<PAGE>   1
                                                                    EXHIBIT 10.3


                                  AMENDMENT TO
                             OPERATING AGREEMENT OF
                 MEDCATH OF LITTLE ROCK, L.L.C. (the "Company")


         THIS AMENDMENT to the Operating Agreement of the Company is effective
as of January 20, 2000 (the "Amendment").

         This Amendment is made under the terms of Section 11.1(e) of the
Operating Agreement in order to ensure that the Company remains in compliance
with all federal and state laws, rules, regulations and interpretations thereof.
The undersigned have also determined that this Amendment will not materially
reduce the economic return on investment in the Company to any of its Members.

         Accordingly, the Operating Agreement is hereby amended as follows:

         1.       A new Section 5.16 is hereby added to the Operating Agreement
                  as follows:

                           SECTION 5.16 Guarantee Fee. In the event that any
                  Member of the Company or its Affiliates provide a guarantee of
                  any indebtedness of the Company which is acceptable to and
                  required by the Company's lenders ("Guarantor Members") and
                  such guarantees are not provided on a pro rata basis by all
                  other Members of the Company (the "Nonguarantor Members"),
                  then the Guarantor Members shall be paid an annual guarantee
                  fee equal to (a) the amount of such indebtedness which is
                  guaranteed by the Guarantor Members or its Affiliates,
                  multiplied by (b) .0075, multiplied by (c) the percentage
                  Membership Interest in the Company owned by the Nonguarantor
                  Members (the "Guarantee Fee"). The Guarantee Fee shall be paid
                  quarterly and the expense thereof shall be allocated to the
                  Nonguarantor Members as follows:

                                    (a) The Guarantee Fee shall be deducted from
                           the Cash Distributions otherwise distributable to the
                           Nonguarantor Members and shall be paid to the
                           Guarantor Members;

                                    (b) To the extent that at the time such
                           Guarantee Fee is due to be paid hereunder there are
                           no anticipated Cash Distributions, then the Company
                           shall pay such Guarantee Fee to the Guarantor Members
                           and the amount of such payments shall be charged to
                           the Capital Accounts of the Nonguarantor Members;

                                    (c) When Cash Distributions become available
                           for distribution to the Members in the future, the
                           Cash Distributions otherwise distributable to the
                           Nonguarantor Members shall first be retained by the
                           Company to the extent that amounts were previously
                           charged to the Capital Accounts of the Nonguarantor
                           Members in accordance with (b)

<PAGE>   2

                           above and any remaining Cash Distributions shall be
                           distributed to the Members in accordance with Section
                           6.1.

         2.       Section 6.1 shall be deleted in its entirety and the following
                  new Section 6.1 shall be substituted in lieu thereof:

                           SECTION 6.1. Allocations and Distributions of Cash
                  Flow from Operations and Cash from Sales or Refinancing. After
                  repayment of any loans made by the Members to the Company,
                  Cash Flow from Sales or Refinancing shall be allocated, or
                  distributed as Cash Distributions according to the Economic
                  Interests of the Members and Economic Interest Owners which,
                  subject to the provisions of Section 6.6 and Article VII,
                  initially shall be in accordance with their respective
                  Membership Interests shown on Schedule A attached hereto,
                  provided however, that to the extent possible, any Guarantee
                  Fee shall be deducted from the Cash Distributions otherwise
                  distributable to the Nonguarantor Members and paid to the
                  Guarantor Members as set forth in Section 5.16.
                  Notwithstanding anything herein to the contrary no
                  distributions shall be made to Members if prohibited by
                  N.C.G.S. ss. 57C-4-06.

         3.       The following shall be added as the opening phrase of Section
                  6.2:

                           SECTION 6.2. Allocations of Income and Loss. Subject
                  in all events to the terms of Section 6.7:


         4.       Section 6.6(a) is amended by adding the following sentence at
                  the end thereof:

                           Notwithstanding any other provision above, Cash
                           Distributions due to Nonguarantor Members shall be
                           paid only after payments of the Guarantee Fee have
                           first been paid in accordance with Section 5.16.

         5.       The opening phrase of Section 6.6(b) is deleted and the
                  following is substituted in lieu thereof:

                           Subject to any limitations on Cash Distributions
                           imposed by statute and subject to payment of the
                           Guarantee Fee, but notwithstanding any other
                           provision in this Agreement to the contrary, the
                           Company and Members agrees as follows:

         6.       The following shall be added as a new Section 6.7:

                           SECTION 6.7. Special Allocations of Guarantee Fees.
                  Any and all deductions, losses or reductions to Capital
                  Account attributable to the payment by the Company of
                  Guarantee Fees shall be allocated to the Nonguarantor Members
                  in accordance with their relative percentage Membership
                  Interests.


                                       2
<PAGE>   3

         7.       Section 7.3(b)(ii) shall be deleted in its entirety and the
                  following new section shall be substituted in lieu thereof:

                                    (ii) To the payment of all debts and
                           liabilities (including interest), and further
                           including without limitation any accrued but unpaid
                           Guarantee Fees, owed to the Members or their
                           Affiliates as creditors; and

         Except as provided herein, the Operating Agreement shall remain in full
force and effect.

         This Amendment may be signed in counterparts.

         This Amendment shall be effective once it has been signed in accordance
with the terms of the Operating Agreement.

[***]


[***] These portions of this exhibit have been omitted and filed separately
      with the Commission pursuant to a request for confidential treatment.



                                       3