<DOCUMENT>
<TYPE>EX-99
<SEQUENCE>2
<FILENAME>sc0099a.txt
<DESCRIPTION>EXHIBIT 4 -- IRREVOCABLE POWER OF ATTORNEY
<TEXT>
                                                                       EXHIBIT 4


               IRREVOCABLE POWER OF ATTORNEY AND CUSTODY AGREEMENT

                                       for

            Sale of Shares of Common Stock, Par Value $.001 Per Share

                                       of

                        QUINTON CARDIOLOGY SYSTEMS, INC.


To:      John R. Hinson
         Quinton Cardiology Systems, Inc.
         3303 Monte Villa Parkway
         Bothell, Washington  98021
              acting as attorney-in-fact, for
              the undersigned

         Michael K. Matysik
         Quinton Cardiology Systems, Inc.
         3303 Monte Villa Parkway
         Bothell, Washington  98021
              acting as attorney-in-fact, for
              the undersigned

To:      Quinton Cardiology Systems, Inc.
         3303 Monte Villa Parkway
         Bothell, Washington  98021
              as Custodian

Dear Sirs:

                  The  undersigned,  as a holder of shares of common stock,  par
value $.001 per share (the "Common Stock"), of Quinton Cardiology Systems, Inc.,
a Delaware  corporation (the  "Company"),  wishes to enter into this Irrevocable
Power of Attorney and Custody  Agreement in connection with the proposed sale of
shares of Common  Stock,  par value  $.001 per share (the  "Common  Stock") to a
group of  underwriters  (the  "Underwriters")  represented by Needham & Company,
Inc.;  SunTrust  Robinson  Humphries;  Adams,  Harkness  & Hill;  and  Delafield
Hambrecht (the  "Representatives")  for  distribution to the public (the "Public
Offering") in the United  States,  under a  Registration  Statement on Form S-3,
Commission File No. 333-114908 (the "Registration  Statement") at a price and on
terms to be  hereafter  determined  (the  "Initial  Offering").  The offering of
shares  of  Common  Stock to the  public  by the  Underwriters  pursuant  to the
Underwriting  Agreement  (as  defined  below)  is  referred  to  herein  as  the
"Offering."  The  Underwriters  shall only be purchasing  shares of Common Stock
pursuant to the  Underwriting  Agreement.  The maximum  number or  percentage of
shares of Common Stock to be sold by the


<PAGE>

undersigned to the  Underwriters  in the Offering are indicated on the signature
page  hereto and are  referred to herein as the  "Shares."  The  undersigned  is
hereinafter  referred to herein as the "Selling  Shareholder" and, together with
the other selling  shareholders,  if any, in connection  with the Offering,  the
"Selling  Shareholders."  Except as herein provided,  all capitalized terms used
herein  which are  defined in the  Underwriting  Agreement  have the  respective
meanings specified therein. The undersigned  acknowledges receipt of (i) a draft
of the Underwriting Agreement and (ii) a copy of the Registration Statement. The
undersigned  understands that, subject to the terms of this Irrevocable Power of
Attorney  and Custody  Agreement,  the draft of the  Underwriting  Agreement  is
subject to revision  before  execution  and that the  Registration  Statement is
subject to revision before it is declared effective and to amendment thereafter.

         (1) Appointment of Attorney-in-Fact;  Grant of Authority.  For purposes
of effecting the sale of the Shares to the Underwriters,  the undersigned hereby
irrevocably   makes,   constitutes,   and   appoints   the   persons   named  as
attorneys-in-fact  on the first  page  hereof  the true and  lawful  agents  and
attorneys-in-fact  of the undersigned  (each, an  "Attorney-in-Fact")  with full
power and authority to act hereunder  (either singly or jointly,  or through any
additional  Attorney-in-Fact  (a  "Proxy")  duly  appointed  as such  by  either
Attorney-in-Fact),  in any of their sole discretion, as hereinafter provided, in
the  name  of and  for  and  on  behalf  of the  undersigned,  as  fully  as the
undersigned  could if present and acting in person,  with respect to all matters
in  connection  with  the  Public  Offering  and  sale  of  the  Shares  to  the
Underwriters to be sold by the  undersigned  under the  Underwriting  Agreement,
including but not limited to the power and authority to:

          (a)  For the  purpose  of  offering  and  selling  the  Shares  to the
     Underwriters and consummating the other  transactions  referred to therein,
     execute and deliver the  Underwriting  Agreement  by and among the Company,
     the Selling Shareholder and the several  Underwriters (in substantially the
     form  attached as Annex B hereto,  as the same may be amended  from time to
     time as provided in and subject to the  limitations set forth in clause (h)
     below, the "Underwriting  Agreement") (the  undersigned's  approval of such
     execution  and  delivery  of such  agreement  on its  behalf  and any  such
     changes,  additions,  or  other  form  or  provisions  shall  be  evidenced
     conclusively by the execution and delivery of such  Underwriting  Agreement
     by any  Attorney-in-Fact);  carry out and  comply  with each and all of the
     provisions  of the  Underwriting  Agreement,  including  the  making of all
     representations,  agreements,  covenants  and  indemnities  provided in the
     Underwriting  Agreement  to be made by the  undersigned;  and  exercise all
     authority given to the undersigned under the Underwriting Agreement;

          (b) Arrange for,  prepare,  or cause to be prepared  the  Registration
     Statement and any amendment or amendments to the Registration Statement and
     include in the Registration Statement information regarding the undersigned
     delivered  to the  Company or  Company  legal  counsel  by the  undersigned
     explicitly  for  use in the  Registration  Statement  and  Prospectus,  and
     execute,  acknowledge  and  deliver any and all  certificates,  assurances,
     reports,  documents,  letters and consents to  appropriate  authorities  of
     states or  territories  of the United  States,  the  Underwriters  or legal
     counsel  to the  Company  or the  Underwriters,  which  may  reasonably  be
     required  or  deemed  to  be  appropriate  by  either


                                       2
<PAGE>

     Attorney-in-Fact  in  connection  with  the  sale  of the  Shares  and  the
     registration  of the Shares under the  securities  or blue sky laws of such
     states  or  territories  to  facilitate  offers  and  sales of the  Shares;
     provided,  however,  that no such action shall require the  undersigned  to
     qualify to do business or consent to service of process in any jurisdiction
     in  which  it is not  currently  so  qualified  or has  so  consented.  The
     undersigned hereby authorizes the Company and its counsel to make a request
     for acceleration of the Registration Statement on its behalf;

          (c) Sell,  assign and  transfer  to the  Underwriters  pursuant to the
     Underwriting  Agreement up to and including the number of Shares identified
     on the  signature  page of this  Irrevocable  Power of Attorney and Custody
     Agreement and  deposited by the  undersigned  hereunder,  and determine the
     allocation   of  the   Shares   sold   in   the   Initial   Offering.   The
     Attorneys-in-Fact  agree that they will sell to the Underwriters all of the
     Shares received by the undersigned's Zymed subsidiary prior to including in
     the  Offering or selling to the  Underwriters  any other shares held by the
     undersigned;

          (d) Agree upon the price  (including any discounts or  commissions) at
     which  the  Shares  will  be  sold  to  the  Underwriters  pursuant  to the
     Underwriting Agreement; provided that (i) the net proceeds per share (after
     the  deduction  of any  discounts  or  commissions)  to be  received by the
     undersigned  shall not be less than the net  proceeds per share (after such
     deductions)  to be received by the Company in respect of Shares sold by the
     Company,  and (ii) the net proceeds per share (after such deductions) to be
     received  by the  undersigned  shall not in any event be less than $___ per
     share;

          (e)  Endorse  (in  blank,  undated)  on  behalf of the  undersigned  a
     certificate  or  certificates  representing  the  Shares,  or stock  powers
     attached to the  certificates,  and transfer and deliver such  certificates
     representing such Shares to or upon the order of the  Underwriters,  or, if
     the Shares are  registered  in book-entry  form by the  Company's  transfer
     agent or other  authorized  stock  registrar,  authorize by appropriate and
     necessary  action  the  transfer  of  the  Shares  to the  accounts  of the
     Underwriters;

          (f) Give such written  orders and  instructions  to the  Custodian (as
     hereinafter  defined) or the Company's  registrar and transfer agent as any
     Attorney-in-Fact may in his discretion  determine,  with respect to (i) the
     transfer  on the books of the Company of the Shares in order to effect such
     sale (including the names in which new  certificates for such Shares are to
     be issued and the denominations  thereof),  (ii) the delivery to or for the
     account of the  Underwriters  of the  certificates  for such Shares against
     receipt by the  Custodian  (for the account of the  undersigned)  of a wire
     transfer for the purchase price to be paid therefor as set forth in Section
     3 below,  (iii) the remittance to the  undersigned of such wire  transfers,
     and (iv) the return to the undersigned of a new certificate or certificates
     representing the number of shares (if any) of Common Stock represented by a
     certificate or  certificates  deposited  with the  Custodian,  which are in
     excess  of the  number  of  Shares  to be  sold by the  undersigned  to the
     Underwriters;


                                       3
<PAGE>

          (g)  Retain  legal  counsel  in  connection  with any and all  matters
     referred to herein (which counsel fees shall be borne by the Company); and

          (h)  Take,  or cause to be taken,  any and all  further  actions,  and
     execute  and  deliver,   or  cause  to  be  executed  and  delivered,   the
     Underwriting Agreement and any and all agreements,  documents,  instruments
     and  certificates  specified  in the  draft of the  Underwriting  Agreement
     attached to this  instrument  as may be necessary or deemed to be desirable
     by either Attorney-in-Fact to effectuate, implement, or otherwise carry out
     the  transactions  contemplated  by the  Underwriting  Agreement  and  this
     Irrevocable  Power of Attorney and Custody  Agreement  and generally to act
     for and in the name and on behalf of the  undersigned,  with respect to the
     sale of  Shares  to the  Underwriters  and the  offering  of  Shares by the
     Underwriters  and the registration of Shares by the Company pursuant to the
     Securities Act of 1933 (the  "Securities  Act") as fully as the undersigned
     could if personally  present and acting;  provided,  however,  that (1) the
     provisions  in  the   Underwriting   Agreement   relating  to  the  Selling
     Shareholder  or  its  representations,  warranties,  covenants,  rights  or
     obligations  may not be  modified  without  the  consent  of  such  Selling
     Shareholder  and (2) no such action shall  increase  the maximum  number of
     shares to be sold by the  undersigned  above the number of Shares set forth
     on such Selling Shareholder's signature page hereto.

         (2) Irrevocability. The undersigned has conferred and granted the power
of attorney and all other authority  contained  herein in  consideration  of the
Company's  and  the  Underwriters'  proceeding  with,  and for  the  purpose  of
completing, the transactions contemplated by the Underwriting Agreement. Subject
to Section 9 hereof,  the undersigned hereby agrees that all power and authority
hereby  conferred  is coupled with an interest  and is  irrevocable;  and to the
extent  not  prohibited  by law  shall  not  be  terminated  by  any  act of the
undersigned  or by  operation of law whether by the death or  incapacity  of the
undersigned or by the occurrence of any other event.  If, after the execution of
this Irrevocable Power of Attorney and Custody Agreement, any such act, death or
other event shall occur before the completion of the  transactions  contemplated
by the Underwriting Agreement and this Irrevocable Power of Attorney and Custody
Agreement, each Attorney-in-Fact, the Custodian and the Company are nevertheless
authorized  and directed to complete all of such  transactions,  as if such act,
death or other  event had not  occurred  and  regardless  of  whether or not the
Attorney-in-Fact,  the Custodian or the Company  shall have  received  notice of
such act, death or other event.

         (3) Deposit and Delivery of Shares.  The  undersigned  hereby  deposits
with the Company,  as custodian (in such capacity,  the "Custodian") one or more
certificates  representing shares of Common Stock, which represent not less than
the aggregate number of Shares that the undersigned may become obligated to sell
to the Underwriters as set forth on the signature page of this Irrevocable Power
of  Attorney  and Custody  Agreement.  The  undersigned  hereby  represents  and
warrants  to each  Attorney-in-Fact  and the  Custodian  that  each  certificate
delivered  (i) has  been  duly  executed  and is in  negotiable  form or (ii) is
accompanied by a duly executed stock power or powers in blank.  In the event any
of the shares of Common Stock  deposited  with the Custodian by the  undersigned
with are registered in book-entry  form, the undersigned  hereby  designates the
Custodian  as the sole  authority  to hold such  shares  for the


                                       4
<PAGE>

benefit of the  Underwriters  for purposes of performance of the  obligations of
the undersigned pursuant to this Agreement and the Underwriting  Agreement.  The
Custodian  shall hold the shares of Common  Stock,  and shall dispose of them in
accordance  with the written  instructions  of the  Attorney-in-Fact  and as set
forth  herein,  with full  power in the name of,  and for and on behalf  of, the
undersigned.

         The  Custodian is hereby  authorized  and directed by the  undersigned,
subject to the written  instructions  of any  Attorney-in-Fact,  (i) to hold the
shares  of  Common  Stock  in  custody,  (ii) to  make  such  other  appropriate
arrangements as may be necessary for the safekeeping of the certificates,  (iii)
to cause certificates  representing the Shares to be sold to the Underwriters to
be issued,  or, if in book entry form,  to effect the  transfer of the Shares to
the account of the underwriter,  (iv) to deliver the certificates for the Shares
to be  sold by the  undersigned,  or  replacement  certificates  evidencing  the
Shares, to the  Representatives for the accounts of the Underwriters at the date
(or dates) of delivery in accordance  with the  Underwriting  Agreement and this
Irrevocable  Power of Attorney  and Custody  Agreement  and (v) to return to the
undersigned certificates  representing the unsold balance, if any, of the shares
of Common Stock covered by the enclosed certificates.

         The  Custodian  shall  be  fully  entitled  to act and  rely  upon  any
statement,  request,  notice or instruction respecting this Irrevocable Power of
Attorney and Custody  Agreement  given to it by either  Attorney-in-Fact  or any
Proxy thereof.

         (4) The Custodian.  The Custodian's execution of this Irrevocable Power
of  Attorney  and Custody  Agreement  shall  constitute  the  acceptance  by the
Custodian of the agency herein  conferred,  and shall  evidence its agreement to
carry out and perform only those duties set forth in this  Irrevocable  Power of
Attorney and Custody  Agreement in accordance  with the provisions  hereof.  The
Custodian  shall  exercise  the same degree of care toward the  certificates  of
Common Stock deposited  herewith as it exercises toward its own similar property
and shall not be held to any higher  standard  of care  under  this  Irrevocable
Power of Attorney and Custody  Agreement.  No implied  covenants or  obligations
shall be inferred from this Irrevocable  Power of Attorney and Custody Agreement
against the Custodian, nor shall the Custodian be bound by the provisions of any
agreement   among   the   undersigned,   the   Selling   Shareholders   or   any
Attorney-in-Fact or Proxy beyond the specific terms hereof.

         The  Custodian  shall be  entitled  to rely upon any  order,  judgment,
certification,   instruction,  notice  or  other  writing  delivered  to  it  in
compliance with the provisions of this Irrevocable Power of Attorney and Custody
Agreement   without  being  required  to  determine  the   authenticity  or  the
correctness of any fact stated therein or the proprietary or validity or service
thereof.  The Custodian may act in reliance upon any instrument  comporting with
the provisions of this  Irrevocable  Power of Attorney and Custody  Agreement or
signature believed by it to be genuine and may assume that any person purporting
to give  notice or  receipt  or  advice or make any  statement  or  execute  any
document in connection with the provisions hereof has been duly authorized to do
so.


                                       5
<PAGE>

         At any time the  Custodian  may  request in writing an  instruction  in
writing from the Attorneys-in-Fact,  or either of them, or the undersigned,  and
may at its own option  include in such  request the course of action it proposes
to take and the date on which it proposes to act,  regarding any matter  arising
in connection with its duties and obligations hereunder. The Custodian shall not
be liable for acting  without the consent of any such party in  accordance  with
such a  proposal  on or after  the date  specified  therein,  provided  that the
specified  date shall be at least two business  days after such parties  receive
the Custodian's  request for instructions and its proposed course of action, and
provided further,  that, prior to so acting,  the Custodian has not received the
written instructions requested.

         (5) Sale of Shares;  Remitting Net Proceeds.  Each  Attorney-in-Fact is
hereby  authorized  to,  and any of them  shall,  direct  the  Custodian  or its
registrar and transfer agent in writing to deliver  certificates  for, or effect
book-entry  transfer  of,  the  Shares  to be  sold  by the  undersigned  to the
Representatives as provided in the Underwriting  Agreement,  against delivery by
the  Representatives  to the  Custodian  of a wire  transfer,  in same day funds
payable to the order of the Custodian, for the account of the undersigned and in
the amount set forth in the Underwriting Agreement. The Custodian is authorized,
on behalf of the undersigned,  to accept and acknowledge  receipt of the payment
of the purchase price for the Shares to be sold by the undersigned and shall, as
soon as  practicable  but in any event  within one business day after the day it
receives such payment, remit to the undersigned, by wire transfer of immediately
available funds to a bank account  specified by the undersigned on the signature
page  hereof,  or,  if no such  account  is  specified,  by  certified,  bank or
cashier's  check payable to the undersigned and mailed to the undersigned at the
address specified on the signature page hereof (or such other account or address
or may be  specified  pursuant to notice  delivered  timely in  accordance  with
Section (10) below), its proportionate share of the proceeds of such sales.

         (6)  Representations,   Warranties  and  Agreements.   The  undersigned
represents and warrants to, and agrees with, the Company, the Underwriters, each
Attorney-in-Fact, each other Selling Shareholder and the Custodian that:

          (a)   Authorization   of   Agreements.   All   consents,    approvals,
     authorizations  and orders  necessary for the execution and delivery by the
     Selling Shareholder of this Power of Attorney and Custody Agreement and the
     Underwriting  Agreement,  and for the  sale  and  delivery  of the  Selling
     Shareholder  Firm  Shares to be sold by the Selling  Shareholder  under the
     Underwriting Agreement, have been obtained; and the Selling Shareholder has
     full corporate power and authority to enter into this Irrevocable  Power of
     Attorney and Custody Agreement and the Underwriting  Agreement, to make the
     representations, warranties and agreements hereunder and thereunder, and to
     sell,  assign,  transfer  and  deliver the Shares to be sold by the Selling
     Shareholder  under  the  Underwriting  Agreement.  The sale of the  Selling
     Shareholder Firm Shares to be sold by the Selling Shareholder  Underwriting
     Agreement  and  the   performance  by  the  Selling   Shareholder  of  this
     Irrevocable  Power of Attorney and Custody  Agreement and the  Underwriting
     Agreement and the consummation of the transactions  contemplated hereby and
     thereby will not result in the creation or imposition  of any lien,  charge
     or encumbrance upon any of the assets of the Selling  Shareholder  pursuant
     to the terms or provisions of, or result in


                                       6
<PAGE>

     a breach or violation of any of the terms or provisions of, or constitute a
     default  under,  or  give  any  party  a  right  to  terminate  any  of its
     obligations  under, or result in the acceleration of any obligation  under,
     any  indenture,  mortgage,  deed of trust,  voting  trust  agreement,  loan
     agreement,   bond,   debenture,   note   agreement  or  other  evidence  of
     indebtedness, lease, contract or other agreement or instrument to which the
     Selling  Shareholder is a party or by which the Selling  Shareholder or any
     of its  properties  is bound or affected,  or violate or conflict  with any
     judgment,  ruling,  decree, order, statute, rule or regulation of any court
     or other governmental  agency or body applicable to the Selling Shareholder
     or the organizational documents of the Selling Shareholder.

          (b) Good and Marketable Title.  Assuming that the Selling  Shareholder
     Firm Shares are  indorsed to DTC or in blank,  upon payment for the Selling
     Shareholder Firm Shares and the delivery to DTC or its agent of the Selling
     Shareholder Firm Shares  registered in the name of Cede & Co. or such other
     nominee designated by DTC, and DTC's crediting the Selling Shareholder Firm
     Shares to an  Underwriter's  account  with DTC,  Cede & Co.,  or such other
     nominee  designated by DTC, will be a "protected  purchaser" of the Selling
     Shareholder  Firm  Shares  (as  defined  in  Section  8-303 of the  Uniform
     Commercial  Code as  adopted in the State of New York (the  "Code")),  such
     Underwriter will acquire a valid "security entitlement" (within the meaning
     of  Section  8-501 of the Code) with  respect  to the  Common  Stock to the
     extent  that DTC  credits  the  Selling  Shareholder  Firm  Shares  to such
     Underwriter's  account,  and no  action  based on an  "adverse  claim"  (as
     defined  in  section  8-102  of the  Code)  may be  asserted  against  such
     Underwriter with respect to such security  entitlement  (assuming that such
     Underwriter is without notice of any such adverse claim).

          (c) Due Execution of Agreements.  This  Irrevocable  Power of Attorney
     and Custody  Agreement has been duly executed and delivered by or on behalf
     of the Selling  Shareholder,  and constitutes a valid and binding agreement
     of the  Selling  Shareholder  in  accordance  with  its  terms,  except  as
     enforceability may be limited by the application of bankruptcy, insolvency,
     reorganization,  moratorium  or  other  laws  affecting  creditors'  rights
     generally or by general principles of equity; and the Attorneys-in-Fact and
     the  Custodian  have been duly  authorized  by the Selling  Shareholder  to
     deliver  the  Selling  Shareholder  Firm  Shares on  behalf of the  Selling
     Shareholder in accordance with the terms of this Agreement.  At the Closing
     Time, the Underwriting Agreement will have been duly executed and delivered
     by or on behalf of the Selling Shareholder

          (d) Absence of Manipulation. The Selling Shareholder has not taken and
     will not at any time take,  directly or indirectly,  any action (other than
     entering  into the lock-up  agreement  contemplated  by Section 5(n) of the
     Underwriting  Agreement) designed, or that might reasonably be expected, to
     cause or result in, or that will constitute,  stabilization of the price of
     shares  of  Common  Stock to  facilitate  the sale or  resale of any of the
     Shares;  provided that the Selling  Shareholder  and its affiliates are not
     prohibited from making or amending any filings with the Commission required
     to be made or amended in connection  with the  execution of this  Agreement
     and consummation of the transactions contemplated hereby.


                                       7
<PAGE>

          (e)   Absence  of  Further   Requirements.   No   consent,   approval,
     authorization or order of, or any filing or declaration  with, any court or
     governmental  agency or body is required in connection with the sale of the
     Selling   Shareholder  Firm  Shares  by  the  Selling  Shareholder  or  the
     consummation  by the Selling  Shareholder of the  transactions  on its part
     contemplated by this  Irrevocable  Power of Attorney and Custody  Agreement
     and the  Underwriting  Agreement,  except such as may be required under the
     Act or the Rules and  Regulations  and such as may be required  under state
     securities  or Blue  Sky  laws or the  by-laws  and  rules  of the  NASD in
     connection with the purchase and  distribution  by the  Underwriters of the
     Shares to be sold by the Selling Shareholder.

          (f)  Restriction on Sale of Securities.  The Selling  Shareholder  has
     duly  executed and  delivered to the  Custodian a lock-up  agreement in the
     form of Schedule III attached to the Underwriting Agreement.

          (g)  Certificates  Suitable for Transfer.  Certificates for all of the
     Shares to be sold by such Selling Shareholder  pursuant to the Underwriting
     Agreement, in suitable form for transfer by delivery or accompanied by duly
     executed  instruments  of transfer or assignment  in blank with  signatures
     guaranteed,  have  been  placed  in  custody  with  the  Custodian  to  the
     Underwriters pursuant to the Underwriting Agreement.

          (h) No Association with NASD. Neither such Selling Shareholder nor any
     of  his/her/its  affiliates  (within  the  meaning  of  NASD  Conduct  Rule
     2720(b)(1)(a))  directly, or indirectly through one or more intermediaries,
     controls,  or is controlled  by, or is under common  control with, or is an
     associated  person  (within the meaning of Article I,  Section  1(q) of the
     By-laws of the National  Association of Securities  Dealers,  Inc.) of, any
     member firm of the National Association of Securities Dealers,  Inc., other
     than as set  forth  on  Annex A  hereto  or the  shareholder  questionnaire
     provided to the Company.

          (i) Form  W-9/W-8.  The  undersigned  has delivered to the Custodian a
     true and complete copy of United States  Treasury  Department  Form W-9/W-8
     (or other  applicable  form or statement  specified by Treasury  Department
     regulations in lieu thereof).

          (j) Opinion.  The  undersigned  shall  provide to the  Custodian,  for
     delivery to the  Underwriters,  the opinion of the  undersigned's  internal
     counsel contemplated by Section 6(f) of the Underwriting Agreement.

         The foregoing  representations,  warranties  and agreements are for the
benefit of and may be relied upon by each  Attorney-in-Fact,  the  Company,  the
Underwriters, the Custodian, and their respective legal counsel. The undersigned
will notify the Company in writing  immediately  of any changes in the foregoing
information and representations,  warranties and agreements which should be made
as a result of  developments  occurring  after the date  hereof and prior to the
Closing Date or any Date of Delivery under the Underwriting  Agreement,  and the
Company  and  Attorneys-in-Fact  may  consider  that there has not been any such
development unless advised to the contrary.


                                       8
<PAGE>

         (7) Ownership of Shares.  Subject to the terms hereof, until payment in
full of the  purchase  price  for  such  Shares  being  sold by the  undersigned
pursuant to the  Underwriting  Agreement  has been made by or for the account of
the Underwriters, the undersigned shall remain the owner of the Shares and shall
have all rights thereto which are not inconsistent  with this Irrevocable  Power
of Attorney and Custody Agreement.  However, until such payment in full has been
made or until the Underwriting  Agreement has been  terminated,  the undersigned
agrees that the undersigned will not give, sell, pledge, hypothecate,  grant any
lien or security  interest in,  transfer,  deal with or contract with respect to
the Shares or any interest therein,  except to the Underwriters  pursuant to the
Underwriting Agreement (and, other than with respect to the Shares to be sold to
the Underwriters pursuant to the Underwriting  Agreement, in accordance with the
lockup  letter  signed by the  undersigned  in the form of  Schedule  III to the
Underwriting Agreement).

         (8) Liability and  Indemnification.  (a) Each  Attorney-in-Fact and the
Custodian  are  authorized  to accept this  Irrevocable  Power of  Attorney  and
Custody  Agreement and take any and all actions under this Irrevocable  Power of
Attorney  and  Custody  Agreement  as  they  shall,  in  their  own  discretion,
determine,  except as explicitly limited herein. Each  Attorney-in-Fact  and the
Custodian assume hereunder no  responsibility or liability to the undersigned or
to any other  person or  entity,  other  than to deal with the  Shares  held and
received  by  either   Attorney-in-Fact  or  deposited  with  the  Custodian  in
accordance with the provisions of this Irrevocable Power of Attorney and Custody
Agreement  and to deal  with the  proceeds  from  the sale of the  undersigned's
Shares in accordance with the provisions hereof.  Neither  Attorney-in-Fact  (in
such  capacity) nor the Custodian (in such  capacity)  make any  representations
with respect to and shall have no responsibility for the Registration  Statement
or Prospectus and shall not be liable to the  undersigned or any other person or
entity pursuant to this Irrevocable  Power of Attorney and Custody Agreement for
any  error  of  judgment  or for any act done or  omitted  to be done or for any
mistake  of fact or law except  for the gross  negligence,  bad faith or willful
misconduct  of each  Attorney-in-Fact  or  Custodian,  as the case  may be.  The
undersigned agrees that each Attorney-in-Fact and the Custodian may consult with
counsel  experienced in such matters of their own choice (which counsel shall be
paid by the Company and may, but need not, be counsel  retained on behalf of the
Company or any Selling Shareholder) and each  Attorney-in-Fact and the Custodian
shall have full and complete  authorization  and protection for any action taken
or suffered by each  Attorney-in-Fact  or the Custodian  hereunder in good faith
and in accordance with the advice of such counsel.

          (b) Neither Attorney-in-Fact nor the Custodian, as such, shall or will
     have any interest in the Shares deposited hereunder. The undersigned agrees
     to pay all  stock  and  other  transfer  taxes  relating  to  such  Selling
     Shareholder's  Common  Stock  resulting  from the sale of such  Shares  and
     agrees to reimburse,  indemnify and hold harmless each Attorney-in-Fact and
     the  Custodian  from any amounts that either of them is obligated to pay in
     the way of such stock and other transfer taxes.

          (c)  Neither  any   Attorney-in-Fact   nor  the  Custodian  makes  any
     representation as to the validity,  value, genuineness or collectability of
     any  security,  document or  instrument  held by or  delivered to either of
     them.


                                       9
<PAGE>

          (d) Neither any Attorney-in-Fact nor the Custodian will be called upon
     to advise or has  advised  the  undersigned  as to the merits of selling or
     retaining the Shares.

          (e) This  Irrevocable  Power of Attorney  and Custody  Agreement  sets
     forth  exclusively the respective duties of each  Attorney-in-Fact  and the
     Custodian  with  respect  to any and all  matters  pertinent  hereto and no
     implied duties or obligations  shall be read into this Irrevocable Power of
     Attorney  and Custody  Agreement  against  either  Attorney-in-Fact  or the
     Custodian.

         (9)  Withdrawal,   Termination  and  Release  of  Shares.  (a)  If  the
Underwriting  Agreement  is  entered  into on  behalf of the  undersigned,  this
Irrevocable  Power of Attorney  and Custody  Agreement,  other than  Section (8)
hereof, shall terminate  automatically on the 36th day following the date of the
Underwriting Agreement, and shall thereafter be of no further effect.

          (b) If the Underwriting  Agreement shall not be entered into on behalf
     of the undersigned, or it shall not become effective pursuant to its terms,
     or if the Underwriting Agreement shall be terminated pursuant to its terms,
     or if the  shares  agreed to be sold as  contemplated  by the  Underwriting
     Agreement are not purchased and paid for by the  Underwriters  on or before
     June 30, 2004, then after such date the Attorney-in-Fact  shall, unless the
     undersigned  has agreed in  writing to extend the term of this  Irrevocable
     Power of Attorney and Custody  Agreement,  instruct promptly in writing the
     Custodian to return to the  undersigned  the Shares or the shares of Common
     Stock held for its account, together with any applicable stock powers.

          (c) In the  event  shares of Common  Stock  are sold  pursuant  to the
     Underwriting  Agreement,  the  Custodian  shall return any shares of Common
     Stock (with applicable stock powers) not purchased by the Underwriters.

          (d) Except as provided  in this  Section  (9),  and subject to Section
     (1), the  undersigned  shall have no right to revoke its request to include
     the Shares in the  Registration  Statement or to decline to sell the Shares
     as contemplated by the Underwriting Agreement.

          (e)  Termination  of this  Irrevocable  Power of Attorney  and Custody
     Agreement  shall not affect  any lawful  action  done or  performed  by the
     Custodian, the Attorney-in-Fact or the Company pursuant to this Irrevocable
     Power of Attorney and Custody  Agreement  prior to the  termination of this
     Irrevocable  Power of Attorney and Custody  Agreement.  The  provisions  of
     Section (8), other than the first sentence of paragraph (a) thereof,  shall
     survive  termination  of this  Irrevocable  Power of  Attorney  and Custody
     Agreement.

         (10)  Notices.  Any  notices  required  to be  given  pursuant  to this
Irrevocable  Power of Attorney and Custody Agreement shall be deemed given if in
writing  and  delivered  in  person,   by  overnight   courier  or  by  telecopy
subsequently confirmed by letter delivered by certified U.S. Mail, (i) if to the
Company, to Quinton Cardiology Systems, Inc., 3303 Monte Villa Parkway, Bothell,
Washington  98021,  Attention:  Chief  Executive  Officer;  (ii)  if  to  either


                                       10
<PAGE>

Attorney-in-Fact,  to the persons named as  attorneys-in-fact  on the first page
hereof;  and  (iii)  if to the  undersigned  at the  address  set  forth  on the
signature  page  hereof,  or at such other  address  and fax number as any party
shall communicate to the other parties by notice delivered as aforesaid.

         (11) APPLICABLE LAW. THE VALIDITY, ENFORCEABILITY,  INTERPRETATION, AND
CONSTRUCTION OF THIS IRREVOCABLE  POWER OF ATTORNEY AND CUSTODY  AGREEMENT SHALL
BE  DETERMINED  IN  ACCORDANCE  WITH THE INTERNAL  LAWS OF THE STATE OF NEW YORK
(WITHOUT GIVING EFFECT TO THE CONFLICT OF LAW PRINCIPLES THEREOF).

         (12) Miscellaneous.  (a) This Irrevocable Power of Attorney and Custody
Agreement may be signed in any number of counterparts, each executed counterpart
constituting an original but all together constituting only one instrument.

          (b) This  Irrevocable  Power of Attorney and Custody  Agreement  shall
     inure to the benefit of, and shall be binding upon, the undersigned and the
     undersigned's heirs, executors, administrators,  successors and assigns, as
     the case may be.

          (c) If any provision of this Irrevocable Power of Attorney and Custody
     Agreement is found to be unenforceable as applied in any particular case or
     circumstance in any applicable  jurisdiction  because it conflicts with any
     other  provision  of  this  Irrevocable   Power  of  Attorney  and  Custody
     Agreement,  or any  constitution,  statute or rule of public policy, or for
     any other reason, such finding shall not render the provision unenforceable
     in any other case or  circumstance,  or render any other  provision of this
     Irrevocable  Power of Attorney and Custody  Agreement  unenforceable to any
     extent whatsoever.

          (d) The undersigned hereby irrevocably  submits in any suit, action or
     proceeding arising out of or relating to this Irrevocable Power of Attorney
     and Custody Agreement,  or any of the transactions  contemplated hereby, to
     the  jurisdiction  and venue of any federal or state court in the County of
     New York, State of New York.

          (e) The  Underwriters  and the Company are hereby  deemed  third-party
     beneficiaries of this Irrevocable  Power of Attorney and Custody  Agreement
     and are entitled to rely on the provisions hereof as if signatories hereto.

          (f) No party may assign any of its  rights or  obligations  under this
     Irrevocable  Power of Attorney  and Custody  Agreement  without the written
     consent  of  all  other  parties,  which  consent  may be  withheld  in the
     reasonable discretion of the party when consent is sought.  Notwithstanding
     the  foregoing,  the Company may engage,  consult with or assign any of its
     rights,  duties or  obligations  as Custodian to its transfer  agent or any
     other party who normally  serves in such capacity,  who shall be deemed the
     Custodian for all purposes hereunder in addition to the Company.


                                       11
<PAGE>

          (g) This  Irrevocable  Power of Attorney and Custody  Agreement may be
     modified only by a written amendment signed by all the parties hereto,  and
     no waiver of any provision  hereof shall be effective unless expressed in a
     writing signed by the party to be charged.







                                       12
<PAGE>



         This  Irrevocable  Power of  Attorney  and Custody  Agreement  shall be
effective as of the date hereof.

                                            Very truly yours,


                                            ------------------------------------
                                            PHILIPS ELECTRONICS NORTH AMERICA
                                            CORPORATION

Dated: ________________                     By
                                              ----------------------------------
                                              Name:

                                              Title:

Address, Telephone Number                   Philips Electronics North America
and Fax Number:                             Corporation
                                            1251 Avenue of the Americas
                                            New York, NY  10020
                                            Attention:  Anthony Eltvedt
                                            (212) 536-0702 (T)
                                            (212) 536-0712 (F)

Wire Instructions:                          Bank:

                                            ABA No.:

                                            Account Name:

                                            Account No.:

Total Number of  Shares of Common  Stock
      Deposited    for   Sale   to   the
      Underwriters in the form of Common
      Stock   (Represents   the  maximum
      number  of  shares  that you could
      sell  in  the  Initial  Offering):    1,394,024


                                       13
<PAGE>



                       ACCEPTANCE BY THE ATTORNEY-IN-FACT


         John R. Hinson  hereby  accepts  his  appointment  as  Attorney-in-Fact
pursuant to the foregoing  Irrevocable Power of Attorney and Custody  Agreement,
and agrees to act in accordance with the terms of said agreement.

Dated:
       ----------------
                                                 By
                                                     ---------------------------
                                                           Attorney-in-Fact


                       ACCEPTANCE BY THE ATTORNEY-IN-FACT

         Michael K. Matysik hereby accepts his  appointment as  Attorney-in-Fact
pursuant to the foregoing  Irrevocable Power of Attorney and Custody  Agreement,
and agrees to act in accordance with the terms of said agreement.

Dated:
       ----------------
                                                 By
                                                     ---------------------------
                                                           Attorney-in-Fact




                                       14


<PAGE>



                           ACCEPTANCE BY THE CUSTODIAN


                  Quinton  Cardiology  Systems,   Inc.,  as  Custodian,   hereby
acknowledges  receipt of the securities  described in this Irrevocable  Power of
Attorney and Custody  Agreement (and in the form described herein) and agrees to
act in accordance with this Irrevocable Power of Attorney and Custody Agreement.


Dated:                                      QUINTON CARDIOLOGY SYSTEMS, INC.,
       ----------------                        as Custodian

                                               By
                                                  ------------------------------
                                                      Authorized Signatory


                                       15
<PAGE>



                            ACCEPTANCE BY THE COMPANY


         Quinton  Cardiology  Systems,  Inc.  hereby  accepts  the terms of this
Irrevocable Power of Attorney and Custody Agreement.

Dated:                                      QUINTON CARDIOLOGY SYSTEMS, INC.
       ----------------
                                            By
                                               ---------------------------------
                                            Name:

                                            Title:





                                       16

</TEXT>
</DOCUMENT>
