The most characteristic manifestation of hypertension is increased blood pressure.
Usually, high blood pressure can be established by examining the pulse.When palpating the pulse on the radial artery, a hard pulse (p. durus) is determined, caused by an increase in intra-arterial pressure and tonic contraction of the arterial walls.However, since the lumen of a medium-sized artery decreases slightly during hypertension, the filling of the pulse changes little.When recording pulse fluctuations graphically (on a sphygmogram), the pulse wave is weak, rounded, and has a slight rise and fall (pulsus tardus);the dicrotic wave is barely perceptible.
The study of blood pressure by the auscultatory method remains the best way to simultaneously determine systolic, diastolic and pulse pressure.In cases of hypertension, all three values are generally elevated.Systolic increases most significantly;diastolic increases to a lesser extent.
If we compare the percentage increase in systolic and diastolic pressure in hypertension compared to the average values of both pressures under normal conditions, the increase will be almost equal.So, if we take 120 mm Hg as the normal value for systolic pressure and 70 mm Hg for diastolic pressure.Art., then with blood pressure equal to 160 mm Hg. Art.(maximum) and 90 mm Hg. Art.(minimal), the increase compared to the norm in relation to the two values will be almost the same (90 versus 70 and 160 versus 120).With a reading of 180/100 mmHg.Art.at first glance, it appears that the systolic is increased much more significantly than the diastolic (180 versus 120 and 100 versus 70);if we compare it to normal ratios, the percentage increase will be almost equal.
Often, in the initial period (stage I) of hypertension, there is an increase in systolic or diastolic pressure (usually the first, less often the second).Perhaps it depends on the baseline level before the illness (each person is individual).
The relationship between diastolic and systolic pressure is influenced by:
- degree of elasticity of the walls of large arteries,
- contractile force of the heart.
It is well known that a decrease in the elasticity of the arteries contributes to an increase in systolic pressure (in its most pronounced form this occurs with atherosclerosis of the central arteries).
In hypertension, changes in the elasticity of the walls of large vessels are observed, which results in an increase in pulse pressure.Under the same conditions, when the heart begins to weaken, the amplitude decreases: the systolic pressure decreases, the diastolic pressure remains high.
Already at the beginning of the disease there is a tendency to pressor reactions.Measuring blood pressure shows that in some patients its level does not exceed the upper limit of the age norm, but the values obtained during measurement are higher than usual for a given person, while in others it exceeds the upper limit of the age norm.Increased pressure in hypertension is observed under the influence of various influences - mental, emotional, reflexes - and remains at a high level from several minutes to several hours.
The first measurement usually gives higher numbers (random pressure) than repeat measurements taken 5 to 10 to 15 minutes later.The difference between the value of the random pressure and that of the main pressure is called “additional pressure”;its value in people suffering from hypertension is significantly greater than in healthy people.The main pressure is considered to be that obtained during the study of basal metabolism (i.e. in bed, in the morning after sleep, on an empty stomach).The smallest value of the indicator after repeated measurements under normal circumstances is conventionally called "almost the main pressure".
“Additional pressure” undoubtedly expresses the degree of mental (emotional) excitement or tension of the patient at that moment and the degree of excitability of his nervous system which regulates blood pressure.Experience shows that in the prehypertensive period the level of additional pressure in patients is usually greater than in individuals who have not shown a tendency to develop hypertension.
When comparing the degree of pressive influence of certain nervous influences, it should be noted that the most acute stimulus is the word.Therefore, it would not be an exaggeration to say that the level of high blood pressure in people with hypertension and in people who are predisposed to it is most influenced by the influences of the second signaling system.
High blood pressure tests in hypertension
They also tried to determine the tendency to hypertension by means of reflex irritations.In this regard, special attention was paid to the so-called cold test.After a short period of rest, the subject's blood pressure is measured in supine position, then the hand of the other hand is immersed for one minute in water at a temperature of 4°;at the time of immersion, then measure the level every 30 seconds until it stabilizes.An increase in systolic pressure of more than 20 mmHg.Art., diastolic more than 15 mm Hg. Art.serves as an indicator of increased vasopressor responsiveness.People who found it were called "hyper-reactors", those who didn't find it were called "hypo-reactors".Among healthy people, hyperreactors represent 15%.
The cold test received mixed reviews.The conditions under which the test is performed play an important role in the pressor effect for a given test.The pressor reaction to cold in a person who is hot, due to the decrease in the tone of his blood vessels, is weaker than in the same person in conditions of cooler external temperature.The reflex reaction to cold depends on the usual influences of temperature, occupation and living conditions.It is well known that people become dependent on the temperature factor.In hardy people, the cold test may be weak, but in people sensitive to cold, it can be strong.
The cold test is based on the reflex reaction of the vasomotor center in response to sudden thermal (and partly painful) stimulation in the periphery.The pressor reaction to cold weakens after taking alcohol, bromine and barbiturates.
Sometimes the responses to a cold test turn out to be paradoxical: high blood pressure does not occur with hypertension, and sometimes it even decreases.
It is interesting to compare these data with the results of determining blood pressure after exposure to heat.When warming the hand, people suffering from hypertension often experience not a decrease, but an increase in blood pressure (a hand immersed in warm water does not turn red, but turns pale).Therefore, cold and heat can sometimes produce the same type of vasoconstrictor vasoconstrictor effect.
The effects of temperature can hardly be used as a method of assessing the responsiveness of the apparatus that regulates high blood pressure in hypertension, since they do not reflect the specifics of the disorders that cause hypertension.Vascular testing using pharmacological agents has been proposed.One of them is a test with glycerol trinitrate.After taking 2 drops of glycerol trinitrate (under the tongue), blood pressure (systolic and diastolic) decreases significantly.The decrease is more pronounced in people with a sharp increase in blood pressure due to hypertension.The reduction is particularly significant in cases of unstable blood pressure;Sometimes such a decrease is observed in persistent hypertension.In later stages of hypertension (with the development of arteriolosclerotic changes in the kidneys), a nitroglycerin test gives a slight decrease in hypertension, which can be used to diagnose renal forms (or stages) of hypertensive states.
The same results (depressant effect) are obtained by a test with inhalation of isoamyl nitrite.Glycerol trinitrate, like isoamyl nitrite, acts mainly through central vasomotor devices, thus characterizing the increased excitability of these centers in hypertension.
The sodium amytal test has gained popularity.The subject, bedridden, receives 0.2 g of sodium amytal every hour 3 times;blood pressure is measured before administering the drug and every half hour after taking it (for 3 hours).The difference between the initial and lowest levels determines the magnitude of the depressant effect.After taking the second powder, sleep usually occurs.Generally, sodium amytal helps lower blood pressure not only in the first hours, but also in the following days, sometimes even several days;the patient's well-being improves.However, this effect is not always observed: some patients have intolerance to the drug.
Unlike the nitrite test, which causes a rapid drop in pressure, during the sodium amytal test it gradually decreases.The degree of its decrease after taking sodium amytal is especially important at the beginning of the disease.At the end of the period, in the presence of arteriolosclerotic changes in the kidneys, the decrease is usually small or absent.
Since the effect of barbiturates is undoubtedly central, a sodium amytal test characterizes the state of the devices regulating blood pressure in the cortical and subcortical areas.When using different doses of the drug (small and large), it is possible to judge by blood pressure the phase states of the vasopressor nerve centers (sometimes high and low doses give the same effect, or small doses have a more distinct depressant effect than large doses).
In addition to tests based on depressant action, many tests have been proposed based on pressor action - with stopping breathing, inhalation of carbon dioxide, taking phenamine, but they are not without a negative effect on the condition of patients, although they probably determine no less the tendency to hypertension in its early stage and in the so-called premorbid state.
Having discovered a tendency to a short-term increase in blood pressure in a particular person, you should not immediately make a diagnosis of hypertension, much less inform the person being examined about it.Under favorable environmental conditions, pressor reactions can completely disappear.
High blood pressure according to the stage of hypertension
The increase in pressure in the early stage of hypertension occurs only periodically (transient phase).The more neuropsychically difficult the patient's living conditions, the longer and more frequent the periods of high blood pressure in hypertension, and the shorter and rarer the periods of normal levels.Treatment measures and compliance with the diet are of great importance.Under the influence of rest and treatment in the initial transient phase of hypertension with its benign course, the indicator often decreases to normal for a long time.
An increasingly persistent tendency to increase blood pressure during hypertension and maintain its pathological level indicates the further development of the disease, moving to stage II.In phase A of stage II, blood pressure is unstable (labile phase).Its level can fluctuate within significant limits.Under the influence of rest, it decreases for a short time to a level close to normal, although it is not maintained at this level for a long time.However, under the influence of treatment, a long-term decrease in the indicator to normal can be achieved.
During the day, blood pressure in hypertension can fluctuate significantly.In the morning it is generally weaker than in the evening.After eating, it increases slightly, then gives a significant decrease.During nighttime sleep, it decreases more sharply in hypertensive people than in healthy people.
As the disease progresses, blood pressure becomes more firmly established at a high level (phase B of stage II, stable).Certainly, even at this stage there are sometimes periods of decline.Sometimes remission occurs under the influence of long-term treatment for a fairly long period.However, this phase is usually characterized by persistent and high hypertension.Depressant tests at this stage indicate the functional nature of high blood pressure in hypertension.
In stage III, blood pressure is usually persistently elevated.Hypertension is maintained by a certain number of factors, among which undoubtedly the involvement of the kidney.However, with a decrease in the excitability of the vasopressor centers during strokes or under the influence of heart failure (the appearance of decompensation due to overstrain of the contractile function of the hypertrophied heart), a decrease in blood pressure is observed.Moderate heart failure has little effect on the level of the indicator;sometimes it even increases during this period (stagnation factor).
As for venous pressure in hypertension, it is usually within the normal range and increases only in cases of heart failure.True, in some patients, even in the early stages of the disease, slightly increased values of venous pressure can be noted, which even led to the hypothesis of excitation of the “venomomotor center”, as a result of which the tone of the venous walls increases (however, we are not able to judge the latter, since intravenous pressure is usually measured by blood).Blood pressure in the capillaries is difficult to determine.By capillaroscopy, in the nail bed, a narrowing of the arterial curvatures of the precapillaries and an expansion of the venous curvatures are usually determined;Variability in hair pattern (“play” of them) is typical.