First Year $303,600 per year $25,300 per month Second Year $303,600 per year $25,300 per month Third Year $309,600 per year $25,800 per month Fourth Year $309,600 per year $25,800 per month

Exhibit 10.5.1

FIRST ADDENDUM TO LEASE

This First Addendum to Lease (the “First Addendum”) made as of December 21, 2008, is to that certain Lease for the real property located at 350 Oakgrove Parkway, Vadnais Heights, Minnesota, made as of December 15, 2003, by and between Vadnais Heights Investment Company, a Minnesota general partnership, MCHA Capital, LLC, a Minnesota limited liability company, Robert Tipler and Richard K. Mathews (collectively “Lessor”) and Angeion Corporation, a Minnesota corporation, and Medical Graphics Corporation, a Minnesota corporation, (collectively “Tenant”) (the “Lease”), which Lessor’s interest in the Lease has been assigned to VRT Properties, LLC, a Minnesota limited liability company. All capitalized terms in the Lease shall have the same meaning in this First Addendum, except that Lessor is now VRT Properties, LLC, a Minnesota limited liability company.

WHEREAS, the term of the Lease will expire as of June 30, 2009, and Lessor and Tenant desire to enter into this First Addendum regarding Tenant’s continued occupancy of the Premises.

NOW, THEREFORE, in consideration of the foregoing and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Lessor and Tenant agree that the following sections of the Lease are amended by this First Addendum as follows:

1.   TERM.   The term of this Lease (“Term”) shall be extended for one (1) year commencing July 1, 2009 and terminating on June 30, 2010.

4.   RENT.   Tenant agrees to pay Lessor rent in the annual amount of $316,800.00, which shall be payable in monthly installments of $26,400.00, payable in advance on the first day of each and every month for and during the full term of this Lease, at the office of Lessor.