Diagnosis of arterial hypotension

Anamnesis

When collecting an anamnesis, the data on hereditary complications for cardiovascular diseases are refined, and the age of manifestation of cardiovascular pathology in relatives should be specified. It is necessary to find out the peculiarities of pregnancy and labor in the mother with the purpose of revealing possible perinatal pathology, special attention should be paid to the level of arterial pressure in the mother during pregnancy. It is important to remember that low blood pressure in the mother during pregnancy contributes to the defeat of the central nervous system and creates the prerequisites for the formation of arterial hypotension in the child.

It is necessary to find out the presence of psychotraumatic circumstances in the family and school that contribute to the occurrence of arterial hypotension, disturbances in the day regimen (lack of sleep) and nutrition (irregular, inadequate nutrition). It is necessary to assess the level of physical activity (physical inactivity or, on the contrary, increased physical activity, for example, employment in sports sections, which can lead to a syndrome of sports overexertion).

Daily ionization of blood pressure

This study allows you to identify the initial deviations in the daily rhythm and the magnitude of blood pressure. In this case, the following signs are taken into account: mean values of arterial pressure (systolic, diastolic, mean hemodynamic, pulse) per day, day and night; indices of the time of hypo- and hypertension in different periods of the day (day and night); variability of blood pressure in the form of standard deviation, coefficient of variation and daily index.

The basis for assessing the level of blood pressure in a patient is the average values of blood pressure (systolic, diastolic, mean hemodynamic, pulse).

The time index of hypotension. It allows you to estimate the duration of the decrease in blood pressure during the day. This indicator is calculated from the percentage of measurements that are below the 5th percentile of the SBP or DBP for 24 hours or separately for each time of day (Table 90-4). The time index of hypotension exceeding 25% for systolic or diastolic blood pressure is unequivocally treated as pathological. With the unstable form of arterial hypotension, the time index is in the range of 25-50%, with a stable form - more than 50%.

Parameters of the 5th percentile of arterial pressure according to the data of daily monitoring in children aged 13-15

Day (time)	Girls		Boys
	SBP, mmHg	DBP, mmHg	SBP, mmHg	DBP, mmHg
	87	45	94	49
Day (8-22 hours)	96	53	98	55
Night (23-7 hours)	79	47	86	48

The daily hypotension index gives an idea of the circadian organization of the daily profile of blood pressure. It is calculated as the difference between the mean daily and night values of blood pressure in percent of the daily average. In the majority of healthy children (according to our data, 85% of cases), arterial pressure at night is reduced by 10-20% compared to daytime indices.

Groups of patients, depending on the value of the daily index of blood pressure

• Normal decrease in blood pressure at night. The daily index of blood pressure is in the range of 10-20%. In the English-language literature, such persons are referred to the group "dippers".
• No decrease in blood pressure at night. The daily index of blood pressure is less than 10%, such persons are referred to the group " non dippers".
• A marked decrease in blood pressure at night. Circadian blood pressure index - 20% (group « over- dippers»).
• A rise in blood pressure at night. Circadian blood pressure index less than 0% (group « night- peakers»).

Children with arterial hypotension diurnal blood pressure index often varies according to the type « over- dippers».

Electrocardiography

With arterial hypotension, there are no specific changes in the electrocardiogram. However, the following changes are often found: sinus bradycardia, migration of the pacemaker, AV blockade of the 1st degree, syndrome of early repolarization. These changes reflect the excessive influence of the parasympathetic nervous system on the cardiovascular system. For differential diagnosis of the neurogenic genesis of these changes, it is possible to perform a drug test with anticholinergic atropine. 0.1% solution of atropine is administered subcutaneously or intravenously from the calculation of 0.02 mg / kg, but not more than 1 ml. The ECG is recorded at the time of injection, at 5, 10 and 30 minutes after the administration of the drug. When the AV-blockade is VAG-dependent, the AV-conduction is restored, the manifestations of the migration of the pacemaker disappear.

Cardiogram

The study allows us to confirm the functional nature of changes in the cardiovascular system with arterial hypotension and to identify changes in intracardiac hemodynamics of adaptive-compensatory nature. Structural changes in the heart with arterial hypotension do not reveal. The end diastolic volume of the left ventricle can be increased at the level of 75-95th percintile, and the final systolic volume of the left ventricle is within the normal range, which reflects the increased ability of the myocardium to relax.

Echocardiography allows you to objectively assess cardiac hemodynamics in terms of cardiac and percutaneous ejection.

Tilt test

Tilt test - passive clinorostatic test. This study was proposed by Kenny in the 80s of the XX century. To identify pathological reactions of the autonomic nervous system to orthostatic stress. The sample is considered a gold standard in the diagnosis of orthostatic disorders and other neurotransmitter syncopal conditions.

Tilt test is to change the position of the patient's body from horizontal to vertical. Under the influence of gravitational forces, blood is deposited in the lower part of the body, the pressure of filling the right parts of the heart decreases, which causes a whole group of pathological reflexes. During the test, ECG, blood pressure and electroencephalogram are constantly recorded. It is the ECG record that allows us to identify the symptomatic bradycardia and to decide the need for an implantation of the pacemaker.

The sample is spent in the morning hours on an empty stomach in a quiet, moderately lit room. The adaptation period in the lying position lasts 10-15 minutes. Then, with the help of a special tilt table, the child is passively transferred to a vertical position up to a standing angle of 60-70 °. The rise of the table should not be more than 70 °, as with increasing the angle of inclination the specificity of the research decreases, with a decrease in the angle of inclination its sensitivity decreases. The duration of the vertical position is limited to 40 minutes in children over 12 years and 30 minutes in children under 12 years old. The sample is discontinued after this time or when an unconscious or pronounced pre-occlusive condition occurs.

During the run, the samples are continuously recorded ECG, blood pressure monitoring. It is also advisable to constantly assess the indices of central hemodynamics (stroke and minute volume of circulation, total peripheral vascular resistance with chest rheography according to Kubicek), to eliminate the epileptic activity at the time of syncope during the entire study, an electroencephalogram is recorded.

Variants of development of syncope

• Mixed variant (VASIS 1). Arterial hypotension and bradycardia arises (heart rate to 50 per minute for a duration of no more than 10 s).
• Cardioinhibitory variant (VASIS 2). There is a pronounced bradycardia (a decrease in the heart rate to 40 per minute for a duration of at least 10 s) or asystole (a pause of at least 3 s), while the arterial pressure remains constant.
• Vasodepressor version (VASIS 3). When the syncope develops, severe arterial hypotension develops with a slight (less than 10%) decrease or even an increase in heart rate. This option is typical for children with arterial hypotension.

Bicycle ergometry

Bicycle ergometry - a test with a dosed physical load - allows you to assess exercise tolerance, as well as assess the associated hemodynamic changes (PWC170 technique). With arterial hypotension, the power of the submaximal exercise load (PWC170) and the total volume of work performed (A) are significantly decreased. Decrease in diastolic blood pressure below 30 mm Hg. Is regarded as an antihypertensive reaction. Decrease in tolerance to exercise and inappropriate changes in blood circulation are most pronounced with stable arterial hypotension.

Rheoencephalography

The method allows to assess the state of vascular tone in arterial hypotension. In vascular changes with arterial hypotension there are no specific features, they can be considered as a result of changes in circulatory conditions. Changes in vascular tone are different. Perhaps both a reduction in vascular tone (25%), and its increase (44%), in other cases, the tone of the vessels will not change. Hypervolaemia is detected in 75% of cases, hypovolemia - only in 9%. Increased vascular tone is a manifestation of autoregulation of cerebral circulation. As a rule, an increase in arteriolar vascular tone is combined with a violation of venous tone. An increase in venous tone, and especially its decrease lead to difficulty in venous outflow from the cranial cavity, which causes excitation of the baroreceptors of venous sinuses.

Electroencephalography

The study makes it possible to evaluate the features of the reconstruction of the bioelectrical activity of the cerebral cortex. In children with arterial hypotension, an irregular a-rhythm is detected on the electroencephalogram, mainly medium- and low-amplitude, interhemispheric asymmetry in amplitude of a-rhythm, dysrhythmic changes in brain bioelectric activity (frequent changes in amplitude and frequency, inadequate modulation of a rhythm at rest ). In children with severe course of arterial hypotension, more pronounced changes in the bioelectrical activity of the brain are revealed, indicating a decrease in its functional state with increased excitability of the cortical neurons. The main manifestation of background electroencephalography is a mismatch between increased activity of stem, mezencephalic desynchronizing devices of thalamus and hypothalamus. And its degree depends on the severity of the course of arterial hypotension.

Echoencephaloscopy

In 30% of children with arterial hypotension, the expansion of the lateral ventricles and the third ventricle of the brain is revealed, as well as an increase in echo pulsation in excess of 35%.

Craniography

Signs of intracranial hypertension syndrome include increased finger impressions along the cranial vault, an increase in the severity of the vascular pattern, and enlargement of the veins. The listed changes reveal in 1/3 of cases. Mainly in severe arterial hypotension.

Investigation of the fundus

When examined by an oculist, 80% of the cases reveal changes on the fundus in the form of enlargement and fullness of retinal veins, swelling along the vessels. These symptoms reflect an increase in intracranial pressure.

Determination of the state of the autonomic nervous system

It includes an evaluation of the initial vegetative tone according to the clinical tables (taking into account the number of sympathetic and parasympathetic signs), vegetative reactivity (according to cardiointervalographic data in the horizontal and vertical position) and carrying out vegetative tests.

Eye-cardiac reflex (Asnera Danyini) is determined in a horizontal position after resting for 15 minutes. Exercise cautious pressure on the eyeballs until there is a slight pain. Prior to the examination, and 15 seconds after the beginning of the pressure, an ECG is recorded. Normally, the heart rate decreases by 10-15 per minute. With excessive vagotonia, massage of the eyeballs reveals a pronounced bradycardia with a heart rate of up to 30 per minute, arterial hypotension, which can clinically appear dizziness, and in some cases, loss of consciousness.

Massage of the carotid sinus (cervical vegetative reflex of Tchermak-Goering

The study allows revealing excessive vagotonic reactivity, as evidenced by pronounced bradycardia and arterial hypotension. The sample is held in a horizontal position, massage is performed in the upper third of the sternocleidomastoid muscle, somewhat below the angle of the lower jaw. Continuous ECG monitoring is performed. For the norm take a slowing heart rate at 12-15 per minute, lowering blood pressure by 10 mmHg, slowing the respiration rate. The pathological results of the test include a sudden and significant slowdown in heart rate without lowering blood pressure (vaso-cardial type); marked decrease in blood pressure without slowing the pulse (depressor type); dizziness or faintness (cerebral type).

Determination of the vegetative maintenance of the organism's activity according to the active clinoortostatic test

With normal reaction of the cardiovascular system to the clinoortostatic test, the state of health does not change, there are no complaints, changes in heart rate and arterial pressure are within the normal range.

Change in blood pressure and heart rate, corresponding to the normal version of the clinoortostatic test

Indicators	Initial values	Change when performing a clinoortostatic test
Heart rate, in minutes	Below is 75	Increase by 15-40%
	75 to 90	Increase by 10-30%
	Above 91	Increase by 5-20%
SBP, mmHg	Below 95	From -5 to +15 mmHg.
	96 to 114	From -10 to +15 mmHg.
	115 to 124	From -10 to +10 mmHg.
	Above 125	From -15 to +5 mmHg.
DBP, mmHg	Below 60	From -5 to +20 mm Hg.
	61 to 75	From +0 to +15 mmHg.
	75 to 90	From +0 to +10 mmHg.

Pathological types of reaction of heart rate and blood pressure during clinoortostatic test.

• Hypersympaticotonic - excessive reaction of systolic and diastolic blood pressure and heart rate.
• Hyper-diastolic - excessive reaction of diastolic blood pressure, systolic blood pressure decreases, pulsatile arterial pressure decreases, compensatory increases heart rate.
• Tachycardic - excessive reaction of heart rate, usual change of systolic and diastolic arterial pressure.
• Asympaticotonic - insufficient reaction of arterial pressure and heart rate.
• Sympathoasthenic - at the beginning of the test, the change in blood pressure and heart rate is within the normal range, however, a sharp decrease in arterial pressure occurs during the 3-6th minute, compensatory tachycardia, dizziness, and possibly the development of a syncopal condition.

In children with arterial hypotension, the most characteristic types of reactions are sympathetic-asthenic, which reflects orthostatic hypotension, or asympathicotonic.

Psychological testing

The test of unfinished sentences gives an idea of the existence of conflicts over 14 sections of microsocial relations, significant for the child. At the same time, the relations between the child and family members, fellow practitioners, teachers are evaluated, and hidden, often unconscious fears, fears, feelings of guilt, uncertainty in the future are revealed.

The Spielberger test allows you to assess the level of reactive and personal anxiety.

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