Diagnosis of arterial hypertension

When collecting anamnesis, it is necessary to obtain information about the life history and disease, as well as about the hereditary burden of cardiovascular diseases in the family, while it is necessary to clarify the age of manifestation of cardiovascular pathology in relatives. The course of pregnancy and childbirth is analyzed to identify possible perinatal pathology.

It is necessary to find out about any conflict situations in the family and school, sleep and rest disorders (lack of sleep), obtain information about the nature of eating habits, paying special attention to irregular, unbalanced nutrition, excessive salt intake (tendency to add salt to already cooked food). The presence of bad habits is specified: alcohol consumption, smoking, taking certain medications (amphetamine, pressor drugs, steroids, tricyclic antidepressants, oral contraceptives), drugs and other stimulants, including those of plant origin (food additives). It is necessary to assess physical activity: hypodynamia or, on the contrary, an increased level of physical activity (sports classes, which can lead to sports overexertion syndrome).

The child's complaints (headache, vomiting, sleep disturbances), blood pressure level and duration of arterial hypertension are clarified, and previously administered antihypertensive therapy is clarified.

A thorough examination of the patient is performed. Attention is paid to the condition of the skin. Changes in the skin may be manifestations of one of the diseases causing symptomatic arterial hypertension. Café-au-lait spots are often observed with pheochromocytoma. Livedo reticularis is a characteristic symptom of periarteritis nodosa. The presence of striae is characteristic of hypercortisolism. Neurofibromatous nodes indicate the possibility of Recklinghausen's disease. Increased skin moisture is characteristic of thyrotoxicosis or vegetative-vascular dystonia syndrome.

During examination, swelling of the jugular veins is assessed as a criterion for venous hypertension. Auscultation of noise over the carotid artery should be assessed as a possible symptom of aortoarteritis, an enlarged thyroid gland may indicate hypo- or hyperthyroidism.

Auscultation includes both the cardiac region and the abdominal cavity to detect renal vascular stenosis. It is necessary to determine the pulsation in the peripheral arteries to detect asymmetry and/or decreased pulsation, which allows one to suspect coarctation of the aorta or aortoarteritis. When examining the abdomen, space-occupying lesions (Wilms tumor, abdominal aortic aneurysm, polycystic kidney disease) are excluded. Auscultation of noise over the aorta or renal arteries may reflect the presence of coarctation of the aorta, renal artery stenosis.

Assessment of sexual development is carried out using the Tanner scale.

ECG is a mandatory diagnostic method. It evaluates signs of atrial overload and the condition of the terminal part of the ventricular complex to detect increased sensitivity of beta-adrenergic receptors to catecholamines. A decrease in the ST segment and smoothing of the T wave are indications for a drug test with obzidan at a rate of 0.5 mg/kg.

Echocardiography is a mandatory diagnostic method that allows us to identify:

• signs of left ventricular hypertrophy (the thickness of the interventricular septum and the posterior wall of the left ventricle is more than the 95th percentile of the distribution of this indicator);
• increase in the mass of the left ventricular myocardium (over 110 g/m2 ⁾;
• impaired diastolic function of the left ventricle, decreased relaxation of the left ventricle (decrease in the early peak of diastolic filling E/A <1.0 according to transmitral Doppler flow data), which serves as a criterion for stable forms of arterial hypertension and reflects the presence of diastolic dysfunction of the hypertrophic type.

Cardiac hemodynamics are assessed based on cardiac and stroke output indicators; total peripheral vascular resistance is calculated indirectly using the Frank-Poiseuille formula:

OPSS = BP _avg x 1333 x 60 + MO,

Where BP is the mean hemodynamic arterial pressure (BP = 1/3 pulse BP + DBP); MO is the minute volume of blood circulation (MO = stroke volume x HR).

Depending on the indicators of minute volume and total peripheral vascular resistance, three types of hemodynamics are distinguished: eukinetic, hyperkinetic and hypokinetic.

Characteristics of hemodynamic types in healthy children

Type of hemodynamics	Central hemodynamic parameters
	Cardiac index, l/ m2	Total peripheral vascular resistance, dynes/cm/sec*
		Normal	Increased	Reduced
Eukinetic	3.1-4.6	1057-1357	>1375	<1057
Hyperkinetic	>4.6	702-946	>946	<702
Hypokinetic	<3.1	1549-1875	>1В75	<1549

X-ray examination is practically uninformative, except in cases of coarctation of the aorta, when a specific sign is determined - rib erosion.

Examination of the fundus reveals narrowing and tortuosity of small arteries, and possibly dilation of the veins of the fundus.

The state of the autonomic nervous system must be assessed using clinical tables to assess the initial autonomic tone, autonomic reactivity (according to cardiointervalography data) and autonomic support of activity (according to the results of the clinoorthostatic test).

Echoencephalography is performed in cases of frequent complaints of headaches, clinical signs of hypertension syndrome to exclude intracranial hypertension.

Rheoencephalography allows to detect the disturbance of vascular tone in cerebral vessels, difficult venous outflow. In children with hyper- and hypokinetic types of hemodynamics, a decrease in vascular blood filling is often noted. The obtained data serve as an indication for the prescription of drugs to improve microcirculation.

Ultrasound examination of the kidneys in combination with urine tests is a screening to exclude renal genesis of arterial hypertension; if necessary, excretory urography is performed.

The biochemical study includes the following tests:

• determination of the blood lipid spectrum (total cholesterol, triglycerides; high-density lipoprotein cholesterol);
• conducting a glucose tolerance test (for obesity);
• determination of the level of catecholamines (adrenaline, norepinephrine, if pheochromocytoma is suspected - vanillylmandelic acid);
• assessment of the activity of the renin-angiotensin-aldosterone system (determination of the level of renin, angiotensin and aldosterone).

Method of daily monitoring of arterial pressure

Daily monitoring of arterial pressure allows verification of initial deviations in the daily rhythm and magnitude of arterial pressure, and to conduct differential diagnostics of various forms of arterial hypertension.

During daily monitoring of arterial pressure, the following parameters are calculated: average values of arterial pressure (systolic, diastolic, mean hemodynamic pulse) per day, day and night; indices of arterial 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.

Average values of arterial pressure (systolic, diastolic, mean hemodynamic, pulse) provide a basic idea of the patient's arterial pressure level and more accurately reflect the true level of arterial hypertension than single measurements.

The hypertension time index allows to estimate the time of increase of arterial pressure during the day. This indicator is calculated by the percentage of measurements exceeding normal arterial pressure values for 24 hours or separately for each time of the day. The time index exceeding 25% for SBP is definitely considered as pathological. In case of labile form of arterial hypertension the time index fluctuates from 25 to 50%, in case of stable form it exceeds 50%.

The daily index gives 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. Most healthy children typically experience a 10-20% decrease in blood pressure at night compared to daytime values. There are four possible variants depending on the daily index value.

50th and 95th percentile values of blood pressure according to 24-hour monitoring data in children and adolescents depending on height (Soergel et al., 1997)

Height, cm	Blood pressure during the day, mmHg		Blood pressure during the day, mmHg		BP during the night, mmHg
	50th percentile	95th percentile	50th lercentile	95th percentile	50th percentile	95th percentile

Boys

120	105/65	113/72	112/73	123/85	95/55	104/63
130	105/65	117/75	113/73	125/85	96/55	107/65
140	107/65	121/77	114/73	127/85	97/55	110/67
150	109/66	124/78	115/73	129/85	99/56	113/67
160	112/66	126/78	118/73	132/85	102/56	116/67
170	115/67	128/77	121/73	135/85	104/56	119/67
180	120/67	130/77	124/73	137/85	107/55	122/67

Girls

120	103/65	113/73	111/72	120/84	96/55	107/66
130	105/66	117/75	112/72	124/84	97/55	109/66
140	108/66	120/76	114/72	127/84	98/55	111/66
150	110/66	122/76	115/73	129/84	99/55	112/66
160	111/66	124/76	116/73	131/84	100/55	113/66
170	112/66	124/76	118/74	131/84	101/55	113/66
180	113/66	124/76	120/74	131/84	103/55	114/66

• Normal decrease in blood pressure at night: the daily blood pressure index fluctuates between 10 and 20% (in English-language literature, such individuals are classified as “dippers”).
• No decrease in blood pressure at night: daily index less than 10% (such individuals are classified as “non-dippers”).
• Excessive decrease in blood pressure at night: daily index more than 20% (“over-dippers”).
• Increase in blood pressure at night: daily index less than 0% (“night-peakers”).

Normally, children do not have night-time blood pressure values that exceed average daytime values (“night-peakers”). Such a daily blood pressure profile is typical for individuals with symptomatic arterial hypertension.

In healthy children, the minimum values of average hemodynamic arterial pressure are observed at 2 a.m., then arterial pressure increases and reaches the first peak at 10-11 a.m., moderately decreases at 4 p.m., and the second peak is noted at 7-8 p.m.

The method of daily monitoring of arterial pressure is necessary for differential diagnosis of various forms of arterial hypertension.

The data of daily blood pressure monitoring in children allow avoiding overdiagnosis of arterial hypertension by detecting an increase in blood pressure due to an excessive anxiety reaction associated with a medical examination - the phenomenon of "white coat hypertension". The frequency of the phenomenon of "white coat hypertension" among children with arterial hypertension, according to our data, is 32%, while the daily blood pressure profile shows short-term increases in blood pressure above the norm, while the average blood pressure values remain within the permissible values.

The criteria for diagnosing labile forms of arterial hypertension based on daily blood pressure monitoring data are as follows:

• an increase in the average values of systolic and/or diastolic blood pressure from the 90th to 95th percentile of the distribution of these parameters for the corresponding growth indicators;
• excess of the standard values of the arterial hypertension time index during the day and/or night time by 25-50%;
• increased variability in blood pressure.

The diagnostic criteria for stable forms of arterial hypertension based on 24-hour blood pressure monitoring are listed below:

• an increase in the mean values of systolic and/or diastolic blood pressure above the 95th percentile of the distributions of these parameters for the corresponding growth indicators;
• exceeding the standard values of the arterial hypertension time index during the day and/or night time by more than 50%.

Daily monitoring of arterial pressure allows developing differential diagnostic criteria for prescribing non-drug vegetotropic or hypotensive therapy. Non-drug methods of correcting high arterial pressure are indicated for occasional increases (with "white coat hypertension"). Children with the phenomenon of "white coat hypertension" are subject to long-term dispensary observation as being at risk for developing arterial hypertension. Daily monitoring of arterial pressure allows assessing the effectiveness of hypotensive therapy, establishing the correct intervals between drug doses during the day, and avoiding unjustifiably high doses of hypotensive drugs.

A dosed physical load test provides important information for diagnosing arterial hypertension in children and adolescents. It allows determining tolerance to physical load, identifying maladaptive hemodynamic shifts that occur during physical load (hypertensive type of hemodynamics). Adolescents with arterial hypertension are characterized by lower indicators of the power of the load performed and the volume of work performed. A decrease in physical performance is more typical for adolescents with stable arterial hypertension.

Children with arterial hypertension during the test with dosed physical load have higher levels of DBP and SBP compared to children with normal blood pressure. The frequency of hypertensive reaction of blood pressure to physical load (blood pressure level over 170/95 mm Hg) is 42% in the labile form of arterial hypertension, and 80% in the stable form.

Diagnosis of target organ damage

Timely diagnostics of target organ damage, primarily detection of cardiac remodeling and changes in the vascular wall, is extremely important for determining the stage of the disease and assessing the prognosis of children with high blood pressure. High blood pressure contributes to atherosclerotic vascular damage. This position was confirmed by the data of a morphological study of the state of the cardiovascular system in adolescents and young adults who died as a result of accidents. A close relationship was established between elevated blood pressure and the severity of the atherosclerotic process in the aorta and coronary arteries, as well as the occurrence of myocardial hypertrophy. These patterns were confirmed by the results of non-invasive methods for diagnosing vascular damage, such as echo-Dopplerography, in young people with arterial hypertension. It was found that an increase in blood pressure in childhood is associated with an increase in the thickness of the average and internal dimensions of the carotid arteries intima-media already at the age of 20-30 years.

Left ventricular hypertrophy is the most obvious sign of target organ damage in arterial hypertension. Currently, the most informative non-invasive method for diagnosing myocardial hypertrophy is Doppler echocardiography. The main criterion for diagnosing left ventricular myocardial hypertrophy is myocardial mass. According to the recommendations of the IV report on the diagnosis and treatment of arterial hypertension of the National Educational Program, the following formula should be used to assess the left ventricular myocardial mass:

LVMM = 0.8x(1.04xTMZH + EDR + TZSLZh) ³ - EDR ³ +0.6,

Where LVM is the left ventricular myocardial mass (g), IVST is the thickness of the IVS (cm), EDD is the end-diastolic dimension of the left ventricle (cm), and LPDT is the thickness of the posterior segment of the left ventricle (cm).

Considering that myocardial mass is closely associated with weight and height indicators, a more informative criterion for left ventricular hypertrophy is the left ventricular mass index, which levels out the effect of excess body weight on this indicator. The left ventricular mass index is calculated as the ratio of the LVM to the height value (m) raised to the power of 2.7. Then the value of this indicator is compared with percentile tables. A single, so-called hard criterion indicating the presence of hypertrophy is the LVM index equal to or greater than 51 g/m ^2.7. This value corresponds to the 99th percentile of the indicator in children and adolescents. This value of the LVM index is closely associated with a high risk of adverse outcomes of arterial hypertension in adult patients. Myocardial hypertrophy is detected in 34-38% of children and adolescents with arterial hypertension. About 55% of adolescents with arterial hypertension have a LVM index greater than the 90th percentile, and in 14% it exceeds 51 g/ ^m2.7.

Arterial hypertension is associated with the process of myocardial remodeling. Thus, concentric myocardial hypertrophy, which serves as a predictor of a high risk of developing cardiovascular complications in adults, was noted in 17% of children, in 30% there was eccentric hypertrophy, associated with a lower risk of complications in adulthood. Detection of left ventricular hypertrophy is extremely important, since it serves as an absolute indication for prescribing antihypertensive therapy. It should be emphasized that the determination of the LMMI index should be carried out dynamically to assess the effectiveness of the therapy. Detection of left ventricular hypertrophy is a more unfavorable prognostic factor for assessing the severity of arterial hypertension compared to changes in the thickness of the carotid artery (intima/media index) and detection of microalbuminemia.

Several studies have shown a relationship between hypertension and retinopathy.

Diagnostics of psychological characteristics of adolescents with arterial hypertension

The sensitivity of the cardiovascular system of adolescents to emotional impacts is determined by constitutional-typological and personal characteristics. In this regard, it is advisable to include psychological testing using the Eysenck, Spielberger, and Wolff tests in the examination plan for adolescents with arterial hypertension. The choice of these tests is due to their high information content combined with ease of implementation. Their implementation does not require the participation of a psychologist and is available to a pediatrician or cardiologist.

The Eysenck test allows identifying the characterological features of adolescents. Extraversion is understood as such personality traits as sociality, sociability, activity, cheerfulness, optimism, aggressiveness, individuality. Extraversion is typical for adolescents. Introversion is understood as such personality traits as restraint, a tendency to introspection and internal experiences, strict control over emotions and feelings. Introversion is more typical for adolescents with arterial hypertension.

Introversion is combined with increased sympathicotonic activity. Emotional lability is indicated by high scores on the neuroticism scale.

The connection between arterial hypertension and anxiety is well known. According to academician B.D. Karvasarsky, anxiety is a mental state, the determining factor in which is the condition of uncertainty. The Spielberger test allows us to identify the level of both personal and reactive anxiety. Personal anxiety is a characterological feature of an individual, reactive anxiety is a reaction to a stressful situation. Adolescents with arterial hypertension are characterized by elevated levels of both reactive and personal anxiety according to the Spielberger test.

The Wolf test allows to identify behavioral features characteristic of types A and B behavior. Classic psychological characteristics of type A behavior are thirst for competition, feeling of lack of time, aggressiveness, hostility, purposefulness, desire for leadership, high degree of control over behavior in situations threatening undesirable outcomes for the subject. Children with type A behavior are irritable under stress and aggressive during play. Type A is more common in boys than in girls. In addition, boys are more likely to have such components of type A behavior as aggression and thirst for competition, which is associated with a greater release of catecholamines. These factors may contribute to a greater predisposition of men compared to women to cardiovascular diseases. Type A behavior is characterized by more frequent damage to the vascular endothelium.

Thus, psychological testing allows us to identify maladaptive behavioral characteristics, such as increased anxiety and a tendency toward aggressive reactions, which require psychological correction.

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