Exhibit 10.25

Cambridge Heart, Inc.

1 Oak Park Drive

Bedford, MA 01730

December 15, 2006

Jeffrey J. Langan

619 Princes Point Road

Yarmouth, ME 04096

Dear Jeff:

This letter agreement (the “Agreement”) between Cambridge Heart, Inc.
(“Cambridge Heart”) and you (the “Executive”) will confirm our agreement
concerning the details of the Executive’s separation from Cambridge Heart. The
Executive and Cambridge Heart are referred to together herein as the “Parties”.

1. Separation From Employment. Cambridge Heart accepts the Executive’s
resignation, effective December 15, 2006 (the “Separation Date”), as an
employee, officer and director of Cambridge Heart and from any other position
that the Executive may hold with Cambridge Heart. The Parties hereby agree that
the Employment Agreement dated October 13, 2006 between Cambridge Heart and the
Executive is hereby terminated effective as of the Separation Date, except for
the provisions of Section 7 through 23, inclusive, of the Employment Agreement,
which remain in full force and effect.

2. Final Salary Payment. Cambridge Heart will pay the Executive a final regular
salary payment (subject to all required withholding of taxes) for the period
from December 1, 2006 until the Separation Date on the next regular payroll date
following the Separation Date of this Agreement (the “Final Salary Payment”).
The Executive acknowledges that payment of the Final Salary Payment shall
constitute payment in full of all amounts due to the Executive from Cambridge
Heart for accrued wages, benefits (including, without limitation, accrued,
unused vacation leave, bonuses, earned commissions and scheduled advances) and
any other payments accrued through the Separation Date or to which the Executive
is otherwise entitled in connection with the Executive’s employment with
Cambridge Heart or the termination of such employment, except for payments
expressly provided for in this Agreement.

3. Severance Benefits. In consideration for the Executive’s execution of and
compliance with this Agreement and provided that the Executive does not revoke
any portion of the release contained in Section 5 of this Agreement, Cambridge
Heart agrees to provide the Executive with the severance benefits described in
the following subparagraphs (a), (b) and (c):

(a) From the Separation Date until April 13, 2007 (the “Payment Period”),
Cambridge Heart shall pay to the Executive installments of the Executive’s base
salary at the rate in effect as of the Separation Date ($240,000 per year),
subject to all required withholding of taxes, and on the same schedule as
executives of Cambridge Heart then receive regular salary payments, such
installments to begin on the first regular payroll date following the Effective
Date of this Agreement (as defined in paragraph 16).

 

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(b) The Executive will have the opportunity to continue to participate in
Cambridge Heart’s group medical and dental insurance programs (the “Health
Plans”) pursuant to the health care continuation provisions of the federal COBRA
law. If the Executive is eligible for COBRA coverage, elects to continue
coverage under the Health Plan pursuant to COBRA and otherwise maintains
eligibility for COBRA coverage, Cambridge Heart agrees to pay to the Health
Plans insurer during the Payment Period an amount equal to the portion of the
premiums for health care coverage paid by Cambridge Heart for Cambridge Heart’s
Chief Executive Officer’s and other senior executives’ coverage under the Health
Plans. The Executive’s eligibility to participate in and receive benefits under
the Health Plans shall remain subject to the terms and conditions of the Health
Plans. Cambridge Heart’s obligation to pay a portion of the premiums for health
care coverage on behalf of the Executive during the Payment Period shall
terminate immediately upon the Executive’s becoming eligible (either as a
participant or a dependent) to participate in a plan providing comparable or
superior health care benefits sponsored by another employer, provided, however,
that this sentence shall not apply in regards to the health coverage currently
provided to the Executive under the Anthem Blue Cross/Blue Shield of Maine
program.

(c) Notwithstanding the Executive’s separation from Cambridge Heart, the
following options shall continue to vest in accordance with their original
terms: (i) stock options granted to the Executive in connection with his
appointment as Chief Executive Officer on October 13, 2006 to purchase 200,000
shares of common stock of Cambridge Heart at an exercise price of $2.49 per
share, 100,000 become exercisable on January 13, 2007 and 100,000 of which
become exercisable on April 13, 2006 (the “Surviving Employee Options”) shall
continue to become exercisable in accordance with their terms and thereafter
shall remain exercisable in accordance with their original term, (ii) stock
options granted to the Executive in connection with his service as a director on
September 19, 2005 to purchase 138,750 shares of common stock of Cambridge Heart
at an exercise price of $0.30 per share, 46,250 are currently exercisable and
46,250 of which become exercisable on each of September 19, 2007 and 2008 (the
“2005 Director Options”), shall continue to become exercisable in accordance
with their original term and thereafter shall remain exercisable in accordance
with their original term, and (iii) stock options granted to the Executive in
connection with his service as a director on October 30, 2006 to purchase 30,000
shares of common stock of Cambridge Heart at an exercise price of $2.90 per
share, 10,000 of which become exercisable on each of October 30, 2007, 2008 and
2009 (the “2006 Director Options”), shall continue to become exercisable in
accordance with their original term and thereafter shall remain exercisable in
accordance with their original term. The Executive understands, and Cambridge
Heart acknowledges, that Cambridge Heart shall properly account for the
Surviving Employee Options, the 2005 Director Options, and the 2006 Director
Options in accordance with GAAP. The Surviving Employee Options, the 2005
Director Options and the 2006 Director Options shall be governed by the terms
and conditions of the 2001 Stock Incentive Plan. All other stock options granted
to the Executive are hereby immediately cancelled and forfeited.

If the Executive revokes a portion of the release contained in Section 5 of this
Agreement in accordance with Section 16, then in consideration for the
Executive’s execution of and compliance with this Agreement, Cambridge Heart
shall pay to the Executive as a reduced

 

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severance benefit (in lieu of the benefits set forth in (a) through (c) above)
$20,000 payable on April 13, 2007.

The Executive hereby acknowledges and agrees that (i) the foregoing severance
benefits are in excess of all other payments, benefits, and things of value to
which the Executive would be entitled if the Executive did not execute and
comply with this Agreement; and (ii) the severance benefits shall not be deemed
to be salary or other compensation to the Executive for purposes of any plans,
programs or arrangements maintained or contributed to by Cambridge Heart to
provide benefits to its executives, directors or officers.

4. Return of Property. The Executive agrees to return to Cambridge Heart on or
before the Separation Date, all property of Cambridge Heart used or obtained by
the Executive in connection with the Executive’s employment that is in the
Executive’s possession or control, including, without limitation, any computers,
equipment, credit cards and keys issued to the Executive.

5. Release. The Executive hereby acknowledges and agrees that this Agreement is
intended to be a complete and final settlement of any and all causes of action
or claims that the Executive has had, now has or may now have, whether known or
unknown against Cambridge Heart or any of the persons or entities specified
below. The Executive hereby, on behalf of the Executive, the Executive’s
executors, heirs, administrators, assigns and anyone else claiming by, through
or under the Executive, waives, releases, covenants not to sue and forever
discharges Cambridge Heart, its predecessors, successors, related corporations,
subsidiaries, divisions and affiliated organizations, and each and all of their
present and former officers, directors, shareholders, representatives, agents,
promoters, executives and attorneys (hereinafter “Releasees”), and each and all
of them of, from and with respect to any and all debts, demands, actions, causes
of action, suits, covenants, contracts, agreements, promises, torts, damages,
claims, demands and liabilities whatsoever of any name and nature, both in law
and in equity (hereinafter “Claims”) that the Executive now has, may now have or
ever had against each or any of the Releasees by reason of any matter, cause or
thing whatsoever from the beginning of the world to the date hereof, including,
but not limited to, any Claims arising out of, based upon or connected with the
Executive’s employment by Cambridge Heart, the compensation, benefits and
working conditions for that employment and/or the termination of that
employment, and any Claims that may exist under federal, state or local laws,
including, but not limited to, any Claims based on race, disability, color,
national origin, marital status, age or sex, but excluding any right to
indemnification to which the Executive may be entitled, whether by contract, by
charter or by-law provision, or otherwise. The foregoing waiver and release
includes, without limitation, a waiver and release of any rights and Claims that
the Executive may have under Title VII of the Civil Rights Act of 1964, the
Equal Pay Act, the Americans with Disabilities Act, the Family and Medical Leave
Act, the Executive Retirement Income Security Act of 1974, the Worker Adjustment
and Retraining Notification Act, the Age Discrimination in Employment Act of
1967, as amended, 29 U.S.C. § 621 et seq. (the “ADEA”)(except that this
Agreement does not waive or release any rights or claims under the ADEA that may
arise after the execution of this Agreement or otherwise bar the Executive from
challenging this Agreement’s compliance with the provisions of 29 U.S.C. §
627(f)(1)), the Fair Labor Standards Act, or the state and local laws of
Massachusetts.

 

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Cambridge Heart, on behalf of itself and its predecessors, successors,
subsidiaries, related corporations, divisions, and affiliated organizations
waives, releases, covenants not to sue and forever discharges the Executive and
the Executive’s executors, heirs, administrators and assigns (hereinafter the
“Executive Releasees”), and each and all of them of, from and with respect to
any and all Claims that Cambridge Heart now has, may now have or ever had
against the Executive by reason of any matter, cause or thing whatsoever from
the beginning of the world to the date hereof, including, but not limited to,
any Claims arising out of, based upon or connected with the Executive’s
employment by Cambridge Heart, and any Claims that may exist under federal,
state or local laws; provided, however, that this release shall not apply to
Claims that are unknown to Cambridge Heart as of the date hereof.

6. Non-Disparagement. The Parties agree that any public disclosure of the
circumstances surrounding the Executive’s separation from Cambridge Heart shall
be agreed upon by the Parties prior to its disclosure, except for disclosure
required by law, including, without limitation, applicable securities laws. The
Executive agrees not to make any adverse remarks whatsoever concerning any of
the officers or directors of Cambridge Heart or the business, operations,
strategies, policies, prospects, affairs or financial condition of Cambridge
Heart, except as required by law. Cambridge Heart agrees that it will not make
any adverse remarks whatsoever concerning the Executive and that it will
instruct each of its directors and officers not to make any adverse remarks
whatsoever concerning the Executive, except as required by law.

7. Confidential Information; Non-Solicitation. The Executive acknowledges that
during the course of his employment he has had access to confidential
information of Cambridge Heart. The Executive further acknowledges and agrees
that the Executive has no rights to use, copy or disclose any confidential or
proprietary information owned, or provided to, the Executive by Cambridge Heart.
The Executive acknowledges and agrees that the restrictions against disclosure
and use of confidential information set forth in Section 8 of the Employment
Agreement shall remain in full force and effect and shall apply to Confidential
Information and Proprietary Information (as each is defined in the Employment
Agreement) obtained by the Executive during the Payment Period. The Executive
acknowledges and agrees that the non-solicitation restrictions set forth in
Section 10 of the Employment Agreement shall survive the Separation Date and
remain in full force and effect until December 13, 2008.

8. Reasonable Assistance. During the Payment Period, the Executive agrees to
make himself available upon reasonable notice and provide to Cambridge Heart
such transition assistance as is reasonably requested by the senior management
of Cambridge Heart without the payment of any other compensation for such
assistance, except that Cambridge Heart agrees to reimburse the Executive for
expenses actually and reasonably incurred by the Executive (including, but not
limited to, travel, lodging and meal expenses) the Executive incurs in relation
to providing such transition assistance.

9. Indemnification and Reimbursement of Legal Fees. Cambridge Heart hereby
confirms that, in the event that the Executive is a party to any lawsuit by
reason of the fact that he was an employee, a director or an officer of
Cambridge Heart or by reason of any action taken

 

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or omitted by the Executive in such capacity, the Executive shall be entitled to
be indemnified by Cambridge Heart against all expenses (including attorneys’
fees) incurred by him in connection with such lawsuit in accordance with the
terms and procedures set forth in the Amended and Restated Certificate of
Incorporation of Cambridge Heart.

10. Compliance with Agreement. All payments (including, without limitation, the
severance benefits) to be made to the Executive and benefits to be made
available to the Executive in accordance with the terms of this Agreement, and
the performance by Cambridge Heart of its other obligations hereunder, shall be
conditioned on the Executive’s continued compliance in all material respects
with the covenants set forth in this Agreement. In the event compliance is not
continued within ten (10) days after notice of such failure to comply has been
given in writing to the Executive, Cambridge Heart shall have the right to seek
repayment of all severance benefits earned or paid up to the time compliance has
ceased.

11. Interpretation. Nothing in this Agreement shall be construed as an admission
by Cambridge Heart or any of its shareholders, agents, employees, directors or
representatives, past or present, that it or they violated any law or regulation
or any other legal or equitable obligation it or they have or ever had to the
Executive.

12. No Obligation to Re-Employ. The Executive agrees and recognizes that as of
the Separation Date he will have permanently and irrevocably severed his
employment relationship with Cambridge Heart, that he shall not seek employment
with Cambridge Heart at any time in the future, and that Cambridge Heart has any
obligation to employ him in the future.

13. Enforcement of Covenants. The Parties agree that irreparable damages would
occur in the event that Sections 4, 5, 6 and 7 of this Agreement are not
performed by the party obligated thereunder in accordance with their specific
terms. It is accordingly agreed that the other party will be entitled to an
injunction or injunctions to prevent breaches of the party obligated thereunder
and to enforce specifically the terms and provisions hereof in any court having
jurisdiction, this being in addition to any other remedy to which it is entitled
at law or in equity.

14. Severability. If any term or provision of this Agreement or the application
thereof to any person, property or circumstance shall to any extent be invalid
or unenforceable, then at the election of the party primarily benefited by such
term or provision, the remainder of this Agreement or the application of such
term or provision to persons, property or circumstances other than those as to
which it is invalid or unenforceable shall not be affected thereby, and each
term and provision of this Agreement shall be valid and enforced to the fullest
extent permitted by law.

15. Consultation with Attorney. The Executive is hereby advised to consult with
an attorney before signing this Agreement and has had an opportunity to do so.
The Executive acknowledges that he fully understands this Agreement, that he has
had a reasonable time to consider this Agreement, and that he is knowingly and
voluntarily entering into this Agreement.

16. ADEA Claims. As to any and all claims, demands, actions, causes of action,
suits, damages, losses and expenses, known or unknown, that the Executive may
have pursuant to

 

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ADEA, the Executive acknowledges that he has twenty-one (21) days from the time
the Executive received this Agreement to consider whether to sign it. The
Executive affirms that if he chooses to sign the Agreement before the end of
those twenty-one (21) days, it is because the Executive freely chose to do so
after carefully considering the terms of this Agreement as to any ADEA claims
and contacting anyone whom the Executive chose to consult, including but not
limited to, an attorney. The Executive further understands and acknowledges that
once the Executive signs this Agreement, the Executive will then have seven
(7) calendar days, if he so chooses, to revoke the release in Section 5 of this
Agreement solely as to any claims arising under the ADEA. The Executive
acknowledges that once signed, this Agreement is immediately effective and
enforceable as to any and all claims, except that this Agreement will not be
effective or enforceable as to any claim under the ADEA until the seven
(7) calendar day revocation period expires (the “Effective Date”).

17. Miscellaneous. This Agreement shall be governed by and construed in
accordance with the laws of the Commonwealth of Massachusetts without regard to
conflicts of law principles. The obligations of Cambridge Heart and the
Executive hereunder shall inure to the benefit of and be binding on the
respective heirs, personal representatives, successors and assigns of the
Parties. This Agreement embodies the entire agreement and understanding among
the Parties concerning the Executive’s employment and the termination thereof
and incorporates and supersedes all other agreements with regard to the
Executive’s employment and the termination thereof.

18. Amendment. This Agreement may be amended or modified only upon the written
mutual consent of the parties.

 

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If the foregoing is in accordance with your understanding, please sign and
return the enclosed copy of this letter, whereupon this letter and such copy
will constitute a binding agreement under seal between Cambridge Heart and you
on the basis set forth above.

 

Very truly yours,

CAMBRIDGE HEART, INC.

By: /s/ Robert P. Khederian

Name: Robert P. Khederian

Title: Chairman of the Board

Acknowledged and agreed to this

15th day of December 2006:

/s/ Jeffrey J. Langan

Jeffrey J. Langan

 

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