RU2687178C1 - Method of determining efficiency of functioning of the cardiovascular system of a person under load - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention refers to medicine, namely to clinical physiology and cardiology, and can be used to determine the human cardiovascular function under load. Body weight (BW) is measured. Heart rate (HR), systolic blood pressure (SBP), diastolic arterial pressure (DBP) are measured. A minute blood volume index (MBVI) is calculated to indicate the ratio of minute blood volume to volume of circulating blood. Measurements of HR, SBP and DBP are performed immediately after performing a uniform controlled physical activity, which is carried out for 1 minute, power (W) in the range of values from (2.5⋅BW) to (3⋅BW). Thereafter, a power value of 1 kg of body weight of the test subject and 1 volume of circulating blood (W):W=W/BW/MBVI, where W is power of performed load, W; BW is tested body weight, kg; MBVI is the index of minute blood volume, and by value Wmethod includes assessing the level of cardiovascular function efficiency: very high W>2.055, high 1.605<W≤2.055, above average 1.3317<W≤1.605, average 1.065<W≤1.3317, below average 0.8883<W≤1.065, low W≤0.8883.EFFECT: method provides objective assessment of efficiency of cardiovascular system functioning under load and simplification of estimation determination due to use of physiologically justified formulas during calculations.1 cl, 4 tbl, 3 ex

Description

The invention relates to medicine, namely to determine the effectiveness of the functioning of the cardiovascular system of a person according to blood pressure and pulse after the test exercise and can be used in clinical physiology, physical culture and sports, cardiology and other fields of medicine.

Nowadays, methods of researching human performance based on recording indicators of the cardiovascular system have become widespread after performing a physical exercise of 3-4 W per 1 kg of body weight per minute and duration of 3-5 minutes, which is uniform in time. As a load, use the step test, veloergometer, treadmill - treadmill.

A typical example is the PWC170 performance study method (Phisical Working Capacity). The essence of the PWC170 test is to determine the load power at which the heart rate (HR) reaches 170 beats per minute (Guide to practical exercises in normal physiology. / Edited by SM Budylina, VM Smirnova. - M: Publishing Center "Academy", 2005. - p. 288-292). This "reference" physiological point for comparison was chosen from the following considerations. During exercise, the minute blood volume (IOC) increases due to an increase in the systolic volume of the heart and heart rate. Systolic volume with hard work increases by 1.5-3 times (on average 2 times). The main increase in the IOC is due to an increase in heart rate. When light and moderately severe, the heart rate increases in parallel with the increase in oxygen consumption. But this happens while there is a linear relationship between the developed power and heart rate (i.e. up to 170 beats per minute; a further increase in heart rate is accompanied by a decrease in the volume of systolic surge).

During the test PWC170, the subject performs two loads of moderate intensity. Each load is performed for 3-5 minutes with a 3-minute interval of rest and without preliminary warm-up. Each load (climbing steps of different heights - from 20 to 50 cm) is performed with a certain frequency of climbing steps: 1st — with a frequency of 20 times per minute, 2nd — with a frequency of 30 times per minute.

Power loads (W) when climbing on steps is determined by the formula: W = МТ⋅Н⋅N⋅1,333, where W is the power of work, kgm / min (6 kgm / min = 1 W); MT is the test mass, kg; H - step height, m; N is the number of rises (climbing steps) per minute; 1,333 - the estimated coefficient (when descending from the step, the power of the work performed is 30% of the power during the ascent).

Physical performance is determined by the formula:

PWC170 = W1 + (W2-W1) ⋅ (170-HR1) / (HR2-HR1)

where W1 and W2 are the capacities of the 1st and 2nd loads; HR1 and HR2 - HR after the 1st and 2nd loads.

The “adequacy” of such an assessment of human performance and its relationship with the efficiency of the cardiovascular system is easy to show with a simple example.

If you take 2 test subjects with the same MT, who in the first and second samples made the same number of ascents (20 in the first and 30 in the second), then the Win W2 powers will be the same as the difference between them (W2-W1). In this case, the estimate of PWC170 will depend solely on HR1 and HR2 recorded after performing the tests, and, more precisely, on the ratio (170-HR1) / (HR2-HR1).

Suppose that, in the first test subject, HR1 = 90 beats / min, and HR2 = 145 beats / min; (170 - 90) / (145 - 90) = 80/55 = 1.45.

In the second test, HR1 = PO beats / min, and HR2 = 150 beats / min; (170-PO) / (150-PO) = 60/40 = 1.5.

The first subject has a lower heart rate both after the first and after the second load, i.e. these loads were performed with a lesser load on the part of the cardiovascular system according to this indicator. But since the second test subject has a smaller difference between (HR2-HR1), when approximated by PWC170, it will be rated as more efficient, which is not true. The first test subject was more trained, for which the first test was obviously a small load. For the second test person, the first test was a serious burden, which caused excessive mobilization of the cardiovascular system.

In fact, it is impossible to objectively characterize the performance only by the efficiency of the cardiovascular system under load. To do this, you need to use more and work performance with the load of the respiratory system and power indicators. But the efficiency of the cardiovascular system under load is, of course, one of the fundamental indicators of human health. The question is how to properly evaluate it. It is impossible to do, based only on the particular performance of cardiovascular work, such as heart rate, systolic blood pressure (MAP), diastolic blood pressure (DBP). An integral indicator of the cardiovascular system, which has a physiological meaning, and allows for the production of objective performance indicators when it is used, is necessary.

And there is such an indicator (Pat.RU 2535914, 2014). This is the index of the minute blood volume (IMC), derived from the basic hemodynamic equations and showing the relationship between the minute blood volume (IOC) and circulating blood volume (BCC): IMOC = IOC / BCC. Despite the fact that it characterizes the ratio of volume values, it can be calculated on the basis of the registration of particular indicators of the cardiovascular system, i.e. HR, SAD, DAP:

IMOK = (GARDEN + DAD) ⋅Tpi / DAD / (Tsts-Tpi),

where SAD is systolic blood pressure; DBP - diastolic blood pressure; Tsts - the period of the cardiac cycle, calculated by the formula Tsts = 60 / HR; TPI - the period of exile, calculated by the formula:

Tpi = 0,268⋅Tsts ^0,36 .

IMOC allows reducing the power value (W) first, to one kg (W / MT) for leveling the differences of subjects on MT, and then, to one BCC (W _{kg bcc} = W / MT / IMOC). This value (W _{kg bcc} ) shows how much power the load performed falls on one kg MT for the load period, when one BCC passed through the circulation.

With this approach, there is no need both in orientation to the “reference” point of the heart rate (170 beats / min), and in carrying out 2 samples with different load power. One sample with an estimated load of 2.5-3 W / kg per minute is sufficient. The duration of the load test performed can also be reduced to 1 minute. Uniform loading within 3-5 minutes with a power of 2-4 W / kg "in regular intervals" is carried out only by the trained people (athletes). Minute load is just that interval of time when even not trained people can carry out the load without changing the pace.

If the load is performed in the form of a step test, then in addition to HR, GARDEN, and DBP, which are measured immediately after the load is performed, the number of ascents and the height of the step must be recorded.

The power of the executed load (W, W) is determined by the formula: W = МТ⋅Н⋅N⋅1,333 / 6, МТ - body weight, kg; H - step height, m; N is the number of rises (climbing steps) per minute; 1,333 - the estimated coefficient (when descending from a step, the power of the work performed is 30% of the power during ascent); 1/6 - the conversion factor kgm / min to watts.

The power of the executed load, reduced to one kg of MT and to one BCC: W _{kg bcc} = W / MT / IMOC. According to the value of W _{kg ock} , the level of efficiency of functioning of the cardiovascular system is determined.

The purpose of the proposed method to objectively assess the efficiency of the functioning of the cardiovascular system under load, to simplify the method of its determination due to the use of physically and physiologically sound formulas in the calculations.

The invention is as follows.

In the subject at rest, the body mass (MT, kg) is measured. Then, the subject performs an exercise of 2.5–3 W / kg for one minute, after which the heart rate (HR), systolic blood pressure (MAP), and diastolic blood pressure (DBP) are immediately measured. Calculate the index of the minute blood volume (IMOC) using the formula:

IMOK = (GARDEN + DAD) ⋅Tpi / DAD / (Tsts-Tpi),

where Tsts is the period of the cardiac cycle,

Tsts = 60 / ChSS;

Tpi - the period of exile, calculated by the formula Tpi = 0,268⋅Tsts ^0,36 ; The power of the executed load (W, W) results in 1 kg of body weight and 1 volume of circulating blood (W _{kg bcc} ):

W _{kg OCC} = W / MT / IMOC,

and by the value of W _{kg bcc} assess the level of effectiveness

The implementation of the method is as follows.

For measurements of MT (weight, kg), heart rate, GARDEN, DBP, any certified apparatus can be used for their automatic, semi-automatic, manual measurement. In a test subject, MT is measured at rest, then the subject performs a physical exercise with a capacity of 2.5-3 W / kg for a minute, measured heart rate, GARDEN, DBP, calculated IMOC using the formula:

IMOK = (GARDEN + DAD) ⋅Tpi / DAD / (Tsts-Tpi),

where Tsts is the period of the cardiac cycle, Tsts = 60 / HR; Tpi - the period of exile, calculated by the formula Tpi = 0,268⋅Tsc ^0.36

The power of the performed load (W, W) results in 1 kg of body weight and 1 volume of circulating blood (W _{kg bcc} ): W _{kg bcc} = W / MT / IMOC, and the value of W _{kg bcc} evaluates the level of efficiency:

The implementation of the method is illustrated by the following examples.

Example 1. A test subject with MT = 66 kg completed 30 ascensions per step with a height of 40 cm (0.4 m), HR = 150 beats / min; SAD = 160 mmHg; DBP = 100 mm Hg

Power performed load:

W = MT⋅N⋅N⋅1,333 = 66⋅0,4⋅30 1,333 = 1055,736 kgm / min

or 1055,736 / 6 = 175.956 W / min

TSC = 60 / HR = 60/150 = 0.4 s;

Tpi = 0,268⋅Tsts ^0,36 = 0,268⋅0,4 ^0,36 = 0,193

IMOK = (GARDEN + DAD) ⋅Tpi / DAD / (Tsts-Tpi) =

= (160 + 100) ⋅ 0.193 / 100 / (0.4-0.193) =

= 260⋅0,193 / 100 / 0,207 = 2,424

Power reduced to 1 kg Mt and 1 BCC:

W _{kg otsk} = W / MT / IMOK = 175,956 / 66 / 2,424 = 1,0998

This is the average level of efficiency of functioning of the cardiovascular system (1.065 <W _{kg bcc} ≤ 1.3317).

Example 2. A test subject with MT = 66 kg completed a 30 minute ascent per step with a height of 40 cm (0.4 m), HR = 84 beats / min; SAD = 149 mm Hg; DBP = 95 mmHg

Power performed load:

W = MT⋅N⋅N⋅1,333 = 66⋅0,4⋅30⋅1,333 = 1055,736 kgm / min

or 1055,736 / 6 = 175.956 W / min

TSC = 60 / HR = 60/84 = 0.714 s;

Tpi = 0,268⋅Tsts ^0,36 = 0,268⋅0,714 ^0,36 = 0,237

IMOK = (GARDEN + DAD) ⋅Tpi / DAD / (Tsts-Tpi) =

= (149 + 95) ⋅ 0.237 / 95 / (0.714-0.237) =

= 244⋅0.237 / 95 / 0.477 = 1.276

Power reduced to 1 kg Mt and 1 BCC:

W _{kg otsk} = W / MT / IMOK = 175,956 / 66 / 1,276 = 2,089

This is a very high level of efficiency of the functioning of the cardiovascular system (W _{kg bcc} > 2.055).

Example 3. A test subject with MT = 60 kg completed 60 revolutions of the pedals of a bicycle ergometer in 1 minute, while the pedal resistance control was set to receive a load power of 180 W (3⋅60); after loading HR = 90 beats / min; SAD = 140 mmHg; DBP = 85 mm Hg

TSC = 60 / HR = 60/90 = 0.6667 s;

Tpi = 0,268⋅Tsts ^0,36 = 0,268⋅0,667 ^0,36 = 0,2316

IMOK = (GARDEN + DAD) ⋅Tpi / DAD / (Tsts-Tpi) =

= (140 + 85) ⋅ 0.2316 / 85 / (0.6667-0.2316) =

= 225⋅0.2316 / 85 / 0.4351 = 1.409

Power reduced to 1 kg Mt and 1 BCC:

W _{kg otsk} = W / MT / IMOK = 180/60 / 1,409 = 2,129

This is a very high level of efficiency of the functioning of the cardiovascular system (W _{kg bcc} > 2.055).

Thus, the method is quite simple in execution, it allows you to objectively evaluate the efficiency of the cardiovascular system under load, due to the use of physiologically sound formulas in the calculations.

Claims (7)

The method of determining the effectiveness of the functioning of the cardiovascular system of a person under load, including the measurement of body mass (MT), measurement of heart rate (HR), systolic blood pressure (MAP), diastolic blood pressure (DBP), calculation of the index of minute blood volume (IMOC) showing the ratio of the minute volume of blood to the volume of circulating blood, characterized in that the measurement of heart rate, SBP and DBP are performed immediately after performing a uniform controlled physical activity, which It is conducted for 1 minute, with a power (W, W) in the range of values from (2.5⋅MT) to (3⋅MT), after which the power is reduced to 1 kg of the body weight of the test and 1 volume of circulating blood (W _{kg⋅ ock} ): W _kg⋅ock = W / MT / IMOC, where W is the power of the executed load, W; MT - the body weight of the test, kg; Imok - index of minute blood volume, and the value of the cardiovascular system's efficiency is assessed by the value of W _kg⋅ock : very tall W _kg > 2.055 tall 1.605 <W _kg ≤ 2.055 above the average 1.3317 <W _kg 1.605 average 1.065 <W _kg⋅ock ≤ 1.3317 below the average 0.8883 <W _kg ≤1.065 low W _kg ⋅ 0,8883