ECG recording during exercise is obtained in the same manner as the basic ECG at rest. The only difference is that the subject is physically active now. For this purpose we utilize a treadmill. The intensity of the performed work on the treadmill is measured in metabolic equivalents (METs).
Exercise stress test is performed to measure fitness of the patient and the corresponding cardiovascular changes (ergometry).
In the examples below exercise stress testing should not be carried out:
- in a fresh heart attack - at least 2 weeks must pass
- in severely high blood pressure at rest,
- in fresh thrombosis or embolism (fresh vessel blockage caused by blood clots)
- in severe heart failure.
Prior to the exercise test, we record an ECG at rest. Then the patient starts exercising by walking on a treadmill. Every three minutes the workload is increased to a higher level (speed and incline of the treadmill). During the test we constantly monitor the ECG and measure the blood pressure at every stage. Both variables continue to be measured for approximately 6 minutes after the end of the test.
We abandon the test if any of the following occurs:
- changes in the ECG graph or a heart rhythm disorder,
- characteristic chest pain (angina pectoris)
- an excessive elevation of blood pressure,
- drop in blood pressure during the exercise,
- difficulty breathing, dizziness,
- muscular fatigue,
- maximal heart rate regardless of age.
The purpose of the stress test is to achieve maximum heart rate and the estimated workload depending on the age, weight and gender of the tested subject, because only in this case we can conclude in a relatively reliable manner that no serious heart disease is present.
In very rare cases it can lead to severe heart failure, severe heart arrhythmias or a heart attack.
One option is stress echocardiography. This is an ultrasound observation of the heart function changes under exercise stress.
Disturbed blood flow in the heart muscle may be shown by scintigraphy of the heart and cardiac catheterization.
A 24-hour ECG measurement can reveal arrhythmias during physical exertion, but the said the examination is not standardized.