Five cases of sudden cardiac death due to Presence of the Mahaim fiber

To find out some morphological features for the diagnosis of sudden cardiac deaths.The CCS from 165 cases of sudden death without extracardiac causes of death were sampled by using the method described previously.Serial sections were prepared for histological observation and immunohistochemical staining.Five cases with Mahaim's fiber were discovered.It accounted for 3% in the sudden death group;All 5 cases belongs to the bundle ventricular bundle type.The characteristics of Mahaim's fibers were found as follows:The fibers were 10～35μm in transverse diameter,usually with abundant cytoplasm,lightly stained.The bodies of the cells of the Mahaim's fiber which originate from the HB were slender,with nuclei in the middle of the cells,while the shape of cells of LBB type varies with the origin of the Mahaim's fiber,the size of cells nieveased gradually from up downward.The cells were not bifurcated,but some of the cells were surrounded by a thin layer of fibrous tissue.Mahaim's fiber is a A V by path which may lead to fatal outcome.