What is an electrocardiogram?
The electrocardiogram (ECG) is a complementary diagnostic test that aims to evaluate the electrical activity of the heart. It is one of the most commonly performed exams and is usually the first approach to screening for cardiovascular diseases.
The electrocardiogram can detect the activity of the electrical impulses generated in the heart, namely when these are altered as in cases of arrhythmias or acute myocardial infarction. Each contraction, or beat, of the heart muscle emits an electrical impulse comparable to a pattern considered normal.
How is the electrocardiogram done?
The resting electrocardiogram is a simple, non-invasive and rapid test, lasting approximately 10 minutes. It should be performed in a calm environment, with the patient lying down and with the torso bare.
For the electrocardiogram to record the heartbeat, six electrodes are placed in the chest area and one in each of the patient's limbs, which in turn are connected by a cable to the electrocardiograph (the device with which the electrocardiogram is performed). This device thus records the electrical activity of the heart through traces that will then be interpreted by the doctor.
In what clinical situations is the electrocardiogram indicated?
The electrocardiogram should be performed whenever there is a suspicion of any cardiovascular disease, since it is an examination that provides a lot of information about the structure and functioning of the heart.
In situations of arrhythmias or acute myocardial infarction may even be the only test necessary to confirm the diagnosis and allow rapid treatment to be advanced.
Is any preparation required to take the exam?
No prior preparation is required to perform the electrocardiogram.
Are there several types of electrocardiogram?
yes. The most commonly used electrocardiogram is done at rest, but there are other types:
- Electrocardiogram at rest: it is a simple, quick test performed with the patient lying down
- stress electrocardiogram: this is a longer test as it is intended to record the electrical activity of the heart, through the electrodes placed on the patient, while the patient exercises on a treadmill or a stationary bike. This test makes it possible to evaluate the activity of the heart under stress conditions, to show possible undisclosed changes in the electrocardiogram at rest
- Holter electrocardiogram: is a type of electrocardiogram that records the activity of the heart for 24 hours, through a portable device. It thus makes it possible to study the heartbeat of the heart over the course of a day, to then be compared with the activities and symptoms
Are there any contraindications to the electrocardiogram?
There are no contraindications and anyone can take the test, including pregnant women and newborns. However, in people who are unable to fully rest, for example due to tremors, the result may not be interpretable.
Are there any risks associated with taking the exam?
No. The electrocardiogram at rest is a test that does not present any risk to health.
In the case of stress electrocardiogram, it is important that it is performed in the presence of a doctor.
Source: Portuguese Society of Cardiology