Exhibit 4.1 DATA CRITICAL CORPORATION AMENDMENT TO PREFERRED SHARES RIGHTS AGREEMENT This Amendment to Preferred Shares Rights Agreement (this "Amendment") is made as of the 19th day of July, 2001 by and between Data Critical Corporation, a Delaware...

                                                                     Exhibit 4.1

                           DATA CRITICAL CORPORATION

                AMENDMENT TO PREFERRED SHARES RIGHTS AGREEMENT

     This Amendment to Preferred Shares Rights Agreement (this "Amendment") is
made as of the 19th day of July, 2001 by and between Data Critical Corporation,
a Delaware corporation (the "Company") and Mellon Investor Services LLC,
formerly known as ChaseMellon Shareholder Services, L.L.C., a New Jersey limited
liability company (the "Rights Agent").

                                    RECITALS
                                    --------

     WHEREAS, the Company and the Rights Agent are parties to that certain
Preferred Shares Rights Agreement dated as of June 15, 2000 (the "Agreement").
Any capitalized terms not specifically defined herein shall have the meanings
ascribed to them in the Agreement.

     WHEREAS, the parties wish to amend the Agreement as provided herein.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto agree as
follows:

     1.  Section 1 of the Agreement is hereby amended by inserting the following
sentence at the end of Section 1(m), which is the definition of "Person" under
the Agreement:

          "Notwithstanding the foregoing, for all purposes under this Agreement,
     the term "Person" shall not include General Electric Company, a New York
     corporation ("GE") or any Affiliates of GE."

     2.  Each party represents and warrants to the other party that it has full
power and authority to execute and deliver this Amendment and to perform the
transactions contemplated hereunder.

     3.  The terms and provisions of the Agreement, as amended hereby, shall
remain in full force and effect.  All references to the "Agreement" contained
therein shall mean the Agreement, as amended by this Amendment.

     4.  This Amendment may be executed in one or more counterparts, all of
which shall be considered one and the same agreement.


     IN WITNESS WHEREOF, each of the Company and the Rights Agent has caused
this Amendment to be signed by their respective officers duly authorized as of
the date first written above.

                                    DATA CRITICAL CORPORATION


                                    By: /s/ Xxxxxxx X. Xxxxxxx
                                        ---------------------------
                                    Name: Xxxxxxx X. Xxxxxxx
                                    Title: Chief Executive Officer


                                    MELLON INVESTOR SERVICES LLC


                                    By: /s/ Xxxxxx X. Xxxxxxxx
                                        ---------------------------
                                    Name: Xxxxxx X. Xxxxxxxx
                                    Title: Assistant Vice President

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