A 42-year-old man presents to the emergency department with…
A 42-year-old man presents to the emergency department with severe muscle pain and weakness after intense physical activity. Blood tests reveal a markedly elevated level of creatine phosphokinase (CPK). CPK is an enzyme found predominantly in skeletal muscle, heart muscle, and brain tissue. When muscle cells are damaged, CPK leaks into the bloodstream, causing elevated serum levels. Elevated CPK is commonly used as a biomarker to detect muscle injury, myocardial infarction, or other conditions involving muscle breakdown. Question:An increased blood concentration of creatine phosphokinase (CPK) most likely indicates: