As a stress test technician, you are responsible for performing electrocardiogram (ECG) tests on patients while they exercise or walk on a treadmill to gather data on their heart. You monitor the patient and their heart during exercise and record exercise intensity, patient pain levels, and blood pressure. You must ensure the proper placement of electrodes on the patient's body to obtain appropriate data. You must inform the appropriate care providers with any cardiac abnormalities or concerns that occur before, during, or after ECG testing. Duties also include maintaining the ECG equipment, keeping the ECG lab clean, and restocking supplies as needed.