Striated muscle ultrastructure in intermittent claudication.

Twenty-four biopsy specimens from the lower leg muscles of 21 patients with intermittent claudication were studied by electron microscopy. Sixteen of the specimens contained hypertrophic, atrophic, autolytic, or phagocytic fibers, or other forms of macroscopic fiber degeneration. Of the pathological changes in the cell organelles, the most common was simple myofibrillar degeneration, followed by slightly pathological mitochondria and excessive accumulations of glycogen and lipofuscin. Different types of basement membrane alterations and central nuclei were present in 16 of the biopsy specimens. Most of the pathological changes were the same as those previously reported by others to occur in specific diseases of muscle. There was some positive correlation of the degree of pathological changes to the estimated clinical severity of claudication.