<PAGE>   1
 
   
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 13, 1998
    
 
                                                      REGISTRATION NO. 333-56971
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
   
                                AMENDMENT NO. 3
    
                                       TO
 
                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
 
                                INCONTROL, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
<TABLE>
<S>                                              <C>
                   DELAWARE                                        91-1501619
           (STATE OF INCORPORATION)                  (I.R.S. EMPLOYER IDENTIFICATION NUMBER)
</TABLE>
 
                            6675 - 185TH AVENUE N.E.
                           REDMOND, WASHINGTON 98052
                                 (425) 861-9800
   (ADDRESS AND TELEPHONE NUMBER OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
 
                                KURT C. WHEELER
                 CHAIRMAN, PRESIDENT & CHIEF EXECUTIVE OFFICER
                                INCONTROL, INC.
                            6675 - 185TH AVENUE N.E.
                           REDMOND, WASHINGTON 98052
                                 (425) 861-9800
           (NAME, ADDRESS AND TELEPHONE NUMBER OF AGENT FOR SERVICE)
                            ------------------------
 
                                   COPIES TO:
 
                               STEPHEN M. GRAHAM
                                 ALAN C. SMITH
                                PERKINS COIE LLP
                         1201 THIRD AVENUE, 40TH FLOOR
                         SEATTLE, WASHINGTON 98101-3099
                                 (206) 583-8888
 
        Approximate date of commencement of proposed sale to the public:
     FROM TIME TO TIME AFTER THIS REGISTRATION STATEMENT BECOMES EFFECTIVE.
 
     If the only securities being registered on this form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box.  [ ]
 
     If any of the securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, as amended, other than securities offered only in connection with dividend
or interest reinvestment plans, check the following box. [X]
 
     If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering.  [ ]
 
     If this form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering.  [ ]
 
     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box.  [ ]
                            ------------------------
 
     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933 OR UNTIL THIS REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
 
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<PAGE>   2
 
Information contained herein is subject to completion or amendment. A
registration statement relating to these securities has been filed with the
Securities and Exchange Commission. These securities may not be sold nor may
offers to buy be accepted prior to the time the registration statement becomes
effective. This prospectus shall not constitute an offer to sell or the
solicitation of an offer to buy nor shall there be any sale of these securities
in any State in which such offer, solicitation or sale would be unlawful prior
to registration or qualification under the securities laws of any such State.
 
   
                  SUBJECT TO COMPLETION DATED AUGUST 13, 1998
    
 
PROSPECTUS
 
                         400,000 SHARES OF COMMON STOCK
                                       OF
 
                                INCONTROL, INC.
 
     This Prospectus relates to the resale of up to 400,000 shares (the
"Shares") of Common Stock, $.01 par value per share (the "Common Stock"), of
InControl, Inc. (the "Company"). The Shares may be offered by certain
stockholders of the Company (the "Selling Stockholders") or by their pledgees,
donees, distributees or other successors in interest, from time to time in
transactions (which may include block transactions) in the over-the-counter
market through the Nasdaq National Market ("Nasdaq"), or on one or more other
securities markets and exchanges, in privately negotiated transactions, or
otherwise, at fixed prices that may be changed, at market prices prevailing at
the time of sale, at prices relating to such prevailing market prices or at
negotiated prices. The Selling Stockholders may effect such transactions by
selling the Shares directly to or through broker-dealers, and such
broker-dealers may receive compensation in the form of discounts, concessions or
commissions from the Selling Stockholders and/or the purchasers of the Shares
for whom such broker-dealers may act as agents or to whom they may sell as
principals, or both (which compensation as to a particular broker-dealer may be
in excess of customary commissions). See "Selling Stockholders" and "Plan of
Distribution."
 
     None of the proceeds from the sale of the Shares by the Selling
Stockholders will be received by the Company. The Company has agreed to bear all
expenses (other than selling commissions and fees and stock transfer taxes) in
connection with the registration and sale of the Shares being offered by the
Selling Stockholders. The Company has agreed to indemnify the Selling
Stockholders and any broker-dealers who act in connection with the sale of the
Shares hereunder against certain liabilities, including liabilities under the
Securities Act of 1933, as amended (the "Securities Act").
 
     The Company sold all of the Shares to the Selling Stockholders in a private
transaction on April 20, 1998. The Shares of Common Stock sold in such
transaction constitute the Shares being registered hereunder. In connection with
any sales, the Selling Stockholders and any brokers participating in such sales
may be deemed to be "underwriters" within the meaning of the Securities Act. See
"Selling Stockholders."
 
   
     The Common Stock is quoted on Nasdaq under the symbol "INCL." On August 11,
1998, the closing sales price for the Common Stock as reported on Nasdaq was
$5.625 per share.
    
                            ------------------------
        THE COMMON STOCK OFFERED HEREBY INVOLVES A HIGH DEGREE OF RISK.
                    SEE "RISK FACTORS" BEGINNING ON PAGE 4.
                            ------------------------
  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
 EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
   AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
                               CRIMINAL OFFENSE.
                            ------------------------
   
                The date of this Prospectus is August   , 1998.
    
<PAGE>   3
 
                             AVAILABLE INFORMATION
 
     The Company is subject to the informational requirements of the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), and in accordance
therewith files reports, proxy statements and other information with the
Securities and Exchange Commission (the "Commission"). Such reports, proxy
statements and other information filed by the Company may be inspected and
copied (at prescribed rates) at the public reference facilities maintained by
the Commission in Washington, D.C. (450 Fifth Street, N.W., Judiciary Plaza,
Washington, D.C. 20549) and at the Commission's Regional Offices in New York (7
World Trade Center, 13th Floor, New York, New York 10048) and Chicago (Citicorp
Center, 500 West Madison Street, Suite 1400, Chicago, Illinois 60661). The
Company is an electronic filer and the Commission maintains a web site that
contains reports, proxy and information statements and other information
regarding registrants that file electronically with the Commission. The address
of the web site is "http://www.sec.gov." The Company's reports, proxy statements
and other information may also be inspected at the offices of the National
Association of Securities Dealers, Inc., 1735 K Street, N.W., Washington, D.C.
20006.
 
     This Prospectus is part of a Registration Statement on Form S-3 (together
with all amendments and exhibits thereto, the "Registration Statement") filed
with the Commission under the Securities Act with respect to the Shares offered
hereby. This Prospectus does not contain all the information set forth in the
Registration Statement, certain portions of which have been omitted in
accordance with the Commission's rules and regulations. For further information
with respect to the Company and the Shares offered hereby, reference is made to
the Registration Statement and the exhibits thereto. The statements in this
Prospectus are qualified in their entirety by reference to the contents of any
agreement or other document incorporated herein by reference, a copy of which is
filed as an exhibit to either the Registration Statement or other filings by the
Company with the Commission.
 
                           FORWARD-LOOKING STATEMENTS
 
     This Prospectus includes "forward-looking statements" within the meaning of
the Private Securities Litigation Reform Act of 1995 (the "PSLRA"). The PSLRA
provides a "safe harbor" for such statements to encourage companies to provide
prospective information about themselves so long as such information is
identified as forward-looking and is accompanied by meaningful cautionary
statements identifying important factors that could cause actual results to
differ materially from those projected in the information. All statements other
than statements of historical fact made in this Prospectus or incorporated by
reference are forward-looking. In particular, the statements herein regarding
the availability of adequate funding, progress in the Company's clinical trials,
the granting and timing of regulatory approval for the Company's primary
product, the METRIX System, the status of competitive treatments and products
for the treatment of atrial fibrillation, and the availability and adequacy of
third-party reimbursement for the Company's products are forward-looking
statements. Forward-looking statements represent management's current
expectations and are inherently uncertain. Investors are warned that the
Company's actual results may differ significantly from management's expectations
and, therefore, from the results discussed in such forward-looking statements.
Factors that might cause such differences include, but are not limited to, the
"Risk Factors" described herein.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
     The Company will provide without charge to each person, including any
beneficial owner, to whom a copy of this Prospectus is delivered, upon such
person's written or oral request, a copy of any and all of the documents
incorporated by reference herein (other than exhibits to such documents, unless
such exhibits are specifically incorporated by reference into the information
that this Prospectus incorporates). Requests should be directed to InControl,
Inc., 6675 - 185th Avenue N.E., Redmond, Washington 98052, Attention: Secretary,
telephone: (425) 861-9800.
 
                                        2
<PAGE>   4
 
     The following documents filed with the Commission by the Company are
incorporated by reference into this Prospectus:
 
          (1) The Company's Annual Report on Form 10-K, as amended by Form
              10-K/A No. 1 and Form 10-K/A No. 2, for the year ended December
              31, 1997;
 
          (2) The Company's Quarterly Report on Form 10-Q, as amended by Form
              10-Q/A No. 1 and Form 10-Q/A No. 2, for the quarter ended March
              31, 1998;
 
   
          (3) The Company's Current Report on Form 8-K, as amended by Form 8-K/A
              No. 1, Form 8-K/A No. 2 and Form 8-K/A No. 3, dated April 20,
              1998;
    
 
   
          (4) The Company's Current Reports on Form 8-K dated June 26, 1998 and
              August 10, 1998;
    
 
   
          (5) The description of the Common Stock contained in the Company's
              Registration Statement on Form 8-A as of September 8, 1994,
              including any amendment or report filed for the purpose of
              updating such description; and
    
 
   
          (6) The description of the Company's rights contained in the Company's
              Registration Statement on Form 8-A filed with the Commission on
              March 1, 1996, including any amendment or report filed for the
              purpose of updating such description.
    
 
     All documents filed with the Commission by the Company pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of this
Prospectus and prior to the termination of the offering of the Shares shall be
deemed to be incorporated by reference into this Prospectus and to be a part
hereof from the respective dates of filing such documents. Any statement
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed modified, superseded or replaced for purposes of this
Prospectus to the extent that a statement contained herein or in any
subsequently filed document that also is or is deemed to be incorporated by
reference herein modifies, supersedes or replaces such statement. Any statement
so modified, superseded or replaced shall not be deemed, except as so modified,
superseded or replaced, to constitute a part of this Prospectus.
                            ------------------------
 
     The Company's principal executive offices are located at 6675 - 185th
Avenue N.E., Redmond, Washington 98052, telephone: (425) 861-9800.
 
                                        3
<PAGE>   5
 
                                  RISK FACTORS
 
     THIS PROSPECTUS AND THE DOCUMENTS INCORPORATED HEREIN BY REFERENCE CONTAIN
FORWARD-LOOKING STATEMENTS THAT INVOLVE RISKS AND UNCERTAINTIES. THE STATEMENTS
CONTAINED IN THIS PROSPECTUS THAT ARE NOT PURELY HISTORICAL ARE FORWARD-LOOKING
STATEMENTS WITHIN THE MEANING OF SECTION 27A OF THE SECURITIES ACT AND SECTION
21E OF THE EXCHANGE ACT, INCLUDING, WITHOUT LIMITATION, STATEMENTS REGARDING THE
COMPANY'S EXPECTATIONS, BELIEFS, ESTIMATES, INTENTIONS AND STRATEGIES ABOUT THE
FUTURE. WORDS SUCH AS "ANTICIPATES," "EXPECTS," "INTENDS," "PLANS," "BELIEVES,"
"SEEKS," ESTIMATES," VARIATIONS OF SUCH WORDS AND SIMILAR EXPRESSIONS ARE
INTENDED TO IDENTIFY SUCH FORWARD-LOOKING STATEMENTS, BUT THEIR ABSENCE DOES NOT
MEAN THE STATEMENT IS NOT FORWARD-LOOKING. THESE STATEMENTS ARE NOT GUARANTEES
OF FUTURE PERFORMANCE AND ARE SUBJECT TO CERTAIN RISKS, UNCERTAINTIES AND
ASSUMPTIONS THAT ARE DIFFICULT TO PREDICT; THEREFORE, ACTUAL RESULTS MAY DIFFER
MATERIALLY FROM THOSE EXPRESSED OR FORECASTED IN ANY SUCH FORWARD-LOOKING
STATEMENTS AS A RESULT OF CERTAIN FACTORS, INCLUDING THOSE SET FORTH IN THE
FOLLOWING RISK FACTORS, ELSEWHERE IN THIS PROSPECTUS AND IN THE DOCUMENTS
INCORPORATED HEREIN BY REFERENCE. THE COMPANY UNDERTAKES NO OBLIGATION TO UPDATE
PUBLICLY ANY FORWARD-LOOKING STATEMENTS, WHETHER AS A RESULT OF NEW INFORMATION,
FUTURE EVENTS OR OTHERWISE. POTENTIAL INVESTORS SHOULD CONSIDER CAREFULLY THE
FOLLOWING FACTORS, AS WELL AS THE MORE DETAILED INFORMATION CONTAINED IN THE
DOCUMENTS INCORPORATED BY REFERENCE, BEFORE MAKING A DECISION TO INVEST IN THE
SHARES OFFERED HEREBY.
 
MARKET ACCEPTANCE; SUBSTANTIAL DEPENDENCE ON SINGLE PRODUCT
 
     Regulatory approval is required in all important markets in which the
Company plans to sell the METRIX System. There can be no assurance, however,
that such approval will be obtained in a timely manner, if at all. Even if
regulatory approval is obtained in each market, there can be no assurance that
the METRIX System will gain market acceptance in any area. Moreover, in Europe,
market acceptance will depend upon the successful completion of various
post-regulatory approval protocols designed to demonstrate the clinical benefits
of the METRIX System, including improvements in patients' quality of life and
the cost-effectiveness of the therapy.
 
     The METRIX System is a new invasive approach to the treatment of atrial
fibrillation ("AF"). Currently, the METRIX System may be marketed only in
Europe, and there are no other implantable devices to treat AF on the market
anywhere in the world. The timing and rate of adoption of new medical technology
cannot be predicted. Substantial clinical experience with the METRIX System will
be required to address patients' and physicians' concerns, including potential
ventricular proarrhythmia, potential shock discomfort and early recurrence of
atrial fibrillation, a condition involving the recurrence of AF within the first
two minutes following a successful cardioversion shock. There can be no
assurance that these concerns will be adequately addressed so as to permit the
successful commercialization of the METRIX System. Since the Company anticipates
that for the foreseeable future it will be substantially dependent on the
successful development and commercialization of the METRIX System and related
future products, failure of the Company to successfully develop and
commercialize the METRIX System and related future products would have a
material adverse effect on the Company's business, financial condition and
results of operations.
 
HISTORY OF LOSSES; FUTURE LOSSES; ABILITY TO CONTINUE AS A GOING CONCERN
 
     The design and development of an implantable medical device has required
the Company to make significant investments in research and development
activities since its incorporation in November 1990 and, as such, the Company
has accumulated a deficit of $138.8 million as of March 31, 1998. The Company
reported net losses of $33.5 million, $36.8 million and $23.7 million for the
years ended December 31, 1997,
                                        4
<PAGE>   6
 
1996 and 1995, respectively. In addition, the Company reported a $9.1 million
loss in the quarter ended March 31, 1998. The Company expects to incur
substantial additional losses in the near future. The Company's independent
auditors have included an explanatory paragraph in their report covering the
December 31, 1997 consolidated financial statements, which expresses substantial
doubt about the Company's ability to continue as a going concern. The Company
expects that revenues from clinical trials and sales of the Company's products
will increase, which will moderate future deficit growth. Future increases in
expenses are expected to be primarily due to the Company's continuing investment
in research and development efforts, increases in clinical trial activities, the
maintenance of the European sales organization, the expansion of domestic
marketing and sales capabilities and increasing domestic manufacturing activity.
The amount and timing of the Company's future revenues and, as a result, the
amount and timing of the Company's future losses will be affected by, among
other things, the availability of adequate funding, the progress and costs of
preclinical studies and clinical trials, including the recruitment of suitable
patients, the timing of regulatory approvals, the rate of market acceptance and
adoption of the METRIX System and related future products, the availability of
third-party reimbursement for the Company's products, the ability to obtain and
defend patent and intellectual property rights and to market the Company's
products and the status of competing products. There can be no assurance that
the Company will ever achieve profitability or generate product revenues
sufficient to offset the Company's losses.
 
   
CONSUMMATION OF THE TENDER OFFER AND MERGER
    
 
   
     On August 10, 1998, the Company and Guidant Corporation ("Guidant")
announced that they had entered into an Agreement and Plan of Merger dated as of
August 10, 1998 between Guidant, Pegasus Acquisitions Corp. ("Pegasus") and the
Company (the "Merger Agreement") providing for the acquisition of the Company by
Guidant. Pursuant to the Merger Agreement, Guidant has agreed to purchase each
outstanding share of the Company's Common Stock at an offer price of $6.00 per
share (the "Offer Price"). To implement the Merger Agreement, Guidant will
commence a cash tender offer for all outstanding shares of the Common Stock
within five business days of the execution of the Merger Agreement. The
completion of the tender offer is subject to a number of customary conditions,
including the acquisition of a majority of the Company's outstanding Common
Stock on a fully diluted basis and the expiration of the waiting period under
the Hart-Scott-Rodino Antitrust Improvements Act of 1976.
    
 
   
     Following successful completion of the tender offer, and subject to certain
customary conditions, Pegasus, an indirect wholly owned subsidiary of Guidant,
will be merged with and into the Company and the Company will continue as the
surviving corporation. As a result of the merger, each outstanding share of the
Common Stock not tendered pursuant to the tender offer, if any, will be
converted into the right to receive the Offer Price, or such higher price as
Guidant pays pursuant to the tender offer.
    
 
   
     There can be no assurance that the conditions to the tender offer and the
subsequent merger will be satisfied or waived, and, therefore, there can be no
assurance that the tender offer or the subsequent merger will be consummated on
the terms provided in the Merger Agreement, if at all. If the tender offer or
the subsequent merger are not consummated, the Company's stockholders will have
no right to receive the Offer Price pursuant to the tender offer or the Merger
Agreement.
    
 
NEED FOR SUBSTANTIAL ADDITIONAL CAPITAL
 
     The Company expects its cash needs to continue at their present levels in
future periods due to the Company's planned investment in research and
development, anticipated increases in spending on clinical studies and trial
activities and expansion of marketing, sales and manufacturing capabilities. The
Company's future capital requirements will depend on many factors, including the
progress and costs of preclinical studies and clinical trials, the recruitment
of suitable patients, the timing of regulatory approvals, the rate of market
acceptance and the adoption of the METRIX System and related future products,
the availability of third-party reimbursement for the Company's products, the
ability to obtain and defend patent and intellectual property rights and to
market the Company's products and the status of competing products.
 
                                        5
<PAGE>   7
 
     To date, the Company has raised $73.9 million, net of issuance costs,
through the sale of Common Stock and convertible preferred stock in private
placements. In addition, the Company has raised $75.9 million, net of issuance
costs, through its initial and subsequent public offerings. In April 1998, the
Company raised $2.5 million through the sale of 400,000 shares of Common Stock
in a private transaction. The Shares of Common Stock sold in that transaction
constitute the Shares being registered hereunder. The Company raised an
additional $7.5 million through the sale of 7,500 shares of its Series B
Convertible Preferred Stock, $.01 par value (the "Series B Stock") in a private
transaction. For a description of the rights and preferences of the Series B
Stock, see "Description of the Series B Stock" in the Company's Current Report
on Form 8-K, as amended by Form 8-K/A No. 1 and Form 8-K/A No. 2, dated as of
April 20, 1998, incorporated herein by reference.
 
     As a result of its failure to maintain certain minimum levels of cash, the
Company has defaulted under certain of its capital lease arrangements. As a
result, the Company has entered into a letter of credit agreement with the
lessor pursuant to which the Company has agreed to maintain an irrevocable
letter of credit in the face amount of $500,000 for the purpose of securing its
obligations under the lease. At the present time, the Company believes it is
unlikely the lessor will foreclose under the leases or accelerate rental
payments and has received verbal assurances to that effect. However, if funding
continues to be insufficient in the future, notwithstanding the letter of credit
agreement, the lessor may accelerate the payments due under these capital lease
arrangements. Accordingly, the Company has classified $1.6 million of the
amounts payable under these lease arrangements as a current liability in its
consolidated financial statements included in its Quarterly Report on Form 10-Q,
as amended by Form 10-Q/A No. 1 and Form 10-Q/A No. 2. If the lessor were to
foreclose under the leases or accelerate rental payments, it could have a
material adverse effect on the Company's business, financial condition and
results of operations.
 
   
     On August 10, 1998, the Company entered into a credit agreement with
Guidant, pursuant to which the Company is able, subject to certain customary
conditions, to borrow up to an aggregate of $10 million in amounts not to exceed
$3 million per month (both amounts subject to adjustment upwards as provided in
the credit agreement).
    
 
   
     The Company estimates that, at its planned rate of spending, its existing
cash, cash equivalents, securities available-for-sale, and interest income
thereon, including the $10 million in capital that was raised in April 1998 and
the funds available under the Company's $10 million credit agreement with
Guidant, will be sufficient to meet its capital requirements into the first
quarter of 1999. There can be no assurance that the underlying assumed levels of
revenue and expense will prove to be accurate. Whether or not these assumptions
prove to be accurate, if the Company is unable to consummate the transactions
contemplated by the Merger Agreement, the Company will need to raise substantial
additional capital in 1998 to fund operations. The Company intends to seek
additional funding through public or private financing, including equity
financing. Adequate funds for these purposes, whether obtained through financial
markets or from other sources, may not be available when needed or may not be
available on terms favorable to the Company, if at all. If additional funds are
raised by issuing equity securities, dilution to existing shareholders will
result. If funding is insufficient at any time in the future, the Company will
be forced to delay, reduce or eliminate some or all of its research and
development activities, clinical studies and trials and manufacturing and
administrative programs, dispose of assets or technology, or cease operations.
    
 
MANDATORY REDEMPTION OF SERIES B STOCK
 
     The number of shares of Common Stock issuable upon conversion of the Series
B Stock is limited to a maximum share amount of 3,769,000 shares (or such
greater number as is permitted by the rules of Nasdaq) (the "Maximum Share
Amount"), unless the stockholders of the Company approve the issuance of a
greater number of shares (as required by Nasdaq) or Nasdaq waives the
requirement of stockholder approval. If at any time after July 20, 1998, the
number of shares issuable upon conversion of the Series B Stock exceeds the
Maximum Share Amount, the holders of the Series B Stock may compel the Company
to redeem that portion (on a pro rata basis) of their shares as would not have
been convertible because of the Maximum Share Amount restriction. If requested
by the holders of Series B Stock, the Company must redeem shares of Series B
Stock at a price equal to the greater of (i) 115% of the purchase price and any
accrued but unpaid
                                        6
<PAGE>   8
 
   
dividends and (ii) the price that is equal to the number of shares issuable upon
conversion of the Series B Stock multiplied by the average of the closing bid
price of the Common Stock for the previous five trading days. If the market
price of the Common Stock falls below the level necessary to allow full
conversion of the Series B Stock (depending upon the applicable conversion
percentage), the Company may be required to redeem shares of Series B Stock at a
premium or seek stockholder approval for the issuance of a greater number of
shares. Any such redemption of shares of Series B Stock could have a material
adverse effect on the Company's business, financial condition and results of
operations. See "Description of the Series B Stock" in the Company's Current
Report on Form 8-K, as amended by Form 8-K/A No. 1, Form 8-K/A No. 2 and Form
8-K/A No. 3, dated as of April 20, 1998, incorporated herein by reference.
    
 
DEPENDENCE ON REIMBURSEMENT
 
     Successful sales of the METRIX System in the United States and Europe will
depend on the availability of reimbursement from third-party payors such as
government and private insurance plans. There is significant uncertainty
concerning third-party reimbursement of investigational and newly approved
healthcare products, and there can be no assurance that third-party
reimbursement will be made available for the METRIX System or that any
third-party reimbursement that is obtained will be adequate. Government and
other third-party payors are increasingly scrutinizing patient indications for
medical device therapy and limiting coverage. In Europe, post-regulatory
approval study protocols are required before a device will be eligible for
reimbursement through the various national and local health care financing
authorities. There can be no assurance that these European study protocols will
be completed successfully or that reimbursement will be available in a timely
manner, if at all. If adequate coverage and reimbursement levels are not
provided by government and third-party payors for the METRIX System, the
Company's business and financial condition would be materially adversely
affected.
 
EXTENSIVE GOVERNMENTAL REGULATION AND UNCERTAINTY OF PRODUCT APPROVALS
 
     The Company is subject to significant regulation by authorities in the
United States and Europe regarding the approval of devices and the subsequent
marketing, manufacture and distribution of approved devices.
 
     In the United States, the Company's products have and will continue to
undergo clinical testing followed by an extensive Food and Drug Administration
("FDA") approval process. At the end of the first quarter of 1998, the METRIX
System was in clinical trials in the United States in 25 centers, the number
approved by the FDA. The Company currently has 37 patients enrolled in those
trials, with approval to implant up to a maximum of 170 METRIX atrial
defibrillators. There can be no assurance that the clinical trials will
demonstrate that the METRIX System is safe and effective, or that the Company
will receive FDA approval in a timely manner, if at all. The time required to
complete the U.S. trials is dependent on the rate of patient recruitment, the
performance of the device during the trials and the number of times therapy is
applied to patients enrolled in the study. In addition, delays or rejections may
be encountered based on changes in FDA policy that occur during the development
and approval process. FDA approvals may also be limited, which could limit the
patient population to which the Company's products may be marketed and
distributed. Delays, setbacks or approval limitations related to any of the
factors listed above may have a material adverse effect on the Company's
business and financial condition.
 
     After completing the clinical trials, the Company must submit a Pre-Market
Approval ("PMA") application that is supported by extensive data, including
preclinical and clinical trial data, relating to the safety and effectiveness of
the device. As part of the PMA application process the Company will be required
to submit a full description of its facilities, manufacturing methods and
manufacturing controls. The Company must also fully describe the METRIX System
and the System's components in the PMA application. The Company will then be
required to undergo an initial audit, including a facility inspection, to ensure
that the Company is in compliance with the FDA's Quality System Requirements
regulations (formerly known as Good Manufacturing Practices) and the Medical
Device Reporting regulations and other regulations under the Federal Food, Drug
and Cosmetic Act ("FDC Act") and FDA regulations. There can be no assurance that
the Company will be able to comply with such regulations in a timely fashion,
particularly given the Company's limited manufacturing experience.
 
                                        7
<PAGE>   9
 
     Once a PMA application is filed, the FDA may accept it and call for an
advisory panel recommendation or may reject it for insufficient data. Such a
rejection could have significant negative consequences for the Company,
including forcing more costly studies, adversely impacting the market acceptance
of the METRIX System and forcing a possible product recall. After the PMA is
reviewed by the advisory panel, the FDA may approve or reject the product. This
process is lengthy and unpredictable. If the METRIX System PMA application is
approved and the Company markets the METRIX System, the Company will be required
to register with the FDA and to submit device listing information for products
in commercial distribution. The Company and its facilities will then be
periodically re-inspected by the FDA for compliance with the FDC Act and FDA
regulations, including those described above. Labeling and promotional
activities will be subject to scrutiny by the FDA and, in certain circumstances,
by the Federal Trade Commission.
 
     If the FDA determines during the initial audit or during any subsequent
audit that the Company is not in compliance, the FDA has the authority to take
actions that it deems appropriate for any infractions. Such penalties include,
but are not limited to, monetary fines, product recalls, withdrawal of product
approvals, "cease distribution" orders for both domestic and international
products, product seizure and the slowing or stopping of future product approval
processes. In addition, the FDA may institute civil or criminal legal
proceedings against the Company or its officers. Any such action by the FDA
could result in the disruption of the Company's operations for an indeterminate
time, which may have a material adverse effect on the Company's business and
financial condition.
 
     In Europe, the Company has received the needed certifications required in
order to declare compliance with the European Active Implantable Medical Device
Directive ("AIMDD") and affix the conformite europeenne ("CE") mark to the
METRIX System components. While the CE mark allows the Company to distribute and
market the METRIX System throughout the European Community ("EC"), the Company
will need to complete studies regarding the cost benefits of the therapy before
it will be eligible to receive reimbursement approvals from the medical
reimbursing authorities in various EC member countries. There can be no
assurance that such approvals from the reimbursing authorities will be obtained
in a timely manner, if at all. Failure to obtain such approvals could
significantly delay or prevent the adoption of the METRIX System in Europe and
thereby have a material adverse effect on the Company's business and financial
condition.
 
     As part of the CE mark approval process the Company was required to obtain
certifications of its quality system under the AIMDD from TUV Product Services
of Munich, Germany (the "Notified Body"), an organization accredited to provide
such quality system certification. The Notified Body will perform periodic
audits to ascertain whether the Company has maintained its quality system and is
in compliance with the certification requirements under the AIMDD. If
certification is revoked, the Company may be prevented from distributing its
product in the EC. In addition, if an individual EC country's regulatory
authority deems the METRIX System to be "unsafe" for any reason, the Company may
find it impossible to distribute its product throughout the EC. A
de-certification of the Company's quality system or an "unsafe" determination by
any regulatory authority would have a material adverse effect on the Company's
business and financial condition.
 
SIGNIFICANT COMPETITION
 
     The METRIX System is a new technology that must compete with the
established treatments for AF: pharmaceuticals, external electrical
cardioversion, atrioventricular node ablation accompanied by pacemaker
implantation and open-heart surgical ablation. Furthermore, although currently
no implantable device is being marketed to treat AF (with the exception of the
METRIX atrial defibrillator in Europe), certain manufacturers of implantable
ventricular defibrillators and pacemakers are developing dual-chamber
defibrillator systems that will be used to treat patients with both ventricular
and atrial arrhythmias and may be marketed to patients who have only AF. One
such dual chamber defibrillator system has started clinical trials in Europe.
Some of the Company's competitors are also researching other approaches to the
treatment of AF, including endocardial ablation and preventative pacing
techniques. In addition, other companies and research organizations, academic
institutions and governmental agencies may be pursuing alternative approaches
for the treatment of AF. These entities may market products to treat AF either
on their own or through collaborative efforts. The Company believes that the
primary competitive factors in the market for the treatment of
 
                                        8
<PAGE>   10
 
symptomatic AF are therapeutic efficacy, safety and patient acceptance. Many of
the Company's competitors have substantially greater financial and other
resources, larger research and development staffs and more experience and
capabilities in conducting research and development activities, testing products
in clinical trials, obtaining regulatory approvals and manufacturing, marketing
and distributing products than the Company. The Company's competitors may
develop new technologies and products that are available for sale prior to the
METRIX System or that are more effective than the METRIX System. In addition,
competitive products may be manufactured and marketed more successfully than the
METRIX System. Such developments could render the METRIX System less competitive
or obsolete and could have a material adverse effect on the Company's business
and financial condition. In addition, the Company intends for its future
products to include bradycardia pacing technology. Any such products are likely
to face direct competition from more established medical device companies with
financial and other resources significantly greater than those of the Company.
 
DEPENDENCE ON SOLE SOURCES OF SUPPLY
 
     The Company relies on outside vendors to manufacture certain major
components used in the METRIX System. For efficiency reasons, the Company does
not at the present time maintain supply contracts with most of its outside
vendors. A number of significant components, such as hybrid circuits, batteries,
integrated circuits, capacitors and transformers, are supplied by sole source
vendors. For certain of these components, there are relatively few alternative
sources of supply, and establishing additional or replacement suppliers for such
components, particularly hybrid circuits and batteries, cannot be accomplished
quickly. In addition, each supplier and each component must be qualified with
the FDA, and the time required for such qualification may be lengthy. The
establishment of additional or replacement sources of supply would require the
Company to certify the new suppliers, which, in the case of certain components,
would cause a delay in the Company's ability to manufacture its products. The
Company actively maintains its relationships with its suppliers and presently
has no reason to believe that its sources of supply are in danger of disruption.
However, if the Company's supply sources were disrupted and the Company was
unable to obtain acceptable components in a timely manner or find and maintain
suitable replacement suppliers, such a disruption would have a material adverse
effect on the Company's ability to manufacture the METRIX System and therefore
on its business and financial condition.
 
INDUSTRY HISTORY OF PATENT LITIGATION; DEPENDENCE ON PATENTS AND PROPRIETARY
RIGHTS
 
     The segment of the medical device industry that includes implantable
defibrillator systems has been characterized by extensive litigation regarding
patents and other intellectual property rights. Litigation may be necessary to
enforce patents issued to the Company, to protect trade secrets or know-how
owned by the Company or to determine the enforceability, scope and validity of
proprietary rights of others. Such litigation may result in substantial expense
to the Company and significant diversion of effort by the Company's technical
and management personnel. An adverse determination in any such litigation could
subject the Company to significant liability to third parties or require the
Company to seek licenses from third parties. Although patent and intellectual
property disputes in the medical device industry have often been settled through
licensing or similar arrangements, costs associated with such arrangements may
be substantial and could include ongoing royalties. Moreover, there can be no
assurance that necessary licenses would be available to the Company on
satisfactory terms, if at all. If such licenses could not be obtained on
acceptable terms, the Company could be prevented from marketing certain devices
in the METRIX System family or future related products. Accordingly, an adverse
determination in such litigation could have a material adverse effect on the
Company's business and financial condition. The Company's success will depend in
part on its ability to obtain and maintain patent protection for its
technologies. There can be no assurance that issued patents or pending
applications will not be challenged or circumvented by competitors, or that the
rights granted thereunder will provide competitive advantages to the Company.
 
                                        9
<PAGE>   11
 
LIMITED MANUFACTURING AND MARKETING EXPERIENCE
 
     The METRIX System has never been manufactured on a commercial scale and
there can be no assurance that it can be manufactured at a cost or in quantities
necessary to make it commercially viable. There can be no assurance that the
Company's reliance on others for the manufacture of its components will not
result in problems with product supply. Interruptions in the availability of
components would delay or prevent the development and commercialization of the
METRIX System. The Company expects to expand its domestic manufacturing capacity
and its European and domestic marketing and sales capabilities. There can be no
assurance that the Company will be able to recruit and retain skilled sales,
marketing and manufacturing management, direct salespersons or distributors, or
that the Company's expansion efforts will be successful. In markets where the
Company has entered or enters into distribution arrangements for the sale of the
METRIX System, the Company will depend on the efforts of third parties. There
can be no assurance that such efforts will be successful.
 
DEPENDENCE ON KEY PERSONNEL
 
     The Company is highly dependent on certain members of its scientific and
professional staff, the loss of whose services might impede the achievement of
its research and development or strategic objectives. At the present time, the
Company does not have long-term employment agreements with, and does not carry
key person life insurance on, any of its scientific and professional personnel.
Competition among medical device companies for highly skilled and uniquely
experienced scientific and professional personnel is intense. To help retain its
key personnel, the Company offers a salary and benefits structure that is
competitive with its local geographic market, as well as the medical device
industry nationwide. The Company offers a broad-based stock option plan through
which all employees of the Company are granted stock options upon hire, and key
employees are periodically granted additional stock options. The Company has
recently initiated a stock option repricing program, whereby all employees with
underwater options are offered the opportunity to exchange their underwater
options for a lesser number of options with an exercise price equal to the
current market value. The number of new options to which each employee is
entitled is determined by multiplying the number of options being exchanged by
the ratio of the new exercise price to the old exercise price.
 
     The Company's currently limited financial resources may compromise its
ability to compete effectively for skilled personnel. The Company's anticipated
growth and expansion in areas and activities requiring additional expertise,
such as marketing and sales, clinical trials and manufacturing, are expected to
place significant increased demands on the Company's resources. These demands
are expected to require the addition of new professional personnel and the
development of additional expertise by existing personnel. The failure to
recruit such personnel, loss of such existing personnel or failure to develop
such expertise would have a material adverse effect on the Company's business
and financial condition. There can be no assurance that the Company will be able
to retain or recruit needed scientific and professional expertise, particularly
given the Company's currently limited financial resources.
 
PRODUCT LIABILITY AND PRODUCT RECALL
 
     The testing, manufacture, marketing and sale of medical devices entail the
inherent risk of liability claims or product recalls. Although the Company has
not been subject to liability claims or product recalls to date, there can be no
assurances that the Company will not be subject to liability claims or product
recalls for products that have already been distributed or on products to be
distributed in the future. Although the Company maintains product liability
insurance in the United States and in other countries in which the Company
intends to conduct business, including clinical trials and product marketing and
sales, there can be no assurance that such coverage is adequate or will continue
to be available. Product liability insurance is expensive and in the future may
not be available on acceptable terms, if at all. In addition, the Company has
agreed to indemnify certain of its component suppliers for certain potential
product liability. A successful product liability claim or product recall could
inhibit or prevent commercialization of the METRIX System, or cause a
significant financial burden on the Company, or both, and could have a material
adverse effect on the Company's business and financial condition.
 
                                       10
<PAGE>   12
 
SHARES ELIGIBLE FOR FUTURE SALE
 
   
     Sale of substantial amounts of the Common Stock in the public market or the
prospect of such sales could materially and adversely affect the market price of
the Common Stock. As of August 11, 1998, the Company had outstanding 20,974,122
shares of Common Stock, 2,999 shares of Series B Stock convertible into Common
Stock and warrants to purchase 102,901 shares of Common Stock. In addition, as
of August 5, 1998, the Company had granted options to purchase 1,442,217 shares
of Common Stock under its 1990 Restated Stock Option Plan, 1994 Stock Option
Plan for Nonemployee Directors and 1996 Stock Option Plan for Nonemployee
Directors (collectively, the "Stock Option Plans"). All of the shares purchased
under the Stock Option Plans are available for sale in the public market,
subject in some cases to volume and other limitations. Almost all of the
Company's outstanding shares of Common Stock may be sold without substantial
restrictions. Moreover, the Company has filed with the Commission another
registration statement on Form S-3, as amended by Form S-3/A No. 1, Form S-3/A
No. 2 and Form S-3/A No. 3, which registers for resale an aggregate of 2,552,534
shares of Common Stock issuable upon conversion of the Series B Stock sold in
the April 1998 private placement. The number of shares of Common Stock issuable
upon conversion of the Series B Stock changes depending upon the lowest sale
prices of the Common Stock during the applicable measurement period immediately
preceding the date of conversion. Pursuant to the terms of the Certificate of
Designations of the Series B Stock, the number of shares of Common Stock
issuable upon conversion of the Series B Stock is limited to the Maximum Share
Amount, unless the stockholders of the Company approve the issuance of a greater
number of shares (as required by Nasdaq) or Nasdaq waives the requirement for
stockholder approval. See "Description of the Series B Stock -- Conversion" in
the Company's Current Report on Form 8-K, as amended by Form 8-K/A No. 1, Form
8-K/A No. 2 and Form 8-K/A No. 3, dated as of April 20, 1998, incorporated
herein by reference.
    
 
   
     Sales in the public market of substantial amounts of Common Stock,
including sales of Common Stock issued upon conversion of the Series B Stock, or
the perception that such sales could occur, could depress prevailing market
prices for the Common Stock. The conversion terms of the Series B Stock, which
allow holders of the Series B Stock to convert their shares of Series B Stock
into shares of Common Stock at a discount to the current market price of the
Common Stock, and then immediately resell such shares at market prices, could
result in downward pressure on the price of the Common Stock, making it
difficult for a sustained rise in the price of the Common Stock to occur, if
such a rise occurs at all.
    
 
     The existence of the private warrants and any other options or warrants may
prove to be a hindrance to future equity financing by the Company. Further, the
holders of such warrants and options may exercise them at a time when the
Company would otherwise be able to obtain additional equity capital on terms
more favorable to the Company.
 
RISKS ASSOCIATED WITH FOREIGN OPERATIONS
 
     The Company's revenues from international sales of the METRIX System
(primarily in Europe) were 77.2%, 71.6% and 100.0% of total revenues for the
years ended December 31, 1997, 1996 and 1995, respectively, and the Company
currently derives a significant percentage of its revenue from the European
sales of the METRIX System. While the Company anticipates that, as the METRIX
System progresses in clinical trials in the United States, a greater portion of
its future revenues will be derived from the sale of the METRIX System in the
United States, it is possible that European sales of the METRIX System may
continue to account for a significant percentage of the Company's total
revenues. A number of risks are inherent in international operations and
transactions. The Company's business and its representatives, agents and
distributors are subject to laws and regulations of the countries in which they
operate or the Company's products are sold. International sales and operations
may be limited or disrupted by the imposition of government controls, the level
of reimbursement available for use of the METRIX system, export license
requirements, political instability, trade restrictions, changes in tariffs and
difficulties in staffing, coordinating and managing international operations. As
long as the Company's revenues continue to depend substantially on international
sales, they may be adversely affected by fluctuations in foreign currency
exchange rates as well as constraints on the Company's ability to maintain or
increase prices. The Company has not hedged against foreign currency exchange
rate risks to date. The Company may in the future seek to implement
                                       11
<PAGE>   13
 
hedging techniques with respect to foreign currency transactions. There can be
no assurance, however, that such hedging techniques would successfully protect
against foreign currency exchange losses or against other international sales
risks such as exchange limitations, price controls or other foreign currency
restrictions. Any of the foregoing would have a material adverse effect on the
Company's business, financial condition and results of operations.
 
VOLATILITY OF STOCK PRICE
 
   
     Since the Company's initial public offering in September 1994, the price of
the Common Stock has ranged from $2.06 to $18.50 per share. Factors such as the
results of clinical trials by the Company or its competitors, concern as to the
safety or efficacy of products of the Company or its competitors, announcements
of technological innovations or new products by the Company or its competitors,
governmental regulation, healthcare legislation, developments in patent or other
proprietary rights of the Company or its competitors and fluctuations in the
Company's results of operations will have a significant impact on the price of
the Common Stock. Conversion and sale of large amounts of the Series B Stock, or
the perception that such sales could occur, also could have a material adverse
effect on the price of the Common Stock. See "Shares Eligible for Future Sale."
    
 
NASDAQ LISTING REQUIREMENTS
 
     The Common Stock is quoted on the Nasdaq National Market System. The
maintenance criteria for continued quotation on the Nasdaq National Market
System include, among other criteria, (i) net tangible assets of $4.0 million,
(ii) a minimum bid price per share of $1.00, (iii) a public float of 750,000
shares with market value of $5.0 million, (iv) 400 round lot shareholders and
(v) two market makers. If the Company is unable to obtain substantial additional
capital in 1998, it may be unable to maintain net tangible assets of $4.0
million. See "Need for Substantial Additional Capital." The remaining
maintenance criteria, including the minimum bid price of the Common Stock, the
volume and value of its public float, the number of holders of the Common Stock
and the number of market makers in the Common Stock, all are dependent upon
numerous market factors not within the Company's control. Although the Company
presently meets the above maintenance criteria, there can be no assurance that
it will continue to do so.
 
     Failure of the Company to continue to meet such maintenance criteria could
result in the Common Stock losing its Nasdaq National Market System designation.
The Nasdaq National Market System provides brokers and others with immediate
access to the best bid and ask prices and other information about the Common
Stock during each trading day. If the Company were to lose its Nasdaq National
Market System designation, real-time price information for the Common Stock
might cease to be available. As a result, an investor might find it more
difficult to dispose of, or to obtain more accurate quotations as to the price
of, the Common Stock.
 
     If the Company were to lose its Nasdaq National Market System designation,
the Company would seek to have its securities listed on the Nasdaq SmallCap
Market or another securities exchange, subject to the Company's ability to
satisfy the eligibility criteria for such exchange. If the Company were unable
to meet the Nasdaq SmallCap Market maintenance criteria, trading, if any, in the
Common Stock might continue to be conducted in non-Nasdaq over-the-counter
markets. The Common Stock would then be subject to the risk that it could become
characterized as a low-priced or "penny stock" which characterization could have
a material adverse effect on the Common Stock's market liquidity. See "Penny
Stock Regulation." In addition, if the Company was delisted from the Nasdaq
National Market and was unable to obtain listing with the Nasdaq SmallCap
Market, holders of the Series B stock could compel the Company to redeem all or
any portion of the Series B Stock at a price equal to 115% of the purchase price
and any accrued but unpaid dividends. See "Description of the Series B
Stock -- Optional Redemption" in the Company's Current Report on Form 8-K, as
amended by Form 8-K/A No. 1 and Form 8-K/A No. 2, dated as of April 20, 1998 and
incorporated herein by reference. Any such redemption of shares of Series B
Stock could have a material adverse effect on the Company's business, financial
condition and results of operations.
 
                                       12
<PAGE>   14
 
PENNY STOCK REGULATION
 
     Broker-dealer practices in connection with transactions in "penny stocks"
are regulated by certain penny stock rules adopted by the Commission. Penny
stocks generally are equity securities with a price of less than $5.00 (other
than securities registered on certain national securities exchanges or quoted on
the Nasdaq Stock Market system, provided that current price and volume
information with respect to transactions in such securities is provided by the
exchange or system). The penny stock rules require a broker-dealer, prior to a
transaction in a penny stock not otherwise exempt from the rules, to deliver a
standardized risk disclosure document that provides information about penny
stocks and the risks in the penny stock market. The broker-dealer also must
provide the customer with current bid and offer quotations for the penny stock,
the compensation of the broker-dealer and its salesperson in the transaction,
and monthly account statements showing the market value of each penny stock held
in the customer's account. In addition, the penny stock rules generally require
that prior to a transaction in a penny stock the broker-dealer make a special
written determination that the penny stock is a suitable investment for the
purchaser and receive the purchaser's written agreement to the transaction.
These disclosure requirements may have the effect of reducing the level of
trading activity in the secondary market for a stock that becomes subject to the
penny stock rules. If the Common Stock becomes subject to the penny stock rules,
investors may find it more difficult to sell their Common Stock.
 
                              SELLING STOCKHOLDERS
 
     The following table provides certain information regarding the Selling
Stockholders and the number of Shares being offered by them as of July 17, 1998.
 
   
<TABLE>
<CAPTION>
                                                                                    SHARES BENEFICIALLY OWNED
                                                         SHARES THAT MAY BE SOLD          AFTER OFFERING
                                                         ------------------------   --------------------------
                                   SHARES BENEFICIALLY              PERCENTAGE OF                PERCENTAGE OF
                                     OWNED PRIOR TO                 COMMON STOCK                 COMMON STOCK
        NAME AND ADDRESS                OFFERING          AMOUNT     OUTSTANDING    AMOUNT(1)     OUTSTANDING
        ----------------           -------------------   --------   -------------   ----------   -------------
<S>                                <C>                   <C>        <C>             <C>          <C>
Charter Growth Capital L.P.......        400,000(2)      316,608         1.5%        -0-           -0-
525 University Avenue, Suite 1500
Palo Alto, California 94301
 
Charter Growth Capital Co. --
  Investment Fund L.P............        400,000(3)       62,202           *         -0-           -0-
525 University Avenue, Suite 1500
Palo Alto, California 94301
 
CGC Investors, L.P...............        400,000(4)       21,190           *         -0-           -0-
525 University Avenue, Suite 1500
Palo Alto, California 94301
</TABLE>
    
 
---------------
 *  Less than 1%.
 
(1) Assumes the sale of all the Shares offered by each of the Selling
    Stockholders.
 
(2) Includes 83,342 shares held by affiliates of the Selling Stockholder, which
    shares are offered hereby.
 
(3) Includes 337,798 shares held by affiliates of the Selling Stockholder, which
    shares are offered hereby.
 
(4) Includes 378,810 shares held by affiliates of the Selling Stockholder, which
    shares are offered hereby.
 
     Neither of the Selling Stockholders has had any material relationship with
the Company, or any of its affiliates, within the past three years.
 
     The Selling Stockholders have represented to the Company that they
purchased the Shares for their own account for investment only and not with a
view towards the public sale or distribution thereof, except pursuant to sales
registered under the Securities Act or exemptions therefrom. In recognition of
the fact that the Selling Stockholders, even though purchasing the Shares for
investment, may wish to be legally permitted to sell their Shares when they deem
appropriate, the Company agreed with the Selling Stockholders to file with the
Commission under the Securities Act the Registration Statement with respect to
the resale of the
 
                                       13
<PAGE>   15
 
Shares from time to time in transactions in the over-the-counter market through
Nasdaq, in privately negotiated transactions, or through a combination of such
methods of sale, and has agreed to prepare and file such amendments and
supplements to the Registration Statement as may be necessary to keep the
Registration Statement effective until the Shares are no longer required to be
registered for the sale thereof by the Selling Stockholders.
 
                              PLAN OF DISTRIBUTION
 
     All of the Shares offered hereby may be sold from time to time by the
Selling Stockholders, or by their pledgees, donees, distributees, transferees or
other successors-in-interest. The sale of the Shares by the Selling Stockholders
may be effected from time to time in transactions (which may include block
transactions) in the over-the-counter market through Nasdaq, or on one or more
other securities markets and exchanges, in privately negotiated transactions, or
through a combination of such methods of sale, at fixed prices that may be
changed, at market prices prevailing at the time of sale, at prices relating to
such prevailing market prices or at negotiated prices. The Selling Stockholders
may effect the above-mentioned transactions by selling the Shares directly to
purchasers, acting as principals for their own accounts, or by or through
broker-dealers acting as agents for the Selling Stockholders, or to
broker-dealers who may purchase Shares as principals and thereafter sell such
securities from time to time in transactions on any exchange or market on which
such securities are listed or quoted, as applicable, in negotiated transactions,
through a combination of such methods of sale, or otherwise. Such broker-dealers
may receive compensation in the form of discounts, concessions or commissions
from the Selling Stockholders and/or the purchasers of the Shares for whom such
broker-dealer may act as agents or to whom they may sell as principals, or both
(which compensation as to a particular broker-dealer may be in excess of
customary commissions). Any broker-dealer may act as a broker-dealer on behalf
of the Selling Stockholders in connection with the offering of certain of the
shares by the Selling Stockholders. None of the proceeds from the sale of the
Shares by the Selling Stockholders will be received by the Company. In addition,
any of the Shares that qualify for sale pursuant to Rule 144 promulgated under
the Securities Act may be sold in transactions complying with such Rule, rather
than pursuant to this Prospectus.
 
     The Company has the right to suspend use of this Prospectus for a discrete
period of time under certain circumstances.
 
     To the extent required, the amount of the Shares to be sold, purchase
prices, public offering prices, the names of any agents, dealers or
underwriters, and any applicable commissions or discounts with respect to a
particular offer will be set forth by the Company in a Prospectus Supplement
accompanying this Prospectus or, if appropriate, a post-effective amendment to
the Registration Statement.
 
     Any broker-dealers who act in connection with the sale of the Shares
hereunder may be deemed to be "underwriters" within the meaning of Section 2(11)
of the Securities Act, and any commissions received by them and profit on any
resale of the Shares as principal may be deemed to be underwriting discounts and
commissions under the Securities Act. The Company has agreed to bear all
expenses (other than selling commissions and fees and stock transfer taxes) in
connection with the registration and sale of the Shares being offered by the
Selling Stockholders. The Company has agreed to indemnify the Selling
Stockholders and broker-dealers who act in connection with the sale of the
Shares hereunder against certain liabilities, including liabilities under the
Securities Act.
 
     Offers or sales of the Shares have not been registered or qualified under
the laws of any country, other than the United States. To comply with certain
states' securities laws, if applicable, the Shares will be offered or sold in
such jurisdictions only through registered or licensed brokers or dealers.
 
     Under applicable rules and regulations under the Exchange Act, any person
engaged in a distribution of the Shares may be limited in its ability to engage
in market activities with respect to such Shares. In addition and without
limiting the foregoing, each Selling Stockholder will be subject to applicable
provisions of the Exchange Act and the rules and regulations thereunder, which
provisions may limit the timing of purchases and sales of any of the Shares by
the Selling Stockholders. The foregoing may affect the marketability of the
Shares.
 
                                       14
<PAGE>   16
 
     There can be no assurance that the Selling Stockholders will sell any or
all of the Shares offered by them hereunder.
 
                                 LEGAL MATTERS
 
     The validity of the Common Stock offered hereby has been passed upon for
the Company by Perkins Coie, Seattle, Washington.
 
                                    EXPERTS
 
     The consolidated financial statements of the Company appearing in the
Company's Annual Report (Form 10-K) for the year ended December 31, 1997, have
been audited by Ernst & Young LLP, independent auditors, as set forth in their
report thereon (which contains an explanatory paragraph describing conditions
that raise substantial doubt about the Company's ability to continue as a going
concern as described in Note 1 to the consolidated financial statements)
included therein and incorporated herein by reference. Such consolidated
financial statements are incorporated herein by reference in reliance upon such
report given upon the authority of such firm as experts in accounting and
auditing.
 
                                       15
<PAGE>   17
 
------------------------------------------------------
------------------------------------------------------
 
NO DEALER, SALESPERSON OR OTHER PERSON HAS BEEN AUTHORIZED TO GIVE ANY
INFORMATION OR TO MAKE ANY REPRESENTATIONS OTHER THAN THOSE CONTAINED IN THIS
PROSPECTUS IN CONNECTION WITH THE OFFERING HEREIN CONTAINED AND, IF GIVEN OR
MADE, SUCH INFORMATION OR REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN
AUTHORIZED BY THE COMPANY. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL,
OR A SOLICITATION OF AN OFFER TO BUY, THE SHARES OFFERED HEREBY IN ANY
JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE AN OFFER OR
SOLICITATION. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY SALE MADE
HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE AN IMPLICATION THAT THERE HAS
BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY SINCE THE DATE HEREOF.
 
                            ------------------------
 
                               TABLE OF CONTENTS
 
   
<TABLE>
<CAPTION>
                                        PAGE
                                        ----
<S>                                     <C>
Available Information.................    2
Forward-Looking Statements............    2
Incorporation of Certain Documents by
  Reference...........................    2
Risk Factors..........................    4
Selling Stockholders..................   13
Plan of Distribution..................   14
Legal Matters.........................   15
Experts...............................   15
</TABLE>
    
 
------------------------------------------------------
------------------------------------------------------
------------------------------------------------------
------------------------------------------------------
 
                               400,000 SHARES OF
                                  COMMON STOCK
 
                                INCONTROL, INC.
                           -------------------------
                                   PROSPECTUS
                           -------------------------
   
                                AUGUST   , 1998
    
------------------------------------------------------
------------------------------------------------------
<PAGE>   18
 
                                    PART II
 
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION
 
     The following table sets forth the estimated expenses of the registrant in
connection with the issuance and distribution of the securities being registered
(all amounts are estimated except the Securities and Exchange Commission
registration fee). Selling commissions and fees and stock transfer taxes are
payable individually by the Selling Stockholders.
 
<TABLE>
<S>                                                           <C>
Securities and Exchange Commission registration fee.........  $   391
Blue sky filing fees and expenses...........................      500
Legal fees and expenses.....................................   15,000
Accountants' fees and expenses..............................    3,000
Miscellaneous expenses......................................    1,109
                                                              -------
          Total.............................................  $20,000
                                                              =======
</TABLE>
 
ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
     Section 145 of the Delaware General Corporation Law (the "DGCL") provides
that a corporation may indemnify directors and officers as well as other
employees and individuals against expenses (including attorneys' fees),
judgments, fines and amounts paid in settlement in connection with specified
actions, suits or proceedings, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation, i.e.,
a "derivative action") if they acted in good faith and in a manner they
reasonably believed to be in, or not opposed to, the best interests of the
corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe their conduct was unlawful. A similar standard is
applicable in the case of derivative actions, except that (i) indemnification
only extends to expenses (including attorneys' fees) incurred in connection with
the defense or settlement of such actions and (ii) the statute requires court
approval before there can be any indemnification where the person seeking
indemnification has been found liable to the corporation. The statute provides
that it is not exclusive of other indemnification that may be granted by a
corporation's charter, bylaws, disinterested director vote, stockholder vote or
otherwise.
 
     Section 10 of the registrant's Amended and Restated Bylaws (the "Bylaws")
requires indemnification to the fullest extent permitted under Delaware law as
from time to time in effect. Subject to any restrictions imposed by Delaware
law, the Bylaws provide an unconditional right to indemnification for all
expense, liability and loss (including attorneys' fees, judgments, fines, ERISA
excise taxes or penalties and amounts paid in settlement) actually and
reasonably incurred or suffered by any person in connection with any actual or
threatened action, suit or proceeding, whether civil, criminal, administrative
or investigative, by reason of the fact that such person is or was serving as a
director or officer of the registrant or that, being or having been a director
or officer or an employee of the registrant, such person is or was serving at
the request of the registrant as a director, officer, employee or agent of
another corporation, partnership, joint venture, trust or other enterprise,
including an employee benefit plan. The Bylaws also provide that the registrant
may, by action of its Board of Directors, provide indemnification to its
employees and agents with the same scope and effect as the foregoing
indemnification of directors and officers.
 
     Section 102(b)(7) of the DGCL permits a corporation to provide in its
certificate of incorporation that a director of the corporation shall not be
personally liable to the corporation or its stockholders for monetary damages
for breach of fiduciary duty as a director, except for liability for (i) any
breach of the director's duty of loyalty to the corporation or its stockholders,
(ii) acts or omissions not in good faith or that involve intentional misconduct
or a knowing violation of law, (iii) payments of unlawful dividends or unlawful
stock repurchases or redemptions, or (iv) any transaction from which the
director derived an improper personal benefit.
 
                                      II-1
<PAGE>   19
 
     Article 10 of the registrant's Restated Certificate of Incorporation
provides that, to the fullest extent that the DGCL, as it now exists or may
hereafter be amended, permits the limitation or elimination of the liability of
directors, a director of the registrant shall not be liable to the registrant or
its stockholders for monetary damages for breach of fiduciary duty as a
director. Any amendment to or repeal of such Article 10 shall not adversely
affect any right or protection of a director of the registrant for or with
respect to any acts or omissions of such director occurring prior to such
amendment or repeal.
 
     The registrant has entered into an Indemnification Agreement with each of
its executive officers and directors in which the registrant agrees to hold
harmless and indemnify the officer or director to the fullest extent permitted
by Delaware law. Under these Indemnification Agreements, the officer or director
is not indemnified for any action, suit, claim or proceeding instituted by or at
the direction of the officer or director unless such action, suit, claim or
proceeding is or was authorized by the registrant's Board of Directors or unless
the action is to enforce the provisions of the Indemnification Agreement.
 
     No indemnity pursuant to the Indemnification Agreements shall be provided
by the registrant on account of any suit in which a final unappealable judgment
is rendered against an executive officer or director for an accounting of
profits made from the purchase or sale of the registrant's securities by the
executive officer or director in violation of the provisions of Section 16(b) of
the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or for
damages that have been paid directly to the executive officer or director by an
insurance carrier under a directors' and officers' liability insurance policy
maintained by the registrant.
 
ITEM 16. EXHIBITS
   
    
 
   
<TABLE>
<CAPTION>
           EXHIBIT
           NUMBER                             DESCRIPTION
           -------                            -----------
  <S>      <C>        <C>
  (i)        2.1      Agreement and Plan of Merger among Guidant Corporation,
                      Pegasus Acquisitions Corp. and InControl, Inc., dated as of
                      August 10, 1998.
  (i)        4.1      Shareholder Agreement among Guidant Corporation, Pegasus
                      Acquisitions Corp. and the persons listed on Schedule A
                      thereto, dated August 10, 1998.
  (i)        4.2      Second Amendment of Rights Agreement between InControl, Inc.
                      and First Interstate Bank of Washington, N.A., as Rights
                      Agent, dated August 11, 1998.
  (ii)       4.3      Rights Agreement, dated as of February 27, 1996, between the
                      registrant and First Interstate Bank of Washington, N.A., as
                      Rights Agent (Exhibit 2.1).
  (iv)       4.4      First Amendment of Rights Agreement between InControl, Inc.
                      and First Interstate Bank of Washington, N.A., as Rights
                      Agent, dated April 16, 1998 (Exhibit 4.3).
  (iii)      4.5      Form of Stock Purchase Agreement between the registrant and
                      United States Investors, dated July 28, 1997 (Exhibit 4.1).
  (iii)      4.6      Form of Stock Purchase Agreement between the registrant and
                      United States Investors, dated July 25, 1997 (Exhibit 4.2).
  (iv)       4.7      Stock Purchase Agreement between InControl, Inc. and the
                      investors named therein, dated April 20, 1998 (Exhibit 4.4).
  (iv)       4.8      Certificate of Designations of Series B Convertible
                      Preferred Stock (Exhibit 3.1).
  (iv)       4.9      Registration Rights Agreement between the registrant and
                      Advantage Fund II Ltd., dated April 16, 1998 (Exhibit 4.1).
  (iv)      4.10      Registration Rights Agreement between the registrant and
                      Koch Industries, Inc., dated April 16, 1998 (Exhibit 4.2).
             5.1      Opinion of Perkins Coie, counsel to the registrant,
                      regarding the legality of the Shares.
            23.1      Consent of Ernst & Young LLP, Independent Auditors.
            23.2      Consent of Perkins Coie (contained in Exhibit 5.1).
            24.1      Power of Attorney*.
</TABLE>
    
 
---------------
   
(i)  Incorporated by reference to the registrant's Current Report on Form 8-K,
     dated August 10, 1998 as the same exhibit number.
    
 
                                      II-2
<PAGE>   20
 
   
(ii)  Incorporated by reference to the registrant's Registration Statement on
      Form 8-A, as amended, filed March 1, 1996, as the indicated Exhibit
      Number.
    
 
   
(iii) Incorporated by reference to the registrant's Current Report on Form 8-K,
      filed August 11, 1997, as the indicated Exhibit Number.
    
 
   
(iv) Incorporated by reference to the registrant's Current Report on Form 8-K,
     as amended by Form 8-K/A No. 1, Form 8-K/A No. 2 and Form 8-K/A No. 3,
     dated April 20, 1998, as the indicated Exhibit Number.
    
 
   
* Previously filed
    
 
ITEM 17. UNDERTAKINGS
 
     The undersigned registrant hereby undertakes:
 
          (1) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this registration statement;
 
             (i) To include any prospectus required by Section 10(a)(3) of the
                 Securities Act of 1933, as amended (the "Securities Act");
 
             (ii) To reflect in the prospectus any facts or events arising after
                  the effective date of the registration statement (or the most
                  recent post-effective amendment thereof) which, individually
                  or in the aggregate, represent a fundamental change in the
                  information set forth in the registration statement; and
 
             (iii) To include any material information with respect to the plan
                   of distribution not previously disclosed in the registration
                   statement or any material change to such information in the
                   registration statement.
 
          (2) That, for the purpose of determining any liability under the
     Securities Act, each such post-effective amendment shall be deemed to be a
     new registration statement relating to the securities offered therein, and
     the offering of such securities at that time shall be deemed to be the
     initial bona fide offering thereof.
 
          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered that remain unsold at the
     termination of the offering.
 
          (4) That, for purposes of determining any liability under the
     Securities Act, each filing of the registrant's annual report pursuant to
     Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each
     filing of an employee benefit plan's annual report pursuant to Section
     15(d) of the Exchange Act), that is incorporated by reference in the
     registration statement shall be deemed to be a new registration statement
     relating to the securities offered therein, and the offering of such
     securities at that time shall be deemed to be in the initial bona fide
     offering thereof.
 
     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question of whether such indemnification by it is against
public policy as expressed in the Securities Act and will be governed by the
final adjudication of such issue.
 
                                      II-3
<PAGE>   21
 
                                   SIGNATURES
 
   
     Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-3 and has duly caused this Amendment
No. 3 to Registration Statement to be signed on its behalf by the undersigned,
thereunder duly authorized, in the City of Redmond, State of Washington, on the
11th day of August, 1998.
    
 
                                          INCONTROL, INC.
 
                                          By: /s/ KURT C. WHEELER
                                            ------------------------------------
                                            Kurt C. Wheeler
                                            Chairman, President and Chief
                                              Executive Officer
 
   
     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Amendment No. 3 to Registration Statement has been signed by the following
persons in the capacities indicated below on the 11th day of August, 1998.
    
 
<TABLE>
<CAPTION>
                       SIGNATURE                                             TITLE
                       ---------                                             -----
<S>                                                       <C>
/s/ KURT C. WHEELER                                       Chairman, President and Chief Executive
--------------------------------------------------------  Officer (Principal Executive Officer)
Kurt C. Wheeler
 
*    PHILIP A. OKESON                                     Treasurer and Secretary (Principal Financial
--------------------------------------------------------  and Accounting Officer)
Philip A. Okeson
 
*    ALAN D. FRAZIER                                      Director
--------------------------------------------------------
Alan D. Frazier
 
*    DONALD C. HARRISON                                   Director
--------------------------------------------------------
Donald C. Harrison
 
*    MARK B. KNUDSON                                      Director
--------------------------------------------------------
Mark B. Knudson
 
*    MICHAEL J. LEVINTHAL                                 Director
--------------------------------------------------------
Michael J. Levinthal
 
*By: /s/ KURT C. WHEELER
--------------------------------------------------------
     Kurt C. Wheeler
     Attorney-in-Fact
</TABLE>
 
                                      II-4
<PAGE>   22
 
                                 EXHIBIT INDEX
   
    
 
   
<TABLE>
<CAPTION>
           EXHIBIT
           NUMBER                             DESCRIPTION
           -------                            -----------
  <S>      <C>        <C>
  (i)        2.1      Agreement and Plan of Merger among Guidant Corporation,
                      Pegasus Acquisitions Corp. and InControl, Inc., dated as of
                      August 10, 1998.
  (i)        4.1      Shareholder Agreement among Guidant Corporation, Pegasus
                      Acquisitions Corp. and the persons listed on Schedule A
                      thereto, dated August 10, 1998.
  (i)        4.2      Second Amendment of Rights Agreement between InControl, Inc.
                      and First Interstate Bank of Washington, N.A., as Rights
                      Agent, dated August 11, 1998.
  (ii)       4.3      Rights Agreement, dated as of February 27, 1996, between the
                      registrant and First Interstate Bank of Washington, N.A., as
                      Rights Agent (Exhibit 2.1).
  (iv)       4.4      First Amendment of Rights Agreement between InControl, Inc.
                      and First Interstate Bank of Washington, N.A., as Rights
                      Agent, dated April 16, 1998 (Exhibit 4.3).
  (iii)      4.5      Form of Stock Purchase Agreement between the registrant and
                      United States Investors, dated July 28, 1997 (Exhibit 4.1).
  (iii)      4.6      Form of Stock Purchase Agreement between the registrant and
                      United States Investors, dated July 25, 1997 (Exhibit 4.2).
  (iv)       4.7      Stock Purchase Agreement between InControl, Inc. and the
                      investors named therein, dated April 20, 1998 (Exhibit 4.4).
  (iv)       4.8      Certificate of Designations of Series B Convertible
                      Preferred Stock (Exhibit 3.1).
  (iv)       4.9      Registration Rights Agreement between the registrant and
                      Advantage Fund II Ltd., dated April 16, 1998 (Exhibit 4.1).
  (iv)      4.10      Registration Rights Agreement between the registrant and
                      Koch Industries, Inc., dated April 16, 1998 (Exhibit 4.2).
             5.1      Opinion of Perkins Coie, counsel to the registrant,
                      regarding the legality of the Shares.
            23.1      Consent of Ernst & Young LLP, Independent Auditors.
            23.2      Consent of Perkins Coie (contained in Exhibit 5.1).
            24.1      Power of Attorney*.
</TABLE>
    
 
---------------
   
(i)  Incorporated by reference to the registrant's Current Report on Form 8-K,
     dated August 10, 1998 as the same exhibit number.
    
 
   
(ii)  Incorporated by reference to the registrant's Registration Statement on
      Form 8-A, as amended, filed March 1, 1996, as the indicated Exhibit
      Number.
    
 
   
(iii) Incorporated by reference to the registrant's Current Report on Form 8-K,
      filed August 11, 1997, as the indicated Exhibit Number.
    
 
   
(iv) Incorporated by reference to the registrant's Current Report on Form 8-K,
     as amended by Form 8-K/A No. 1, Form 8-K/A No. 2 and Form 8-K/A No. 3,
     dated April 20, 1998, as the indicated Exhibit Number.
    
 
   
* Previously filed