<PAGE>


                                 Promissory Note
                                 ---------------

December 15, 1998

                                                                       $4,000.00

          For value  received,  the  undersigned,  Cardiac  Control  Systems,  a
Delaware  corporation having its principal office at 3 Commerce Boulevard,  Palm
Coast,  Florida 32164 (the "Borrower"),  promises to pay to the order of Alan J.
Rabin, ("the Lender") located at 19 Choctaw Trail, Ormond Beach,  Florida 32174,
(or at any  other  address  notice  of  which  is  given  by the  Lender  to the
Borrower),  in a lawful money of the United States and in immediately  available
funds,  the principal  amount of Four Thousand and 00/100  Dollars  ($4,000) and
interest as provided in the next two paragraphs of this Note. The Borrower shall
pay  the  outstanding  principal  amount  of  this  Note  to the  Lender  in one
installment on or before the Merger Closing Date (as  hereinafter  defined).  If
the Merger  Closing Date shall not have occurred by December 31, 1998,  then the
Borrower shall pay the outstanding  principal  amount of this Note to the Lender
within ten (10) days after written demand from the Lender.  For purposes hereof,
"Merger  Closing  Date" shall mean the date as of which the Borrower and Elecath
(Electro-Catheter  Corporation)  shall have  merged  with  (Catheter  Technology
Group, Inc.), a Delaware corporation ("Surviving Corporation"),  (the "Merger"),
and the Surviving  Corporation  shall have completed its financing in accordance
with the summary financing plan a copy of which has been delivered to the Leader
by Borrower.

          The Borrower shall pay to the Lender interest, calculated on the basis
of a 360 day year,  on the  outstanding  principal  amount of this Note from and
including  December  11,  1998 to but not  including  the date such  outstanding
principal  amount is paid in full at a rate of  fifteen  percent  (15%) per year
provided, however, that (a) in no event shall such interest by payable at a rate
in excess of the maximum rate  permitted by applicable law and (b) solely to the
extent  necessary  to result in such  interest  not being  payable  at a rate in
excess of such  maximum  rate,  any amount that would be reacted as part of such
interest under a final judicial interpretation of applicable law shall be deemed
to have been a mistake and  automatically  canceled,  and if received by Lender,
shall be refunded to the Borrower,  it being the intention of the Lender and the
Borrower  that such  interest not be payable at a rate in excess of such maximum
on December 11, 1998 and continuing  through the date the outstanding  principal
amount of this Note is paid in full.

          The Borrower  shall have the option of paying the principal  amount of
the Note to  Lender in  advance  in full or in part at any time and from time to
time; provided,  however, that upon making any such payment in full the Borrower
shall pay to the Lender all interest  owing  pursuant to this Note and remaining
unpaid and all other  amounts  owing by the  Borrower to the Lender  pursuant to
this Note and remaining unpaid.

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          Borrower represents and warrants to Lender that:

          (a)       This Note has been  authorized and approved by all necessary
                    corporate action of the Borrower; and

          (b)       This Note does not conflict with or violate (i) the articles
                    of  incorporation of bylaws of Borrower or (ii) the terms or
                    conditions of any note,  mortgage,  lease, loan agreement or
                    other material agreement to which the Borrower is a party or
                    by which its assets are subject.

          Borrower  agrees that, for so long as any amount under this Note shall
be outstanding,  it shall not sell or otherwise transfer any product line or any
material part of its assets to any third party. In addition, for so long as this
note remains  outstanding,  Borrower will provide Lender with copies of: (A) its
monthly  financial  statements   (internally  prepared)  as  soon  as  they  are
available,  (B) all  filings  that  Borrower  makes  with the SEC within two (2)
business  days after each such filing and (C) all filings  that any party to the
Merger shall make with the SEC as soon as they are available

          If Borrower fails to pay any amount  pursuant to this Note, or upon or
at any  time or from  time to time  after  the  Borrower  fails to  perform  any
obligations  pursuant to this Note and the continuation of such failure for more
than  thirty  (30) days after  notice of such  failure is given by Lender to the
Borrower,  the  outstanding  principal  amount of this Note,  all interest owing
pursuant to this Note and  remaining  unpaid and all other  amounts owing by the
Borrower to the Lender pursuant to this Note remaining unpaid shall, at the sole
option of the Lender and without any notice,  presentment or protest of any kind
(each of which is waived by the Borrower),  become immediately due. In addition,
upon (1) the  Borrower's  filing  or  having  filed  against  it a  petition  in
bankruptcy  and, in the case of such a petition  filed against it, such petition
not being  dismissed or stayed within thirty (30) days after such filing,  (2) a
trustee  or  receiver  being  appointed  by a court for any of the assets of the
Borrower and such  appointment  not being dismissed or stayed within thirty (30)
days after appointment,  (3) the Borrower's  suspending  business  operations or
becoming insolvent or (4) the Borrower's making a voluntary assignment of any of
its assets for the benefit of creditors,  such outstanding principal amount, all
such  interest and all such other  amounts  shall,  without any notice,  demand,
presentment  or protest  of any kind (each of which is waived by the  Borrower),
automatically become immediately due.

          The  Borrower  shall pay to the Lender on demand each cost and expense
(including, but not limited to, the reasonable fees and disbursements of counsel
to the Lender  whether  retained  for advice,  for  litigation  or for any other
purpose related to this Note) incurred by the Lender  endeavoring to (1) collect
any of the  outstanding  principal  amount  of this  Note,  any  interest  owing
pursuant to this note and remaining unpaid or any other amount of this Note, any
interest  owing  pursuant to this Note and  remaining  unpaid,  (2)  preserve or
exercise any right or remedy of the Lender  relating to, enforce or realize upon
any  guaranty,  endorsement,  collateral  or  other  security  now or  hereafter
directly or  indirectly  securing the payment of, or otherwise  now or hereafter
directly or indirectly  applicable to, any of such outstanding principal amount,
any such interest or any such other amount or (3) preserve or exercise any right
or remedy of the Lender pursuant to this Note.

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          This Note shall be governed by and  interpreted  under the laws of the
State of Florida  (without  reference  to Florida's  principles  of conflicts of
laws).  No  provision,  term, or condition of this Note may be waived or amended
except in writing.




                                              By:  /s/ W. A. Walton
                                                  ------------------------------
                                                        Executive Vice President


STATE OF FLORIDA)
                            :ss.:
COUNTRY OF UNITED STATES)


          On the 15 day of Dec.  in the year  1998,  before me  personally  came
                ----      ------
________________,  to me known,  who, being by my duly sworn, did depose and say
that    he    resides    at    _____________________;    that    he    is    the
_________________________  of Cardiac  Control  Systems,  Inc., the  corporation
described  in and which  executed the above  instrument;  and that he signed his
name thereto by order of the Board of Directors of said corporation.


                                                /s/ Roberta Trueman
                                                ------------------------
[   SEAL   ]    ROBERTA TRUEMAN
[ STATE OF ]    My Comm Exp 12/28/98
[ FLORIDA  ]    Bonded by Service Ins
[  NOTARY  ]    No. CC429959
[  PUBLIC  ]    [x] Personally Known   [ ] Other I.D.