<PAGE>   1
                                                                    EXHIBIT 10.9

                                 AMENDMENT NO. 4


                            DATED AS OF MARCH 8, 2000


                                       TO


                      SECOND AMENDED AND RESTATED REVOLVING
                           LOAN AND SECURITY AGREEMENT


                          DATED AS OF NOVEMBER 21, 1997



                                      AMONG


                             HEALTHGRADES.COM, INC.
                      FORMERLY SPECIALTY CARE NETWORK, INC.

                            HEALTHCARE RATINGS, INC.,

                              PROVIDERWEB.NET, INC.

                                       AND


                             BANK OF AMERICA, N.A.,
                                  AMSOUTH BANK,
                                    PARIBAS,
                           KEY CORPORATE CAPITAL, INC.

                                       AND

                         BANK OF AMERICA, N.A., AS AGENT


<PAGE>   2

                                TABLE OF CONTENTS

<TABLE>

<S>                                                                         <C>
1.       Definitions..........................................................2

2.       Amendments to Agreement..............................................2

3.       Representations and Warranties.......................................4
         3.1      Incorporation...............................................4
         3.2      Due Authorization, No Conflicts, Etc........................5
         3.3      Due Execution, Etc..........................................5

4.       Conditions Precedent.................................................6
         4.1      Conditions Precedent to Effectiveness of Amendment No. 4....6

5.       Effectiveness of Amendment No. 4.....................................8

6.       Closing..............................................................8

7.       Governing Law, Etc...................................................8

8.       Section Titles and Table of Contents.................................9

9.       Arbitration..........................................................9

10.      Counterparts........................................................10

11.      Agreement to Remain in Effect.......................................10
</TABLE>


                                      -ii-
<PAGE>   3

         This Amendment No. 4 to Second Amended and Restated Revolving Loan and
Security Agreement, made and entered into as of this 8th day of March, 2000, by
and among Healthgrades.com, Inc. (formerly Specialty Care Network, Inc.) (the
"Borrower"); the Guarantors, jointly and severally; the various banks and
lending institutions on the signature pages attached hereto together with all
assignees of such banks and lending institutions (each a "Bank" and collectively
the "Banks"); and Bank of America, N.A., successor to NationsBank, N.A.,
successor to NationsBank of Tennessee, N.A., as agent (the "Agent").

                              W I T N E S S E T H:

         WHEREAS, the Borrower, the Guarantors, the Banks, the Swingline Bank,
and the Agent entered into a certain Second Amended and Restated Revolving Loan
and Security Agreement dated as of November 21, 1997, as amended by Amendment
No. 1 thereto dated March 30, 1998, Amendment No. 2 thereto dated April 1, 1998,
and Amendment No. 3 thereto dated September 16, 1999 (collectively the "Loan
Agreement"); and

         WHEREAS, Healthcare Report Cards, Inc. and SCN of Princeton, Inc., both
formerly Guarantors, have each been dissolved; and

         WHEREAS, at the time of its dissolution, Healthcare Report Cards, Inc.
owned ninety percent (90%) of the outstanding shares of HG.com, Inc., which
entity has been merged into Healthcare Ratings, Inc., a newly formed Subsidiary
of the Borrower; and

         WHEREAS, the Borrower has also formed as a new Subsidiary
Providerweb.net, Inc.; and

         WHEREAS, the parties to the Loan Agreement desire to amend the existing
Loan Agreement to delete Healthcare Report Cards, Inc. and SCN of Princeton,
Inc. as Guarantors thereunder, to add Healthcare Ratings, Inc., a Delaware
corporation, and Providerweb.net, Inc., a


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<PAGE>   4

Delaware corporation, as Guarantors, to pledge additional Collateral including
without limitation all outstanding shares issued by Healthcare Ratings, Inc. and
Providerweb.net, Inc. to the Borrower, and to modify certain covenants, all as
hereinafter more specifically set forth;

         NOW THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements set forth herein, and for other good and valuable
consideration, the receipt and legal sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

         1. DEFINITIONS. All capitalized terms used in this Amendment No. 4
which are not otherwise defined herein shall have the respective meanings
ascribed thereto in the Agreement.

         2. AMENDMENTS TO AGREEMENT.

         2.1 In the Exhibits to the Agreement, EXHIBIT A, being the "Form of
Notes", is hereby modified to the extent set forth in the Modification to Term
Loan Note attached hereto as EXHIBIT 1.

         2.2 Section I of the Agreement, DEFINITIONS, is hereby amended by
adding thereto the following new definitions as follows:

                  "AMENDMENT NO. 4 EFFECTIVE DATE" has the meaning specified in
         Section 5 of Amendment No. 4.

         In addition to the foregoing new definitions, the following definitions
are hereby amended: "COMMITTED AMOUNT" is hereby amended to equal that amount
set forth opposite each Bank's signature hereto, which amount is for a Term Loan
only; "GUARANTOR" is hereby amended to add Healthcare Ratings, Inc. and
Providerweb.net, Inc. as Guarantors; and "TOTAL COMMITMENTS" is hereby amended
to replace the figure of Twelve Million Five Hundred Thousand and No/100 Dollars
($12,500,000.00) with the figure Eight Million One Hundred Thousand and No/100
Dollars ($8,100,000.00) in non-revolving Term Loans.


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<PAGE>   5

         2.3 Paragraph 2.1 is hereby amended to delete that portion of the
second sentence beginning with "provided" and to insert thereafter the
following:

         provided, immediately upon receipt but in any event before July 1,
         2000, the Borrower shall also apply as a principal prepayment on the
         Notes the full amount of Borrower's federal tax refund for 1999, said
         prepayment to be applied in inverse order of maturity.

         2.4 Healthcare Ratings, Inc. and Providerweb.net, Inc. hereby agree to
become parties to the Loan Agreement and each hereby grants to the Agent on
behalf of the Banks a security interest in the Collateral, including without
limitation the grant of the security interest described in Section 4.3 of the
Loan Agreement, and confirms that, as more specifically set forth in Section 4.4
thereof, said liens are first and prior liens.

         2.5 Borrower hereby covenants with the Banks that, at all times during
the term hereof, it shall maintain cumulative cash deposits with any one or more
of the Banks of no less than the lesser of: (i) Five Million and No/100 Dollars
($5,000,000.00), or (ii) 100% of the outstanding Obligations from time to time,
which cash shall be used at maturity to pay off the Term Loans and all other
Obligations. The Banks hereby covenant with the Borrower that the Banks shall
not exercise any right of setoff against said deposits unless and until there is
a payment default by the Borrower with respect to principal and/or interest on
the Obligations, including without limitation Borrower's failure to pay
principal and interest after an acceleration of the Obligations.

         2.6 Subparagraph 6.2(H) is hereby deleted in its entirety and replaced
with a new subparagraph 6.2(H) as follows:

         (H) On the 15th and 30th of each month, a bimonthly report setting
         forth the following information: (a) the amount and location of cash
         deposits held by Borrower with each of the Banks, and (b) the status of
         any payments to be received by Borrower from each its managed



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<PAGE>   6

         Practices, including without limitation The Specialist, MAOS, Orlin &
         Cohen, Lima, SEN, and the like.

         2.7 As consideration for the Banks agreeing to this Amendment No. 4,
the Borrower has herewith delivered to the Banks as a non-refundable fee 165,000
shares of common stock of the Borrower, as follows: 66,000 shares issued to Bank
of America, N.A. or its designee; 33,000 shares issued to AmSouth Bank or its
designee; 33,000 shares issued to Key Corporate Capital, Inc. or its designee;
and 33,000 shares issued to Paribas or its designee. This stock is issued
pursuant to the provisions of TCA '47-24-101, and is intended as an "equity
participation" in Borrower and not as interest on the Obligations. In addition,
the Borrower agrees to enter into a registration rights agreement with each of
the Banks (or their respective designees) with respect to such stock granting to
the Banks (or their designee) piggyback registration rights.

         3. REPRESENTATIONS AND WARRANTIES. To induce the Banks and the Agent to
enter into this Amendment No. 4, the Borrower and Guarantors jointly and
severally represent and warrant to the Banks and the Agent as follows:

         3.1 INCORPORATION. Healthgrades.com, Inc. is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware; has the corporate power to own its properties and to engage in the
business it conducts, and is duly qualified and in good standing as a foreign
corporation in the jurisdictions wherein the nature of its business or the
ownership of its properties requires it to be so qualified. Healthcare Ratings,
Inc. is a corporation duly organized, validly existing and in good standing
under the laws of the State of Delaware; has the corporate power to own its
properties and to engage in the business it conducts, and is duly qualified and
in good standing as a foreign corporation in the jurisdictions wherein the
nature of its business or the ownership of its properties requires it to be so
qualified. Providerweb.net, Inc. is


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<PAGE>   7

a corporation duly organized, validly existing and in good standing under the
laws of the State of Delaware; has the corporate power to own its properties and
to engage in the business it conducts, and is duly qualified and in good
standing as a foreign corporation in the jurisdictions wherein the nature of its
business or the ownership of its properties requires it to be so qualified.

         3.2 DUE AUTHORIZATION, NO CONFLICTS, ETC. The execution, delivery and
performance by the Borrower and Guarantors of this Amendment No. 4 and any and
all other agreements, instruments and documents to be executed and/or delivered
by the Borrower and Guarantors pursuant hereto or in connection herewith, and
the consummation by the Borrower and Guarantors of the transactions contemplated
hereby or thereby: (a) are within their respective corporate powers; (b) have
been duly authorized by all necessary corporate action, including without
limitation, the consent of stockholders where required; (c) do not and will not
conflict with or result in any breach of, or constitute with the passage of time
or the giving of notice or both, a default under (i) any Requirement of Law or
(ii) any agreement to which Borrower or any Guarantor is a party or by which
they, or any of their respective property, is bound; and (d) do not require the
consent, authorization by, or approval of, or notice to, or filing or
registration with, any governmental authority or any other Person other than
those which have been obtained and copies of which have been delivered to the
Agent pursuant to Subsection 4.1(a)(ii) hereof, each of which is in full force
and effect.

         3.3 DUE EXECUTION, ETC. This Amendment No. 4 and each of the other
agreements, instruments and documents to be executed and/or delivered by the
Borrower or any Guarantor pursuant hereto or in connection herewith (a) has been
duly executed and delivered, and (b) constitutes the legal, valid and binding
obligation of the Borrower and each Guarantor, enforceable



                                     - 5 -
<PAGE>   8

against it in accordance with its terms, subject however to state and federal
bankruptcy, insolvency, reorganization and other laws and general principles of
equity affecting enforcement of the rights of creditors generally.

         4. CONDITIONS PRECEDENT. The effectiveness of this Amendment No. 4 is
subject to the fulfillment of the following conditions precedent on or prior to
the Amendment No. 4 Effective Date (as hereinafter defined in Section 5 hereof):

         4.1 CONDITIONS PRECEDENT TO EFFECTIVENESS OF AMENDMENT NO. 4. The Agent
shall have received, on or prior to the Amendment No. 4 Effective Date, the
following, each dated on or prior to the Amendment No. 4 Effective Date unless
otherwise indicated, in form and substance satisfactory to the Agent and in
sufficient copies for each Bank:

             (a) Certified copies of (i) the resolutions of the Board of
Directors of the Borrower and each Guarantor approving this Amendment No. 4 and
each other agreement, instrument or document to be executed by it pursuant
hereto or as contemplated hereby, and (ii) all documents evidencing other
necessary corporate action and required governmental and third party approvals,
licenses and consents with respect to this Amendment No. 4 and the transactions
contemplated hereby.

             (b) A certificate of the Secretary or an Assistant Secretary of
Borrower and each Guarantor certifying the names and true signatures of the
officers of Borrower and each Guarantor who have been authorized to execute on
behalf of Borrower and each Guarantor this Amendment No. 4 and any other
agreement, instrument or document executed or to be executed by Borrower or any
Guarantor in connection herewith.


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<PAGE>   9

             (c) A certificate dated the Amendment No. 4 Effective Date signed
by the President or any Vice-President of Borrower, to the following effect:

                                    (i) The representations and warranties of
                  the Borrower contained in Sections 3.1, 3.2, and 3.3 of this
                  Amendment No. 4 are true and correct on and as of such date as
                  though made on and as of such date;

                                    (ii) No Default or Event of Default has
                  occurred and is continuing, and no Default or Event of Default
                  would result from the execution and delivery of this Amendment
                  No. 4 or the other agreements, instruments and documents
                  contemplated hereby; and

                                    (iii) The Borrower has paid or agreed to pay
                  all amounts payable by it pursuant to the Agreement as amended
                  hereby (including, without limitation, all legal fees and
                  expenses of Banks' counsel incurred in connection herewith) to
                  the extent then due and payable.

             (d) Executed Modifications to Term Loan Notes in the form attached
hereto as EXHIBIT 1.

             (e) Guaranty and Suretyship Agreement executed by each Guarantor,
in substantially the form of EXHIBIT 2 hereto.

             (f) Amendment to Amended and Restated Pledge Agreement executed by
the Borrower, in favor of the Agent for the benefit of the Banks, in
substantially the form of EXHIBIT 3 hereto, pledging all of the outstanding
stock of each Guarantor, together with the originals of such certificates and
executed stock powers of attorney.



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<PAGE>   10

             (g) A favorable opinion of Messrs. Baker Donelson Bearman &
Caldwell, counsel to the Borrower, in substantially the form of EXHIBIT 4
hereto, and as to such other matters as any Bank, through the Agent, may
reasonably request.

             (h) Evidence satisfactory to the Bank that the Borrower has closed
the sale of additional stock in Borrower to investors in an amount sufficient to
net to the Borrower no less than Fourteen Million and No/100 Dollars
($14,000,000.00) in cash proceeds.

         5. EFFECTIVENESS OF AMENDMENT NO. 4. This Amendment No. 4 shall become
effective at such time as (a) each of the conditions precedent set forth in
Section 4.1 hereof shall have been satisfied, and (b) counterparts of this
Amendment No. 4, executed and delivered by the Borrowers, the Guarantors, the
Banks, and the Agent shall have been received by the Agent (or, alternatively,
confirmation of the execution hereof by such parties shall have been received by
the Agent). The date upon which the conditions described in clauses (a) and (b)
of the foregoing sentence shall have been fulfilled is referred to herein as the
"Amendment No. 4 Effective Date".

         6. CLOSING. The Closing under this Amendment No. 4 shall occur on the
Amendment effective Date at the offices of Boult, Cummings, Conners & Berry,
PLC, 414 Union Street, Nashville, Tennessee 37219, or such other location as the
parties may agree.

         7. GOVERNING LAW, ETC. This Amendment No. 4 shall be governed by, and
construed in accordance with, the laws of the State of Tennessee as provided in
Section 10.9 of the Agreement, which Section is incorporated herein by reference
and made a part hereof as though set forth in full herein.



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         8. SECTION TITLES AND TABLE OF CONTENTS. The Section Titles and Table
of Contents contained in this Amendment No. 4 are and shall be without
substantive meaning or content of any kind whatsoever and are not a part of the
agreement among the parties hereto.

         9. ARBITRATION. Any controversy or claim between or among the parties
hereto including but not limited to those arising out of or relating to this
Instrument, Agreement or document or any related instruments, agreements or
documents, including any claim based on or arising from an alleged tort, shall
be determined by binding arbitration in accordance with the Federal Arbitration
Act (or if not applicable, the applicable state law), the Rules of Practice and
Procedure for the Arbitration of Commercial Disputes of Judicial Arbitration and
Mediation Services, Inc. (J.A.M.S.), and the "Special Rules" set forth below. In
the event of any inconsistency, the Special Rules shall control. Judgment upon
any arbitration award may be entered in any court having jurisdiction. Any party
to this Agreement may bring an action, including a summary or expedited
proceeding, to compel arbitration of any controversy or claim to which this
agreement applies in any court having jurisdiction over such action.

                  (a) Special Rules. The arbitration shall be conducted in the
city of the Borrower's domicile at the time of the execution of this instrument,
agreement or document and administered by J.A.M.S. who will appoint an
arbitrator; if J.A.M.S. is unable or legally precluded from administering the
arbitration, then the American Arbitration Association will serve. All
arbitration hearings will be commenced within 90 days of the demand for
arbitration; further, the arbitrator shall only, upon a showing of cause, be
permitted to extend the commencement of such hearing for up to an additional 60
days. In any such arbitration, the prevailing party will be awarded attorney's
fees, costs of arbitration and all out-of-pocket expenses against the defaulting
party.



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<PAGE>   12

                  (b) Reservation of Rights. Nothing in this instrument,
agreement or document shall be deemed to (i) limit the applicability of any
otherwise applicable statutes of limitation or repose or any waivers contained
in this Agreement; or (ii) be a waiver by the Agent or Banks of the protection
afforded to them by 12 U.S.C. '91 or any substantially equivalent state law; or
(iii) limit the right of the Agent or Banks hereto (A) to exercise self help
remedies such as (but not limited to) set off, or (B) to foreclose against any
real or personal property collateral, or (C) to obtain from a court provisional
or ancillary remedies such as (but not limited to) injunctive relief, writ of
possession or the appointment of a receiver. The Agent or Banks may exercise
such self help rights, foreclose upon such property, or obtain such provisional
or ancillary remedies before, during or after the pendency of any arbitration
proceeding brought pursuant to this instrument, agreement or document. Neither
this exercise of self help remedies nor the institution or maintenance of an
action for foreclosure or provisional or ancillary remedies shall constitute a
waiver of the right of any party, including the claimant in any such action, to
arbitrate the merits of the controversy or claim occasioning resort to such
remedies.

         10. COUNTERPARTS. This Amendment No. 4 may be executed in any number of
counterparts and by different parties hereto in separate counterparts, each of
which when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same instrument.

         11. AGREEMENT TO REMAIN IN EFFECT. Except as expressly provided herein,
the Agreement and each other Collateral Document shall be and shall continue in
full force and effect in accordance with its respective terms.



                                     - 10 -
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         IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 4
to be executed by their respective officers thereunto duly authorized, as of the
date first above written.

                                            BORROWER

                                            HEALTHGRADES.COM, INC., FORMERLY
                                            SPECIALTY CARE NETWORK, INC.



                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------


                                            GUARANTORS AND SUBSIDIARIES

                                            HEALTHCARE RATINGS, INC.


                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------


                                            PROVIDERWEB.NET, INC.


                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------



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<PAGE>   14


<TABLE>
<S>                                         <C>
                                            BANKS



Committed Amount:                           BANK OF AMERICA, N.A., successor
$3,240,000.00                               to NationsBank, N.A., successor to
                                            NationsBank of Tennessee, N.A., as
                                            Agent


                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------


Committed Amount:
$1,620,000.00                               AMSOUTH BANK



                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------


Committed Amount:                           PARIBAS
$1,620,000.00


                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------


Committed Amount:                           KEY CORPORATE CAPITAL INC.,
$1,620,000.00                               A MICHIGAN CORPORATION



                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------


                                            AGENT
                                            BANK OF AMERICA, N.A., AS AGENT


                                            BY:
                                                ------------------------------

                                            TITLE:
                                                   ---------------------------
</TABLE>



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