An ECG, or electrocardiogram, is a graphic representation of the electrical activity of the heart muscle as it contracts and relaxes. When the ECG is obtained on a heart that is working harder due to exercise or medication-induced stress, the test is called an exercise ECG, or "stress test." This test is useful in detecting problems that may not be apparent while the heart is at rest.
The exercise test is generally safe. A small amount of risk does exist since exercise stresses the heart. Extremely rare complications include abnormal heart rhythms and a heart attack. Experienced personnel are available to handle any emergency.
Doctors can see how well your heart functions during exertion by studying what happens during the exercise test.
The exercise test is especially useful in diagnosing blockages in the coronary arteries. When the coronary arteries are blocked or narrowed, the heart muscle may not be getting enough oxygen during exercise. This often results in symptoms of angina (chest pain) and abnormal changes on the ECG.
The exercise ECG test can be performed in the doctor's office or at the hospital. A trained technician will place several electrodes (small sticky patches) on your chest and shoulders to allow recording of the ECG during exercise. Wires link the electrodes to an ECG machine. A cuff will be applied to your arm to monitor your blood pressure during the test.
You will be shown how to step onto the treadmill and how to use the support railings to maintain your balance. The treadmill starts slowly, and then the speed and incline are increased gradually.
Your blood pressure will be checked every few minutes, and the ECG will be carefully watched for abnormal changes. You will be instructed to report any symptoms, such as chest pain, shortness of breath, leg fatigue, or dizziness.
The test may end when you become too tired to continue or when you experience significant symptoms. Other times, the test may be stopped when you reach your peak heart rate or when your ECG shows abnormal changes.
After the exercise portion of the test is over, you'll be helped to a chair or a bed. Your blood pressure and ECG will be monitored while you recover. The technician will remove the electrodes and cleanse the electrode sites. The test typically takes between 45 minutes to one hour, which includes preparation for the test, the exercise portion, and the recovery period.
Typically, the doctor will review the images at a later time and prepare a report detailing his findings. We will forward a report to the patient's doctor as well as notify the patient of the results. It may take three to four days for the doctor to receive the report.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.