654.12A  Priority of advances under mortgages.
  Subject to section 572.18, if a prior recorded mortgage contains the notice prescribed in this section and identifies the maximum credit available to the borrower, then loans and advances made under the mortgage, up to the maximum amount of credit together with interest thereon, are senior to indebtedness to other creditors under subsequently recorded mortgages and other subsequently recorded or filed liens even though the holder of the prior recorded mortgage has actual notice of indebtedness under a subsequently recorded mortgage or other subsequently recorded or filed lien. So long as credit is available to the borrower, payment of the outstanding mortgage balance to zero shall not extinguish the prior recorded mortgage if it contains the notice prescribed by this section. The notice prescribed by this section for the prior recorded mortgage is as follows:
  NOTICE:  This mortgage secures credit in the amount of ......................... Loans and advances up to this amount, together with interest, are senior to indebtedness to other creditors under subsequently recorded or filed mortgages and liens.
  However, the priority of a prior recorded mortgage under this section does not apply to loans or advances made after receipt of notice of foreclosure or action to enforce a subsequently recorded mortgage or other subsequently recorded or filed lien.
84 Acts, ch 1272, §2; 90 Acts, ch 1001, §1