computer graphics and automatic pattern recognition technologies [4, 5] (see Figure 1).

Figure 1. Staged ECG processing algorithm:

initial ECG (а); its phase trajectory – phased pattern (b); a fragment of the phased pattern, illustrating the Т-peak of the single-channel ECG and its symmetry detection principle (D2/D1)

Analyzed in the data processing procedure were a few parameters of the phased pattern including its symmetry versus the T-peak of the single-channel ECG (, units). The study was carried out at the premises of the football club Tavriya. 25 football players trained afield were subject to the study. The individual functionality was rated by the maximal/ moderate test loads with application of an instant mobile gas analyzer Oxycon Mobile (Jaeger) and MetaMax 3B (Cortex). The individual heart rates versus loads were tested by Polar pulsometer (Finland). The football players were subjected to a constant shuttle run/ walk test: the testee was to move between two markers (lines or cones) that were 20 m apart from each other. The statistical data processing was made using the STATISTICA 6.0 software package (StatSoft, Inc., IBM, USA). We estimated the discrepancies in the distribution of characteristics. The significance of differences between similar indicators in the independent samples was determined using the non-parametric Mann-Whitney U-test. In terms of normal distribution, the parametric Student's t-test was used.

Results and discussion. At the first stage, we found that, because of the increasing demands to aerobic performance in terms of the maximum oxygen consumption (MOC), the percentage of athletes with fixed cardiohemodynamic disorders increased (Table 1).

Table 1. Statistical data* on incidence of dysfunctional and pathological conditions in athletes with differently directed dynamic component of training activity (n=2167)

Note. RBB – right bundle branch; QRS – electrical cardiac axis; * – findings of the retrospective study conducted in the Republican Medical Exercises Dispensary of the Crimea in 1996-2014.

It was found that, against this background, over 20% of athletes diagnosed with cardiac abnormalities terminated their sports activities in the clinic during the next 2 years. It was revealed that the "adaptation cost" exceeded the compensatory capabilities, which could lead to a breakdown in adaptation, which, in turn, is incompatible with elite sports. Off-clinic control of training afield is relevant and contributes to the improvement of physical fitness of athletes, especially in sports with high dynamic loads, football in particular.

At the second stage, we evaluated the football players' functional fitness level and compared the T-peak symmetry rates obtained by means of phasometry characterizing the quality of repolarization. The survey data reflected the general level of the athletes' functional fitness and defined the specifics of correlation between these generally accepted parameters and phasometric indicators. Table 2 represents a high degree of negative correlation between  and MOC, which is consistent with the previously obtained results and is yet more proof that this indicator is important as a marker of cardiometabolic processes. Thus, we detected a correlation of the quiescent-state T-peak symmetry with the maximum oxygen consumption sagging rate. Changes in the repolarization processes, quantified by the growth of the T-peak symmetry rate, reflect the threshold myocardial oxygen consumption rate and can be expressed by the linear MOC regression equation (ml min^-1 kg^-0,75) = 210-60*. Table 2 represents the correlation relationships between the functional fitness level of the examined football players and their T-peak symmetry rate. based on the findings, we developed a values matrix (Table 3) to instantly rate the level of functional fitness of a football player.

Table 2. Correlation relationship between functional fitness level and T-peak symmetry rate (, units) in highly skilled football players, n=25

Note. Spearman's rank correlation is significant at p<0.05.

Table 3. Determination of the level of functional fitness in terms of the T-peak symmetry

Therefore, the phaseometric index of the T-peak symmetry fairly represents the level of functional reserves of the athlete’s body and can be used to solve the actual problem of prognostic evaluation of cardiac activity.

Conclusions:

• Preventive control over training afield is especially relevant for athletes with a high dynamic component of training activity, for instance, football players.

• The maximum oxygen consumption rate in the football players was found to decrease with the increase in the quiescent-state T-peak symmetry.

• We developed a values matrix to instantly rate the individual functionality and competitive fitness in football trainings.

References

1. Aghajanyan N.A., Bayevsky R.M., Berseneva A. P. Uchenie o zdorovye i problemy adaptatsii [Study of health and adaptation problems]. Stavropol, 2000, 173 p.
2. Andryushchenko L.B., Vitko S.Yu., Shutova Т.N. Fizkulturno-ozdorovitelnye tekhnologii v ukreplenii sostoyaniya zdorovya studentov i sotrudnikov vuza [Sport and recreational technologies in health promotion of students and university staff]. Sovremennye problemy nauki i obrazovaniya, 2016, no. 5, p. 261.
3. Minina E. N. Novy podkhod v izuchenii vzaimosvyazi funktsionalnoy podgotovlennosti i elektrogeneza u sportsmenov s ispolzovaniem etalonnogo kardiotsikla [New approach to study of relationship between functional fitness and electrogenesis in athletes using reference cardiocycle]. Vestnik novykh meditsinskikh tekhnologiy. Electronic edition, 2014, no. 1. Publication 1-8. Available at: http: // medtsu.tula.ru/VNMT/Bulletin/E2014-1/4931.pdf (Date of access: July 3, 2014).
4. MikhaylovaA.V., Smolensky A.V. Perenapryazhenie sportivnogo serdtsa [Overtension of sports heart]. Lechebnaya fizkultura i sportivnaya meditsina, 2009, no.12 (72), pp. 26-32.
5. Feinzilberg L.S. Kompyuternaya diagnostika po fazovomu portretu elektrokardiogrammy [Computer diagnosis of ECG phase pattern]. Kiev: Obrazovanie Ukrainy publ., 2013, 190 p.       

Corresponding author: fizkult@teoriya.ru

Abstract

Prognostic ratings of cardiac activity in football are designed with application of integral highly-informative sets of markers to trace, on an off-clinical basis, potential cardiovascular system disorders in the training process to both prudently manage training loads and analyze myocardial responses to regular trainings and competitive stresses. 25 footballers were sampled for the study. We applied a computerized PHASOGRAP® test system to read and analyze the ECG data, with the single-channel ECG data being processed in the phased space with application of the computer graphics and automatic pattern recognition technologies. Analyzed in the data processing procedure were a few parameters of the phased pattern including its symmetry versus the T-peak of the single-channel ECG (bT, units). The individual functionality was rated by the maximal/ moderate test loads with application of an instant mobile gas analyzer Oxycon Mobile (Jaeger) and MetaMax 3B (Cortex) system. The individual heart rates versus loads were tested by Polar pulsometer (Finland-made). Objective of the study was to analyze benefits of the prognostic ratings of cardiac activity in modern football using the cardiac activity phase measurement tools. The study data showed correlation of the quiescent-state T-peak symmetry with the maximum oxygen consumption sagging rate. Based on the study data, we developed a values matrix to instantly rate the individual functionality and competitive fitness in football trainings.