Certificates issued to paramedics and cardiac technicians pursuant to this chapter may be revoked for good cause by the department in accordance with established rules and regulations, after notice to the certificate holder of the charges and an opportunity for hearing. Such proceedings shall be conducted in accordance with Chapter 13 of Title 50, the "Georgia Administrative Procedure Act." The department shall have the authority to conduct investigations and subpoena any documents relating to the fitness of paramedics and cardiac technicians. Such documents may be used in any hearing conducted by the department.