After entering the left atrium, the blood goes through the second atrioventricular valve called the mitral valve into the left ventricle.

进入左心房后，血液穿过第二个房室瓣膜，称为二尖瓣，进入左心室。

In this case, since it's the mitral valve, we call this mitral regurgitation.

在这种情况下，由于是二尖瓣，我们称之为二尖瓣反流。