Diagnosis of arterial hypotension

Anamnesis

When collecting anamnesis, data on hereditary burden of cardiovascular diseases is clarified, while it is necessary to clarify the age of manifestation of cardiovascular pathology in relatives. It is necessary to clarify the features of the course of pregnancy and childbirth in the mother in order to identify possible perinatal pathology, special attention should be paid to the level of blood pressure in the mother during pregnancy. It is important to remember that low blood pressure in the mother during pregnancy contributes to damage to the central nervous system and creates the prerequisites for the formation of arterial hypotension in the child.

It is necessary to determine the presence of psychotraumatic circumstances in the family and school that contribute to the development of arterial hypotension, disruptions to the daily routine (lack of sleep) and nutrition (irregular, inadequate nutrition). It is necessary to assess the level of physical activity (hypodynamia or, on the contrary, increased physical activity, for example, classes in sports sections, which can lead to sports overexertion syndrome).

Daily blood pressure monitoring

This study allows us to identify initial deviations in the daily rhythm and value of arterial pressure. The following features are taken into account: average values of arterial pressure (systolic, diastolic, average hemodynamic, pulse) per day, day and night; indices of hypo- and hypertension time in different periods of the day (day and night); variability of arterial pressure in the form of standard deviation, variation coefficient and daily index.

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

Hypotension time index. It allows to estimate the duration of the decrease in arterial pressure during the day. This indicator is calculated by the percentage of measurements that are below the 5th percentile of SBP or DBP for 24 hours or separately for each time of day (Table 90-4). The hypotension time index exceeding 25% for systolic or diastolic arterial pressure is definitely considered pathological. In case of non-stable arterial hypotension, the time index is within 25-50%, in case of stable form - exceeds 50%.

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

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

The daily hypotension index provides an idea of the circadian organization of the daily blood pressure profile. It is calculated as the difference between the average daytime and nighttime blood pressure values as a percentage of the daily average. In most healthy children (according to our data, 85% of cases), blood pressure at night is reduced by 10-20% compared to daytime values.

Groups of patients depending on the value of the daily arterial pressure index

• Normal decrease in blood pressure at night. The daily blood pressure index is within 10-20%. In English-language literature, such people are referred to as "dippers".
• No decrease in blood pressure at night. The daily blood pressure index is less than 10%, such people are classified as "non-dippers".
• Marked decrease in blood pressure at night. Daily blood pressure index is more than 20% (the "over-dippers" group).
• Increase in blood pressure at night. Daily blood pressure index is less than 0% (group of "night-peakers").

In children with arterial hypotension, the daily arterial pressure index often changes according to the “over-dippers” type.

Electrocardiography

In arterial hypotension, there are no specific changes in the electrocardiogram. However, the following changes are often detected: sinus bradycardia, pacemaker migration, first-degree AV block, and early repolarization syndrome. 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, a drug test with the anticholinergic drug atropine can be performed. A 0.1% solution of atropine is administered subcutaneously or intravenously at a rate of 0.02 mg/kg, but not more than 1 ml. The ECG is recorded at the time of administration, 5, 10, and 30 minutes after administration of the drug. In the case of vagal-dependent AV block, AV conduction is restored, and manifestations of pacemaker migration disappear.

Zhocardiography

The study allows confirming the functional nature of changes in the cardiovascular system in arterial hypotension and identifying changes in intracardiac hemodynamics of an adaptive-compensatory nature. Structural changes in the heart in arterial hypotension are not revealed. The left ventricular end-diastolic volume may increase at the level of 75-95th percintile, while the left ventricular end-systolic volume is within normal values, which reflects the increased ability of the myocardium to relax.

EchoCG allows for an objective assessment of cardiac hemodynamics based on cardiac and stroke output indicators.

Tilt test

Tilt test is a passive clino-orthostatic test. This study was proposed by Kenny in the 80s of the 20th century to identify pathological reactions of the autonomic nervous system to orthostatic stress. The test is considered the gold standard in the diagnosis of orthostatic disorders and other neurotransmitter syncopal states.

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

The test is carried out 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, using a special tilt table, the child is passively transferred to a vertical position to a standing angle of 60-70°. The table elevation should not be more than 70°, since an increase in the tilt angle reduces the specificity of the study, and a decrease in the tilt angle reduces its sensitivity. The duration of the vertical position is limited to 40 minutes for children over 12 years old and 30 minutes for children under 12 years old. The test is stopped after this time or if fainting or a pronounced pre-fainting condition occurs.

During the test, ECG is continuously recorded and arterial pressure is monitored. It is also advisable to constantly evaluate central hemodynamic parameters (stroke and minute volume of blood circulation, total peripheral vascular resistance using chest rheography according to Kubicek); to exclude epileptic activity at the time of fainting, an electroencephalogram is recorded throughout the study.

Variants of development of fainting conditions

• Mixed variant (VASIS 1). Severe arterial hypotension and bradycardia occur (heart rate up to 50 beats per minute lasting no more than 10 seconds).
• Cardioinhibitory variant (VASIS 2). Severe bradycardia (heart rate decrease to 40 beats per minute lasting at least 10 sec) or asystole (pause duration at least 3 sec) occurs, while arterial pressure remains constant.
• Vasodepressor variant (VASIS 3). With the development of a syncopal state, severe arterial hypotension develops with a slight (less than 10%) decrease or even increase in heart rate. This variant is typical for children with arterial hypotension.

Bicycle ergometry

Bicycle ergometry is a test with a dosed physical load that allows one to assess tolerance to physical load, as well as to evaluate concomitant hemodynamic changes (PWC170 method). In case of arterial hypotension, the power of the submaximal load performed (PWC170) and the total volume of work performed (A) are significantly reduced. A decrease in diastolic blood pressure below 30 mm Hg is regarded as a hypotensive reaction. A decrease in tolerance to physical load and inappropriate changes in blood circulation are most pronounced in case of stable arterial hypotension.

Rheoencephalography

The method allows to evaluate the state of vascular tone in arterial hypotension. Vascular changes in arterial hypotension do not have certain features, they can be considered as a result of changes in blood circulation conditions. Changes in vascular tone are different. Both a decrease in vascular tone (25%) and an increase (44%) are possible, in other cases the vascular tone will not change. Hypervolemia 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 the venous sinuses.

Electroencephalography

The study allows to evaluate the features of the restructuring of the bioelectrical activity of the cerebral cortex. In children with arterial hypotension, the electroencephalogram reveals an irregular a-rhythm, mainly medium- and low-amplitude, inconstant interhemispheric asymmetry in the amplitude of the a-rhythm, dysrhythmic changes in the bioelectrical activity of the brain (frequent rhythm changes in amplitude and frequency, insufficient modulation of the a-rhythm at rest). In children with severe 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 cortical neurons. The main manifestation of background electroencephalography is a mismatch between the increased activity of the stem, mesencephalic desynchronizing apparatuses of the thalamus and hypothalamus. Moreover, its degree depends on the severity of arterial hypotension.

Echoencephaloscopy

In 30% of children with arterial hypotension, dilation of the lateral ventricles and the third ventricle of the brain is detected, as well as an increase in echo pulsation by over 35%.

Craniography

Signs of intracranial hypertension syndrome include increased finger impressions on the cranial vault, increased vascular pattern, and varicose veins. The listed changes are detected in 1/3 of cases, mainly in severe arterial hypotension.

Fundus examination

When examined by an ophthalmologist, in 80% of cases changes are detected in the fundus in the form of dilation and plethora of the retinal veins, edema along the vessels. The listed symptoms reflect an increase in intracranial pressure.

Determination of the state of the autonomic nervous system

It includes an assessment of the initial vegetative tone using clinical tables (taking into account the number of sympathetic and parasympathetic signs), vegetative reactivity (according to cardiointervalography data in horizontal and vertical positions) and conducting vegetative tests.

The oculocardiac reflex (Aschner-Dagnini) is determined in a horizontal position after resting for 15 minutes. Careful pressure is applied to the eyeballs until a slight pain sensation appears. An ECG is recorded before the examination and 15 seconds after the start of pressure. Normally, the heart rate decreases by 10-15 per minute. In case of excessive vagotonia, massage of the eyeballs allows to detect pronounced bradycardia with a heart rate of up to 30 per minute, arterial hypotension, which clinically can manifest as dizziness, and in some cases, loss of consciousness.

Carotid sinus massage (cervical autonomic reflex of Chermak-Gering

The study reveals excessive vagotonic reactivity, as evidenced by pronounced bradycardia and arterial hypotension. The test is carried out in a horizontal position, massage is performed in the area of the upper third of the sternocleidomastoid muscle, slightly below the angle of the lower jaw. At the same time, continuous ECG monitoring is carried out. The norm is considered to be a slowdown in the pulse rate by 12-15 per minute, a decrease in blood pressure by 10 mm Hg, a slowdown in the respiratory rate. Pathological test results include a sudden and significant slowdown in heart rate without a decrease in blood pressure (vasocardial type); a marked decrease in blood pressure without a slowdown in the pulse (depressor type); dizziness or fainting (cerebral type).

Determination of vegetative support of the body's activity according to the data of the active clinoorthostatic test

With a normal response of the cardiovascular system to the clinoorthostatic test, the state of health does not change, there are no complaints, changes in heart rate and blood pressure are within normal values.

Changes in blood pressure and heart rate corresponding to the normal variant of the clinoorthostatic test

Indicators	Initial values	Changes during the clinoorthostatic test
Heart rate, in min	Below 75	Increase by 15-40%
	From 75 to 90	Increase by 10-30%
	Above 91	Increase by 5-20%
SBP, mmHg	Below 95	From -5 to +15 mm Hg.
	From 96 to 114	From -10 to +15 mm Hg.
	From 115 to 124	From -10 to +10 mm Hg.
	Above 125	From -15 to +5 mm Hg.
DBP, mmHg	Below 60	From -5 to +20 mm Hg.
	From 61 to 75	From +0 to +15 mm Hg.
	From 75 to 90	From +0 to +10 mm Hg.

Pathological types of heart rate and blood pressure reactions during the clinoorthostatic test.

• Hypersympathicotonic - excessive response of systolic and diastolic blood pressure and heart rate.
• Hyperdiastolic - excessive reaction of diastolic blood pressure, systolic blood pressure decreases, pulse blood pressure decreases, and heart rate increases in compensation.
• Tachycardic - excessive heart rate response, normal change in systolic and diastolic blood pressure.
• Asympathicotonic - insufficient response of blood pressure and heart rate.
• Sympathoasthenic - at the beginning of the test, the change in blood pressure and heart rate is within normal limits, but after 3-6 minutes there is a sharp decrease in blood pressure, compensatory tachycardia, dizziness, and possible development of a syncopal state.

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

Psychological testing

The unfinished sentences test provides an idea of the presence of conflicts in 14 sections of microsocial relationships that are significant for the child. At the same time, the relationships between the child and family members, classmates, teachers are assessed, and hidden, often unconscious fears, concerns, feelings of guilt, and uncertainty about the future are revealed.

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

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ], [ 8 ]