In left area , the contour and size of the left ventricle and left atrium and the shape and coaptation of the mitral valve could be visualized.

• 左区能显示整个左室、左房的大小,二尖瓣的形态与对合情况,二尖瓣脱垂者可见叶瓣游离缘处某一区域向左房脱出。