What does trace mitral regurgitation mean?

VERY MILD valve leak: Trace means 'very mild' and mitral valve regurgitation means 'leak'. It happens when your mitral valve doesn't close tightly, which allows blood to flow backward in your heart. When the 'leak' is moderate-severe you may develop symptoms of tiredness & fatigue. The worst thing: 'heart failure' requiring heart surgery and valve replacement (but you are no where near that stage) so, no worries here.