Okla. Stat. tit. 85A, § 85A-14: Cardiovascular, coronary, pulmonary, respiratory, or

cerebrovasculary accidents and myocardial infarctions.

A. A cardiovascular, coronary, pulmonary, respiratory, or

cerebrovascular accident or myocardial infarction causing injury,

illness, or death is a compensable injury only if, in relation to

other factors contributing to the physical harm, the course and

scope of employment was the major cause.

B. An injury or disease included in subsection A of this

section shall not be deemed to be a compensable injury unless it is

shown that the exertion of the work necessary to precipitate the

disability or death was extraordinary and unusual in comparison to

the employee's usual work in the course of the employee's regular

employment, or that some unusual and unpredicted incident occurred

which is found to have been the major cause of the physical harm.