The most characteristic manifestation of hypertension is increased blood pressure.
Usually, high blood pressure in hypertension can be established by examining the pulse.When palpating the pulse on the radial artery, a hard pulse (p. durus) is determined, caused by increased intraarterial pressure and tonic contraction of the walls of the arteries.However, due to the fact that the lumen of a medium-sized artery during hypertension decreases slightly, the filling of the pulse changes little.When recording pulse fluctuations graphically (on a sphygmogram), the pulse wave is low, rounded, and has a slight rise and fall (pulsus tardus);the dicrotic wave is barely perceptible.
Studying blood pressure using the auscultatory method is still the best way to simultaneously determine systolic, diastolic and pulse pressure.In hypertension, all three values are usually elevated.Systolic increases more significantly;the diastolic increases to a lesser extent.
If we compare the percentage increase in systolic and diastolic blood pressure in hypertension to the average values of both pressures in normal conditions, the increase will be almost the same.So, if we take as normal value 120 mm Hg for systolic pressure and 70 mm Hg for diastolic pressure.Art., therefore with a blood pressure equal to 160 mm Hg.Art.(maximum) and 90 mm Hg.Art.(minimum), the increase compared to the norm with respect to both values will be almost the same (90 compared to 70 and 160 compared to 120).With a reading of 180/100 mmHg.Art.at first glance it seems that the systolic has increased much more significantly than the diastolic (180 versus 120 and 100 versus 70);if we compare it with normal ratios, the increase in percentage terms will be almost the same.
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 this depends on the basic level before the disease (each person is individual).
The relationship between diastolic and systolic pressure is influenced by:
- degree of elasticity of the walls of the large arteries,
- contractile force of the heart.
It is 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 is reflected in an increase in pulse pressure.Under the same conditions, when the heart begins to weaken, the amplitude decreases: systolic pressure decreases, diastolic pressure remains high.
Already at the beginning of the disease there is a tendency to pressor reactions.Blood pressure measurement 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 normal for a particular person, while in others it exceeds the upper limit of the age norm.Increased pressure in hypertension is observed under the influence of various factors - mental, emotional, reflex - and remains at a high level from several minutes to several hours.
The first measurement usually gives higher numbers (random pressure) than repeated measurements taken 5-10-15 minutes later.The difference between the random pressure value and the main pressure value 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 "near main pressure".
“Additional pressure” undoubtedly expresses the degree of excitement or mental (emotional) tension of the patient at this moment and the degree of excitability of his nervous system which regulates blood pressure.Experience shows that in the prehypertensive period, the magnitude of additional pressure in patients is usually more significant than in subjects who have not shown a tendency to develop hypertension.
Comparing the degree of pressor influence of some nervous influences, it should be noted that the most acute stimulus is speech.Therefore, it is not an exaggeration to say that the level of high blood pressure in hypertension and in people predisposed to it is more influenced by influences through the second signaling system.
Test for high blood pressure in hypertension
They also tried to determine the tendency to hypertension by 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 the 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 and then measure the level every 30 seconds until level.An increase in systolic blood pressure greater than 20 mmHg.Art., diastolic above 15 mm Hg.Art.serves as an indicator of increased blood pressure reactivity.The people who discovered it were called “hyperreactors,” those who didn't find it were called “hyporeactors.”Among healthy people, hyperreactors account for 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 warm person, due to the decreased tone of his blood vessels, is lower than in the same person in cooler external temperature conditions.The reflex reaction to cold depends on the usual influences of temperature, profession and living conditions.It is well known that people become dependent on the temperature factor.In hardened people, the cold test may be weak, but in people sensitive to cold it may be strong.
The cold test is based on the reflex reaction of the vasomotor center in response to thermal (and partly painful) stimulation suddenly caused in the periphery.The pressor reaction to cold weakens after taking alcohol, bromine and barbiturates.
Sometimes the answers to the cold test turn out to be paradoxical: in hypertension, high blood pressure does not occur, 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 hot water does not turn red, but becomes pale).As a result, cold and heat can sometimes produce the same type of vasoconstrictor effect.
Temperature effects can hardly be used as a method to evaluate the reactivity of the apparatus that regulates high blood pressure in hypertension, because they do not reflect the specifics of the disorders that underlie hypertension.Vascular tests using pharmacological agents have been proposed.One of these is a glycerol trinitrate test.After taking 2 drops of glycerol trinitrate (under the tongue), blood pressure (systolic and diastolic) decreases significantly.The decrease is more pronounced in subjects with sharply increased blood pressure due to hypertension.The reduction is particularly significant in case of unstable blood pressure;Sometimes such a decrease is observed in persistent hypertension.In advanced 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 conditions.
The same results (depressant effect) are obtained with an isoamyl nitrite inhalation test.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 some popularity.The subject, who is in bed, is administered sodium amytal 0.2 g every hour 3 times;blood pressure is measured before administration of the drug and every half hour after taking it (for 3 hours).The difference between the initial and lowest levels determines the extent of the depressant effect.After taking the second powder, sleep usually occurs.Typically, sodium amytal helps to lower blood pressure not only in the first few hours, but also in the following days, sometimes even for several days;the patient's well-being improves.However, this effect is not always observed: some patients experience intolerance to the drug.
Unlike the nitrite test, which causes a rapid drop in pressure, during the sodium amytal test the pressure decreases gradually.The degree of its decrease after taking sodium amytal is especially significant at the beginning of the disease.In the late 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 in nature, a sodium amytal test characterizes the state of devices regulating blood pressure in cortical and subcortical areas.When using different doses of the drug (small and large), it is possible to judge from the blood pressure the phase states of the vasopressor nerve centers (sometimes large and small doses give the same effect, or small doses have a more distinct depressant effect than large doses).
In addition to tests based on depressive action, many tests based on pressor action have been proposed - with stopping breathing, inhaling carbon dioxide, taking phenamine, but they are not without negative effects on the condition of patients, although they probably no less determine the tendency to hypertension in its initial stage and in the so-called premorbid state.
Having discovered the tendency to short-term increases in blood pressure in a particular person, one should not immediately make a diagnosis of hypertension, much less inform the examined person about it.Under favorable environmental conditions, pressor reactions can disappear completely.
High blood pressure depending on the stage of hypertension
The increase in pressure in early-stage hypertension occurs only periodically (transitional phase).The more difficult the patient's living conditions are from a neuropsychic point of view, the longer and more frequent are the periods of high blood pressure in hypertension, and the periods of normal levels are shorter and rarer.Therapeutic measures and adherence to the regimen 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 returns to normal for a long time.
An increasingly persistent tendency to increase blood pressure during hypertension and the preservation of its pathological level indicate 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 vary within significant limits.Under the influence of rest, it decreases for a short period of time to a level close to normal, although it is not maintained at this level for a long time.Under the influence of treatment, however, it is possible to achieve a long-term decrease in the indicator to normal.
During the day, blood pressure in hypertension can vary widely.In the morning it is usually lower than in the evening.After eating, it increases slightly, then decreases significantly.During night sleep, it decreases more sharply in hypertension than in healthy people.
As the disease progresses, blood pressure increasingly stabilizes at a high level (phase B of stage II, stable).True, even at this stage there are sometimes periods of decline.Sometimes remission occurs under the influence of long-term therapy for a sufficiently 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 number of factors, undoubtedly including kidney involvement.However, with a decrease in the excitability of vasopressor centers during brain strokes or under the influence of heart failure (the occurrence of decompensation due to overload of the contractile function of the hypertrophic heart), a decrease in blood pressure is observed.Moderate heart failure has little effect on the indicator level;sometimes it even increases during this period (stagnation factor).
As for venous pressure in hypertension, it usually falls within the normal range and increases only with heart failure.True, in some patients, even in the initial stages of the disease, slightly increased values of venous pressure can be found, which even led to the assumption of excitation of the "venomotor 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 with blood).Blood pressure in the capillaries is difficult to determine.Capillaroscopically in the nail bed there is usually a narrowing of the arterial loops of the precapillaries and a dilation of the venous loops;Variability of the capillary pattern (“play” of them) is typical.