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                                                                   EXHIBIT 10.20

                                      NOTE

$197,450.00                                                Sunnyvale, California

                                                               December 23, 1996

1.   FOR VALUE RECEIVED, Earle Canty promises to pay to Cardiac Pathways
Corporation, a California corporation (the "Company"), or order, the principal
sum of One Hundred Ninety Seven Thousand Four Hundred Fifty Dollars ($197,450),
together with interest in the unpaid principal hereof from the date hereof at
the rate of six and four tenths percent (6.4%) per annum.

2.   Principal shall be due and payable in installments as follows: upon sale of
the shares, or any portion thereof (the "Shares"), underlying the options
granted to the undersigned by the Company on January 22, 1996 (the "Options"),
fifty percent (50%) of the proceeds from the sales of such Shares shall be due
and payable as an installment to be applied against the principal amount of this
Note; provided, however, that if no principal shall remain unpaid under this
Note, such proceeds shall be applied against the principal of any other note the
undersigned shall have made with the Company under which the principal amount is
not fully paid, but shall not be applied against interest due under this Note or
any other such note. Interest shall be due and payable in equal annual
installments on the last day of each fiscal year of the Company during which
this Note is outstanding. Should the undersigned fail to make full payment of
principal or interest for a period of 10 days or more after the due date
thereof, the whole unpaid balance on this Note of principal and interest shall
become immediately due at the option of the holder of this Note. Any remaining
indebtedness evidenced by this Note, if not sooner paid, shall be due and
payable upon the Maturity Date (as hereinafter defined). Payment of principal
and interest shall be made in lawful money of the United States of America.

3.   Notwithstanding anything to the contrary contained in this Note, the entire
principal balance and all accrued and unpaid interest thereon shall, at the
option of the Company, be due and payable upon that date (the "Maturity Date")
which is the earlier of:

     A.   The date of termination or cessation of employment of the undersigned
with the Company for any reason, whether voluntary or involuntary, and whether
with cause or without cause;

     B.   The fifth (5th) anniversary of the date of this Note.

4.   The undersigned may at any time prepay all or any portion of the principal
or interest owing hereunder.

5.   This note is subject to the terms of the Options. This Note is secured in
part by a pledge of the Company's Common Stock under the terms of a Security
Agreement of even date herewith and is subject to all the provisions thereof.


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6.   The holder of this Note shall have recourse against the undersigned, and
shall not be required to proceed against the collateral securing this Note in
the event of default.

7.   This Note may be amended or modified, and provisions hereof may be waived,
only by the written agreement of the undersigned and the Company. No delay or
failure by the Company in exercising any right, power or remedy hereunder shall
operate as a waiver of such right, power or remedy, and a waiver of any right,
power or remedy on any one occasion shall not operate as bar or waiver of any
such right, power or remedy on any other occasion. Without limiting the
generality of the foregoing, the delay or failure by the Company for any period
of time to enforce collection of any amounts due hereunder shall not be deemed
to be a waiver of any rights of the Company under contract or under law. The
rights of the Company under this Note are in addition to any other rights and
remedies which the Company may have.

8.   The undersigned hereby acknowledges that the Company has made no
representation or warranty to the undersigned concerning the income tax
consequences of the loan to the undersigned, and the undersigned shall be solely
responsible for ascertaining and bearing such tax consequences.

9.   Should any action be instituted for the collection of this Note, the
reasonable costs and attorney's fees therein of the holder shall be paid by the
undersigned.



                                                     /s/  Earle Canty
                                                     ---------------------------
                                                     Earle Canty