Electrocardiograph (EKG) technicians use EKG machines on patients to read the trace electrical impulses transmitted by the heart throughout the body. The EKG machine helps doctors to diagnose heart problems and it is very important for eventual treatment. Individuals in this field must have at least a high school diploma, but those that receive higher training can expect a better salary and a more supervisory role. Those individuals with more experience and training can also administer Holter monitoring and stress testing to patients. EKG technicians typically earn around $26,600 a year.