Mitral valve repair is a useful method of surgical treatment for mitral valvular regurgitation, and has less complication.

According to the valvular theory, the vibrations affected by the mitral and tricuspid valves closure in early systole produce the first heart sound (S1). S1 usually includes many frequency components.

Mitral and other valvular regurgitation were significantly more severe in group ISCM than group OMI.