QUOTE: "What will happened if don't accept treatment after discovered heart valve leaking? Is it will easier to get tired, hardly to breath & awful, feel like to fainted?"
If you have moderate to severe leakage (regurgitation) and not treated, you will have the symptoms you describe. With severe leakage there will be less blood pumped into circualtion with each heartbeat, and the stress to the heart will eventually cause it to fail.
Which valve? and how much is it leaking? Many people have a slight leak and it doesn't affect their quality of life.