三房心为一种少见的先天性心脏病 ,约占总数的 0 .1% 0 .4% [5] 。本病临床诊断困难 ,易和二尖瓣病变相混淆。现将我院经手术证实的 3例报告如下。例 1　男 ,2 4岁 ,因反复发作心慌 ,气喘 2 0余年 ,劳动后加重入院就诊。查体 :慢性病容 ,发育营养中等 ,二尖瓣区可闻及Ⅲ级收缩 Third heart is a rare congenital heart disease, accounting for 0.1% of the total 0.4% [5]. Clinical diagnosis of this disease is difficult and easy to be confused with mitral valve disease. Now the hospital confirmed by surgery in 3 cases are as follows. Example 1 male, 2 4 years old, because of recurrent palpitation, asthma more than 20 years after work, increase hospital admission. Physical examination: chronic disease, developmental nutrition, mitral valve area can be heard and Ⅲ grade contraction