How to find senior note holder

[Va Vester]

If i purchase a second lien foreclosure, i understand that the property will be encumbered by the senior lien.

How do i find who the senior note holder is, since the loan could have been sold? Is waiting for the note holder to initiate foreclosure the only way to find out who the actual lien holder is? Will there be any tax implications for the previous owner if i pay off the first?

Can the senior lien holder refuse a payoff from me?