Treadmill Test - Causes, Symptoms and Treatment. MF.

Indications for treadmill test
Contraindications
Preparation for
procedure Treadmill test method
Decoding results
Complications

The heart muscle( myocardium) is the most powerful and hardy muscle in the human body. Thanks to the myocardium, a continuous flow of blood is carried out across all organs and tissues and providing oxygen and nutrients to the cells of the body. But the cells of the myocardium also need oxygen, so that they fully fulfill their contractile function. To do this, the heart braids the network of blood vessels, which are called coronary, or coronary. If these arteries are partially or completely blocked by thrombi or atherosclerotic plaques, they become impassable for blood, and then a mismatch arises between the blood supply and myocardial oxygen demand. This is especially pronounced in cases of physical exertion, when there is an increase in the heart rate( heart rate), and the myocardium needs more oxygen than at rest. This condition leads to the development of coronary heart disease( CHD) and myocardial infarction.

Usually these diseases brightly manifest themselves clinically and with the help of additional research methods( ECG, 24-hour ECG monitoring, echocardiography).But sometimes the coronary heart disease may be asymptomatic or manifest as non-specific symptoms. In such cases, the doctor may assign a treadmill test to the patient to clarify the diagnosis.

Treadmill is an instrumental diagnostic method based on the use of physically controlled dosed physical activity( walking on a treadmill) in order to increase the heart rate, which is used to evaluate myocardial response to an increased demand for oxygen. Thus, the treadmill test allows you to identify the presence of certain heart diseases, and to confirm or disprove the diagnosis in case of poorly informed ECG data or a discrepancy of clinical symptoms with ECG.

Treadmill Testing Equipment

In addition to routine testing, there are modifications to the treadmill test - treadmill with gas analysis ( lung function evaluation with the study of the concentration of oxygen and carbon dioxide on inhalation and exhalation), stress echocardiography( conduction of ultrasound of the heart before andafter physical exertion), conducting a test with a Doppler study( examining the blood flow in the heart before and after the load).

Indications for treadmill test

1. Examination of patients who do not complain of cardiovascular system:
- persons over 40 years of age engaged in socially important occupations( public transport drivers, pilots, pilots, drivers, etc.), andas well as those involved in sports,
- men over 40 years and women over 50 years who have a history of two or more risk factors for heart disease - diabetes, arterial hypertension, the presence of sudden cardiac death in close relatives mSixty years of age, increased blood cholesterol levels and associated lipid metabolism disorders, obesity, smoking,
- patients older than 40 years before routine surgery in the field of gynecology, general surgery, urology, oncology and other surgical profiles( if necessary)

2.Examination of patients with heart complaints:
- diagnosis of coronary artery disease, clarification of the functional class( FC is a classification criterion that allows to differentiate the degree of manifestation of clinical or instrumental conditionsdepending on the degree of physical activity),
- evaluation of ongoing medical therapy, or cardiac surgery,
- diagnosis of "silent" myocardial ischemia( asymptomatic ischemia detected on the ECG),
- diagnosis of arterial hypertension, cardiac rhythm disturbances( paroxysmal ciliaryarrhythmias, atrial tachyarrhythmias), arterial blood flow in the lower extremities,
- examination of disability in patients with IHD or after myocardial infarction.

Contraindications for research

Despite the ease of use, availability, accurate diagnosis and safety for the patient, there are still contraindications for conducting a treadmill test. These include:

- acute vascular pathologies - acute myocardial infarction, stroke, exfoliating aortic aneurysm, systemic thromboembolism( pulmonary, mesenteric, femoral arteries), thrombosis of the lower extremity veins,
- acute infectious and febrile conditions,
- acute rheumatic fever, acute pericarditis, acutemyocarditis,
- chronic heart diseases in decompensation stage - heart defects, severe heart failure, pulmonary edema, complicated rhythm disturbances,
- respiratory, digestive, enokrinnoy systems decompensated( asthma, liver cirrhosis, diabetes, etc.),
- acute surgical pathology( acute pancreatitis, gastric ulcer and complicated, etc.).

Patient preparation for the

test The patient can be sent to perform a treadmill test at the department of functional diagnostics from a polyclinic or a profile department of a hospital( cardiological, surgical or other profile in the case of a pre-planned surgical procedure).The direction is performed by a therapist, cardiologist or physician. Before the examination, the patient must undergo other diagnostic methods - ECG, holter( daily) ECG monitoring, ultrasound of the heart.

One day prior to the examination, the patient, in agreement with the attending physician, should cancel preparations that affect the heart rate and improve coronary blood flow( beta-blockers, nitroglycerin and its analogs).It is also necessary to exclude or reduce the number of cigarettes smoked and restrict coffee consumption, since the substances in them contain a direct effect on the frequency of contractions and may distort the results of the survey.

Three to four hours before the study, the patient is allowed to take a light breakfast, but it is better not to take food immediately before the test. The water regime is allowed in the usual volume.

How is the treadmill test

? As already mentioned, the patient is sent to the treadmill test in a planned order from the polyclinic or the profile department of the hospital where he was hospitalized at the time of the study. After receiving ECG results, echocardiography and examination by a therapist or cardiologist, the nurse accompanies the patient to the department of functional research methods. Then he is invited to the office and asked to lie down on the couch for measuring blood pressure( BP) and recording the ECG at rest( before exercise).To do this, the patient is placed electrodes on the chest with a plaster and fixes the cuff from the tonometer( apparatus for measuring blood pressure) on the shoulder.

After registration of the received data, the patient is asked to occupy a comfortable position on the treadmill and begin walking in the rhythm habitual for him. At the same time, ECG and AD are continuously recorded on the computer monitor of the doctor. Every three minutes the incline of the treadmill changes and the rate of movement accelerates, that is, a dosed increase in physical activity occurs. This continues until the patient begins to experience unpleasant subjective sensations or discomfort( headache, dizziness, shortness of breath, severe chest pains or other pains in the heart that are characteristic of IHD).Also, the study can be discontinued if there is a significant increase in blood pressure, there are signs of heart rhythm disturbances or myocardial ischemia on the ECG.

After walking, the registration of blood pressure and ECG lasts about another ten minutes, then the doctor interprets the results and issues his conclusion. After this, the patient is taken to the department or, if sent from the polyclinic, he can go home if he feels well and does not reveal life-threatening conditions during the examination. The duration of the procedure is about forty minutes( of which 9 - 12 minutes are allocated directly to the physical load), without causing in most cases a significant disturbance of well-being, since at the slightest discomfort the study can be stopped at the request of the patient.

Decoding of test results

As with any medical examination, an independent analysis of the test results is unacceptable. The certificate must be evaluated by the attending physician. Nevertheless, it is important for the patient to know that the main purpose of the test treadmill is to find out if he has coronary artery disease or other cardiac and vascular diseases, and also to determine the individual threshold of tolerance for physical exertion, which plays a rolein the subsequent tactics of treatment( for example, if a patient has pain or changes on the ECG at the slightest load, it must be further examined by coronary angiography and determine the appropriateness of using the surgical method of treatment ANDBS).

Let's stop on the analysis of the received data. In conclusion, the level of lifting and speed of the track must be indicated, the level of exercise tolerance( TFN) - high, medium or low, changes in blood pressure and ECG( heart rate, ST segment elevation or depression( depression), rhythm disturbance)through which the blood pressure and heart rate are normalized after stopping the test.

The test results are evaluated by whether the submaximal( 75% of maximum) heart rate was achieved( 140-160 beats per minute, depending on sex and age).If achieved, and the patient does not experience any pain, shortness of breath, a significant increase in blood pressure, cardiac failure recorded on the ECG, and no ischemia of the myocardium, the sample is considered negative, that is, the data in favor of the expected diagnosis is not enough.

The sample is considered positive in the event that the patient has complaints of heart pain and / or objective signs of myocardial ischemia on the ECG.

A sample is considered to be a doubtful if the patient is not concerned with symptoms typical of coronary disease, and no diagnostic changes are found on the ECG.

The test may be of little informative if the study was discontinued at the request of the patient due to other circumstances not related to the occurrence of complaints from the heart and blood vessels.

In addition to these results, the conclusion indicates the type of response of blood pressure to the load - normotonic( maximal blood pressure rises to 190/100 mm Hg), moderately hypertensive( BP within 190/100 - 210/100 mm Hg), hypertensive( blood pressure more210/100 mm Hg), hypotonic( BP 140/80 - 150/90 mm Hg), sympathic asthenic( a gradual increase in blood pressure in the process of loading followed by a sharp drop in blood pressure at the height of the load or in the first minute of the recovery period after stopping walking).

Are there any complications during the test?

Complications in the conduct of a treadmill test occur in extremely rare cases. These include syncopal conditions( syncope, collapse with a sharp drop in blood pressure), stroke, acute myocardial infarction, ventricular fibrillation, atrial fibrillation and other rhythm disturbances, sudden cardiac death, asthmatic attack in patients with bronchial asthma.

Prevention of complications is a thorough examination of the patient before the study with the identification of possible contraindications, as well as increased supervision of the doctor conducting the examination, the condition and well-being of the subject.

Doctor therapist Sazykina O.Yu.