Left atrial ultrastructure in mitral valvular disease.

摘要: Light microscopic and ultrastructural observations were made on left atrial tissues obtained from 14 patients at the time of operation for correction mitral valvular disease. Cardiac muscle cells varied in size but most frequently hypertrophied. In fibrotic areas, present all atria, tended to be isolated adjacent exhibited degenerative changes varying severity. These consisted or proliferation Z-band material cytoskeletal filaments, myofibrillar loss, elements free extended junctional sarcoplasmic reticulum, variations number mitochondria, occurrence abnormal dissociation intercellular junctions, formation spherical microparticles, accumulation lysosomal degradation products. Hypertrophy was considered lead cellular degeneration, with decrease loss contractile function. Atrial fibrillation associated severe degeneration. The severity degeneration greater regurgitation, without stenosis, than pure stenosis.