An electrocardiographic exercise test (ECG) is a test to assess the efficiency of the circulatory system and control blood pressure during increased physical activity. In addition, it allows you to diagnose the causes of chest pain, making it possible to determine whether the patient suffers from ischemic heart disease. It also contributes to the determination of the patient’s condition after a heart attack. [1]
Indications for performing an exercise test
- Assessment of patients with congenital or acquired heart defects,
- Suspicion of ischemic heart disease. (assessment of the severity and effectiveness of treatment)
- Assessment of patients with cardiac arrhythmia,
- The opinion of patients over 40, leading a sedentary lifestyle, who plan to start intensive physical training,
- Monitoring the progress of rehabilitation of patients after cardiac surgery,
- Evaluation of people performing specific professions (mainly men over 40) and competitive sports [2]
Contraindications
Absolute contraindications that make it impossible to conduct an electrocardiographic stress test:
- Recent myocardial infarction (especially 2 days after myocardial infarction),
- acute inflammation of the heart,
- acute pericarditis,
- Uncontrolled symptomatic heart failure,
- acute pulmonary embolism,
- recent lung infarction,
Relative contraindications that allow the exercise test to be performed with extreme caution:
- Hypertrophic cardiomyopathy (disease of the heart muscle causing it to enlarge or thicken),
- electrolyte disturbances,
- Left coronary artery stenosis,
- Heart rhythm abnormalities
- Severe hypertension (>200 mmHg systolic, >110 mmHg diastolic)
- Aortic aneurysm <6 cm in diameter
- Mental or physical conditions preventing the examination [2]
What does the stress test look like?
Before performing an exercise ECG, an interview with the patient is conducted, as well as a resting ECG to assess the work of the heart. If the measurement does not show any contraindications, you can proceed to the next stage, which is the cardiac stress test.
In the appropriate places on the chest, arms and legs, measuring electrodes are glued, which, connected to the camera, record the work of the heart. A cuff is placed on the arm to control blood pressure. The test is performed on a treadmill or bicycle ergometer.
The patient gradually overcomes an increasing load until the heart rate reaches its maximum value. The examination is closely monitored by the attending physician (usually a cardiologist). In the event of adverse symptoms such as vomiting, dizziness, chest pain or an unexpected increase or decrease in blood pressure, the doctor should stop the examination.
The next stage focuses on observing the work of the heart while reducing the intensity of exercise. The doctor analyzes the pressure and the record of the ECG curve returning to baseline values. The test results are then analyzed in detail. [3]
Exercise test – interpretation of results
After performing the electrocardiographic analysis, the doctor considers the changes caused by the increase in physical load. We can expect two stress test results, positive or negative. A positive result occurs when there is an abnormality in the ECG or when the test is stopped because the patient is not feeling well. Such a result indicates the presence of ischemic heart disease, which requires further testing, such as coronary angiography, to determine subsequent treatment. However, if the patient does not report any symptoms and there are no undesirable abnormalities in the cardiogram, the result is negative.
Preparation for the stress test
- For trouble-free application of the electrodes, men should shave their chest hair.
- About 3 hours before the examination, it is recommended not to eat, drink sweet drinks and refrain from smoking.
- Alcohol consumption is prohibited at least 24 hours before the examination.
- No physical effort should be made at least 12 hours before the test (exercise, long walks, heavy lifting).
- Clothing and footwear should be comfortable.
- Before the examination, the patient takes all regular medications. However, you should always consult your doctor who may change his mind
- Testing should not be performed during an infection.
- The patient should bring:
- referral for examination,
- a list of medications taken,
- results of previous exercise tests,
- results of additional tests
- After the examination, the patient should remain under medical supervision for up to 30 minutes. (4)
Exercise test in ischemic heart disease
Ischemic heart disease is a consequence of insufficient supply of oxygen and energy substrates in relation to the demand of the heart muscle. Most often it is caused by atherosclerosis of the coronary arteries. The deposition of atherosclerotic plaques in the walls of the arteries leads to their narrowing and reduced blood flow, which leads to hypoxia of the heart muscle. A typical symptom of the disease is chest pain, which is characterized by choking, burning or burning. They are frequently accompanied by dizziness, palpitations, shortness of breath or anxiety. It is worth noting that the patient at the beginning of the disease may seem healthy. Diagnosis of the disease largely depends on meticulously collected medical history. However, additional tests are needed to determine the course of treatment. One of them is the resting ECG, but it is characterized by low sensitivity and specificity.
The effectiveness of this test can be obtained only when pain is present, while at rest the result can be normal, proving that the patient is healthy. The electrocardiographic stress test, which is characterized by low sensitivity and high specificity, may turned out to be very competent. At the time of increasing physical effort, the heart rate and blood pressure increase, and ECG changes are characteristic of coronary artery disease. However, it should be remembered that the attempt is also subject to errors and may yield false results. [5]
Bibliography:
- Scherf, D., & Schaffer, A. I. (1952). The electrocardiographic exercise test. American Heart Journal. https://doi.org/10.1016/0002-8703(52)90250-0
- Fletcher G.F., Balady G.J., Amsterdam E.A. i wsp. Exercise standards for testing and training: a statement for healthcare professionals from the American Heart Association. Circulation 2001; 104: 1694–1740.
- Rechciński, T. (2021). Elektrokardiograficzna próba wysiłkowa. https://publicum.umed.lodz.pl/info.seam id=AML93a4abce38774e349b6aef3cdb9033f7
- Ogórek-Tęcza, B. [. (2016). Elektrokardiograficzna próba wysiłkowa. [W : badania diagnostyczne w schorzeniach układu sercowo-naczyniowego]. https://ruj.uj.edu.pl/xmlui/handle/item/136665
- Parol, G. (2014). Non-invasive diagnostics of ischaemic heart disease — which option to choose? Parol | Folia Cardiologica. https://journals.viamedica.pl/folia_cardiologica/article/view/38291/27147
