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EXHIBIT 99.4
PROXY
THORATEC LABORATORIES CORPORATION
PROXY SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS:
The undersigned hereby appoints each of Keith Grossman and Cheryl Hess
as proxy holders, each with full power of substitution, to vote all the shares
of common stock of Thoratec Laboratories Corporation, a California corporation
("Thoratec"), that the undersigned is entitled to vote at the special meeting of
Thoratec's shareholders to be held at 6035 Stoneridge Drive, Pleasanton,
California, on __________, 2000, at [1:00 P.M.] Pacific Standard Time or any
adjournments or postponements of that meeting. The proxy holders are directed to
vote as specified below with respect to the four proposals summarized below. If
no instructions appear below, this proxy will be voted FOR all of those
proposals. The four proposals are to approve: (1) the proposed merger of
Lightning Acquisition Corporation, a wholly-owned subsidiary of Thoratec
("Merger Sub"), into Thermo Cardiosystems Inc. ("TCA"), in which 0.835 of a
share of Thoratec common stock will be issued in exchange for each outstanding
share of common stock of TCA (other than TCA shares whose holders properly
exercise statutory appraisal rights) and TCA will become a wholly-owned
subsidiary of Thoratec, all in accordance with the Agreement and Plan of Merger
dated as of October 3, 2000 among Thoratec, Merger Sub, TCA and Thermo Electron
Corporation (the "Merger Agreement"), (2) an amendment to Thoratec's 1997 Stock
Option Plan (the "Plan"), to increase the number of shares reserved for issuance
under options granted under the Plan by 3,600,000 in addition to any increase
authorized under proposal 3 to facilitate Thoratec's assumption of outstanding
TCA options in the merger and future option grants to TCA personnel, (3) an
amendment to the Plan to increase the number of shares reserved for issuance
under options granted under the Plan by 2,800,000, which is in addition to any
increase authorized by proposal 2 and which will allow Thoratec to continue to
attract and retain qualified Thoratec personnel and (4) an amendment to
Thoratec's Articles of Incorporation to change the corporate name of Thoratec
from Thoratec Laboratories Corporation to Thoratec Corporation.
The directors recommend a FOR vote on each of the above items.
(CONTINUED AND TO BE SIGNED ON REVERSE SIDE.)
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FOLD AND DETACH HERE
Please mark your vote as [X] indicated in this example.
<TABLE>
<CAPTION>
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PROPOSAL FOR AGAINST ABSTAIN
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<S> <C> <C> <C>
1. The merger of a subsidiary of
Thoratec Laboratories Corporation
into Thermo Cardiosystems Inc.,
the related Merger Agreement and
the issuance of Thoratec stock in
the merger.
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2 Amendment to Thoratec's 1997
Stock Option Plan to increase the
number of reserved shares by
3,600,000.
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3. Amendment to Thoratec's 1997 Stock
Option Plan to increase the number of
reserved shares by 2,800,000.
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4. Amendment to Thoratec's Articles of
Incorporation to change the name of
Thoratec to Thoratec Corporation.
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</TABLE>
Signature ___________________________
Signature ___________________________
Date _________, 200_
Signature(s) must be exactly as name(s) appear on this proxy. If signing as an
attorney, executor, administrator, trustee or guardian, please give full title
as such. If signing for a corporation or other entity, please indicate the
capacity in which you represent that entity. When shares are registered in the
names of more than one person, each such person should sign this proxy.
2
