Why would you need a mitrial valve replacement or "valvuloplasty"?

These are different: Valvuloplasty is done for mitral stenosis (calcified valve not opening well). Essentially it is a balloon guided across the valve and opened, causing the valve to "crack" open, to allow flow through the valve. It is not an open heart surgery. Mitral valve replacement or mitral valve repair are heart surgeries to fix a very leaky valve or a very calcified valve that does not open well.

Leaks: The valve is like a door and should open and close well. If not, and leaks a lot, repair or replacement are great treatments! called mitral regurgitation and several causes, from congenital, rheumatic, prolapse or infection are some of them.