Objective This study was aimed to discover the pathogenesis of focal atrial fibrillation originated from pulmonary veins,through observing the histological structure and special cells of pulmonary veins by using the methods of hematoxylin and eosin staining and PGP9.5 antigen immunohistochemistry.MethodsThe pulmonary veins were obtained from 11 healthy pigs,fixed in 10% phosphate buffered formalin solution,embedded in paraffin,serially sectioned (5μm) transversely and longitudinally.Alternate sections were ...