The ECG Technician is responsible for educating patients on all testing procedures, properly positioning patients, electrode application, judging the quality of ECG tracings, attaching various arrhythmia monitor devices, and facilitating stress testing under the supervision of a Cardiologist, APP, or Clinical Exercise ... Electrocardiogram (ECG) technicians use special devices and medical techniques to record the electrical impulses transmitted by a patient's heart. Data collection and analysis of ECGs by electrocardiogram technicians helps doctors, nurses and other healthcare professionals diagnose a patient's disease.