The stress test, also called ergometric test, stress test or electrocardiogram under stress, is a test that allows you to study the functioning of the heart when subjected to physical effort; in the cardiopulmonary exercise test the response of the lungs is also evaluated.
The test consists of collecting, during intense physical activity, information regarding:
- the change in the number of beats and rhythm of the heart recorded through the electrocardiogram
and when the doctor requests it:
- the change in blood pressure levels
- the variation in the values relating to respiratory function
- consumption of oxygen
When health conditions do not allow it, fatigue is reproduced through the administration of drugs (such as dipyridamole, dobutamine or adenosine).
The test is prescribed after performing other investigations including: electrocardiogram, spirometry or echocardiocholordoppler.
The stress test allows you to ascertain the presence of heart or respiratory problems that would not emerge in conditions of rest. In particular, the exam is used to verify:
- the presence of problems with the vessels that carry blood to the heart (coronary arteries) and the need, or not, to proceed with other specific tests to ascertain the presence of coronary artery disease
- the functioning of the heart and, therefore, the presence or absence of heart failure (heart failure) and ischemic heart disease
- the functioning of the heart after an episode of angina pectoris, after a myocardial infarction or angioplasty and the evolution towards heart failure
- the presence of arrhythmias recording the time of the test when abnormalities in the rhythm or number of heartbeats occur
- the state of health of the heart when performing long-term drug therapies, the need or not to modify them, the possibility of resuming physical activity and at what intensity
Furthermore, with the stress test, it is possible to evaluate possible breathing difficulties (dyspnea) and changes in blood pressure.
The exam is also used in fitness visits for competitive sports, in checks on athletes and certain categories of workers.
It is recommended that you ask your doctor if you need to stop any ongoing care and book the stress test at a hospital.
In the days preceding it, it is recommended not to drink alcohol or spirits; on the same day it is advisable not to drink coffee, not to smoke, not to make efforts, not to eat in the previous 2/3 hours and to dress in a tracksuit and sneakers.
Remember to bring all the tests performed previously and related to the pathology to be investigated at the time of the examination.
Before the start of the test, adhesive electrodes will be applied to the chest, back and limbs, the blood pressure cuff will be placed, the index finger will be inserted into an instrument to measure blood oxygenation (oximeter) and, if cardiopulmonary exercise testing is required, a mouthpiece will be placed on the face.
The test consists of recording an electrocardiogram, first at rest and then while walking on a treadmill, or pedaling on an exercise bike, with increasing levels of effort.
During the test, in fact, the speed and the incline of the treadmill or the resistance of the pedals of the exercise bike are increased.
The electrocardiogram (ECG) is monitored continuously and blood pressure is measured at predetermined intervals; generally the exercise continues until the number of beats reaches 80/90 percent of the maximum values predicted for age and sex or checks for muscle exhaustion; the test is stopped first only if breathing becomes too labored, if chest pain appears, if you feel dizzy, if significant abnormalities are recorded in the electrocardiogram, if blood pressure values become too high or too bass.
The phase following the most intense activity is also very important, called the recovery phase, in which an increasingly less intense movement is performed until the effort is gradually recovered. This phase usually lasts about 5 minutes.
The risk of falling ill is very low, however performing the test in an equipped health facility together with qualified personnel ready to intervene helps to make the examination safer.
The stress test is absolutely not indicated in some cases, for example in acute myocardial infarction (AMI), heart failure with disorders that cannot be controlled with drugs, in aortic aneurysm or in the case of ongoing infectious diseases.
The doctor compares the information collected during all the different stages of the examination, from those related to the most intense activity to those related to recovery, with reference values for age groups and sex.
If you have reached the end of the test without difficulty, as it could happen if the test was performed to obtain "fitness for" competitive sports or for a periodic check-up, and no specific disorders emerged, it means that the heart is functioning well. and the test passed.
If the results are not among those considered normal, or if important disturbances have appeared during the test, the doctor may interrupt the examination prematurely and prescribe the appropriate therapy.
If, on the other hand, during the examination the cause of the ailments for which it was prescribed was not identified, the doctor may ask for further tests such as, for example, an exercise scan or a stress echocardiography; if the information collected suggests the presence of coronary heart disease, coronary angiography will be prescribed.
Colecchia D. Guidelines for the ergometric test. SMORRL notebooks, : 6, 1995
Foundation for your heart, HFC Onlus ANMCO