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                                                               EXHIBIT 10.43



                           RAYTEL MEDICAL CORPORATION

                                 PROMISSORY NOTE

                                  $15,000,000

                         Dated as of September 2, 1996

         FOR VALUE RECEIVED, the undersigned, RAYTEL MEDICAL CORPORATION, a
Delaware corporation (hereinafter, together with its successors in title and
assigns, called the "BORROWER"), promises to pay on or before the Final Maturity
Date (as defined in the Credit Agreement to which reference herein is made to
the order of BANK OF BOSTON CONNECTICUT (hereinafter, together with its
successors in title and assigns, called the "BANK"), at the Agent's Head Office,
the principal sum of FIFTEEN MILLION DOLLARS ($15,000,000), in immediately 
available funds or, if less, the aggregate unpaid principal amount of the Loans
made by the Bank to the Borrower pursuant to the Credit Agreement to which
reference is hereinafter made and to pay interest, in like money, on the unpaid
principal amount owing hereunder from time to time from the date hereof until
payment in full of such principal amount as provided in the Credit Agreement.

         This Note is made and delivered by the Borrower pursuant to Section 2.4
of the Amended and Restructured Credit Agreement dated as of July __, 1996 by
and among the Borrower, the Bank and Bank of Boston Connecticut in its capacity
as agent for itself and the lenders therein named (as amended and in effect from
time to time, the "Credit Agreement"), and is entitled to the benefits and is
subject to the provisions of the Credit Agreement All capitalized terms used
herein which are defined in the Credit Agreement shall have the same meanings
herein as therein.

         The Borrower also promises to pay interest on the unpaid principal
amount of the Loans outstanding until paid in full at the rates per annum set
forth in or established pursuant to the Credit Agreement. Such interest shall be
payable on such dates as are determined from time to time pursuant to the Credit
Agreement and shall be calculated as therein provided.

         The Borrower has the right in certain circumstances to prepay the
principal of this Note on the terms and conditions specified in the Credit
Agreement.

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         If any Default or Event of Default shall occur, the entire unpaid
principal amount of this Note and all of the unpaid interest accrued thereon may
become or be declared due and payable in the manner and with the effect provided
in the Credit Agreement.

         The Borrower and all guarantors and endorsers hereby waive presentment,
demand, protest and notice of any kind in connection with the delivery,
acceptance, performance and enforcement of this Note, and also hereby assent to
extensions of time of payment or forbearance or other indulgences without
notice.

         This Note and the obligations of the Borrower hereunder shall be
governed by, and interpreted and determined in accordance with, the laws of the
State of Connecticut.

         THE BORROWER HEREBY REPRESENTS, COVENANTS AND AGREES THAT THE PROCEEDS
OF THE LOANS SHALL BE USED FOR GENERAL COMMERCIAL PURPOSES AND AS FURTHER
PROVIDED IN THE CREDIT AGREEMENT. AND THAT THIS NOTE IS PART OF A "COMMERCIAL
TRANSACTION" AS DEFINED BY THE STATUTES OF THE STATE OF CONNECTICUT. THE
BORROWER HEREBY WAIVES ALL RIGHTS TO NOTICE AND PRIOR COURT HEARING OR COURT
ORDER UNDER CONNECTICUT GENERAL STATUES SECTIONS 52-278A ET SEQ. AS AMENDED OR
UNDER ANY OTHER STATE OR FEDERAL LAW WITH RESPECT TO ANY AND ALL PREJUDGMENT
REMEDIES THE BANK MAY EMPLOY TO ENFORCE ITS RIGHTS AND REMEDIES HEREUNDER. MORE
SPECIFICALLY, THE BORROWER ACKNOWLEDGES THAT BANK'S ATTORNEY MAY, PURSUANT TO
CONNECTICUT GENERAL STATUES, SECTION 52-278F, ISSUE A WRIT FOR A PREJUDGMENT
REMEDY WITHOUT SECURING A COURT ORDER. THE BORROWER ACKNOWLEDGES AND RESERVES
ITS RIGHT TO NOTICE AND A HEARING SUBSEQUENT TO THE ISSUANCE OF A WRIT FOR
PREJUDGMENT REMEDY BY BANK'S ATTORNEY. THE BANK ACKNOWLEDGES THE BORROWER'S
RIGHT TO SAID HEARING SUBSEQUENT TO THE ISSUANCE OF SAID WRIT.

         IN WITNESS WHEREOF, the Borrower has caused this Note to be signed in
its corporate name by its duly authorized officer on the day and in the year
first above written.

                                               RAYTEL MEDICAL CORPORATION

                                               By: /s/ E. Payson Smith, Jr.
                                                  ---------------------------
                                               Name: E. Payson Smith, Jr.

                                               Title: Senior Vice President
                                                      & Chief Financial Officer