1.  Firefighter defined.  For the purposes of this section, "firefighter" means an active member of a municipal fire department or of a volunteer firefighters association if that person is a member of a municipal fire department or volunteer firefighters association and if that person aids in the extinguishment of fires, regardless of whether or not that person has administrative duties or other duties as a member of the municipal fire department or volunteer firefighters association.  

2.  Presumption.  There is a rebuttable presumption that a firefighter received the injury or contracted the disease arising out of and in the course of employment, that sufficient notice of the injury or disease has been given and that the injury or disease was not occasioned by the willful intention of the firefighter to cause self-injury or injury to another if the firefighter has been an active member of a municipal fire department or a volunteer firefighters association, as defined in Title 30‑A, section 3151, for at least 2 years prior to a cardiovascular injury or the onset of a cardiovascular disease or pulmonary disease and if: