I'm thinking that refugnation is probably a transcription error for regurgitation. You see transcription errors in medical reports sometimes. I've never heard of refugnation and could not find it on a casual internet search. Trivial regurgitation of the tricuspid valve (or any of the other heart valves) is common.
In and of itself, trivial regurgitation of a heart valve does not affect a person's health, but I understand your curiosity as to why it was underlined. Perhaps it was underlined merely because it is so severely misspelled, though.
Since you presumably had some kind of symptoms that caused the echocardiogram to be ordered, it will be important to obtain an interpretation from the referring doctor. That's who can give you a real answer, but in the meantime, I would not be worried about having "refugnation."
Thank u very much