"When the total CPK level is very high, it most often means there has been injury or stress to muscle tissue, the heart, or the brain. It can be because of brain injury or stroke: Convulsions, Delirium tremens, Dermatomyositis or polymyositis, Electric shock, Heart attack, Inflammation of the heart muscle (myocarditis), Lung tissue death (pulmonary infarction), Muscular dystrophies, Myopathy, Rhabdomyolysis. Muscle tissue injury is most likely. When a muscle is damaged, CPK leaks into the bloodstream."