When is this exam indicated?
It is a fundamental method for investigating heart disease, including ischemic heart disease (suspected or known), and for evaluating non-cardiological clinical conditions. It is of little value for the diagnosis of heart failure. With symptoms of dyspnea or fatigue, impaired exercise performance is a sign of decompensation, although it is not specific. For patients not undergoing therapy for decompensation, a normal exercise test rules out the diagnosis of heart failure. However, for patients with a confirmed diagnosis of decompensation, exercise tests help to determine the severity of the disorder and the possibility to monitor the process.
How is it performed?
Traditionally it is performed either on the exercise bike or treadmill, electrodes are applied on the chest and back for recording the electrocardiogram and placed on the arm sleeve for pressure detection. The person should be dressed in sports clothes and sneakers, after a light meal taken at least 3-4 hours before. Its duration is variable, the purpose is to reach a certain heart rate that is dependent on age (the formula 220-age is used), it also depends on the degree of training, the behavior of the pressure, the appearance of any symptoms or abnormal signs on the electrocardiogram that suggest the interruption of the test. On average, trained people are able to run or cycle for as long as 10-15 minutes, less trained people stop earlier. Considering the time required for the preparation and the time needed for rest after the test and the result expectation, it is necessary to estimate a total of 45-60 minutes.
The possible risks are: the occurrence of anginal pain, signs of coronary ischemia, arrhythmias, excessive pressure increase. In fact they are exactly what one is looking for, not by chance the stress test is "a provocative test". They are usually transient and pass by discontinuing the effort. However, the test must be carried out by experienced physicians equipped with the appropriate tools to deal with complications (drugs, oxygen, defibrillator). Serious and/or unresolvable complications are very rare, the important point is to evaluate well beforehand the absolute and relative contraindications. The test cannot be performed by those who are unable to walk.