Abstract
Eighty two hearts in hypertensives and nonhypertensives were used in order to make the basis of evaluation of the histopathologic finding in sino-atrial node. In early decades, 2/3 or more of sino-atrial node consisted of nodal fiber. With advancing age, collagenous and elastic fibers in nodal tissue increased. Seventh decade or over collagenous and elastic fibers occupied 2/3 or more of nodal tissue. Fatty infiltration into nodal tissue was frequently seen in early life. Changes of central arteries were seen in hypertensives. However, there were no differences between hypertensives and nonhypertensives in sino-atrial nodes.
