ECG tests with dosed physical activity (veloergometry, treadmill test)

ECG tests with dosed physical activity (veloergometry, treadmill test) are widely used in modern cardiology. The main idea of ​​the study is that physical activity is an ideal and natural type of provocation, which allows a full assessment of the physiological compensatory-adaptive mechanisms, and in case of latent or overt pathology, an assessment of the degree of defective functionality of the cardiovascular system.

For the test, a bicycle ergometer (bicycle) or a treadmill (treadmill) are most often used. These devices differ from ordinary treadmills and bicycles in that they have an accurate load regulator. During the period of work on simulators and for a certain period of time after training, the patient’s heart function is taken.

Indications for testing

The indication for testing is latent coronary heart disease, which is not confirmed by other diagnostic methods. An exercise ECG is also performed for people with impaired cardiac conduction, those who plan to dramatically increase the rhythm of life and physical activity. With the help of diagnostics, it is possible to determine the type of arrhythmia, which is caused by increased physical exertion.

Bicycle ergometry, treadmill test are also used to assess the severity of valvular heart ducts. Based on the findings of the study, surgeons can determine with a high degree of accuracy the tactics of actions during the operation for heart valve replacement.

The technique allows to examine patients who have suffered a heart attack. The procedure is carried out to evaluate the effectiveness of the therapeutic actions performed and determine the maximum allowable physical activity. Doctors draw up a rehabilitation plan and a prognosis for the further condition of patients.

A cardiologist directs the test. The study is available in all diagnostic and treatment facilities, subject to the availability of appropriate equipment.

Contraindications for testing

Of the absolute contraindications, it is worth noting:

• acute aortic dissection;
• pulmonary infarction;
• symptomatic heart failure that is difficult to control;
• severe symptomatic aortic stenosis;
• unstable angina;
• the presence of myocardial infarction (in the first two days).

Relative contraindications include:

• High degree AV block;
• physical and psycho-emotional inferiority, which prevents the implementation of physical activity;
• HCM (hypertrophic cardiomyopathy);
• severe bradyarrhythmia and tachycardia;
• severe hypertension;
• electrolyte disturbances;
• stenosis of the heart valves in a pronounced state;
• the presence of lesions of the trunk of the left coronary artery.

Preparation for the procedure

A few days before the diagnosis, the doctor reduces (if possible) the dosage of drugs that affect the cardiovascular system. Three hours before testing, you should completely stop eating food and liquids (especially with caffeine). Before the procedure, it is recommended to exclude physical activity and nervous strain.

Diagnostic technique

First, electrocardiograph electrodes are applied to the patient. Then active testing begins.

Bicycle ergometry – diagnostics is carried out by using an exercise bike with the presence of stepped physical activity. On the simulator, the specified power is provided with a pedaling speed of at least sixty revolutions / minute – it is important to understand that the patient independently monitors the indicators, since arrow deviations indicate a decrease or increase in the power being performed.

The test unit is 1kgm/min and 1W. The procedure is carried out by using a continuous increasing load in steps of 25 to 50 watts. One step lasts three minutes.

The treadmill test is an exercise-type test that involves simulating walking up under ECG control. Metabolic units of measurement (MET) correspond to the unit of oxygen consumption at rest. 1 MET is equal to 3,5 ml O2/kg min.

The load can be adjusted within a wide range, and is controlled by a diagnostician regarding the patient’s condition. After carrying out a large load, it is necessary to create a “cooling” period for the patient in order to avoid the development of post-exercise hypotension.

Criteria for stopping testing

Clinical and electrocardiographic criteria signaling the termination of loads: a sharp attack of angina pectoris; the presence of 85% of heart contractions from the maximum limit; violation of rhythm and cardiac conduction; marked general weakness.

Interpretation of results

Samples can be non-informative, doubtful, positive and negative. A negative test is when the patient reaches the maximum heart rate, as a result of which he develops signs of myocardial ischemia. A positive test – signs of myocardial ischemia appear regardless of the absence or presence of an angina attack. If the samples are not brought to the maximum heart rate, they are considered non-informative or incomplete.

A doubtful sample is the presence of clinical and electrocardiographic changes of an unreliable nature.

It is important to consult a cardiologist at the first sign of angina pectoris or heart failure to prevent the development of more serious pathologies. Early diagnosis is the key to effective treatment.

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