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                                                                   EXHIBIT 10.2


                                AMENDMENT NO. 2
                                       TO
                               SUBLEASE AGREEMENT


     THIS IS AMENDMENT NO. 2 dated as of February 14, 2001 ("Amendment No. 2")
to the SUBLEASE AGREEMENT dated as of August 19, 1988, as amended by Amendment
No. 1 thereto dated January 1, 1990 (as so amended, the "Sublease Agreement")
by and between Thermo Electron Corporation, a Delaware corporation and
successor to Thermedics Inc., a Delaware corporation ("TEC"), and Thermo
Cardiosystems Inc., a Massachusetts corporation ("TCA"). Unless otherwise
indicated, terms used in this Amendment No. 2 that begin with capital letters
and are not defined here have the meanings given them in the Sublease
Agreement. Except as provided otherwise in this Amendment No. 2, references to
Articles are to Articles of the Sublease Agreement and references to Sections
are to Sections of the Master Lease (as defined below).


                                    RECITALS

     A. TCA subleases property from TEC located at 470 Wildwood Street in
Woburn, Massachusetts under the Sublease Agreement.

     B. The Sublease Agreement is subject to the terms of the lease dated
November 1983 between WGO Limited Partnership, a Massachusetts limited
partnership, and TEC, as amended July 15, 1993 and extended by letter dated
August 12, 1998 (as so amended and extended, the "Master Lease").

     C. TCA is a party to an Agreement and Plan of Merger (the "Merger
Agreement") dated as of October 3, 2000 pursuant to which, upon satisfaction of
certain conditions, TCA will be acquired by Thoratec Laboratories Corporation,
a California corporation that will soon drop "Laboratories" from its corporate
name ("Thoratec").

     D. Section 7.2(i) of the Merger Agreement requires that the Sublease
Agreement be amended as set forth in this Amendment No. 2.


ACCORDINGLY, THE PARTIES AGREE AS FOLLOWS:


1.   ADDITIONAL PARKING SPACES

     Article I is amended so that TEC shall provide to TCA the exclusive use of
75 parking spaces as indicated on the Parking Plan attached as Exhibit A;
provided,

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however, that TEC shall not be obligated to supply such spaces if such spaces
are currently required to be provided to another tenant of the subleased
property.


2.   LIMITATION ON LIABILITY

     The second sentence of Article VI is replaced in its entirety with the
following: "TCA will exonerate, indemnify and hold harmless TEC against all
claims, suits, obligations, liabilities and damages, including attorneys'
fees, arising out of any failure by TCA to perform, fulfill or observe any
obligation or liability of TEC set forth in the Sublease Agreement which TCA is
obligated to perform hereunder, or any negligent act or omission by TCA."


3.   NOTICES

     All notices provided to TCA pursuant to Article VIII shall also be
provided in the manner set forth in Article VIII to Thoratec at 6035 Stoneridge
Drive, Pleasanton, California 94588, Attn.: Chief Financial Officer.


4.   RIGHT TO CURE

     TEC will provide prompt written notice to TCA and Thoratec of any breach
of the Master Lease or any event of default under Section 19 of the Master
Lease and will take all actions reasonably necessary to promptly cure such
breach or event of default within the time period permitted for such cure. If
TEC fails to cure any such breach or event of default within five days of the
notice of such breach or event of default, TCA may, at its sole discretion,
take actions reasonably necessary to cure any such breach or event of default.
TCA may offset any amount owed to TEC against the costs of curing such breach
or event of default. TCA shall have no obligation to pay any fees owed under
Section 28 of the Master Lease upon any optional termination by TEC under such
section.


5.   RIGHT OF FIRST REFUSAL

     In the event that the current subtenant of the space located at the
premises which is not subject to the Sublease Agreement (the "Additional
Space") notifies TEC that it no longer intends to sublease the Additional Space
from TEC, TEC shall notify TCA and TCA shall have the right, upon written
notification within 10 days from the date so notified by TEC, to sublease the
Additional Space on the same terms and conditions as such Additional Space is
currently subleased by such other subtenant.


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6.   ACKNOWLEDGEMENT
     ---------------

     TCA hereby acknowledges that except to the extent otherwise provided in
the Sublease Agreement, as amended by this Amendment No. 2, the Sublease
Agreement, as so amended, shall be deemed to contain all of the same covenants,
terms and provisions as are contained in the Master Lease, including without
limitation the expiration of the term thereof on February 29, 2004.


     IN WITNESS WHEREOF, the parties have executed and delivered this Amendment
No. 2 as of the date first written above.

                                                 THERMO CARDIOSYSTEMS INC., a
                                                 Massachusetts corporation

                                            By:/s/ Robert Michael Kleine 2/9/01
                                               ---------------------------------
                                               Name: Robert Michael Kleine
                                               Title: CEO

                                                 THERMO ELECTRON CORPORATION, a
                                                 Delaware corporation

                                            By:/s/ Theo Melas-Kyriazi
                                               -----------------------
                                                Name: Theo Melas-Kyriazi
                                                Title: CFO



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