Myocardial scintigraphy preparation for the study. What is myocardial scintigraphy? Myocardial scintigraphy after drug loading

Heart disease requires careful examination so that the time to identify problems and prescribe a course of treatment. There are different options for how you can find out what malfunctions in the main organ of the human body. One of the effective methods for checking the heart is using myocardial scintigraphy, which shows how the blood supply to the myocardium occurs.

When is myocardial scintigraphy used?

Using this method, you can understand the degree of filling one of the parts of the heart with blood. It is myocardial scintigraphy that allows you to determine the localization of a place that has failed from a violation of the blood flow of the heart.

This method is most often used when performing exercise tests along with the use of a bicycle ergometer, as well as a treadmill.

Indications for this procedure:

there is a need to assess the activity of the left ventricle when heart disease is observed, as well as changes in ECG parameters;
it is necessary to evaluate the effectiveness of the treatment;
detection of angina pectoris;
assess the risks of complications that may arise.

Myocardial scintigraphy is a key method for determining coronary vascular disease. It helps to determine not only the zone of poor blood supply to the myocardium, the so-called ischemia, but also to distinguish it from the zone of tissue necrosis. This helps not to make mistakes during the treatment, as well as to increase its effectiveness.

The first rule to follow for conducting this study is that nothing should be eaten before it is carried out. Myocardial scintigraphy is performed exclusively on an empty stomach.

In addition, for the correct results of the procedure, it is necessary that the liver be absolutely clean from radiopharmaceuticals during the procedure. Therefore, do not schedule a tomography within the next hour before the scintigram. This will lead to the fact that the liver has time to clear itself of previous dox medications.

At the same time, the same radiopreparations are not allowed to enter the stomach and duodenum. This result is achieved by the absence of taking medications of this group 2-3 hours before the procedure, as well as the fact that it is performed on an empty stomach.

The essence of the scintigraphy procedure and its implementation

Myocardial scintigraphy is a study that is carried out by introducing radioactive isotes into the body, after which a picture of the movement of this substance in the myocardial region is taken, which makes it possible to determine how the blood flow passes and the degree of its insufficiency. This procedure is carried out using a gamma tomograph, which is a diagnostic radiological device of nuclear medicine.

It is more common to call the procedure of myocardial scintigram perfusion. It is carried out using radioactive thallium or technitium. This study helps to achieve a result, but it is mainly carried out with physical activity. This is due to the fact that the isotope must be administered at the moment when the patient feels an attack of myocardial ischemia, and it is just provoked by the load. In this method, the image can be obtained within a few minutes after the introduction of radioactive thallium, as it gives the best and fastest development.

In addition to this method, in medicine, myocardial scintigraphy is also performed using vasodilators, which increase pervusion in the area where there is a normal blood supply. Accordingly, areas where there are fewer isots are less perfused, which indicates the location of ischemia. To better view the result, a tomographic image is used. Although sometimes used and semi-quantitative analysis.

Evaluation of the result of myocardial scintigram is carried out according to the following scheme:

visual examination and image evaluation using three axes of the heart for control;
quantitative analysis to evaluate the difference between the accumulation of isotopes in different areas of the myocardium, is carried out using computer technology;
localization of the defect from the walls;
assessment of the vital activity of myocardial segments.

Reasons for incorrect research results

Sometimes it happens that the result shows a positive one, but in fact, the reasons are completely different. This may be due to various factors. But the main reasons that lead to a false positive result when myocardial scintigraphy is performed are:

a large body weight of the patient, provoked by obesity, because due to the large amount of fat, a poor image is obtained;
the large size of the mammary glands, which, in turn, also close the view of the equipment;
too high placement of the diaphragm, which also creates a shutter for viewing the picture of the movement of isots;
the presence of a tendency to accumulate, which leads to the fact that the substance is poorly excreted from the body and remains with each subsequent study, distorting the result.

Cardiac examinations, such as a myocardial scintigram, always require attention and a very responsible attitude. Therefore, it is important to know how to prepare for it in order to get accurate results.

Scintigraphy is an innovative method of radionuclide diagnostics developed on the basis of high-precision nuclear medicine technologies. The use of radioactive isotopes makes it possible to detect pathological changes in organs and systems at the initial stage of their development. This method enables the radiologist to assess the extent of damage and functional abnormalities at the molecular and cellular level.

While other hardware-diagnostic methods reveal only anatomical and physiological disorders. Myocardial scintigraphy is of particular importance, since such a study of the heart muscle makes it possible to identify complicated or atypical cases of various heart pathologies, in particular, coronary disease.

Radionuclide diagnostics of the heart

The diagnostic method of nuclear medicine is based on the use of radioisotopes integrated with cardiac drugs (radiopharmaceuticals). Such a substance is injected into the examined person, and through continuous blood circulation, is delivered directly to the myocardium. The degree of absorption (absorption) of radionuclides by the heart muscle shows its real blood supply.

A special label on the preparation transmits the emitting signal to the detector of the gamma camera, where it is processed and rebuilt using a special computer program into a visual image on the monitor. On a two-dimensional (2D) picture displayed on the screen, it visualizes in detail the anatomical and topographic, functional state of the myocardium, and specific areas with pathologies.

A healthy muscle vigorously absorbs radioisotope compounds, a necrotic area (dying, affected by ischemia) does not have the ability to absorb. Radionuclide diagnostics occupies a leading position in cardiology, because it is such an examination through which it is possible to detect a cardiac anomaly that is not subject to other studies, in particular, echocardiography (ultrasound) and electrocardiography (EGC).

The principle of operation of a radionuclide preparation during scintigraphic examination

Prerogative aspects

Scintigraphy is a study designed not only to determine cardiac pathologies. With its help, the skeletal system, thyroid and parathyroid glands, abdominal organs, and other body systems are examined. The advantage of cardiac radionuclide diagnostics lies mainly in the identification of severe complications of ischemia and the ability to predict their further development. IHD (ischemic heart disease) is determined at an early stage, as well as in cases where the latent form of the disease prevents its detection using other examinations.

Other prerogatives include:

safety. The dose of radioisotopes absorbed by the heart muscle does not harm the body, and does not entail any consequences of irradiation;
no penetration interference into the body (non-invasiveness);
painlessness;
The procedure has virtually no side effects.

Special measures to prepare the body for the examination are not provided.

Preparations and types of procedures

Myocardial scintigraphy is carried out with the participation of radionuclides: Technetra, Miovuila, Teboroxime, Technetium. The preparations quickly disperse in active cardiac tissues, are well fixed by a gamma camera, have a short time interval of decay, and are quickly excreted from the body. For the objectivity of the results, the study is carried out in two stages.

The initial procedure is carried out at rest. Before or synchronously with radiodiagnostics, an electrocardiographic examination (ECG) is performed. Repeated diagnosis suggests the presence of a load that provokes an attack of coronary disease. In anticipation of an attack, the patient is injected with a substance, the active tension of the myocardium and blood vessels helps to obtain more accurate data.

By the conductivity of the drug, the vessels determine the speed and quality of blood flow. The smaller the number of accumulated isotopes in one or another part of the vessel, the less volume of blood it is able to pass. Consequently, stenosis (narrowing) or thrombosis (formation of an obstruction to blood flow) develops in these places.

Load types

The increase in myocardial contractions is achieved in two ways:

natural physical activity. The load is carried out through a sports mini-training of the patient on a cardio stepper or a bike path - simulators equipped with special devices.
Forced medication. It is produced with the help of injections of certain medications that stimulate the activation of heart contractions.

Cycling is one of the types of natural exercise during myocardial scintigraphic examination (second stage of the procedure)

The end result will be a comparative analysis of myocardial functionality indicators.

Main Diagnostic Features

A detailed analysis of the obtained image allows the doctor to establish the presence or absence of the following changes: the speed, volume and degree of heart blood supply deficiency, dead areas of the myocardium, post-infarction scars, areas affected by ischemia. By evaluating the results, the doctor can predict the further course of the disease and possible complications.

Appointments and contraindications

Cardiac scintigraphy is performed to detect pathologies of the organ, and as a control examination for diagnosed diseases. The quality and effectiveness of therapy after heart surgery is assessed.

The main indications for the appointment are:

chest pain (cardialgia), the etiology of which was not revealed by ultrasound and ECG;
IHD (cardiac ischemia);
necrosis of certain areas of the myocardium (heart attack);
the ability of the heart muscle to contract in response to stimulation;
preoperative diagnostics (surgery of the heart and coronary vessels);
checking the status of pacemakers;
examination of the heart with contraindications to MRI.

In addition, scintigraphy is carried out as a preventive measure in people with a predisposition to diseases of the cardiovascular system (hypertension, diabetics, smokers), as well as in unfavorable heredity from heart disease. The examination is recommended as a preventive measure for men aged 45+ and people experiencing constant stress.

This procedure, due to the high information content of the results of assessing cardiac load, is popular with professional athletes. The procedure is not prescribed in the presence of severe allergic reactions to radiopharmaceuticals, cardiac decompensation. Relative (relative or temporary) contraindications include:

perinatal period in women. The study is allowed only for vital indications of an emergency nature, since the risk of teratogenic (external harmful) effects of radioisotopes on the baby is likely;
inflammation of the myocardium;
exacerbation of hypertension;
atrial fibrillation (atrial fibrillation);
violation of the cardia (valve function);
influenza virus infections.

In chronic diseases, the examination must be carried out in the remission stage. During lactation, a woman is allowed to undergo scintigraphy, observing the conditions for a temporary cessation of feeding (2-4 days after the examination). Expressed milk during this interval is strictly forbidden to give to a child.

Relative contraindications may be temporary. When the condition stabilizes, the patient is allowed to the procedure

Preparatory measures

Advance preparation for the study consists in stopping course therapy with certain medications for 2–4 weeks: bromine-containing drugs for anxiety and cough, drugs with iodine prescribed for hypothyroidism and other diseases, iodine for external use (skin damage, iodine mesh), stimulants erections (for men). It is mandatory to consult a cardiologist on the use of cardiac drugs.

Excluded coffee and "energy" a couple of days before the procedure. Immediately prior to cardiac scans, a fasting regimen of 8 to 12 hours should be observed. The patient must notify the radiologist about the presence of allergic reactions, chronic pathologies. Particular attention is paid to the degree and form of bronchial asthma. Women need to warn a medical specialist about a hypothetical (alleged) pregnancy. You can not do an x-ray with a contrast agent and a scintigraphy on the same day.

Carrying out radionuclide diagnostics

Myocardial scintigraphy is performed on special equipment under the supervision of a radiologist. The procedure itself can be divided into several stages:

Removal of cardiac indicators. The patient undergoes an ECG examination, which takes no more than a quarter of an hour.
Administration of a substance to a patient. A medical specialist gives an intravenous injection of a radiopharmaceutical.
Waiting period. It is necessary to wait for the complete penetration and distribution of the chemical compound in the body, in particular in the tissues of the myocardium (the time range is from 20 to 30 minutes).
Study at rest. It is the responsibility of the patient during the procedure to maintain a static horizontal position. Any body movements can negatively affect the quality of the images, and, accordingly, the reliability of the results.
Loaded scintigraphy. The patient conducts a mini-training on the simulator. As an alternative to sports exercises (if the patient is physically weak), the stress test is performed using injections of special cardiac stimulators. For provocative tachycardia, cardiotonic drugs are most often used: Dobutamine, Curantil, Dipyridamole. During the period of action of drugs or physical activity, the patient undergoes an ECG and pressure measurement.

At the moment of maximum increase in heart rate, the radiopharmaceutical is re-introduced. After dispersal of the substance in the heart tissues, after about half an hour, another procedure is performed on a gamma tomograph. In total, radionuclide diagnostics takes about three hours, depending on the physical condition of the subject.

Survey results

Decoding of the survey results is carried out according to the established algorithm on a comparative analysis scale. Comparing the normative indicators with the data obtained, the doctor determines the presence and degree of changes in myocardial tissues: assessment of the location of the heart relative to the axes, the presence of defects, their localization and scale, assessment of the activity of the radiopharmaceutical in the affected areas.

Comparing the results of the scintigram (images) carried out at rest and load, the degree of manifestation of the paroxysmal nature of ischemia is determined. Radiopharmaceuticals can be of two categories. Some tend to accumulate in areas of the heart that are not subject to changes, and in areas of the myocardium with necrosis, the absorption of radioisotopes will be low. Others, on the contrary, accumulate in defective tissues.

The doctor evaluates the results depending on the drug used. The patient presents the scintigraphy protocol to the attending cardiologist, who determines the further tactics of conservative therapy or decides on a heart operation.

Estimates of the accumulation of the radiopharmaceutical in the myocardium along three axes: short (top row), long vertical and long horizontal (bottom row)

Post-procedural manifestations

Complications after the examination are observed, extremely, rarely in patients with unstable blood pressure, it is possible to exceed the indicators, allergy sufferers can fix the presence of skin rashes. This is not dangerous, the allergy is stopped by taking conventional antihistamine drugs in 2-3 days. The dose of cardiac stimulants usually does not affect the activity of the heart after the procedure.

Within 24-48 hours after the procedure, the patient is advised to change the drinking regimen. It is necessary to drink more water or other liquid (except alcohol) to speed up the process of excretion of radionuclides from the body. Diagnosis using nuclear medicine methods is carried out only in large Russian cities. Therefore, patients decide where to get a scintigraphy based on their geographical location and financial viability. For example, in the NTSSSH them. A.N. Bakuleva, a radionuclide examination of the myocardium costs about 7,000 rubles.

Pathologies of the cardiovascular system occupy almost the first place among all human diseases. The provocateurs of such conditions are the unfavorable ecological situation and the rhythm of life in the modern world.

Among the most common heart diseases, pathologies of the coronary vessels are distinguished. They can cause disability or even death.

The standard diagnostic methods used cannot provide complete information, since the study is carried out at rest for a short period of time. A thorough examination of deviations is required, for which highly informative methods are used. These include myocardial scintigraphy.

However, not all people know what it is, how safe it is, and in what cases it is prescribed.

Description of the procedure

Scintigraphy is a special method that allows you to examine the blood circulation in the coronary vessels by injecting radioactive isotopes that tend to accumulate in the myocardium. After that, a picture is taken showing the movement of radionuclides along the vascular walls of the heart. The picture determines the conductivity of the blood flow, the lack of blood supply to the tissues.

The main advantage of the method lies in its information content and the possibility of repeated use during the day, since the drug is removed from the bloodstream for a long time.

Also, the examination is done with the presence of functional tests and with a load, which more accurately determines the degree and location of ischemia.

Among the disadvantages of the method are:

The need to take special care when working with radiopharmaceuticals.
The complexity of the method, which is important, since there are other methods that do not require impressive costs (ECG, ultrasound).
Visualization of only pathological myocardium. Only a zone with an increased or low accumulation of a substance falls under registration. This may be an indicator of not only acute, but also chronic ischemia.

There are two main ways to conduct research:

Myocardial perfusion scintigraphy is a method for diagnosing coronary heart disease. For research, radioactive thallium is used. The method is considered more informative compared to electrocardiography, which is carried out under the influence of physical activity.
With the use of drugs of the vasodilating group. The injected agent allows you to expand the lumen of the vessels and increase their patency. In places where there is a smaller accumulation of isotopes, the volume of throughput blood will be weak, indicating pathology in these areas.

When is scintigraphy performed?

This method of examination is prescribed in the following cases:

the first diagnosis of a patient with cardiovascular pathologies;
as a preventive measure for people at risk;
the need to obtain a more accurate diagnosis if the symptoms are similar to other diseases;
selection of effective tactics for the treatment of the patient and his recovery.

In addition, the procedure is assigned:

if there is a need to assess the functioning of the left ventricle with altered ECG parameters;
to confirm or exclude the presence of angina pectoris;
to establish the appropriateness of the use of certain methods of therapy, such as coronary bypass surgery, angioplasty, stenting;
in order to find out the reasons that contributed to the development of cardialgia.

Scintigraphy is necessary, since the choice of methods of treatment and surgical intervention will depend on its results. The procedure can be carried out only on the recommendation of a cardiologist, when there is a need for:

establishing the level of blood supply to tissues;
general assessment of blood flow;
detection of places of localization of scar areas after a heart attack or foci of ischemia, which receive less oxygen and the necessary nutrition during exercise.

Indications and contraindications for

Myocardial scintigraphy is prescribed for patients with already confirmed coronary heart disease and for its establishment.

Indications for the application of the procedure:

Identification of factors that provoke pain in the retrosternal region.
Preventive examination of people who belong to the risk group. It:
- those who have hypertension or diabetes;
- those who have high cholesterol levels;
- persons over the age of 45 (for the male half of the population), and from 55 - for women;
- smokers with a long history in this field;
- people with a hereditary predisposition to heart disease.

Examination of people who are engaged in professional sports (examination is carried out immediately on the eve of competitions or training).
Establishment of angina pectoris and heart attacks.
Monitoring the patient's condition and assessing the effectiveness of the therapy.
Operations or other surgical procedures performed on the heart.

Contraindications for scintigraphy:

pregnancy and lactation period;
hypertension;
myocarditis;
failures of heart rhythms;
severe heart failure;
the patient's body weight exceeds 120 kilograms;
serious infectious diseases accompanied by high fever;
aortic stenosis.

Patient preparation

Before starting the procedure, the patient is introduced to the rules. He is told how to properly prepare for scintigraphy, they reveal the presence of all possible contraindications.

Preparation for the study is as follows:

24 hours before the start of the examination, do not eat foods that contain caffeine, as well as cola and chocolate.
It is recommended to stop taking certain medications, which may cause the results of the examination to be incorrect.
If the patient has contraindications, as well as a tendency to allergic reactions, it is necessary to tell the doctor about this in advance.
The procedure is contraindicated for pregnant women. Before the study, you must make sure that there is no pregnancy.
After a scintigraphy, nursing mothers should stop breastfeeding for 48 hours.
In the case of men taking Viagra and other similar drugs, the doctor should also be warned about this.

12 hours before the examination, you can not eat at all. Patients with diabetes can only eat low-fat foods.

Research progress

How is a standard perfusion scintigraphy performed:

30 minutes before the start, a radiopharmaceutical (RP) is injected into the patient's vein. During this time, thallium spreads through the bloodstream and concentrates in the organs.
After that, the gamma camera scans the myocardium by capturing radio emission and converting them into images.
The duration of scintigraphy is 2-4 hours. This time is enough to conduct a study of the heart at rest and during physical exertion. This stage involves both natural and pharmacological stress myocardial scintigraphy.

During physical activity, the heart needs more oxygen. Against the background of the load, the blood flow begins to increase. With violations in the circulatory system, such stress will indicate the problem even brighter.

To get stress of a natural nature, use a treadmill or exercise bike. When running, the intensity of the load gradually increases. All indicators will be displayed on the monitor. When maximum stress is reached, the patient is re-injected with a dose of a radioisotope substance.

With existing contraindications to physical exercises, use a drug load. Drugs that mimic sports activities increase the pulse and contractions of the heart.

Based on the results of image comparison, the presence of ischemic foci in the heart is confirmed or refuted.

Deciphering the results

Analysis starts from the top of the heart muscle with a gradual advance to the base. In assessing the deviations are divided into defects of a transient or permanent nature. Compare images at rest and under load.

Emotional stresses are characterized by transient defects and are not detected in a calm state. Permanent changes do not occur, which will indicate the presence of a heart attack.

Analysis of the accumulation of radiopharmaceuticals is done using a quantitative scale from 0 to 3 points. Such a system makes it possible to accurately determine the complexity of ongoing violations.. A radioactive agent tends to accumulate only in places of active metabolic processes, that is, in tissues not affected by ischemia.

The scheme used in the analysis of scintigraphy parameters:

images are studied and images are analyzed along three axes;
do quantitative analysis;
determine the location of defects in relation to the heart;
evaluate the viability and establish the degree of damaged areas of the myocardium.

Among the factors that can distort the results of the survey, there are:

increased tendency of tissues to absorb radionuclides;
large mammary glands;
high location of the diaphragm of a congenital nature;
many subcutaneous fat deposits.

How safe is it

Many patients are interested in the dangers of such a procedure. It should be noted that this is a completely painless and safe method. Radioisotopes introduced into the body do not harm health. Normally, they are excreted in a period of up to two days.

Side effects may occur:

skin allergy;
drops in blood pressure;
frequent urination.

Such conditions are not considered dangerous and are eliminated by means of medications.

Procedure price

Myocardial scintigraphy is one of the expensive, but quite affordable methods. Depending on the level of the medical organization and the region, prices will differ.

For example, in medical centers in Moscow, the cost of a two-stage procedure is about 16,000 rubles. Carrying out scintigraphy only at rest costs within 7500 rubles.

Where such a procedure is done, the attending physician can tell.

Diseases of the cardiovascular system among other pathologies occupy almost the first place. The reasons for their occurrence are a number of adverse factors and the rhythm of human life.

A certain group of diseases of the heart muscle are a threat to human life and require immediate treatment.

For the timely detection of diseases, highly informative research methods are used, among which myocardial scintigraphy is distinguished.

Description of the method

Myocardial scintigraphy is a nuclear scan of the heart muscle when drugs are used that contain radioactive isotopes. The drugs are administered intravenously. They begin to circulate through the human body and enter the heart.

The functionality of the myocardium is assessed based on the degree of saturation with radionuclides. The absence of deviations is established with the active absorption of particles. In the case when the presence of empty areas is noted, ischemia is diagnosed.

Due to the presence of several types of research, specialists are able to timely identify the presence of the disease, determine the localization and degree of the pathological process.

Kinds

To identify certain features of the course of pathology, several types of diagnostic research are used. To establish a latent form of angina pectoris, special stress tests are prescribed, which are performed using special simulators or medicines.

Scintigraphy with technetium pyrophosphate

The technique is prescribed for suspected myocardial infarction, which has an atypical and asymptomatic course, as well as in complex clinical cases.

The diagnosis is established due to the properties of the drug to accumulate in necrotic tissue areas. Based on the results of the study, the specialist evaluates the depth and extent of the spread of the pathological process. In the pictures, the affected area looks like a spot.

Perfusion scintigraphy

For research, thallium is used, which is absorbed by the tissues of the heart muscle, depending on the intensity of the blood flow. The disease is established in the presence of "cold spots". They appear on the picture as a result of vasoconstriction, through which thallium does not enter.

Myocardial perfusion scintigraphy is performed under load or at rest. This allows you to conduct a complete study of the state of the heart muscle.

stress test

The method allows you to assess the level of performance of the heart under stress. For this, a treadmill is used. During the test, constant monitoring of blood pressure, the frequency of contractions of the heart muscle is necessary. ECG is also monitored.

After reaching the maximum performance, the specialist re-introduces radioactive isotopes. After 30 minutes, a heart examination is performed on a scintigram.

Isotope scintigraphy with pharmacological loading

In cases where it is impossible to conduct a stress test due to the presence of certain contraindications, the load is simulated with the help of drugs. For this, Dobutamine is administered intravenously. It increases the oxygen demand of the heart. In cases where the presence of a defect is established after the administration of the drug, this indicates angina pectoris. A heart attack or cardiosclerosis is diagnosed with persistent areas of reduced blood flow.

Indications

Myocardial scintigraphy is prescribed both for patients with already established diseases of the heart muscle, and in order to clarify the preliminary diagnosis. After a thorough study of the results of the study, the doctor determines the further course of therapy, the need for surgical intervention.

The indications for the study are:

Identifications the reasons pain in the chest.
Prevention in a group of patients at risk of developing heart muscle diseases.
Holding operations on the heart or coronary vessels.
Survey athletes before the competition.
Previously transferred heart attack.
Installed angina.

Cardiac muscle diagnostics are also prescribed to patients in order to monitor ongoing treatment to determine its effectiveness. In the case when angina pectoris is established, the study is carried out at the time of the attack. This allows you to assess the nature of the course and other features of the pathology.

Contraindications

Myocardial scintigraphy, despite its safety, has a number of contraindications. The procedure is not assigned in the following cases:

Period pregnancy and lactation.
infectious lesions characterized by a significant increase in body temperature.
heart attack severe myocardium.
Hypertensive crisis.
Cardiac failure in the acute period.
Diseases characterized by damage valves hearts.
Attack of atrial fibrillation arrhythmias.

The study is also not performed in cases where the patient is diagnosed with myocarditis. Before the procedure, the doctor carefully examines the patient's history to determine the presence of contraindications.

Training

In order for the results of the study to be accurate, it is necessary to properly prepare for the procedure.

The patient must inform the doctor about the medication. In some cases, they should be discarded, as the diagnostic results may be incorrect. Also, the specialist should be informed in the presence of allergic reactions to medicines, food.

When prescribing myocardial scintigraphy to nursing mothers, if it is impossible to carry out another diagnostic method, a woman should stop breastfeeding for at least 2 days.

If a man takes Viagra and similar drugs, it is necessary to inform the doctor about this.

12 hours before the study, you must completely refuse to eat. In cases where the patient is diagnosed with diabetes, it is allowed to take a small amount of low-fat food.

How is the procedure carried out

Myocardial scintigraphy is not considered a complicated procedure, but the duration is from 2 to 4 hours, depending on the method of examination. Before the procedure, a drug is administered intravenously, which includes radioactive isotopes.

Half an hour later, the patient is placed in a special gamma camera that scans the heart muscle. Her work is based on capturing radioactive radiation and converting it into a series of images.

During the procedure, a study of the heart muscle is performed at rest and during exercise. Based on the images, a specialist can establish the presence of certain myocardial diseases, since all violations of his work are well visualized.

Load scintigraphy

To conduct this type of study, not only a drug with radioactive elements is used, but also a treadmill or exercise bike. The study begins with a low-intensity functional test, the frequency and level of which increase gradually.

During the patient's exercise, the specialist takes readings of blood pressure, heart rate, and ECG. In cases where it is impossible to conduct a study with a natural load, it is imitated with the help of drugs. Under their influence, the heart begins to experience a lack of oxygen, as a result of which the pulse quickens, blood pressure rises.

At the maximum intensity of the load, the drug is administered intravenously with radioactive isotopes. Scanning is carried out after half an hour in several different projections.

What diseases helps to identify

Myocardial scintigraphy helps to establish certain heart diseases and confirm the preliminary diagnosis.

In cases where the study used the waist, in the picture with ischemia or necrosis are defined as "cold spots". This is due to the fact that the tissues affected by the pathological process do not absorb radioactive isotopes.

If a storage defect occurs after a load on the heart, angina pectoris is established. In this case, the attack of the disease is caused by physical activity. If this defect is observed at rest, the patient is diagnosed with cardiosclerosis or infarction.

With the use of technetium, the tissues of the heart muscle accumulate radioactive particles much better. In the event of a lesion, "hot spots" are observed. In the absence of diseases, the accumulation of isotopes does not occur.

The results of the study are evaluated only by the specialist who performed the procedure.

results

To decipher the received images, the specialist uses specially designed computer programs and computer cards. They help to get more information about defects in the heart muscle.

First of all, the specialist compares the pictures taken before and after physical exertion. By studying them, you can:

Inspect heart along its axes.
Determine a place localization pathological process.
Reveal viability affected areas of the heart muscle.
Determine the degree of accumulation radioactive isotopes in different areas of the myocardium.

Only a highly qualified specialist can correctly decipher the research data.

Possible Complications

Myocardial scintigraphy is considered a completely safe procedure, even though radioactive isotopes are used in the study. But the level of exposure at the same time does not exceed the radiation of the X-ray preparation. Thanks to modern equipment, it can be reduced to a minimum.

The isotopes that are introduced into the body are not hazardous to the patient's health and are excreted naturally within two days.

But after myocardial scintigraphy, side effects may develop, which is due to the individual sensitivity of the patient's body to drugs. Possible side effects include:

allergic reactions. They appear as a skin rash.
increased frequency urination.
A sharp change in blood pressure pressure.

In exceptional cases, the development of a heart attack or a life-threatening disruption of the myocardium is noted. This complication is diagnosed in 1 patient out of 30 thousand.

When using drugs that mimic physical activity, side effects may also occur in the form of dizziness, shortness of breath and pain in the retrosternal region. They completely disappear after the specialist introduces a special solution that neutralizes the effect of the drugs.

Advantages and disadvantages

First of all, myocardial scintigraphy is the most informative method for studying the heart muscle. In addition, unlike most methods for detecting defects, the study can be carried out several times during the day. This is due to the fact that the administered drug remains in the blood for another 48 hours.

But the procedure also has a number of disadvantages. First of all, the study does not allow assessing the patency of the coronary vessels, but only the state of the heart muscle. Only the area of increased or low accumulation of the radioactive preparation is established on the image.

Despite the fact that the study practically does not emit radioactive radiation, careful work with the apparatus and solution for intravenous administration is required.

Myocardial scintigraphy is considered a labor-intensive method. If possible, it is replaced by an ultrasound examination of the heart muscle. The procedure also helps to identify the presence of certain defects or irregularities.

Also, one of the disadvantages is the cost of the study, which is higher than the price of an MRI. But despite this, the technique is popular with patients, as it allows you to identify the disease even at the initial stage of its development.

Myocardial scintigraphy is a modern, informative method for studying the heart muscle. It has a minimum number of contraindications and allows you to identify certain diseases of the heart muscle at the initial stage of development, when the pathology proceeds without symptoms.

To obtain reliable results, the patient must properly prepare for the procedure and strictly follow the doctor's recommendations. The interpretation of the results is carried out by the specialist who conducted the study.

To get a complete picture, he uses special programs and maps. The method is completely safe, and the study can be carried out several times a day, which allows you to compare previously obtained results with the latest ones.

Radioisotope scintigraphy is also known as "nuclear scanning". This is a very informative ultra-modern method of radiation diagnostics, with which you can evaluate the work of various human organs and systems. With the help of scintigraphy, doctors can determine errors in the blood supply to the myocardium even at a routine examination and identify the problem in time. If there is already a problem, this diagnostic method helps to adjust the treatment to achieve its maximum effect.

What is myocardial scintigraphy?

Among other options for this non-invasive study, there is myocardial scintigraphy. During this procedure, a substance with radioactive isotopes is injected through a vein into the subject. The radioactive marker, along with the bloodstream, spreads throughout the body, including entering the myocardium. A gamma camera that captures the radiation of the marker shows its distribution in the heart muscle. In which part of the myocardium there will be a large concentration of the marker, there is a better blood flow and vice versa.

Active absorption of the drug means normal blood supply, and in places of ischemia of the heart, its absorption is weak.

The gamma camera takes pictures where all these areas are clearly visible.

In myocardial perfusion scintigraphy, radioactive thallium is used. Myocardial scintigraphy with a load or with samples is possible. This method of determining coronary artery disease is more sensitive compared to electrocardiography, also performed with physical activity. With its help, you can more accurately find the position of the focus of ischemia.

When a person is physically active, the heart is forced to work more intensively, therefore it itself needs additional oxygen and nutrition. Normally, this leads to increased blood circulation in the coronary network that feeds the heart. But in the presence of ischemia during exercise, an increase in the nutrition of the heart muscle may not occur, or it will be insufficient. Comparing scintigrams obtained at rest and activity, you can understand the whole clinical picture, analyze it and find areas with ischemia.

Video about myocardial scintigraphy:

Method capabilities

Myocardial scintigraphy can:

determine the degree of circulatory failure;
in general, assess the coronary blood supply to the myocardium;
visualize ischemic foci that occur during exercise, and scar tissue at the site of a previous infarction;
to differentiate zones with insufficient blood circulation from those already subjected to necrosis;
assess the possibility of complications.

The results obtained will influence the tactics of treatment and planning of surgical intervention.

Indications for myocardial scintigraphy

Thanks to scintigraphy, it is possible to understand the degree of blood filling of any heart chamber and identify the exact places where the heart begins to malfunction due to impaired blood supply. Most often, this study is combined with treadmill tests and bicycle ergometry as an exercise.

Indications for myocardial scintigraphy are as follows:

to detect angina pectoris;
when ECG changes or symptoms of heart disease appear;
to assess the work of the left ventricle;
for preventive diagnostics among risk groups of cardiovascular diseases (before invasive procedures, surgeries, sports);
to assess the risk of possible complications;
to find out the causes of chest pain;
to assess the functionality of the heart muscle after myocardial infarction;
to determine the success of the drug therapy, angioplasty, coronary bypass grafting;
for the diagnosis of coronary heart disease (this is one of the best methods for the study of coronary artery disease) and the study of its contractile potential.

At the same time, scintigraphy can be equally useful both at the stage of diagnosing disorders of the coronary circulation, and with already confirmed diagnoses. After all, with the help of it, you can more accurately assess the degree of ischemia and choose a more adequate treatment strategy. For example, when a diagnosis has been made using computed tomography or catheterization, scintigraphy is prescribed, which will shed light on the need for surgical intervention in relation to the coronary vessel.

Contraindications for scintigraphy

Despite its effectiveness, scintigraphy has contraindications:

excessive obesity (body weight over 120-130 kg);
pregnancy;
general infections accompanied by fever;
severe ailments that do not allow loading the cardiovascular system;
high and uncontrollable blood pressure;
severe heart failure or acute myocardial infarction;
severe cardiac arrhythmia and heart valve defects (especially aortic stenosis).

Preparation for the procedure

After the appointment of scintigraphy, the patient is given some recommendations:

Refuse food a few hours before the procedure. On the last day before the examination, do not take caffeinated products: coffee, tea, chocolate, Coca-Cola, etc.
Tell your doctor about all the medications you take regularly, some of which he will suggest that you temporarily stop using.
Women of childbearing age should be sure that they are not pregnant.

Nursing mothers need to express all the milk before the procedure in order to feed the baby with it for 2 days after the procedure. The fact is that the radioactive marker will be present all this time in breast milk, so it is impossible to feed the baby with it for 2 days after the procedure.

Men should warn the doctor in advance if they use Levitra, Viagra and similar drugs. The fact is that in the process of research, the appearance of angina pectoris is possible, which will have to be stopped with nitro-drugs, and those, in turn, are incompatible with means of increasing erection.
Patients with asthma should also warn a specialist about their disease.
In order for the scintigraphy results not to be distorted, the patient's liver must be free of radionuclides. Therefore, it is impossible to put next in time such studies as computed tomography, since after it the liver will still “glow”, at least an hour.
It is also impossible to allow radioactive substances to enter the gastrointestinal tract, which is facilitated by the ban on food and taking such medications 2-3 hours before the start of the procedure.

Myocardial scintigraphy

Initially, the procedure is performed when the patient is in a calm state, and then he is offered a normalized physical activity, against which the work of the heart is monitored.

A small dose of a radioactive marker (thallium or technetium-labeled tetrofosmin) is injected into a patient's vein through a catheter.
This substance, along with the bloodstream, spreads throughout the body, entering the heart, where it is best adsorbed by intact myocardial cells.
At this time, the specialist analyzes the distribution pattern of the marker in the heart using a gamma camera that captures the radiation of a radioactive substance, and the results are displayed in the form of dynamic and static images synchronized with the ECG.
By determining the concentration of isotopes, it is possible to compare the blood supply in different parts of the heart. If the marker is actively absorbed, then there is a normal blood supply in this place, and where the radionuclides are poorly absorbed, there are areas with ischemia or necrosis.
After the introduction of the marker, about half an hour should pass, after which the gamma camera starts to work, taking a series of pictures, in which all zones are very clearly visible.
Then the heart is subjected to a load, and the procedure takes place against the background of the partial decay of a radioactive element. The standard source of physical activity is a bicycle ergometer or a treadmill.
If physical stress is contraindicated for the patient, then they resort to a pharmacological option - they administer drugs that speed up and increase heart contractions (dobutamine, dipyridamole, adenosine), while monitoring pressure, pulse and taking an electrocardiogram.
At maximum physical activity, the marker is re-introduced, and half an hour after that, three axial scanned projections of the heart are made.

If the patient feels pain in the chest, pressure, shortness of breath, cramps in the legs, dizziness, then right during the procedure, he must tell the doctor about it.

The whole procedure takes a long time - from 2 to 4 hours. A big plus is the non-invasiveness of scintigraphy (without tissue excision).

Deciphering the results

Depending on the type of radioactive isotope used by scintigraphy, the decoding will differ diametrically.

When using a marker with thallium areas of the myocardium that have undergone necrosis or ischemia absorb it to a lesser extent, and normal tissues are much more active. That is, at the site of ischemia in the image there will be an empty spot with minimal accumulation. If such an accumulation defect appears as a result of physical activity, then it speaks of an angina pectoris attack, and if it is present in a calm state, then this is most likely cardiosclerosis or MI.

The interpretation of the results is usually carried out by the same specialist who performed the procedure. In order to more accurately identify defect zones and subsequently study them, polar maps of the cardiac axes and specific computer programs are used. The analysis starts from the upper cardiac region and gradually moves from the short axis to the base. Deviations are regarded as permanent or transient defects. The images taken under load and at rest are compared. Transient defects that appear during emotional stress do not occur in a calm state. But invariable defects that do not change in any condition may indicate a previous heart attack.

The amount of adsorbed radioactive substance in the tissues is determined on the basis of quantitative analysis and is indicated on a scale from 0 to 3 points. With this, it is possible to more accurately assess the degree of changes in tissues. Analysis of the results of scintigraphy is carried out according to the following algorithm:

First, the images are studied visually and images of the myocardium are viewed in three projections.
Then quantitative analysis is carried out using digital technologies to determine the difference between the concentrations of the marker in different parts of the heart.
The position of defects relative to the walls of the heart is specified.
The degree of damage and the viability of problem areas are assessed.

With a positive test, the following indicators are important:

the multiplicity of the accumulation defect, that is, the areas affected by ischemia;
determination of the boundaries of scar tissue after a heart attack in areas with a low concentration of the marker;
detection of the focus of a transferred infarction by a defect in the accumulation of isotopes;
deviations in the accumulation of isotopes in lung tissues;
determination of the defect of accumulation that appears at low load with a pulse rate of 120 beats per minute.

Why might the result be wrong?

Sometimes the results are interpreted as positive, although in reality things are not so rosy. There are various reasons for this, the most important of which are:

overweight of the subject, for example, due to obesity - in this case, the fat layer significantly degrades the image quality;
large mammary glands act in the same way as the fatty layer;
too high a diaphragm becomes a barrier to display the isotope distribution pattern;
the tendency of the body to accumulate a marker that is poorly excreted from the body, increasingly distorting the results of subsequent procedures.

In order to obtain the most accurate and unambiguous results from such a subtle research method, proper preparation for this procedure is necessary.

Is scintigraphy safe?

The emergence of modern devices and new technologies has made it possible to reduce the harmful effects of radioactive gamma radiation on the patient's body.

The minimum possible amounts of radioactive markers, which are quickly eliminated from the body, are involved in the diagnosis.

But they may have an allergic reaction (redness, rash, swelling of the face, skin of the feet and hands), frequent urination, pressure surges. If exercise-mimicking drugs are used, they may also cause side effects. When working with the simulator, patients with cardiac problems may experience chest pain. True, such phenomena are not dangerous and are quickly eliminated by drugs.

Prices for myocardial scintigraphy

This high-tech procedure, by definition, cannot be cheap, not only due to expensive equipment, but also due to a rather long duration (2-4 hours), but the price of a cardiac scintigraphy also depends on:

the level of the medical institution itself;
the region in which it is located.

If myocardial scintigraphy is done in Moscow, the prices for it are as follows:

at rest - about 7 000 rubles;
the price of myocardial scintigraphy with and without load is about 15 000 rubles.

Have you already done myocardial scintigraphy? Or were you just given this diagnosis? Tell us about your feelings and results in the comments - share them with others.