<PAGE>   1
                                                                 EXHIBIT 10.27.2

                    THIRD AMENDMENT TO EMPLOYMENT AGREEMENT

        This Third Amendment to Employment Agreement (the "Amendment") is made
as of December 22, 2000, between Radiance Medical Systems, Inc., a Delaware
corporation (the "Company"), and Michael R. Henson, an individual ("Executive").

                                    RECITALS

        WHEREAS, the Company currently employs Executive pursuant to that
certain Employment Agreement dated January 14, 1999, as amended on February 1,
1999 and December 10, 1999 (the "Employment Agreement"); and

        WHEREAS, the Company and Executive desire to amend the Employment
Agreement to change the Executive's position, job responsibility and salary as
set forth in the Employment Agreement, and as provided in greater detail below;

        NOW THEREFORE, in consideration of the mutual agreements and covenants
hereinafter set forth and for other valuable consideration, the Company and
Executive hereby agree as follows:

                                   AGREEMENT

        1.      DEFINITIONS.

        Unless otherwise defined herein, capitalized terms used herein shall
have the meanings assigned to them in the Employment Agreement.

        2.      AMENDMENT TO SECTION 1 OF THE EMPLOYMENT AGREEMENT.

        Section 1 of the Employment Agreement is hereby amended to read in its
entirety as follows:

                "1.     EMPLOYMENT. Effective January 1, 2001, the Company
        hereby agrees to employ the Executive as the Chairman of the Board of
        Directors, reporting to the Board of Directors of the Company, and the
        Executive accepts such employment and agrees to devote one-half of all
        his business time and effort and skills on such reasonable duties as
        shall be assigned to him by the Company commensurate with such
        position."

        3.      AMENDMENT TO SECTION 3.1 OF THE EMPLOYMENT AGREEMENT.

        Section 3.1 of the Employment Agreement is hereby amended to read in
its entirety as follows:

                "3.1    SERVICE WITH THE COMPANY. Effective January 1, 2001,
        during the term of this Agreement, the Executive agrees to perform
        such reasonable duties and on such basis as shall be assigned to him
        from time to time by the Board of Directors; such duties, however, to be
        commensurate with the Executive's position as Chairman of the Board of
        Directors of the Company. In particular, and without limitation, such
        duties shall include, within the guidelines set by the Board of
        Directors, developing strategic policies for the Company, coordinating
        the Board of Directors activities and the various committees of the
        Board of Directors, including but not limited to the Audit Committee and
        the Compensation


<PAGE>   2

     Committee, and managing projects as requested by the Board of Directors."

     4.  AMENDMENT TO SECTIONS 4.1. AND 4.2 OF THE EMPLOYMENT AGREEMENT.

     Sections 4.1 and 4.2 of the Employment Agreement are hereby amended as
     follows:

          Effective January 1, 2001, Executive's Base Salary is $160,000 and the
     Executive will not be eligible for a bonus.

     5.   MISCELLANEOUS.

          (a)  Continuing Force and Effect. Except as herein expressly amended,
all terms, covenants and provisions of the Employment Agreement are and shall
remain in full force and effect and all references therein to such Employment
Agreement shall henceforth refer to the Employment Agreement as amended by this
Amendment. This Amendment shall be deemed incorporated into, and a part of, the
Employment Agreement.

          (b)  Counterparts. This Amendment may be executed in any number of
counterparts, each of which shall be deemed an original, but all such
counterparts together shall constitute but one and the same instrument.

     IN WITNESS WHEREOF, we have set our hands hereto as of the date first
above written.

RADIANCE MEDICAL SYSTEMS, INC.


/s/ JEFFREY THIEL
--------------------------------------------
Jeffrey Thiel, President and Chief Executive
Officer


EXECUTIVE


/s/ MICHAEL R. HENSON
--------------------------------------------
Michael R. Henson


                                       2