Modern methods for diagnosing heart disease have achieved unprecedented efficacy. In addition to the standard cardiogram, there is a whole list of ways to identify pathologies. One of the most effective modern methods is stress echocardiography with physical activity. Who is diagnosed with? What are the prerequisites for the procedure? What is stress echocardiography aimed at? We will try to answer these and other questions.
What is stress echocardiography?
Stress ECG is a modern method for the study of ischemic diseases, the implementation of which is characterized by the creation of a load on the patient's body, which leads to an increase in the frequency of contractions of the heart muscle.
Local violations of the contractility of individual tissue sites are a direct sign of the development of pathology. In most cases, it is simply impossible to fix the minimum deviations in the work of the heart muscle during a normal electrocardiogram in a calm state. On the contrary, stress echocardiography allows you to accurately determine the presence of ischemic pathologies in the early stages of development.
A brief excursion into history
The principles of the diagnostic technique were described in the medical literature by American researchers of coronary heart disease R. Rost and L. Vann in 1979. A few years later the first ever stress echocardiography was performed on a horizontal bicycle ergometer. Subsequently, co-authors of the scientific treatise L. Erbel and S. Berthe, who joined the project, proposed replacing physical activity with the use of pharmacological and electrostimulating methods of influencing the cardiovascular system of patients during research.
In domestic practice, M. Alekhin was engaged in improving the diagnostic method. “Stress echocardiography” (PDF format) today is a sought-after guide. In this scientific work, the researcher reflected all the diagnostic experience accumulated over many years. Here, the specialist was able to display the evidence base, which confirms the feasibility of the procedure in order to study cardiac ischemia, other diseases of the cardiovascular system.
The principle of diagnosis
Stress echocardiography is based on the proposition that, when ischemia forms in the cardiac myocardium, the ability of the left ventricle to contractility in the area of the coronary artery worsens. A prerequisite for the development of pathology is a violation of venous blood flow.
Stress echocardiography allows you to record the reaction of individual zones of the left ventricular myocardium to increased, sharp loads that are on the patient's body. In addition to bringing the cardiovascular system to a state of overstrain, when performing a study, the performance of the heart muscle is also visualized in the form of a graph, which makes the method an effective tool for conducting complex diagnostics.
Study preparation
In preparation for the diagnosis, the patient is prescribed pharmacological preparations containing nitrates, which can slow down the heart rhythm and lower blood pressure. Thus, the heart muscle is protected from the active production of adrenaline under stressful loads, which can cause a general deterioration of the patient's condition.
On the day of the study, the patient is allowed to use nitroglycerin, with the help of which probable angina attacks are stopped. However, the patient must be warned in advance by the cardiologist about taking the preparations containing the substance.
Recommendations for stress echocardiography include refusing to eat about 6 hours before the diagnosis. Before the study, limited fluid intake is also welcome. The day before the diagnosis, the patient must abandon caffeine, since its tonic effect on the body can affect the accuracy of the results. No smoking is allowed immediately before the procedure.
Indications for diagnosis
In what cases is this type of diagnosis used? Stress echocardiography is prescribed to patients:
- with suspected development of painless myocardial ischemia;
- the need to assess the condition of the coronary arteries;
- study of the viability of myocardial tissue;
- heart attack, chronic forms of coronary heart disease;
- the need for surgical intervention aimed at shunting, stenting, angioplasty of the coronary arteries;
- the need to evaluate the results of therapy with the use of medications;
- forming a prognosis of the development of cardiac pathologies;
- assessing the likelihood of complications after treatment of cardiovascular diseases;
- preparation for complex operations on the heart, lungs, aorta;
- the need to identify congenital pathologies of heart valves;
- conducting an examination aimed at assessing the patient's ability to work.
Contraindications
Health problems, in the presence of which stress echocardiography is not possible in Vladimir and other cities, include the development of acute myocardial infarction. Patients with aortic aneurysm, severe arterial stenosis, acute heart failure, and hereditary heart defects are not allowed to be examined. Due to the risk of clogging of the heart muscle valves with blood clots, stress echocardiography with exercise is contraindicated in patients who suffer from severe thrombophlebitis. The reason for refusing the procedure is also individual intolerance to the components of pharmacological preparations, which are mandatory introduced into the body in preparation for the study.
Relative contraindications
When absolutely necessary, a stress test can be subjected to:
- pregnant women;
- people with minor mental disorders;
- patients who are obese;
- persons with partial dysfunction of the pancreas;
- patients with diabetes, in which there is a decompensation of the main manifestations of the disease.
The decision to diagnose these categories of patients is made by the doctor.
Load test
Stress echocardiography (Nizhny Novgorod or another city - no matter where it is performed) can be performed using various stress tests. The nature of the test used is determined by the tasks and the objective clinical situation. For example, to determine the tolerance of the patient's body to increased loads, as well as with suspicions of the likely development of heart attacks, resort to dynamic tests. In this case, the study is carried out using a treadmill or bicycle ergometer.
More tolerable for elderly patients is the load on the treadmill. In particular, this approach to the diagnosis does not provoke the occurrence of radicular pain, which can develop when using a bicycle ergometer, on which the patient has to sit in an uncomfortable position. The main drawback of the treadmill is the lack of the ability to create graphs with the results of the study directly during the test. A factor that signals the need to stop the stress test is the excess of the heart rate.
Pharmacological test
About 40% of patients who require stress echocardiography in Yekaterinburg and other cities are not able to adequately tolerate increased physical activity. Such patients are prescribed a pharmacological test.
Currently, stress echocardiography with Dobutamine is widely used. The introduction of a substance into the body opens up the possibility of simulating conditions that arise during physical exertion. The application of this solution allows you to increase blood pressure, increase contractility of the heart muscle. The increased tissue oxygen demand when using the drug causes manifestations that become a good basis for identifying signs of myocardial ischemia.
As an alternative to Dobutamine, Dipyridamole is often used. The test is based on a gradual increase in the dose of a substance in the body. At each stage, the presence of cardiac myocardial contractility disorders is examined. If the heart rate is about 120 beats per minute when the Dipyridamole top-priority norm is introduced into the body, the dose of Atropine in the amount of 1 mg is additionally applied. At the end of the test, 240 mg of "Aminophylline" is administered intravenously, which acts as an antidote to "Dipyridamole".
Results Analysis
The result of stress echocardiography is the receipt of two-dimensional graphic images. The latter make it possible to identify failures in the contractility of the left heart ventricle. When decoding the results, the degree of thickening and mobility of myocardial tissue in individual zones is taken into account.
A preliminary analysis of the graphs is performed by a specialist immediately after receiving them. Upon completion of the diagnosis, the cardiologist can view the video recording of the study in slow motion. Individual fragments of the procedure are often stored on computer disks and represent a good information base for subsequent diagnostic measures.
Where to do stress echocardiography?
To conduct a study using a stress test or pharmacological test, it is enough to contact the nearest cardiography center. Diagnostics are able to specialized offices of state medical institutions. A more expensive option for the procedure may be to make an appointment in a private clinic, which has the equipment necessary for conducting tests and has specialists of relevant qualifications.
Benefits of diagnosing myocardial ischemia using stress echocardiography
Among the main advantages of the method are the following:
- An impressive list of opportunities for studying the features of the functioning of the heart muscle.
- Portability of echocardiographic equipment, which allows tests to be performed outside the hospital.
- The relatively low cost of diagnosis.
- The possibility of a qualitative assessment of the nature of myocardial thickening.
- Safety procedures for the patient.
disadvantages
If we talk about the disadvantages of stress echocardiography, it is worth noting primarily the presence of difficulties in assessing the quantitative results of the samples. For this reason, the determination of accurate results is possible only when diagnosed by an experienced, highly qualified researcher.
Among other things, technical problems often arise during tests. The probability of their appearance on average is about 5-10%.
Finally
Stress echocardiography is still a fairly innovative method for studying coronary heart disease. Such diagnostics are prescribed primarily for patients who have undergone standard electrocardiographic tests, which did not allow obtaining enough information to identify pathologies. Finally, stress echocardiography makes it possible to detect stenosis of the coronary arteries, the picture of which remains unclear after angiography.