ECG An ECG technician, also called as cardio graphic technician, uses electrocardiogram machines to run diagnostic tests to measure a patient’s heart rate, monitor cardiac rhythm. Electrocardiogram Technicians monitor and test a patient’s cardiovascular performance using ECG equipment. By attaching electrodes to a patient’s body and recording the electrical impulses transmitted by a patient’s heart with an ECG the technician provides the data to the patient’s physician for later analysis.