Fibrillation potentials after muscle injury in humans

To study the occurrence and firing pattern of fibrillation potentials, electromyographic recordings were made on 43 patients after a small muscle injury caused by conchotome biopsy or intramuscular injection. The fibrillation potential sequences were manually evaluated from paper records. At 6 to 7 days after the muscle biopsy, most subjects showed fibrillation potentials with gradually increasing or decreasing discharge intervals of 70 to 3,200 msec. Several irregular fibrillation patterns were observed 9 or more days after biopsy. Fibrillation potentials appear to be generated by at least three mechanisms in humans.