Medical Conditions: Aortic Dissection

Cheetham v. Liberty NW [6/11/97] 1997 MTWCC 37 A 51-year old heavy equipment and crane operator suffered an aortic dissection after spending 20 to 30 minutes trying to start a gas powered pump, requiring 50 to 70 pulls on a cord similar to those on lawn mowers. The general criteria for a compensable injury under section 39-71-119(2), MCA (1995) are met where an usual strain at work caused claimant internal physical harm, verified by objective medical findings. In cases of cardiovascular incidents, section 39-71-119(5)(a), MCA (1995), permits compensation "only if the accident is the primary cause of the physical condition in relation to other factors contributing to the physical condition," with "primary cause" defined as "a cause that, with a reasonable degree of medical certainty, is responsible for more than 50% of the physical condition." Where two physicians, one a cardiologist, credibly testified claimant's aortic dissection was more than 50% attributable to his episode of high blood pressure, which in turn was caused by strenuous work activities, the condition is compensable.