RU2341185C1 - Method of evaluation of night depression of systolic arterial pressure at senior age groups at patients with isolated systolic arterial hypertonia - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: define factors F₁ and F₂ under original formulas on change of the cardiac rate from initial in percentage and to change of relations of diastolic arterial pressure to the cardiac rate and as taking into account a waist circle. At F₁ value equal or larger to F₂ value - night depression of systolic arterial pressure is estimated as insufficient, and at F₁ value less than F₂ value - sufficient depression of night systolic arterial pressure.

EFFECT: it is simple in execution, does not demand appreciable time and material inputs, allows performing screening inspections.

2 ex, 1 tbl

Description

The present invention relates to medicine, namely to therapy, cardiology and functional diagnostics, and can be used to assess violations of the circadian rhythm of blood pressure.

Insufficient nocturnal decrease in blood pressure (BP) and nocturnal hypertension are known to be associated with an increased risk of death regardless of the level of average daily blood pressure (Ohkubo T. Relation between nocturnal decline in blood pressure and mortality. The Ohasama study / T. Ohhubo, Y.Imai, I. Tsuji et al. // Amer. J. Hypertens. - 1997. - V.10. - P.1201-1207).

A relationship was also found between an insufficient decrease in blood pressure at night and the frequency and severity of damage to target organs, while it was found that it is the absence of a nightly decrease in blood pressure that causes damage to target organs, and not vice versa (Fratolla A. Prognostic value of 24-hour pressure variability / A. Fratolla, G. Parati, C. Cuspidi et al. // Hypertension. - 1993. - V.11. - P.1133-1137).

A known method for determining insufficient nighttime decrease in blood pressure by analyzing data of intra-arterial daily monitoring of blood pressure (Bevan AT Portable recorder for continuous arterial pressure measurement in man / ATBevan, AJHonour, FHStott // J. Physiol. - 1966. - V.38. - P.186-188).

To estimate the amplitude of fluctuations in the daily rhythm, we used the daily index (SI) indicator, which was determined by taking into account the average blood pressure during night sleep (AD) and during wakefulness (AD). The calculation of SI was carried out according to the formula:

The value of SI determine:

1) a normal decrease in blood pressure at night - SI more than 10%, but less than 20%;

2) insufficient nighttime decrease in blood pressure - SI greater than 0, but less than 10%;

3) nighttime hypertension - SI less than 0;

4) an excessive decrease in blood pressure at night - SI more than 20%, but less than 22%.

Criteria for an insufficient decrease in blood pressure during the night period are SI values from “below zero” to 10%.

The disadvantages of this method include its invasiveness, the risk of complications (infection, bleeding, damage to the median nerve), expensive supplies. This method is extremely rarely used in domestic clinical practice.

The closest in technical essence and accepted by us as a prototype is a method for assessing insufficient nightly decrease in systolic blood pressure, including the determination of blood pressure indicators in dynamics (Kobalava Zh.D. Blood pressure in research and clinical practice / Zh.D. Kobalava, Yu.V. Kotovskaya , V.N. Khirmanov. - M .: Reafarm, 2004, p.130-139). In the implementation of the known method, the tonometer cuff connected to the automatic recorder is applied 2-3 cm above the elbow.

The obtained indices of the daily profile of blood pressure are used, as in a similar method, to determine the SI by the above formula. Criteria for an insufficient decrease in blood pressure during the night period are SI values also from “below zero” to 10%.

The disadvantages of this method include the duration of the study, which is at least 21 hours, while validation requires at least 16 measurements of blood pressure during wakefulness and 8 measurements of blood pressure during sleep (IV Guideline for ambulatory blood pressure monitoring. II Guideline for home blood pressure monitoring. IV ABPM / II HBPM // Arq. Bras. Cardiol. - 2005 Jul. - 85. - Suppl. 2. - P.1-18).

The negative aspects of the known method include significant discomfort during compression by the cuff, which results in disturbance of night sleep, especially in the elderly and senile. This reduces compliance and increases the number of rejections from the study.

The disadvantages of this method should also include multi-stage research, the use of expensive equipment, computer equipment and the participation of highly qualified specialists.

In addition, the equipment of daily blood pressure monitors in primary care facilities remains low, despite the high prevalence of hypertension and widespread indications for the study.

The objective of the invention is to develop a method for evaluating the nightly decrease in systolic blood pressure in patients with isolated systolic arterial hypertension (ISAG) of older age groups, based on generally available research methods.

The technical result of the proposed method is to simplify the method and reduce the time for determining SI.

The technical result is achieved by the fact that the method of evaluating the nightly decrease in systolic blood pressure in patients with isolated systolic hypertension of older age groups is carried out by registering blood pressure indicators in dynamics.

The difference of the proposed method lies in the fact that they measure diastolic blood pressure and heart rate (HR) during an orthostatic test.

A distinctive technique of the proposed method is also the fact that the results of the orthostatic test establish changes in heart rate from the initial percentage, as well as a change in the ratio of diastolic blood pressure to heart rate.

The authors of the proposed method found that one of the evaluation criteria is the waist circumference, measured in centimeters.

The difference between the method is that the coefficients F ₁ and F _{2 are} determined by the formulas:

F ₁ = -54.51 + 0.15 × A ₁ + 20.69 × A ₂ + 1.06 × A ₃

F ₂ = -47.54 + 0.06 × A ₁ + 15.65 × A ₂ + 1.002 × A ₃ ,

where A ₁ - change in heart rate (in percent) when conducting an orthostatic test;

And ₂ - a change in the ratio of diastolic blood pressure to heart rate during an orthostatic test;

And ₃ - waist circumference, see

The authors found that when the value of F ₁ is equal to or greater _{than the} value of F ₂ , the nightly decrease in systolic blood pressure is estimated as insufficient, and when the value of F _{1 is} less than the value of F ₂ , a sufficient decrease in nightly systolic blood pressure.

Comparative analysis with the prototype showed that the proposed method differs from the known and therefore meets the criteria of the invention of "novelty."

From the analysis of patent and specialized literature, the authors found that the proposed method has features that distinguish it not only from the prototype, but also other technical solutions in this field and related fields of medicine.

The proposed method allows, using simple and generally accessible clinical data, to conduct screening examinations of circadian rhythm disturbances in older age groups suffering from ISAH.

Measurement of the waist circumference, registration of changes in heart rate and the ratio of diastolic blood pressure to heart rate during an orthostatic test, followed by determination of the values of the coefficients F ₁ and F ₂ made it possible to assess with an accuracy of 83.6% violations of the nightly decrease in systolic blood pressure.

The coefficients of the discriminant function (K ₁ j, K ₂ j) were established experimentally (table. No. 1).

Table number 1 Variables K ₁ j K ₂ j Δ HR% (A ₁ ) 0.15 0.06 ΔIK (A ₂ ) 20.69 15.65 Waist circumference (cm) (A ₃ ) 1.06 1.002

The authors of the proposed method established the values of the constants for F ₁ = -54.51 and F ₂ = -47.54.

Reducing the evaluation time and simplifying the proposed method is that the measurement of blood pressure and heart rate during an orthostatic test is carried out twice: in a prone position after 5 minutes and in a standing position after 2 minutes.

Thus, the proposed method meets the criterion of "inventive step".

A method for evaluating the nightly decrease in systolic blood pressure in patients with isolated systolic arterial hypertension of older age groups, which makes up the claimed invention, is intended for use in medical practice. The implementation of its capabilities is confirmed by the methods and means described in the application. From the above it follows that the claimed invention meets the condition of patentability "industrial applicability".

The proposed method is as follows.

A specific subject measures the waist circumference in centimeters. Then, against the background of the orthostatic test, blood pressure and heart rate are measured in the supine position with repeated measurement of these indicators in the standing position (orthostasis) after 2 minutes (Aronov D.M. Functional tests in cardiology / D.M. Aronov, V.P. Lupanov / / Functional tests based on a directed change in the venous return of blood to the heart. - M .: MED-press-Inform, 2002. - P.185-186). Then determine the change in heart rate in% of the initial (Δ HR%) and the change in the ratio of diastolic blood pressure (DBP) to heart rate in arbitrary units (ΔIK).

The determination of heart rate changes (in percent) is carried out according to the formula:

where heart rate ₁ is measured initially in the supine position;

Heart rate ₂ - in orthostasis after 2 minutes.

The definition of changes in the relationship of DBP to heart rate in arbitrary units (ΔIK) is carried out according to the formula:

Where

DBP ₁ and heart rate ₁ - initially in the supine position;

DBP ₂ and heart rate ₂ - in orthostasis after 2 minutes.

Using the obtained values, determine the values of F ₁ and F ₂ according to the formulas:

F ₁ = -54.51 + 0.15 × A ₁ + 20.69 × A ₂ + 1.06 × A ₃

F ₂ = -47.54 + 0.06 × A ₁ + 15.65 × A ₂ + 1.002 × A ₃ .

If the value of F _{1 is} greater than or equal to F ₂ , then the subject has a violation of the nightly decrease in systolic blood pressure, if F _{2 is} greater than F ₁ , then the nightly decrease in SBP is sufficient.

The proposed method for evaluating the nightly decrease in systolic blood pressure in patients with isolated systolic hypertension in older age groups is illustrated by examples of specific performance.

Example 1

Patient U., born in 1927 Waist circumference is 85 cm. When conducting an orthostatic test, it is established:

1. Initially in a prone position: HELL = 145/80 mm RT. Art., heart rate = 57 bpm.

The ratio of diastolic blood pressure to heart rate in arbitrary units (IR) = 1.40.

2. In orthostasis after 2 minutes: HELL = 152/85 mm RT. Art., heart rate = 74 bpm. IR = 1.15.

We determine the values of the variables:

ΔIK = 1.40-1.15 = 0.25.

Given that ΔCHSS% = A ₁ , ΔIK = A ₂ , waist circumference 85 cm = A ₃ , we determine the values of F ₁ and F ₂ according to the formulas:

F ₁ = -54.51 + 0.15 × 29.8 + 20.69 × 0.25 + 1.06 × 85 = 45.1

F ₂ = -47.54 + 0.06 × 29.8 + 15.65 × 0.25 + 1.002 × 85 = 43.5.

Therefore, F _{1 is} greater than F ₂ . The patient was found to have an insufficient nightly decrease in systolic blood pressure.

To prove the obtained assessment, daily monitoring of blood pressure was carried out according to the prototype method. According to its results, SI for systolic blood pressure was -7.6. Thus, the results of the estimates coincided.

Example 2

Patient F., born in 1930 Waist circumference is 94 cm. When carrying out an orthostatic test:

1. Initially in the supine position HELL = 140/60 mm RT. Art., heart rate = 65 bpm. The ratio of diastolic blood pressure to heart rate in arbitrary units (IR) = 0.92.

2. In orthostasis after 2 minutes: HELL = 139/60 mm RT. Art., heart rate = 70 bpm. IR = 0.86.

ΔIK = 0.92-0.86 = 0.06 = A ₂ ;

F ₁ = -54.51 + 0.15 × A ₁ + 20.69 × A ₂ + 1.06 × A ₃ = 47.5

F ₂ = -47.54 + 0.06 × A ₁ + 15.65 × A ₂ + 1.002 × A ₃ = 48.2.

Therefore, F _{1 is} less than F ₂ . The patient has a sufficient nightly decrease in systolic blood pressure. Conducted SMAD. According to its results, SI for systolic blood pressure was 17.7. The results are consistent.

Evaluation of the effectiveness of the proposed method was carried out in the experimental group in 70 patients over the age of 75 years with ISAH. The accuracy of the proposed method was 83.6%.

Thus, the proposed method is simple to implement, does not require significant time and material costs. The inventive method makes it possible to evaluate the nightly decrease in systolic blood pressure in patients with ISAH in the older age group, using low-cost and generally available methods. This will allow for screening with subsequent correction of antihypertensive therapy and thereby reduce the risk of complications of arterial hypertension.

Claims (1)

A method for evaluating a night-time decrease in systolic blood pressure in patients with isolated systolic arterial hypertension of older age groups, including registering blood pressure indicators in dynamics, characterized in that diastolic blood pressure and heart rate (HR) are measured during an orthostatic test, the results of which establish changes Heart rate from the initial percentage and change in the ratio of diastolic blood pressure to heart rate, and also measure about waist of circles, and then determine the coefficients of F ₁ and F ₂ by the formulas: F ₁ = -54.51 + 0.15 · A ₁ + 20.69 · A ₂ + 1.06 · A ₃ F ₂ = -47.54 + 0.06 · A ₁ + 15.65 · A ₂ + 1.002 · A ₃ where A ₁ - change in heart rate (in percent) when conducting an orthostatic test; And ₂ - a change in the ratio of diastolic blood pressure to heart rate during an orthostatic test; And ₃ - waist circumference, cm, and when the value of F ₁ equal to or greater _{than the} value of F ₂ , the nightly decrease in systolic blood pressure is estimated as insufficient, and if the value of F ₁ less _{than the} value of F ₂ is a sufficient decrease in night systolic blood pressure.