Exercise stress testing has traditionally been a way to measure factors related to the heart as our heart speeds up with activity. In its simplest form, an exercise test allows us to measure 5 things as we increase our activity:
- Exercise tolerance – as compared with people of the same age and conditioning.
- Blood pressure in response to activity
- Symptoms: for instance does one get chest pain with increasing activity which sometimes is seen with heart disease.
- Ability to monitor one’s EKG since persons with heart disease may show EKG changes with exercise that we do not see at rest.
- Heart rhythm assessment – Some people develop certain heart rhythm abnormalities only with exercise.
When a patient walks on a treadmill we can learn many things about a person’s condition. If a person has chest pain or shortness of breath, is this likely to be related to the heart or another condition? Patients who can walk and have a normal EKG are candidates for this test.
What is a Stress test and how is it done?
Patients are asked to wear comfortable walking shoes and exercise clothing. One shouldn’t eat for 2 hours prior to the test. Our technician will apply electrodes that are stuck to the chest so that one’s EKG can be monitored with walking. A BP cuff is placed to measure blood pressure. A patient will then walk on the treadmill with the elevation and speed increased every 3 minutes until the patient says to stop. This is an open-ended test and will be stopped whenever the patient says that he or she has had enough.
When is a standard stress test not enough?
There are many situations in which simply walking on a treadmill connected to an EKG monitor is neither enough or appropriate.
- In patients who cannot exercise.
- In patients who start with an abnormal EKG
- In patients who are already known to have a heart problem in which more information is necessary.
In all 3 of these situations we recommend testing coupled with imaging. That includes Nuclear stress testing, PET (Positron Emission Tomography) or stress echoes. Many times instead of exercising we will simply inject a material called Lexiscan that will allow us to get the same information without requiring a person to walk. The associated images provide valuable information about the condition of one’s heart arteries.
When does the patient know how he/she did on the stress test?
If one walks on a standard stress test, he or she can be told before they leave as to how they did or whether further testing may be appropriate. When one gets a nuclear stress test, PET scan or stress echo, feedback to the patient will not be ready for at least 24 hours. When a patient is done one of these three tests please ask when and how they can be expected to be notified about their test results.