What is exercise testing?
An exercise test is performed by an Exercise Physiologist to assess the heart's response to stress or exercise. It can be scheduled to assess patient’s symptoms or to monitor their cardiac status over time following heart surgery.
During the test, an EKG (also called ECG) is monitored while your child is exercising on a treadmill or stationary bike. The EKG is one of the simplest and fastest procedures used to evaluate the heart. Electrodes (small, plastic patches) are placed at certain locations on your child's chest. When the electrodes are connected to the EKG machine by lead wires, the electrical activity of your child's heart is measured, interpreted, and printed out for the physician's information and further interpretation.
An EKG tracing and blood pressure measurement will be taken at certain points during the test to compare the effects of increasing stress on the heart.
Additional equipment may be used in specific patients to assess their breathing at rest or during exercise. A resting Spirometry test (also called Pulmonary Function Test) is performed to measure the size and strength of the lungs and rule out potential signs of asthma or lung disease. The Spirometry test is performed by forcefully blowing out one breath for as long as you can until all the air is expelled from your lungs. This single breath effort may be repeated to obtain the best reproducible efforts and lung values. Then, prior to starting the treadmill or stationary bike, a snorkel-style mouthpiece may be placed to measure every breath you take with exercise. This provides information on how efficient the heart and lungs are working together under stress.
On a treadmill, the incline and treadmill speed will be increased periodically in order to make your child exercise harder. If your child is riding a bicycle, he/she will pedal faster against increased resistance. Your child will exercise until reaching a target heart rate (determined by the physician based on your child's age and physical status) or until your child is unable to continue due to fatigue, shortness of breath, chest pain, irregular heart rhythms, or other symptoms.
Exercise testing may also be combined with another diagnostic test called an echocardiogram. The echocardiogram is used to assess the structure and function of the heart through ultrasound. When these two tests are combined it is called a Stress/Echocardiogram. This testing may be used on rare occasions in specific patient populations to assess heart function or blood flow dynamics through valves while the heart is beating faster from exercise, thus adding further information on top of the initial electrical results from the EKG.
How is the exercise test performed?
The procedure is performed in a physician's office, clinic, hospital, or medical center. The equipment used on every patient includes an EKG machine, electrodes (small, plastic patches that stick on the skin), and lead wires which attach to the skin electrodes. A blood pressure cuff attached to an electronic monitoring machine is used. A treadmill or stationary bicycle is used for exercise. Additional breathing equipment may be deemed necessary for specific patients.
Your child will have initial, or "baseline," EKG and blood pressure readings done prior to exercising. He/she will walk on the treadmill or pedal the bicycle during the exercise portion of the procedure. The incline of the treadmill will be gradually increased, or the resistance of the bicycle will be gradually increased, in order to give your child a harder workout. EKG and blood pressure will be monitored during the exercise portion of the test. Your child will then sit after exercising while EKG and blood pressure are monitored for a short time, perhaps another 5 to 10 minutes or so.
The procedure will take approximately one hour, including check-in, preparation, and the actual procedure.
After the procedure, a hospital stay is not necessary, unless your child's physician determines that your child's condition requires further observation or hospital admission.
Your child may feel a little tired or sore for a few hours after the procedure, particularly if he/she is not used to exercising. Otherwise, your child should feel normal within a few hours after the procedure, if not sooner. Staying hydrated and eating a light meal or snack is recommended prior to the test.
Depending on the results of the exercise test, additional tests or procedures may be scheduled by the physician to gather further diagnostic information.