SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C.  20549

                   ___________________________________________


                                    FORM 8-K

                                 CURRENT REPORT



                       Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934



                                 Date of Report
                       (Date of earliest event reported):

                                   May 2, 1997

                    ________________________________________


                            THERMO CARDIOSYSTEMS INC.
             (Exact name of Registrant as specified in its charter)


   Massachusetts                   1-10114                          04-3027040
   (State or other               (Commission                  (I.R.S. Employer
   jurisdiction of               File Number)           Identification Number)
   incorporation or
   organization)


   470 Wildwood Street
   P. O. Box 2697
   Woburn, Massachusetts                                            01888-2697
   (Address of principal executive offices)                         (Zip Code)


                                 (617) 622-1000
                         (Registrant's telephone number
                              including area code)
PAGE
<PAGE>





   Item 2.  Acquisition or Disposition of Assets
            ------------------------------------

        On May 2, 1997, Thermo Cardiosystems Inc. (the "Company") acquired
   International Technidyne Corporation ("ITC"), a wholly owned subsidiary of
   Thermo Electron Corporation ("Thermo Electron"), in exchange for the right
   to receive 3,355,705 shares of the Company's common stock.  ITC is a
   manufacturer of near-patient, whole-blood coagulation-testing equipment and
   related disposables, as well as single-use, premium-priced, skin-incision
   devices. In 1996, ITC had revenues of $34,000,000, with net income of
   $4,700,000.

        The acquisition was made pursuant to an Agreement and Plan of
   Reorganization dated as of May 2, 1997 (the "Agreement"), among the
   Company, ITC Acquisition Inc., a wholly owned subsidiary of the Company
   ("Acquisition"), Thermo Electron, ITC Holdings Inc., a wholly owned
   subsidiary of Thermo Electron that owned ITC ("Holdings"), and ITC.  Under
   the terms of the Merger Agreement, (i) Acquisition merged with and into
   ITC, (ii) outstanding shares of ITC's common stock were canceled and
   converted into the right to receive 3,355,705 shares of the Company's
   common stock, (iii) each outstanding share of Acquisition's common stock
   was canceled and converted into one share of the common stock of ITC, and
   (iv) ITC became a wholly owned subsidiary of the Company.

        The shares of the Company's common stock to be issued in connection
   with the acquisition will be so issued as soon as such shares are listed
   for trading upon the American Stock Exchange, Inc.  The exchange requires
   that the listing be approved by the holders of a majority of the Company's
   outstanding shares present and voting at a shareholders' meeting.  The
   meeting is expected to be held before the end of fiscal 1997.  Thermo
   Electron and Thermedics Inc. ("Thermedics") have each agreed to vote all of
   the shares of the Company's common stock held by them as of the record date
   of the meeting in favor of the listing of the Company's shares and all
   matters related thereto.  Before giving effect to the issuance of the
   shares to be issued pursuant to the Agreement, Thermo Electron and
   Thermedics owned an aggregate of 54.2% of the outstanding common stock of
   the Company.  Giving effect to the issuance of such shares, Thermo Electron
   and Thermedics own an aggregate of 58.1% of such outstanding common stock. 
    
        The consideration to be paid for ITC was based on the Company's
   determination of the fair market value of ITC's business.  Based on the
   average of the closing prices of the Company's common stock as reported on
   the American Stock Exchange for the five trading days ending on March 27,
   1997, the shares to be issued to Thermo Electron had a value of $75,000,000
   prior to the execution of the Agreement.  Prior to the execution of the
   Agreement, Cazenove Incorporated, an investment banking firm, provided a
   written opinion to the Board of Directors of the Company indicating that,
   as of May 2, 1997, the consideration to be paid for ITC was fair to the
   Company from a financial point of view.  

        The Company has no present intention to use ITC's assets for purposes
   materially different from the purposes for which such assets were used
   prior to the acquisition.  However, the Company will review ITC's business
   and assets, corporate structure, capitalization, operations, properties,
   policies, management and personnel and, upon completion of this review, may
   develop alternative plans or proposals, including mergers, transfers of a
   material amount of assets or other transactions or changes relating to such
   business.
PAGE
<PAGE>






   Item 7.  Financial Statements, Pro Forma Combined Condensed Financial
            ------------------------------------------------------------
   Information and Exhibits
   ------------------------

            (a) Financial Statements of Business Acquired: Information
                meeting the requirements of this Item 7(a) will be filed by
                amendment within the time period permitted by Item 7(a)(4) of
                Form 8-K.

            (b) Pro Forma Combined Condensed Financial Information:
                Information meeting the requirements of this Item 7(b) will
                be filed by amendment within the time period permitted by
                Item 7(a)(4) of Form 8-K.

            (c) Exhibits

                2.     Agreement and Plan of Reorganization dated as of May 2,
                       1997, by and among Thermo Cardiosystems Inc., ITC
                       Acquisition Inc., Thermo Electron Corporation, ITC
                       Holdings Inc. and International Technidyne Corporation
                       (incorporated by reference from Exhibit 2.1 to the
                       Company's Quarterly Report on Form 10-Q for the Quarter
                       ended March 29, 1997).

                99.   Opinion of Cazenove Incorporated dated May 2, 1997.



   Item 9.  Sales of Equity Securities Pursuant to Regulation S.
            ---------------------------------------------------

        On May 9, 1997, the Company issued a press release to announce that it
   had entered into an agreement to sell at par $70 million principal amount
   of 4-3/4% convertible subordinated debentures due 2004 (the "Debentures").

        Of that amount, Debentures having an aggregate principal amount of
   $14,475,000 were sold on May 14, 1997 without registration under the
   Securities Act of 1933 (the "Securities Act") in reliance on the exemption
   from registration provided by Regulation S under the Securities Act (the
   "Reg. S Debentures").  The Reg. S Debentures were offered, sold and
   delivered only to non-United States persons outside of the United States,
   its territories and possessions.  (The balance of the Debentures were sold
   in the United States and/or to United States persons in reliance on the
   exemption from registration provided by Rule 144A under the Securities
   Act.)   

        The managers of the Debenture offering were Lehman Brothers
   International (Europe), Salomon Brothers Inc. and Cowen & Company.  The
   total underwriting discounts and commissions applicable to the Reg. S
   Debentures equaled $361,875, or 2.5% of the principal amount thereof. 

PAGE
<PAGE>




        The Debentures will be convertible into shares of the Company's common
   stock at a price of $31.415 per share on or after the later of (i) the
   expiration of the 40-day period that began on May 14, 1997 and (ii) the
   effective date of a registration statement to be filed by the Company
   registering the resale of such shares of Common Stock under the Securities
   Act.


                               SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934,
   the Registrant has duly caused this report to be signed on its behalf by
   the undersigned thereunto duly authorized, on this 15th day of May, 1997.



                                             THERMO CARDIOSYSTEMS INC.


                                             By: /s/ Jonathan W. Painter
                                                 -----------------------
                                                 Jonathan W. Painter
                                                 Treasurer
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SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C.  20549

                   ___________________________________________

                                    FORM 8-K

                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934

                                 Date of Report
                       (Date of earliest event reported):

                                   May 2, 1997

                    ________________________________________

                            THERMO CARDIOSYSTEMS INC.
             (Exact name of Registrant as specified in its charter)

   Massachusetts                   1-10114                          04-3027040
   (State or other               (Commission                  (I.R.S. Employer
   jurisdiction of               File Number)           Identification Number)
   incorporation or
   organization)

   470 Wildwood Street
   P. O. Box 2697
   Woburn, Massachusetts                                            01888-2697
   (Address of principal executive offices)                         (Zip Code)

                                 (617) 622-1000
                         (Registrant's telephone number
                              including area code)
PAGE
Item 2.  Acquisition or Disposition of Assets
            ------------------------------------

        On May 2, 1997, Thermo Cardiosystems Inc. (the "Company") acquired
   International Technidyne Corporation ("ITC"), a wholly owned subsidiary of
   Thermo Electron Corporation ("Thermo Electron"), in exchange for the right
   to receive 3,355,705 shares of the Company's common stock.  ITC is a
   manufacturer of near-patient, whole-blood coagulation-testing equipment and
   related disposables, as well as single-use, premium-priced, skin-incision
   devices. In 1996, ITC had revenues of $34,000,000, with net income of
   $4,700,000.

        The acquisition was made pursuant to an Agreement and Plan of
   Reorganization dated as of May 2, 1997 (the "Agreement"), among the
   Company, ITC Acquisition Inc., a wholly owned subsidiary of the Company
   ("Acquisition"), Thermo Electron, ITC Holdings Inc., a wholly owned
   subsidiary of Thermo Electron that owned ITC ("Holdings"), and ITC.  Under
   the terms of the Merger Agreement, (i) Acquisition merged with and into
   ITC, (ii) outstanding shares of ITC's common stock were canceled and
   converted into the right to receive 3,355,705 shares of the Company's
   common stock, (iii) each outstanding share of Acquisition's common stock
   was canceled and converted into one share of the common stock of ITC, and
   (iv) ITC became a wholly owned subsidiary of the Company.

        The shares of the Company's common stock to be issued in connection
   with the acquisition will be so issued as soon as such shares are listed
   for trading upon the American Stock Exchange, Inc.  The exchange requires
   that the listing be approved by the holders of a majority of the Company's
   outstanding shares present and voting at a shareholders' meeting.  The
   meeting is expected to be held before the end of fiscal 1997.  Thermo
   Electron and Thermedics Inc. ("Thermedics") have each agreed to vote all of
   the shares of the Company's common stock held by them as of the record date
   of the meeting in favor of the listing of the Company's shares and all
   matters related thereto.  Before giving effect to the issuance of the
   shares to be issued pursuant to the Agreement, Thermo Electron and
   Thermedics owned an aggregate of 54.2% of the outstanding common stock of
   the Company.  Giving effect to the issuance of such shares, Thermo Electron
   and Thermedics own an aggregate of 58.1% of such outstanding common stock. 
    
        The consideration to be paid for ITC was based on the Company's
   determination of the fair market value of ITC's business.  Based on the
   average of the closing prices of the Company's common stock as reported on
   the American Stock Exchange for the five trading days ending on March 27,
   1997, the shares to be issued to Thermo Electron had a value of $75,000,000
   prior to the execution of the Agreement.  Prior to the execution of the
   Agreement, Cazenove Incorporated, an investment banking firm, provided a
   written opinion to the Board of Directors of the Company indicating that,
   as of May 2, 1997, the consideration to be paid for ITC was fair to the
   Company from a financial point of view.  

        The Company has no present intention to use ITC's assets for purposes
   materially different from the purposes for which such assets were used
   prior to the acquisition.  However, the Company will review ITC's business
   and assets, corporate structure, capitalization, operations, properties,
   policies, management and personnel and, upon completion of this review, may
   develop alternative plans or proposals, including mergers, transfers of a
   material amount of assets or other transactions or changes relating to such
   business.
PAGE
Item 7.  Financial Statements, Pro Forma Combined Condensed Financial
            ------------------------------------------------------------
   Information and Exhibits
   ------------------------

            (a) Financial Statements of Business Acquired: Information
                meeting the requirements of this Item 7(a) will be filed by
                amendment within the time period permitted by Item 7(a)(4) of
                Form 8-K.

            (b) Pro Forma Combined Condensed Financial Information:
                Information meeting the requirements of this Item 7(b) will
                be filed by amendment within the time period permitted by
                Item 7(a)(4) of Form 8-K.

            (c) Exhibits

                2.     Agreement and Plan of Reorganization dated as of May 2,
                       1997, by and among Thermo Cardiosystems Inc., ITC
                       Acquisition Inc., Thermo Electron Corporation, ITC
                       Holdings Inc. and International Technidyne Corporation
                       (incorporated by reference from Exhibit 2.1 to the
                       Company's Quarterly Report on Form 10-Q for the Quarter
                       ended March 29, 1997).

                99.   Opinion of Cazenove Incorporated dated May 2, 1997.

   Item 9.  Sales of Equity Securities Pursuant to Regulation S.
            ---------------------------------------------------

        On May 9, 1997, the Company issued a press release to announce that it
   had entered into an agreement to sell at par $70 million principal amount
   of 4-3/4% convertible subordinated debentures due 2004 (the "Debentures").

        Of that amount, Debentures having an aggregate principal amount of
   $14,475,000 were sold on May 14, 1997 without registration under the
   Securities Act of 1933 (the "Securities Act") in reliance on the exemption
   from registration provided by Regulation S under the Securities Act (the
   "Reg. S Debentures").  The Reg. S Debentures were offered, sold and
   delivered only to non-United States persons outside of the United States,
   its territories and possessions.  (The balance of the Debentures were sold
   in the United States and/or to United States persons in reliance on the
   exemption from registration provided by Rule 144A under the Securities
   Act.)   

        The managers of the Debenture offering were Lehman Brothers
   International (Europe), Salomon Brothers Inc. and Cowen & Company.  The
   total underwriting discounts and commissions applicable to the Reg. S
   Debentures equaled $361,875, or 2.5% of the principal amount thereof. 

PAGE
The Debentures will be convertible into shares of the Company's common
   stock at a price of $31.415 per share on or after the later of (i) the
   expiration of the 40-day period that began on May 14, 1997 and (ii) the
   effective date of a registration statement to be filed by the Company
   registering the resale of such shares of Common Stock under the Securities
   Act.

                               SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934,
   the Registrant has duly caused this report to be signed on its behalf by
   the undersigned thereunto duly authorized, on this 15th day of May, 1997.

                                             THERMO CARDIOSYSTEMS INC.

                                             By: /s/ Jonathan W. Painter
                                                 -----------------------
                                                 Jonathan W. Painter
                                                 Treasurer