PROMISSORY NOTE

$55,000.00                                      Portola Valley, California 94028
                                                June 5, 1996


    For value received, the undersigned Thomas Afzal (Obligor) whose address is
32 Anderson Way, Menlo Park, California, hereby unconditionally promises to pay
to CardioThoracic Systems, Inc. (the Company) whose address is 3280 Alpine Road,
Portola Valley, CA 94028, or order, in lawful money of the United States, the
principal sum of Fifty-Five Thousand Dollars ($55,000.00) together with interest
accrued from the date hereof on the unpaid principal at the rate of 5.88%.

    PRINCIPAL REPAYMENT.  The outstanding principal amount hereunder shall be
due and payable in two (2) installments of $27,500.00 on January 5, 1997 and
January 5, 1998.  Provided, however, that in the event that Obligor's employment
by, or associated with, the Company is terminated for cause or by voluntary
resignation prior to payment in full of this Note, this Note shall be
accelerated and all remaining unpaid principal shall become due and payable
immediately upon such termination.

    INTEREST PAYMENTS.  Interest shall be calculated on the basis of a three
hundred and sixty (360) day year for the actual number of days elapsed and shall
be payable concurrently with the principal.

    RIGHT OF SET-OFF.  At such time as this Note is due and payable the Company
shall have the right to retain any amounts owing to Obligee in complete or
partial satisfaction of the obligation.

    CANCELLATION OF INDEBTEDNESS.  Notwithstanding the above, should Obligor's
employment or association with the Company continue through the due date of any



installment payment under this Note, then the Company agrees to forgive all
principal and interest due by the terms of this Note for that installment.

    This Note may be prepaid at any time without penalty.  All money paid
toward the payment of this Note shall be applied first to the payment of
interest as required hereunder and then to the retirement of the principal.

    Obligor hereby waives presentment, protest and notice of protest, demand
for payment, notice of dishonor and all other notices or demands in connection
with the delivery, acceptance, performance, default or endorsement of this Note.

    The holder hereof shall be entitled to recover, and Obligor agrees to pay
when incurred, all costs and expenses of collection of this Note, including
without limitation, reasonable attorneys' fees.

    This note shall be governed by, and construed, enforced and interpreted in
accordance with, the laws of the State of California, excluding conflict of laws
principals that would cause the application of laws of any other jurisdiction.


                                       OBLIGOR


                                       /s/Thomas Afzal
                                       -----------------------------------
                                       Thomas Afzal