Long-term monitoring of blood pressure: apparatus, results

High blood pressure to date, it is difficult to surprise anyone. A dangerous trend is that people relate to such a state as to the given, guided by the principle: rest, and everything will go well. But high blood pressure indicators, even situational ones, can be a harbinger of a dangerous disease - hypertension. But how do you know if the increase in BP is caused by some provoking factors (stress, weather conditions, meteosensitivity) or is it the result of a pathological condition of the heart and blood vessels? One-time measurement of pressure does not answer this question. But monitoring of blood pressure during the day or more can fully clarify the situation.

The procedure for non-invasive measurement of blood pressure, lasting a day or more, abbreviated as SMAD. Daily monitoring of blood pressure is considered the most reliable way to determine the true values of blood pressure, which is simply impossible to do in a couple of minutes. The procedure is not burdensome, because the patient does not necessarily have to be in the clinic all this time. And those small requirements that, at the insistence of the doctor, it will be necessary to perform during monitoring, will seem trivial in comparison with the diagnostic value of the procedure.

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

Indications for the procedure

To begin with, it is not necessary to have documented cardiac and vascular diseases to monitor blood pressure. For preventive purposes, this procedure can pass any person who is jealous of their health.

Let's just say, the same hypertensive disease is a rather insidious pathology, and for the time being can not show itself in any way. Years up to 30 people may not even suspect about the presence of this disease, and then start the incomprehensible fluctuations in blood pressure, there is a deterioration in well-being during physical exertion, there is a pronounced meteorological dependence, etc.

But if only this all and limited. In the absence of treatment, hypertension leads to a persistent increase in blood pressure, which in turn is a risk factor for the development of dangerous complications, such as stroke, myocardial infarction, arrhythmia, angina. Against the background of high blood pressure indicators, doctors often diagnose arteriosclerosis of blood vessels, diabetes mellitus and other pathologies associated with impaired blood supply to organs, and thus with disruption of their nutrition and respiration.

The danger of hypertension, which causes difficulties in the diagnosis of pathology, is also that it can have various forms and manifestations that require completely different approaches to treatment:

• Hidden hypertension, which proceeds practically asymptomatically, and therefore the patient may not even suspect about his illness.
• Hypertension of the working day (it is office arterial hypertension), when the increase in blood pressure is noted in connection with the performance of work duties, and when visiting a doctor who conducts blood pressure measurements, the pressure indicators are close to normal.
• Night hypertension. The insidious kind of pathology, when the blood pressure indicators grow, it would seem, from scratch: at rest in the evening and at night.
• Persistent hypertension, resistant to ongoing antihypertensive therapy. In this case, one-time measurements 2-3 times a day do not give a complete clinical picture.
• The "white coat" syndrome. A peculiar variant of situational hypertension, when excitement caused by a visit to a polyclinic or a hospital where people everywhere in white coats are scurrying around (a figurative expression denoting a uniform required in medical institutions) causes a temporary increase in blood pressure, which is fixed by the doctor's apparatus. Excitement, most likely, is associated with an unpleasant childhood experience with doctors.
• Fluctuations in blood pressure, in connection with which patients have a significant deterioration in well-being.
• Symptomatic hypertension, an increase in blood pressure in which it is provoked by violent anxiety, fear, anxiety, etc. (strong emotional factors).
• Boundary arterial hypertension, when the pressure is at the upper limit of the norm, but in some situations it can even cross the line.

All these situations are very difficult to identify by doing one-time BP measurements when a person seeks a doctor for a worsening state of health or undergoes a scheduled physical examination. If there are suspicions of atypical forms of hypertension, of which we spoke, doctors prescribe long-term monitoring of blood pressure in order to observe changes in blood pressure during the day. In some cases, even longer research may be needed to professionally assess the situation and develop measures to stabilize the patient.

Indications for the procedure of SMAD are not only different types of arterial hypertension, but the diagnosis of a possible development of the disease, where it plays an important role:

• hereditary factor of the disease (this type of diagnosis is relevant for hereditary predisposition, if there were cases of hypertension in the genus),
• pregnancy (hormonal adjustment can cause fluctuations in blood pressure),
• risk factors (excess weight, smoking, susceptibility to stressful situations, hormonal background disruptions, autoimmune, allergic, infectious pathologies), capable of provoking the development of hypertension even at a young age,
• pathologies that occur with an increase in blood pressure (for example, diabetes mellitus, cardiac ischemia and heart failure, cerebral vascular pathologies, nighttime apnea syndrome, severe forms of vegetative-vascular dystonia, etc.)
• age (older patients are more prone to hypertension due to the physiological characteristics of this age group and accumulated over the years baggage diseases).

In this case, a person can apply to the clinic for the procedure of SMAD itself or in the direction of the doctor.

Monitoring of blood pressure will be useful not only for those who have high blood pressure, but also for patients with hypotension (persistent lowering of blood pressure, conditioned by constitutional features or provoking factors).

This procedure doctors do not only for purely diagnostic purposes. The study provides information on the selection of patients who need drug treatment. For example, the advisability of antihypertensive drug therapy in the syndrome of "white coat" or office hypertension is highly questionable. In this case, psychological help and correction of the regime of work and rest will be more effective. However, such people have a certain predisposition to increase blood pressure (hypertension), therefore, they are prescribed SMAD to be administered regularly 2-4 times a year.

Monitoring blood pressure for a day or more helps evaluate the effectiveness and safety of drug therapy (for example, some antihypertensive drugs with not significantly elevated blood pressure can reduce it below the norm, which is no less dangerous to health). With its help, you can determine the degree of effectiveness of prescribed medications in each specific case. If no improvement is noted during several procedures, this indicates a resistance to drug treatment. For such patients, individual therapy schemes for arterial hypertension are being developed.

If the patient is forced to take medicines strictly in the allotted time (chronotherapeutic regimen of drug therapy), a very important indicator is the diurnal rhythm of arterial pressure, which is individual for each person. Sometimes it is precisely in the disturbance of the circadian rhythm that the deterioration of the patient's condition, the pressure jumps and even the lack of effectiveness of the prescribed course of therapy are hidden. The method of SMAD provides full information on this issue.

[8], [9], [10], [11]

Preparation

Monitoring of blood pressure is one of those diagnostic and treatment procedures that do not require special preparation from the patient. Nevertheless, an important task of the doctor remains to inform the patient about the purpose of monitoring blood pressure and behavior during the procedure. It is from the awareness of the importance of this diagnostic method and the correct implementation of all medical requirements that the accuracy of the result of the studies and the effectiveness of further treatment depend.

Another particularly important point of preparation for the procedure for long-term monitoring of blood pressure is the preparation of a device for daily monitoring of blood pressure and the selection of a cuff of the appropriate size based on the patient's constitution.

Daily monitoring of blood pressure can be performed in an invasive and non-invasive manner. As part of a non-invasive method for monitoring blood pressure, two methods are considered: auscultatory and oscillometric, which has recently become more prevalent, since it is free from the drawbacks of the previous method.

Invasive method: blood pressure measurements are performed in hospital settings. In this case, a needle is inserted into the artery, connected to the sensor, which continuously records the information coming from it to the magnetic tape.

The auscultatory method is still used in some clinics and is listening to Korotkov's tones with the help of a special microphone, which is applied to the place of pulsation of the vessel in the cuff area. Oscillographic method for measuring blood pressure is a diagnostic measurement of the mean systolic and diastolic pressure for small air pressure pulsations in the cuff.

Both of these methods can be used both in hospital and outpatient settings. Benefit to date in the market of medical equipment there is no shortage of equipment for non-invasive measurement of daily BP. There are presented both domestic developments and foreign technologies. Therefore, it is not difficult to choose the equipment in accordance with wishes and needs.

These can be conventional blood pressure tonometers that measure blood pressure (for example, the AVRM-02 / M model of Hungarian production with the control of the battery charge). But many clinics prefer to use multifunctional devices (Cardio Tens produced in Hungary simultaneously fixes indicators of blood pressure and ECG, and the Japanese system TM-2425/2025 plus everything makes regular measurements of air temperature, the position of the human body, increased physical load on acceleration, etc. .). Apparatus for long-term monitoring of blood pressure is called a holter, hence the name of SMAD - Holter monitoring of blood pressure.

Daily monitoring of blood pressure implies a continuous cycle of specialized equipment. And since all such apparatuses work in an outpatient setting from batteries (or conventional batteries), the doctor must check before starting the procedure whether the battery is enough to conduct the SMAD for the required time. On-site charging is not possible in this case.

The device for monitoring blood pressure consists of a registrar, a display and a cuff that connect to each other and work as a unit. First, the registrar is initialized, for which it joins the PC. A special program allows you to enter in the memory of the registrar individual patient information, set the data fixation periods and intervals with which the BP measurement should be performed, enable or disable the sound signal function before each measurement, note the necessity of displaying the BP and pulse data on the display.

The data on the AD instrument are not recorded permanently, but at regular intervals. The following standards were adopted: during the day, the blood pressure and pulse are measured every 15 minutes, at night - every half hour. If necessary, you can program the unit for other time intervals.

After the initialization of the recorder is made, the cuffs to the device are selected. Usually, the apparatuses of such a plan are equipped with several cuffs, which differ in length and width. Children's cuff has a length of 13-20 cm. For adults, these indices can vary greatly. When choosing the optimal length and width of the cuff, it must be taken into account that it must cover at least 80% of the limb along the perimeter.

The cuff is superimposed on the upper limb in the shoulder region in accordance with the leading side of the body. For most people, the cuff is attached to the left hand, and left-handed to the right.

On the cuff there is a special label, which indicates that the device is attached correctly, if it coincides with the point of greatest pulsation.

Since the pressure measurement is carried out for a long time, and the patient lives normal life at the same time, i.e. Is in motion, the cuff can gradually shift. This can not be allowed, because the results of measurements in this case will be distorted. To avoid displacement of the device relative to the hand, it is recommended to use special disks with a double-sided adhesive coating (such as double-sided scotch tape).

Next, control measurements are made (of the order of 4-6 measurements with an interval of 2 minutes). To do this, first a pneumo-armchair is attached to the patient's shoulder, then with special fasteners a registrar with a display and a sphygmomanometer are attached to it, according to which average values of medical and instrumental values are calculated. Admissible differences between these indices are 10 mm Hg (for systolic or upper pressure) and 5 mm Hg (for lower pressure indicators).

 If the difference in readings exceeds the acceptable values, it is necessary to check the correctness of the cuff setting, change the hand on which blood pressure measurement will be performed, or the type of apparatus for daily monitoring of blood pressure.

[12], [13], [14], [15]

Technique of the blood pressure monitoring

As already mentioned, the device for daily monitoring of arterial pressure measures during the programmed time, fixing measurements in the memory of the device. Those. A person does not take a tonometer during the entire procedure (sometimes a day, sometimes more), and even at night.

The patient is warned in advance that the device for measuring blood pressure can not be wetted. Like any electrical appliance it must be kept away from sources of moisture and electromagnetic radiation. It is forbidden to independently adjust the height of its fastening (it is possible to incorrectly fix the device on the arm, which distorts the results of the study), detach the cuff from the recorder, remove or replace the batteries, repair the allegedly broken device. In this case, it is important to ensure that the details of the cuff attachment to the recorder are not clamped or squashed during sleep.

If the device has strongly slid down, you can correct it, leaving a distance of about 2 cm between its lower edge and the elbow.

During the monitoring of blood pressure, it is not recommended to change the regime of the day and your habits, the only thing that needs to be limited is physical activity on the day of monitoring. It is clear that sports, fitness, etc. Classes should be postponed for another day.

It is necessary to try to forget about the device for the time of the procedure (especially since it is rather light and does not attach to the leading hand, which means it does not create any particular inconvenience), it is less to think about possible bad results of the research, to try to see the readings on the display. Such thoughts and actions cause a state of anxiety and anxiety, which can affect the results of studies in the form of elevated blood pressure.

Night sleep should also be calm, not burdened with thoughts about the indications of the device and possible pathologies. Any nervousness distorts the night measurements and, of course, the final indicators. But the results of measuring the night fall in blood pressure are very important from the point of view of diagnosing hypertension. Patients are even classified into 4 groups on the basis of the SSSAD index (the degree of night blood pressure lowering).

An important duty of the patient during the procedure is the maintenance of special records in the diary of SMAD. But in their records, a person should not display the values of blood pressure and the intervals between measurements (this information is stored in the memory of the device), but his detailed actions during monitoring of blood pressure and changes in well-being. All the emerging symptoms need to make notes in the diary, indicating the time of onset and disappearance of the symptom.

In the afternoon the device measures blood pressure every 10-15 minutes. Before making a measurement, he beeps. This function can be turned off, but for the convenience of the patients themselves, doctors advise to use it. The thing is that during the pressure measurement it is advisable not to move (if the signal is sounded during walking, you need to stop and wait until the second signal sounds, indicating the end of the measurement). The hand on which the device is fixed, it is necessary to lower downwards, and as much as possible to weaken muscles. These requirements are not made by chance, because their violation can badly affect the accuracy of measurements.

At night, the patient moves little and is relaxed enough, so there is no need to monitor the time of measurements.

Monitoring of ECG and blood pressure

If a patient complains of cardiac disruptions and high blood pressure when visiting a doctor, but a one-time electrocardiogram and blood pressure measurement does not show anything suspicious, the doctor still has a lot of questions. These questions can be answered with a fairly simple procedure - measuring ECG and Blood pressure for a longer time. At the same time, ECG and blood pressure monitoring can be performed for 1 day, and sometimes the device is left on the patient's body and for a longer time.

Daily monitoring of the ECG according to Holter is prescribed with the following complaints of patients:

• pressing pains in the field of the heart, which appear sporadically mainly with physical exertion,
• a feeling of palpitation, anxiety, discomfort behind the breastbone and deterioration of health,
• Shortness of breath on the background of the above symptoms,
• the appearance of unexplained weakness and dizziness, fainting, accompanied by the appearance of cold sweat on the face and body,
• feeling of brokenness, fatigue and decay in the morning (without physical exertion),
• violation of the rhythm of the heart, which is accompanied by a short-term loss of consciousness, a palpitation or a feeling that the heart stops,
• attacks of angina pectoris,
• pathology of metabolism: diabetes, disruptions in the thyroid gland,
• period after myocardial infarction,
• increased meteozavisimosti (increased blood pressure, palpitations, a noticeable deterioration in overall health when weather changes).

Long-term monitoring of ECG and blood pressure can be performed for the evaluation of antiarrhythmic and antihypertensive therapy.

This kind of monitoring of the work of the heart makes it possible to track any changes on the cardiogram during the day, those changes that can not be reflected in a short period. The development of this technique belongs to the American scientist N. Holter, in whose honor the method was named.

Daily monitoring of ECG is conducted by analogy with long-term monitoring of blood pressure. A portable electrocardiograph, which approaches its size with a mobile phone, is fastened to the waist of the patient, and electrodes are attached to his chest. The device can be on the patient's body for a day or more, according to the doctor's prescription.

A fairly popular practice in recent years has been the simultaneous carrying out of daily monitoring and blood pressure, and ECG. In this case, the patient will not have to undergo the procedure 2 times. In addition, in both cases, the main requirement is the maintenance of a diary in which the patient's activities should be noted, as well as changes in his state of health during the period of diagnostic measurements.

Joint monitoring allows you to immediately get complete information about the state of the heart and blood vessels, which includes:

• response of the cardiovascular system to exercise,
• information on the work of the heart and blood vessels during night rest,
• fluctuations in blood pressure as a function of physical and emotional stress,
• information about the heart rate during the day or more,
• study of cardiac conduction.

Such an extensive study makes it possible not only to identify episodes of increasing (decreasing) pressure, loss of consciousness, etc., but also to establish the cause of these changes, for example, disturbances of the heart rhythm or blood supply to the myocardium of the heart.

Normal performance

The device for long-term monitoring of arterial pressure remains fixed on the patient's shoulder for a certain time, on the basis of which it is removed and connected to a computer. Reading the information from the Holter memory is done with the help of a special computer program attached to the device. The same program was used when the device was initialized.

On the computer screen, the doctor sees the processed information in the form of tables and graphs that can be printed on a sheet of paper. On the graph, one can observe the curves of the systolic (SBP), diastolic (DBP) and mean (SAD) arterial pressure lines, as well as the pulse rate. What indicators have a special prognostic value for doctors?

First of all, these are mean values of blood pressure, DBP, heart rate and heart rate (pulse). Calculation of average values can be carried out for a day or certain time intervals (wakefulness from 7 am to 11 am, night time from 23 hours to 7 am). It is the average values of the above values that provide valuable information about the arterial pressure in a particular person.

Normally, the average daily pressure is 130/80 mm Hg. If it increases to 135/85, doctors talk about hypertension. For daytime and nighttime blood pressure, the norm is 135/85 and 120/70, respectively. Doctors diagnose "hypertension" if these figures rise to 140/90 and 125/75. As a healthy person, the patient is distinguished by an increase in the average index of blood pressure by only 5 mm Hg.

It is from the analysis of changes in the average values that the effectiveness of anti-hypertensive therapy can be judged.

Another important indicator can be considered the frequency of increase in blood pressure (BPPD). This indicator in different sources can be called the pressure load or the hypertonic load, as well as the time index. It is the number of readings of blood pressure that are above the upper limit of the norm, expressed in percent. In the daytime this border is 140/90, and at night the boundary is within 120/80 mm Hg.

The indicator of PPR can make predictions for the future and make effective therapeutic schemes. At not very high indices, BPPAT is expressed as a percentage of the number of excesses of the norm, and at strongly increased blood pressure values, as the area under the pressure-time curve versus time of day and night, limited to the same 140/90 mmHg.

Great importance in the diagnosis of pathologies of the cardiovascular system is played not only by individual indicators of blood pressure, but also by changes in these indicators during the day. Variability of pressure is determined by the deviation from the daily rhythm curve.

STD is an indicator of the standard deviation from the mean blood pressure schedule. It can be measured as a day, or in the daytime or at night. If the STD of the systolic pressure at any time of the day is equal to or exceeds 15 mm Hg. (for the diastolic day, the indicator is greater than or equal to 14 mmHg at night - 12 mmHg), this indicates a developing hypertensive disease. If only one of the parameters is exceeded, this indicates an increased variability of blood pressure, which may be associated with left ventricular myocardial hypertrophy, carotid arteriosclerosis, pheochromocytoma, renal hypertension, etc.

By changes in the variability of blood pressure, one can judge the effectiveness of the antihypertensive drugs used. Therapy of hypertension should ideally lead to a decrease in the variability of BP indices, if this does not occur, a review of the appointments is needed.

A very important diagnostic index is the daily index. The change in daily (circadian) rhythm of blood pressure can be judged by the degree of night decrease in blood pressure (SNSAD). For systolic blood pressure, this indicator is calculated by the formula: (mean SBP value in daytime - mean value of SBP at night) x 100% / mean SBP value in daytime. By analogy, CASAD is calculated for diastolic pressure, only DBP values are taken instead of SBP values.

The normal indices of SSSAD are in the range of 10-22% (from 60 to 80% of people referred to the Dippers group). The inadequate and excessive decrease in SNDSAD has indicators correspondingly less than 10% and more than 22% (groups of Non-dippers and Over-dippers). On a steady increase in blood pressure indicates a negative index of SNSAD (group Night-peakers).

If daily monitoring of blood pressure indicates an insufficient decrease in blood pressure at night, doctors can assume the following consequences: frequent episodes of strokes, high probability of left ventricular hypertrophy and coronary heart disease, a risk of microalbuminuria developing, which will occur with more severe symptoms. Acute myocardial infarction in such patients often results in a fatal outcome.

As we see, daily monitoring of blood pressure is an extremely important diagnostic procedure, which in many cases helps to save a person's health and life, contributing to the timely and effective conduct of therapeutic actions to improve the functioning of the cardiovascular system and prevent various unpleasant and even dangerous complications.

[16], [17], [18], [19]