1. The mitral valve is located between the left atrium and left ventricle of the heart.
（米特勒瓣位于心脏的左心房和左心室之间。）
2. Mitral valve prolapse is a common heart valve disorder.
（乳腺口瓣脱垂是一种常见的心脏瓣膜疾病。）
3. The patient is undergoing mitral valve repair surgery.
（患者正在接受矫正呼吸训练手术。）