<PAGE>

                                                                    EXHIBIT 10.4

                        AMENDMENT TO EMPLOYMENT AGREEMENT

         THIS AMENDMENT TO EMPLOYMENT AGREEMENT ("Amendment") is made and
entered into as of October 21, 2003, by and between Robert Wenzel, an individual
resident of the State of Minnesota ("Employee"), and Horizon Medical Products,
Inc., a Georgia corporation ("Employer");

                              W I T N E S S E T H:

         WHEREAS, Employee and Employer entered into that certain Employment
Agreement dated May 8, 2002, as amended by Amendment to Employment Agreement
dated November 12, 2002 (collectively, the "Employment Agreement"), and desire
to amend the Employment Agreement in the manner hereinafter provided;

         NOW, THEREFORE, in consideration of the premises and the mutual
promises and agreements contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto intending to be legally bound hereby agree as follows:

         1.       The Employment Agreement is hereby amended by deleting Section
1 in its entirety and by substituting in lieu thereof the following new Section
1:

                           Subject to the terms hereof, the Employer hereby
                  employs Employee, and Employee hereby accepts such employment.
                  Employee will serve as President and Chief Operating Officer
                  of Employer and will be responsible for the operating plans,
                  policies, and profitability of the total Company, subject to
                  the direction of the Chief Executive Officer and the Board of
                  Directors of Employer, with specific duties to include those
                  matters set forth in Exhibit "A" attached hereto. Employee
                  agrees to devote his full business time and best efforts to
                  the performance of such duties and other duties that the Chief
                  Executive Officer or the Board of Directors of Employer (the
                  "Board of Directors") may assign to Employee from time to
                  time. Employee will report to the Chief Executive Officer and
                  his employment with Employer may be terminated by the Chief
                  Executive Officer.

         2.       The Employment Agreement is hereby amended by deleting the
first paragraph in Section 2 in its entirety and by substituting in lieu thereof
the following first paragraph in Section 2:

                           The term of Employee's employment hereunder (the
                  "Term") shall be from May 8, 2002 (the "Effective Date") until
                  the

<PAGE>

                  earlier of (i) October 31, 2005 or (ii) the occurrence of any
                  of the following events:

         3.       The Employment Agreement is hereby amended by deleting
subsection (c) in Section 2 in its entirety and by substituting in lieu thereof
the following subsection (c) in Section 2:

                   (c)     The termination of this Agreement by Employee upon at
                           least one hundred twenty (120) days prior written
                           notice.

         4.       The Employment Agreement is hereby amended by deleting
subsection (d) in Section 2 in its entirety and by substituting in lieu thereof
the following subsection (d) in Section 2:

                  (d)      The termination of this Agreement by Employer without
                           cause upon at least one hundred twenty (120) days
                           prior written notice.

         5.       The Employment Agreement is hereby amended by deleting
subsection (a) in Section 3.1 in its entirety and by substituting in lieu
thereof the following subsection (a) in Section 3.1:

                  (a)      SALARY. Upon the occurrence of the Effective Date (as
                           defined below), but effective as of October 21, 2003,
                           Employee will be paid a Salary of no less than Two
                           Hundred Fifty Thousand Dollars ($250,000.00) per
                           annum, less deductions and withholdings required by
                           applicable law. The Salary shall be paid to Employee
                           in equal monthly installments (or on such more
                           frequent basis as other executives of Employer are
                           compensated). The "Effective Date" means the
                           effective date on which the due date for the
                           principal repayment of the subordinated notes of
                           Employer is extended from March 16, 2004 to July 16,
                           2005 pursuant to the provisions of Amendment No. 1 to
                           Note Purchase Agreement dated October 21, 2003 among
                           Employer, ComVest Venture Partners, L.P., and
                           Medtronic, Inc.

         6.       The Employment Agreement is hereby amended by adding the
following subsections (b)(i), (b)(ii), and (b)(iii) at the end of Section
3.1(b):

                           (i)      For fiscal year 2004, Employee will be
                  entitled to a quarterly bonus (the "2004 Bonus"), based upon
                  Employer's achievement during each calendar quarter of 2004 of
                  net sales and EBITDA under Employer's operating budget for
                  2004 that has been approved by the Board of Directors of
                  Employer (the "2004 Operating Budget"), as follows:

                                      -2-
<PAGE>

                           (A)      If Employer's actual net sales during the
                                    calendar quarter in 2004 are ninety-five
                                    percent (95%) or greater than, but less than
                                    one hundred percent (100%) of, the net sales
                                    for the same calendar quarter in 2004 as
                                    reflected in the 2004 Operating Budget, then
                                    Employee will be entitled to a 2004 Bonus
                                    for such calendar quarter under this
                                    subparagraph (A) calculated under the
                                    formula X times Y, where X is $25,000.00 and
                                    Y is 25%. If Employer's actual net sales
                                    during the calendar quarter in 2004 are one
                                    hundred percent (100%) or greater than the
                                    net sales for the same calendar quarter in
                                    2004 as reflected in the 2004 Operating
                                    Budget, then Employee will be entitled to a
                                    2004 Bonus for such calendar quarter under
                                    this subparagraph (A) calculated under the
                                    formula X times Y, where X is $25,000.00 and
                                    Y is 50%.

                           (B)      If the Employer's actual EBITDA for the
                                    calendar quarter in 2004 is eighty-two
                                    percent (82%) or greater than, but less than
                                    one hundred percent (100%) of, EBITDA for
                                    the same calendar quarter in 2004 as
                                    reflected in the 2004 Operating Budget, then
                                    Employee will be entitled to a 2004 Bonus
                                    for such calendar quarter under this
                                    subparagraph (B) calculated under the
                                    formula X times Y, where X is $25,000.00 and
                                    Y is 25%. If Employer's actual EBITDA for
                                    the calendar quarter in 2004 is one hundred
                                    percent (100%) or greater than the EBITDA
                                    for the same calendar quarter in 2004 as
                                    reflected in the 2004 Operating Budget, then
                                    Employee will be entitled to a 2004 Bonus
                                    for such calendar quarter under this
                                    subparagraph (B) calculated under the
                                    formula X times Y, where X is $25,000.00 and
                                    Y is 50%.

                           (C)      If Employer's actual net sales during the
                                    calendar quarter in 2004 are in excess of
                                    105% of the net sales for the same calendar
                                    quarter in 2004 as reflected in the 2004
                                    Operating Budget and if Employer's actual
                                    EBITDA for the calendar quarter in 2004 is
                                    greater than 105% of the EBITDA for the same
                                    calendar quarter in 2004 as reflected in the

                                      -3-

<PAGE>

                                    2004 Operating Budget, then Employee will be
                                    entitled to a 2004 Bonus for such calendar
                                    quarter under this subparagraph (C)
                                    calculated under the formula X times Y,
                                    where X is $25,000.00 and Y is 110%. If a
                                    bonus is payable under this subparagraph
                                    (C), then no bonus is payable under
                                    subparagraph (A) or subparagraph (B) above.

                           (D)      The Chief Executive Officer of Employer will
                                    establish management business objectives
                                    ("MBOs") for Employee for each calendar
                                    quarter during 2004 and will weight each MBO
                                    so established. If the MBOs for a quarter
                                    are not achieved, then the quarterly bonus
                                    which Employee has earned under subparagraph
                                    (A) and subparagraph (B) above, or
                                    subparagraph (C) above, will be reduced for
                                    the MBOs that are not achieved. Such
                                    reduction will be determined by using a
                                    percentage for the MBOs that are not
                                    achieved. For example, if the MBOs that are
                                    weighted twenty percent (20%) are not
                                    achieved, the reduction percentage will be
                                    20% under both subparagraph (A) and
                                    subparagraph (B) above, or subparagraph (C)
                                    above.

                           (E)      For purposes of the 2004 Bonus, in the event
                                    Employer sells a product line or division
                                    during 2004 or in the event that Employer is
                                    acquired by a third party during 2004, then
                                    the 2004 Bonus for the quarter in which such
                                    event occurs shall be calculated using
                                    actual net sales and EBITDA through the
                                    month end immediately prior to such sale or
                                    acquisition and using net sales and EBITDA
                                    under the 2004 Operating Plan through such
                                    month end.

                           (F)      The 2004 Bonus, if earned for any quarter in
                                    2004, will be payable to Employee on the
                                    next pay period after the financial
                                    statements for such quarter are finalized.

                           (ii)     For the first three quarters of fiscal year
                  2005, Employee will be entitled to a quarterly bonus (the
                  "2005 Bonus"), based upon Employer's achievement during each
                  calendar quarter of 2005 of net sales

                                      -4-

<PAGE>

                  and EBITDA under Employer's operating budget for 2005 that has
                  been approved by the Board of Directors of Employer (the "2005
                  Operating Budget"), as follows:

                           (A)      If Employer's actual net sales during the
                                    calendar quarter in 2005 are ninety-five
                                    percent (95%) or greater than, but less than
                                    one hundred percent (100%) of, the net sales
                                    for the same calendar quarter in 2005 as
                                    reflected in the 2005 Operating Budget, then
                                    Employee will be entitled to a 2005 Bonus
                                    for such calendar quarter under this
                                    subparagraph (A) calculated under the
                                    formula X times Y, where X is $30,000.00 and
                                    Y is 25%. If Employer's actual net sales
                                    during the calendar quarter in 2005 are one
                                    hundred percent (100%) or greater than the
                                    net sales for the same calendar quarter in
                                    2005 as reflected in the 2005 Operating
                                    Budget, then Employee will be entitled to a
                                    2005 Bonus for such calendar quarter under
                                    this subparagraph (A) calculated under the
                                    formula X times Y, where X is $30,000.00 and
                                    Y is 50%.

                           (B)      If the Employer's actual EBITDA for the
                                    calendar quarter in 2005 is eighty-two
                                    percent (82%) or greater than, but less than
                                    one hundred percent (100%) of, EBITDA for
                                    the same calendar quarter in 2005 as
                                    reflected in the 2005 Operating Budget, then
                                    Employee will be entitled to a 2005 Bonus
                                    for such calendar quarter under this
                                    subparagraph (B) calculated under the
                                    formula X times Y, where X is $30,000.00 and
                                    Y is 25%. If Employer's actual EBITDA for
                                    the calendar quarter in 2005 is one hundred
                                    percent (100%) or greater than the EBITDA
                                    for the same calendar quarter in 2005 as
                                    reflected in the 2005 Operating Budget, then
                                    Employee will be entitled to a 2005 Bonus
                                    for such calendar quarter under this
                                    subparagraph (B) calculated under the
                                    formula X times Y, where X is $30,000.00 and
                                    Y is 50%.

                           (C)      If Employer's actual net sales during the
                                    calendar quarter in 2005 are in excess of
                                    105% of the net sales for the same calendar
                                    quarter in 2005 as reflected in the 2005
                                    Operating Budget and if

                                      -5-

<PAGE>

                                    Employer's actual EBITDA for the calendar
                                    quarter in 2005 is greater than 105% of the
                                    EBITDA for the same calendar quarter in 2005
                                    as reflected in the 2005 Operating Budget,
                                    then Employee will be entitled to a 2005
                                    Bonus for such calendar quarter under this
                                    subparagraph (C) calculated under the
                                    formula X times Y, where X is $30,000.00 and
                                    Y is 110%. If a bonus is payable under this
                                    subparagraph (C), then no bonus is payable
                                    under subparagraph (A) or subparagraph (B)
                                    above.

                           (D)      The Chief Executive Officer of Employer will
                                    establish management business objectives
                                    ("MBOs") for Employee for the first three
                                    calendar quarters during 2005 and will
                                    weight each MBO so established. If the MBOs
                                    for a quarter are not achieved, then the
                                    quarterly bonus which Employee has earned
                                    under subparagraph (A) and subparagraph (B)
                                    above, or subparagraph (C) above, will be
                                    reduced for the MBOs that are not achieved.
                                    Such reduction will be determined by using a
                                    percentage for the MBOs that are not
                                    achieved. For example, if the MBOs that are
                                    weighted twenty percent (20%) are not
                                    achieved, the reduction percentage will be
                                    20% under both clause (A) and clause (B)
                                    above, or clause (C) above.

                           (E)      For purposes of the 2005 Bonus, in the event
                                    Employer sells a product line or division
                                    during 2005 or in the event that Employer is
                                    acquired by a third party during 2005, then
                                    the 2005 Bonus for the quarter in which such
                                    event occurs shall be calculated using
                                    actual net sales and EBITDA through the
                                    month end immediately prior to such sale or
                                    acquisition and using net sales and EBITDA
                                    under the 2005 Operating Plan through such
                                    month end.

                           (F)      The 2005 Bonus, if earned for any quarter in
                                    2005, will be payable to Employee on the
                                    next pay period after the financial
                                    statements for such quarter are finalized.

                                      -6-

<PAGE>

                           (iii)    For the period from October 1, 2005 through
                  October 31, 2005, the Compensation Committee of the Board of
                  Directors shall determine in its sole discretion the bonus
                  compensation of Employee for such month.

         7.       The Employment Agreement is hereby amended by deleting the
last sentence in the first paragraph in Section 3.2 in its entirety and by
substituting in lieu thereof the following sentence at the end of the first
paragraph in Section 3.2:

                  If Employee's employment hereunder is terminated by Employer
                  without good cause, Employee shall be deemed to have earned an
                  additional bonus that is equal to the sum of all quarterly
                  bonuses paid by Employer to Employee for the four (4) calendar
                  quarters immediately preceding the effective date of such
                  termination by Employer without good cause. Such bonus
                  compensation shall be payable to Employee in equal periodic
                  payments on the same basis as if Employee continued to serve
                  as an employee hereunder for the twelve (12) months
                  immediately following the effective date of such termination
                  and received his Salary during such period.

         8.       The provisions of this Agreement shall become effective on the
Effective Date. Except as expressly amended above, all other provisions of the
Employment Agreement shall remain in full force and effect. This Amendment
inures to the benefit of, and is binding upon, Employer and its respective
successors and assigns and Employee, together with Employee's executor,
administrator, personal representatives, heirs, and legatees. This Amendment is
intended by the parties hereto to be the final expression of their agreement
with respect to the subject matter hereof and is the complete and exclusive
statement of the terms thereof, notwithstanding any representations, statements,
or agreements to the contrary heretofore made. Except for the Employment
Agreement, this Amendment supersedes and terminates all prior agreements and
understandings between Employer and Employee concerning the subject matter of
this Amendment. This Amendment may be modified only by a written instrument
signed by all of the parties hereto. This Amendment shall be deemed to be made
in, and in all respects shall be interpreted, construed, and governed by and in
accordance with, the laws of the State of Georgia without reference to its
conflicts of law principles. This Amendment may be executed in two or more
counterparts, each of which shall be deemed to be an original, but all of which
together shall constitute one and the same instrument.

                                      -7-
<PAGE>

         IN WITNESS WHEREOF, the parties hereto have executed this Amendment as
of the date first above written.

                                             HORIZON MEDICAL PRODUCTS, INC.

                                             By: /s/ Marshall B. Hunt
                                                --------------------------------
                                                 Marshall B. Hunt,
                                                 Chief Executive Officer

                                             EMPLOYEE:

                                              /s/ Robert Wenzel
                                            ------------------------------------
                                            Robert Wenzel

                                      -8-