<PAGE>

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             ----------------------

                                   FORM 10-K/A
                                (AMENDMENT NO. 1)
            [X] Annual report pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934

                   FOR THE FISCAL YEAR ENDED DECEMBER 31, 2004
                           COMMISSION FILE NO. 0-18602

                                ATS MEDICAL, INC.
             (Exact name of registrant as specified in its charter)

                    MINNESOTA                            41-1595629
         (State or other jurisdiction of   (I.R.S. Employer Identification  No.)
         incorporation or organization)

          3905 ANNAPOLIS LANE
         MINNEAPOLIS, MINNESOTA                       55447
     (Address of principal executive offices)      (Zip Code)

Registrant's telephone number, including area code: (763) 553-7736

Securities registered pursuant to Section 12(b) of the Act: None

Securities registered pursuant to Section 12(g) of the Act: Common Stock $.01
par value

      Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

                                  Yes [X] No [ ]

      Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [X]

      Indicate by check mark whether the registrant is an accelerated filer (as
defined in Rule 12b-2 of the Act).

                                  Yes [X] No [ ]

      The aggregate market value of voting and non-voting stock held by
non-affiliates of the registrant as of June 30, 2004, was approximately
$115,000,000 (based on the last sale price of such stock as reported by the
NASDAQ National Market).

      The number of shares outstanding of each of the registrant's classes of
common stock as of February 27, 2005, was 30,893,227 shares of $.01 par value
common stock.

                       DOCUMENTS INCORPORATED BY REFERENCE

      Pursuant to General Instruction G, the responses to Items 10, 11, 12, and
14 of Part III of this report are incorporated herein by reference to certain
information contained in the registrant's definitive Proxy Statement for its
2005 Annual Meeting of Shareholders to be held on May 5, 2005.

<PAGE>

                                EXPLANATORY NOTE

This Amendment No. 1 on Form 10-K/A ("Form 10-K/A") to our Annual Report on Form
10-K for the fiscal year ended December 31, 2004, initially filed with the
Securities and Exchange Commission (the "SEC") on March 14, 2005 (the "Original
Filing"), is being filed to amend and restate Item 5 of Part II of the Original
Filing, solely to correct a typographical error in the Original Filing. In the
Original Filing, both captions to the table containing quarterly price
information for our common stock were "Fiscal Year 2003" rather than the first
caption reading "Fiscal Year 2003" and then the second caption reading "Fiscal
Year 2004." No other information in the Original Filing is amended hereby.

In addition, pursuant to the rules of the SEC, Item 15 of Part IV of the
Original Filing has been amended to contain currently-dated certifications from
our Chief Executive Officer and Chief Financial Officer, as required by Section
302 of the Sarbanes-Oxley Act of 2002. The certifications of our Chief Executive
Officer and Chief Financial Officer are attached to this Form 10-K/A as Exhibits
31.1 and 31.2, respectively.

Except for the foregoing amended information, this Form 10-K/A continues to
describe conditions as of the date of the Original Filing, and we have not
updated the disclosures contained herein to reflect events that occurred at a
later date.

<PAGE>

                                ATS MEDICAL, INC.
                                 2004 FORM 10-K

                                     PART II

ITEM 5.     MARKET FOR REGISTRANT'S COMMON EQUITY, RELATED STOCKHOLDER MATTERS
            AND ISSUER PURCHASES OF EQUITY SECURITIES

MARKET INFORMATION

Our common stock is traded on the Nasdaq National Market under the symbol
"ATSI." The following table sets forth, for the periods indicated, the high and
low closing sales prices per share of our common stock as reported on the Nasdaq
National Market. These prices do not include adjustments for retail mark-ups,
mark-downs, or commissions.

<TABLE>
<CAPTION>
Fiscal Year 2003:        High      Low
-----------------        -----    -----
<S>                      <C>      <C>
  First Quarter          $1.83    $0.41
  Second Quarter         $3.95    $1.30
  Third Quarter          $4.40    $3.07
  Fourth Quarter         $4.22    $3.50
</TABLE>

<TABLE>
<CAPTION>
Fiscal Year 2004:        High     Low
-----------------        -----    -----
<S>                      <C>      <C>
  First Quarter          $6.49    $3.99
  Second Quarter         $5.75    $3.77
  Third Quarter          $3.99    $3.02
  Fourth Quarter         $4.66    $3.38
</TABLE>

HOLDERS

As of March 10, 2005, we had approximately 630 holders of record of our common
stock.

DIVIDENDS

We have never declared or paid cash dividends. We intend to retain all future
earnings for the operation and expansion of our business. We do not anticipate
declaring or paying cash dividends on our common stock in the foreseeable
future.

REPURCHASES OF COMMON STOCK

We did not repurchase any of our securities during the fourth quarter of 2004.

SALES OF UNREGISTERED SECURITIES

We had no sales of unregistered securities during 2004 that have not been
previously disclosed in a Form 8-K or Form 10-Q.

                                       2
<PAGE>

                                     PART IV

ITEM 15.    EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

FINANCIAL STATEMENTS

Our Consolidated Financial Statements and the Independent Auditor's Report
Thereon are included herein (page numbers refer to pages in this Annual Report
on Form 10-K):

<TABLE>
<S>                                                                                  <C>
Report of Independent Registered Public Accounting Firm                              Page F-1

Consolidated Balance Sheets as of December 31, 2004 and 2003                         Page F-2

Consolidated Statements of Operations for the years ended December 31, 2004,
2003, and 2002                                                                       Page F-3

Consolidated Statement of Changes in Shareholders' Equity for the years ended
December 31, 2004, 2003, and 2002                                                    Page F-4

Consolidated Statements of Cash Flows for the years ended December 31, 2004,
2003, and 2002                                                                       Page F-5

Notes to Consolidated Financial Statements for the years ended December 31,          Page F-6 through
2004, 2003, and 2002                                                                 F-16
</TABLE>

FINANCIAL STATEMENT SCHEDULES

                                ATS MEDICAL, INC.
          SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES
                                 (in thousands)

<TABLE>
<CAPTION>
                                                                  ADDITIONS -
                                                            ----------------------
                                                                        CHARGED TO
                                               BALANCE AT   CHARGED TO    OTHER                   BALANCE AT
                                                BEGINNING   COSTS AND   ACCOUNTS -   DEDUCTIONS     END OF
             DESCRIPTION                        OF PERIOD    EXPENSES    DESCRIBE     DESCRIBE      PERIOD
             -----------                       ----------   ----------  ----------   ----------   ----------
              COLUMN A                          COLUMN B           COLUMN C           COLUMN D     COLUMN E
              --------                          --------           --------           --------     --------
<S>                                            <C>          <C>         <C>          <C>          <C>
VALUATION ACCOUNTS:
    Year Ended December 31, 2004
    Deducted from asset accounts
       Allowance for doubtful accounts            $270        $150           $0      ($ 32)  (1)      $388
       Allowance for obsolete
       inventories                                $200        $  0           $0       $  0            $200
    Year ended December 31, 2003
       Allowance for doubtful accounts            $420        $  0           $0      ($150)  (2)      $270
       Allowance for obsolete
       inventories                                $200        $  0           $0       $  0            $200
    Year ended December 31, 2002
       Allowance for doubtful accounts            $400        $ 20           $0       $  0            $420
       Allowance for obsolete
       inventories                                $200        $  0           $0       $  0            $200
</TABLE>

(1) Uncollectible accounts written off, net of recoveries.

(2) Changes in estimate recovered through a reduction in expenses.

                                       3
<PAGE>

All other schedules have been omitted because of absence of conditions under
which they are required or because the required information is included in the
financial statements or notes thereto.

EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT
NUMBER                                 DESCRIPTION
<S>         <C>
3.1         Restated Articles of Incorporation, as amended to date (Incorporated
            by reference to Exhibit 3.1 to the Company's Annual Report on Form
            10-K for the year ended December 31, 1993 (the "1993 Form 10-K")).

3.2         Bylaws of the Company, as amended to date (Incorporated by reference
            to Exhibit 3.2 to the Company's Annual Report on Form 10-K for the
            year ended December 31, 1996 (the "1996 Form 10-K")).

4.1         Specimen certificate for shares of Common Stock of the Company
            (Incorporated by reference to Exhibit 4.1 to the Company's Annual
            Report on Form 10-K for the year ended December 31, 1997 (the "1997
            Form 10-K")).

10.1**      1987 Stock Option and Stock Award Plan, as restated and amended to
            date (Incorporated by reference to Exhibit 10.1 to the Company's
            Quarterly Report on Form 10-Q for the quarter ended June 30, 1997).

10.2**      ATS Medical Inc. 2000 Stock Incentive Plan (Incorporated by
            reference to the appendix to the Company's Definitive Proxy
            Statement filed on March 28, 2003).

10.3**      Agreement between the Company and Manuel A. Villafana dated
            September 11, 2001 (Incorporated by reference to Exhibit 10.3 to the
            Company's Form 10-K for the year ended December 31, 2001 (the "2001
            Form 10-K")).

10.4        Lease Agreement between the Company and Crow Plymouth Land Limited
            Partnership dated December 22, 1987 (Incorporated by reference to
            Exhibit 10(d) to the Company's Registration Statement on Form S-18,
            File No. 33-34785-C (the "Form S-18")).

10.5        Amendment No. 1 to Lease Agreement between the Company and Crow
            Plymouth Land Limited Partnership, dated January 5, 1989
            (Incorporated by reference to Exhibit 10(e) to the Form S-18).

10.6        Amendment No. 2 to Lease Agreement between the Company and Crow
            Plymouth Land Limited Partnership, dated January 1989 (Incorporated
            by reference to Exhibit 10(f) to the Form S-18).

10.7        Amendment No. 3 to Lease Agreement between the Company and Crow
            Plymouth Land Limited Partnership, dated June 14, 1989 (Incorporated
            by reference to Exhibit 10(g) to the Form S-18).

10.8        Amendment No. 4 to Lease Agreement between the Company and Plymouth
            Business Center Limited Partnership, dated February 10, 1992
            (Incorporated by reference to Exhibit 10.8 to the 1996 Form 10-K).

10.9*       O.E.M. Supply Contract dated September 24, 1990, with CarboMedics,
            Inc. (confidential treatment granted) (Incorporated by reference to
            Exhibit 10.10 to the 1996 Form 10-K).

10.10*      License Agreement dated September 24, 1990, with CarboMedics, Inc.
            (confidential treatment granted) (Incorporated by reference to
            Exhibit 10.11 to the 1996 Form 10-K).
</TABLE>

                                       4
<PAGE>

<TABLE>
<S>         <C>
10.11**     Employment Agreement between the Company and Michael D. Dale dated
            September 18, 2002 (Incorporated by reference to Exhibit 10.12 to
            the Company's Form 10-K for the year ended 2002 (the "2002 Form
            10-K")).

10.12       Helix BioCore, Inc. Self-Insurance Trust Agreement dated February
            28, 1991 (Incorporated by reference to Exhibit 10.13 to the 1996
            Form 10-K).

10.13*      Amendment 1 to License Agreement dated December 16, 1993, with
            CarboMedics, Inc. (confidential treatment granted) (Incorporated by
            reference to Exhibit 10.17 to the 1993 Form 10-K).

10.14*      Amendment 4 to O.E.M. Supply Contract dated December 16, 1993, with
            CarboMedics, Inc. (confidential treatment granted) (Incorporated by
            reference to Exhibit 10.18 to the 1993 Form 10-K).

10.15*      Amendment 5 to O.E.M. Supply Contract dated September 1, 1994, with
            CarboMedics, Inc. (confidential treatment granted) (Incorporated by
            reference to Exhibit 10.19 to the 1994 Form 10-K).

10.16       Letter Agreement between the Company and Sulzer Carbomedics, Inc.,
            dated June 27, 2002 (Incorporated by reference to Exhibit 10.1 to
            the Company's Form 10-Q for the quarter ended June 20, 2002).

10.17       Line of Credit dated August 11, 1994, between the Company and First
            Bank National Association (Incorporated by reference to Exhibit 10.1
            to the Company's Form 10-Q for the quarter ended September 30,
            1994).

10.18       Form of International Distributor Agreement (Incorporated by
            reference to Exhibit 10.22 to the 1994 Form 10-K).

10.19**     Form of Agreement between ATS Medical, Inc. and each officer dated
            June 30, 1995, concerning severance benefits upon a change in
            control (Incorporated by reference to Exhibit 10.23 to the Company's
            Annual Report on Form 10-K for the year ended December 31, 1995 (the
            "1995 Form 10-K")).

10.20**     ATS Medical, Inc. Change in Control Severance Pay Plan (Incorporated
            by reference to Exhibit 10.24 to the 1995 Form 10-K).

10.21       Amendment No. 5 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated May 30, 1996 (Incorporated by reference to
            Exhibit 10.22 to the 1996 Form 10-K).

10.22**     Letter Agreement dated November 1, 2002, extending the agreement
            dated September 11, 2001 between the Company and Manuel A. Villafana
            (Incorporated by reference to Exhibit 10.23 to the 2002 Form 10-K).

10.23       Amendment No. 6 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated November 25, 1997 (Incorporated by reference
            to Exhibit 10.23 to the 1997 Form 10-K).

10.24       1998 Employee Stock Purchase Plan (Incorporated by reference to
            Exhibit 4 to the Company's Registration Statement on Form S-8, File
            No. 333-57527).

10.25**     1998 Management Incentive Compensation Plan (Incorporated by
            reference to Exhibit 10.25 to the 1998 Form 10-K).
</TABLE>

                                       5
<PAGE>

<TABLE>
<S>         <C>
10.26*      Carbon Agreement by and between Sulzer Carbomedics, Inc. and ATS
            Medical, Inc., dated December 29, 1999 (confidential treatment
            granted) (Incorporated by reference to Exhibit 99.1 to the Current
            Report on Form 8-K filed on January 13, 2000 (the "January 2000 Form
            8-K").

10.27*      Amendment 7 to OEM Supply Contract by and between Sulzer
            Carbomedics, Inc. and ATS Medical, Inc., dated December 29, 1999
            (confidential treatment granted) (Incorporated by reference to
            Exhibit 99.2 to the January 2000 Form 8-K).

10.28*      Amendment 2 to License Agreement by and between Sulzer Carbomedics,
            Inc. and ATS Medical, Inc., dated December 29, 1999 (confidential
            treatment granted) (Incorporated by reference to Exhibit 99.3 to the
            January 2000 Form 8-K).

10.29       Amendment No. 7 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated May 18, 2000 (Incorporated by reference to
            Exhibit 10.2 to the Company's Form 10-Q for the quarter ended June
            30, 2000).

10.30       Lease Agreement between the Company and St. Paul Properties, Inc.,
            dated April 29, 2000 (Incorporated by reference to Exhibit 10.1 to
            the Company's Form 10-Q for the quarter ended June 30, 2000).

10.31       Amendment No. 8 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated December 14, 2000 (Incorporated by reference
            to Exhibit 10.32 to the Company's Annual Report on Form 10-K for the
            year ended December 31, 2000 (the "2000 Form 10-K")).

10.32*      Amendment 8 to OEM Supply Contract by and between Sulzer
            Carbomedics, Inc. and ATS Medical, Inc., dated November 3, 2000
            (confidential treatment granted) (Incorporated by reference to
            Exhibit 10.33 to the 2000 Form 10-K).

10.33       Form of U.S. Distribution Agreement (incorporated by reference to
            Exhibit 10.34 to the 2002 Form 10-K).

10.34       Amendment No. 9 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated September 8, 2003 (incorporated by reference
            to Exhibit 10.1 to the Company's Form 10-Q for the quarter ended
            September 30, 2003).

10.35       Form of Employee Stock Option Agreement under the company's 2000
            Stock Incentive Plan (Incorporated by reference to Exhibit 10.2 to
            the Company's Quarterly Report of Form 10-Q for the quarter ended
            September 30, 2004).

10.36       Form of Non-Qualified Stock Option Agreement under the Company's
            2000 Stock Incentive Plan (Incorporated by reference to Exhibit 10.3
            to the Company's Quarterly Report on Form 10-Q for the quarter ended
            September 30, 2004).

10.37       Form of Non-Plan Non-Qualified Stock Option Agreement (Incorporated
            by reference to Exhibit 10.4 to the Company's Quarterly Report on
            Form 10-Q for the quarter ended September 30, 2004).

10.38*      Development and License Agreement dated as of April 26, 2004 between
            the Company and ErySave AB (Incorporated by reference to Exhibit
            10.1 to the company's Quarterly Report on Form 10-Q for the quarter
            ended June 30, 2004).

10.39       Credit Agreement between Silicon Valley Bank and the Company, dated
            July 28, 2004 (Incorporated by reference to Exhibit 10.1 to the
            Company's Quarterly Report on Form 10-Q for the quarter ended
            September 30, 2004).
</TABLE>

                                       6
<PAGE>

<TABLE>
<S>         <C>

+10.40      Amendment No. 10 to Lease Agreement between the Company and St. Paul
            Properties, Inc. dated as of October 1, 2004.

+10.41*     Agent Agreement dated November 9, 2004 between the Company and
            CryoCath Technologies, Inc.

+10.42*     Distribution Agreement dated November 9, 2004 between the Company
            and CryoCath Technologies, Inc.

10.43       Letter Agreement between the Company and Centerpulse USA Holding Co.
            dated July 9, 2003 (Incorporated by reference to Exhibit 10.1 to the
            Company's Form 8-K filed on September 26, 2003).

10.44**     2004 Management Incentive Compensation Plan (Incorporated by
            reference to Exhibit 10.36 to the Company's Form 10-K for the year
            ended December 31, 2003).

21          List of Subsidiaries (Incorporated by reference to Exhibit 21 to the
            Company's Form 10-K for the year ended 2002).

+23         Consent of Ernst & Young LLP.

31.1        Certification of Chief Executive Officer pursuant to Rule 13a-14(a)
            and Rule 15d-14(a) of the Securities Exchange Act, as amended.

31.2        Certification of Chief financial Officer pursuant to Rule 13a-14(a)
            and Rule 15d-14(a) of the Securities Exchange Act, as amended.

+32.1       Certification of the Chief Executive Officer pursuant to 18 U.S.C.
            Section 1350 as adopted pursuant to Section 906 of the
            Sarbanes-Oxley Act of 2002.

+32.2       Certification of the Chief Financial Officer pursuant to 18 U.S.C.
            Section 1350 as adopted pursuant to Section 906 of the
            Sarbanes-Oxley Act of 2002.
</TABLE>

* Pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as amended,
confidential portions of these exhibits have been deleted and filed separately
with the Securities and Exchange Commission pursuant to a request for
confidential treatment.

** Represents a management contract or compensatory plan or arrangement required
to be filed as an exhibit pursuant to Item 15 of Form 10-K.

+ Previously filed with the original Form 10-K for the fiscal year ended
December 31, 2004.

                                       7
<PAGE>

                                   SIGNATURES

            Pursuant to the requirements of Section 13 or 15(d) of the
Securities Exchange Act of 1934, the registrant has duly caused this amendment
to be signed on its behalf by the undersigned, thereunto duly authorized.

Dated:  March 21, 2005                     ATS MEDICAL, INC.

                                           By /s/ Michael D. Dale
                                              ------------------------------
                                           Michael D. Dale
                                           Chief Executive Officer

            Pursuant to the requirements of the Securities Exchange Act of 1934,
this amendment has been signed below by the following persons on behalf of the
registrant and in the capacities indicated on March 21, 2005.

SIGNATURE                                   TITLE

                                    Chief Executive Officer,
                                    President and Chairman of the
                                    Board (principal executive
/s/ Michael D. Dale                 officer)
-----------------------------
Michael D. Dale

                                    Chief Financial Officer
                                    (principal financial and
/s/ John R. Judd                    accounting officer)
-----------------------------
John R. Judd

/s/ David L. Boehnen                Director
-----------------------------
David L. Boehnen

/s/ John D. Buck                    Director
-----------------------------
John D. Buck

/s/ Eric W. Sivertson               Director
-----------------------------
Eric W. Sivertson

/s/ Robert E. Munzenrider           Director
-----------------------------
Robert E. Munzenrider

                                       8
<PAGE>

                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT
NUMBER                              DESCRIPTION
<S>         <C>
3.1         Restated Articles of Incorporation, as amended to date (Incorporated
            by reference to Exhibit 3.1 to the Company's Annual Report on Form
            10-K for the year ended December 31, 1993 (the "1993 Form 10-K")).

3.2         Bylaws of the Company, as amended to date (Incorporated by reference
            to Exhibit 3.2 to the Company's Annual Report on Form 10-K for the
            year ended December 31, 1996 (the "1996 Form 10-K")).

4.1         Specimen certificate for shares of Common Stock of the Company
            (Incorporated by reference to Exhibit 4.1 to the Company's Annual
            Report on Form 10-K for the year ended December 31, 1997 (the "1997
            Form 10-K")).

10.1**      1987 Stock Option and Stock Award Plan, as restated and amended to
            date (Incorporated by reference to Exhibit 10.1 to the Company's
            Quarterly Report on Form 10-Q for the quarter ended June 30, 1997).

10.2**      ATS Medical Inc. 2000 Stock Incentive Plan (Incorporated by
            reference to the appendix to the Company's Definitive Proxy
            Statement filed on March 28, 2003).

10.3**      Agreement between the Company and Manuel A. Villafana dated
            September 11, 2001 (Incorporated by reference to Exhibit 10.3 to the
            Company's Form 10-K for the year ended December 31, 2001 (the "2001
            Form 10-K")).

10.4        Lease Agreement between the Company and Crow Plymouth Land Limited
            Partnership dated December 22, 1987 (Incorporated by reference to
            Exhibit 10(d) to the Company's Registration Statement on Form S-18,
            File No. 33-34785-C (the "Form S-18")).

10.5        Amendment No. 1 to Lease Agreement between the Company and Crow
            Plymouth Land Limited Partnership, dated January 5, 1989
            (Incorporated by reference to Exhibit 10(e) to the Form S-18).

10.6        Amendment No. 2 to Lease Agreement between the Company and Crow
            Plymouth Land Limited Partnership, dated January 1989 (Incorporated
            by reference to Exhibit 10(f) to the Form S-18).

10.7        Amendment No. 3 to Lease Agreement between the Company and Crow
            Plymouth Land Limited Partnership, dated June 14, 1989 (Incorporated
            by reference to Exhibit 10(g) to the Form S-18).

10.8        Amendment No. 4 to Lease Agreement between the Company and Plymouth
            Business Center Limited Partnership, dated February 10, 1992
            (Incorporated by reference to Exhibit 10.8 to the 1996 Form 10-K).

10.9*       O.E.M. Supply Contract dated September 24, 1990, with CarboMedics,
            Inc. (confidential treatment granted) (Incorporated by reference to
            Exhibit 10.10 to the 1996 Form 10-K).

10.10*      License Agreement dated September 24, 1990, with CarboMedics, Inc.
            (confidential treatment granted) (Incorporated by reference to
            Exhibit 10.11 to the 1996 Form 10-K).

10.11**     Employment Agreement between the Company and Michael D. Dale dated
            September 18, 2002 (Incorporated by reference to Exhibit 10.12 to
            the Company's Form 10-K for the year ended 2002 (the "2002 Form
            10-K")).
</TABLE>

                                       9
<PAGE>

<TABLE>
<S>         <C>
10.12       Helix BioCore, Inc. Self-Insurance Trust Agreement dated February
            28, 1991 (Incorporated by reference to Exhibit 10.13 to the 1996
            Form 10-K).

10.13*      Amendment 1 to License Agreement dated December 16, 1993, with
            CarboMedics, Inc. (confidential treatment granted) (Incorporated by
            reference to Exhibit 10.17 to the 1993 Form 10-K).

10.14*      Amendment 4 to O.E.M. Supply Contract dated December 16, 1993, with
            CarboMedics, Inc. (confidential treatment granted) (Incorporated by
            reference to Exhibit 10.18 to the 1993 Form 10-K).

10.15*      Amendment 5 to O.E.M. Supply Contract dated September 1, 1994, with
            CarboMedics, Inc. (confidential treatment granted) (Incorporated by
            reference to Exhibit 10.19 to the 1994 Form 10-K).

10.16       Letter Agreement between the Company and Sulzer Carbomedics, Inc.,
            dated June 27, 2002 (Incorporated by reference to Exhibit 10.1 to
            the Company's Form 10-Q for the quarter ended June 20, 2002).

10.17       Line of Credit dated August 11, 1994, between the Company and First
            Bank National Association (Incorporated by reference to Exhibit 10.1
            to the Company's Form 10-Q for the quarter ended September 30,
            1994).

10.18       Form of International Distributor Agreement (Incorporated by
            reference to Exhibit 10.22 to the 1994 Form 10-K).

10.19**     Form of Agreement between ATS Medical, Inc. and each officer dated
            June 30, 1995, concerning severance benefits upon a change in
            control (Incorporated by reference to Exhibit 10.23 to the Company's
            Annual Report on Form 10-K for the year ended December 31, 1995 (the
            "1995 Form 10-K")).

10.20**     ATS Medical, Inc. Change in Control Severance Pay Plan (Incorporated
            by reference to Exhibit 10.24 to the 1995 Form 10-K).

10.21       Amendment No. 5 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated May 30, 1996 (Incorporated by reference to
            Exhibit 10.22 to the 1996 Form 10-K).

10.22**     Letter Agreement dated November 1, 2002, extending the agreement
            dated September 11, 2001 between the Company and Manuel A. Villafana
            (Incorporated by reference to Exhibit 10.23 to the 2002 Form 10-K).

10.23       Amendment No. 6 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated November 25, 1997 (Incorporated by reference
            to Exhibit 10.23 to the 1997 Form 10-K).

10.24       1998 Employee Stock Purchase Plan (Incorporated by reference to
            Exhibit 4 to the Company's Registration Statement on Form S-8, File
            No. 333-57527).

10.25**     1998 Management Incentive Compensation Plan (Incorporated by
            reference to Exhibit 10.25 to the 1998 Form 10-K).

10.26*      Carbon Agreement by and between Sulzer Carbomedics, Inc. and ATS
            Medical, Inc., dated December 29, 1999 (confidential treatment
            granted) (Incorporated by reference to Exhibit 99.1 to the Current
            Report on Form 8-K filed on January 13, 2000 (the "January 2000 Form
            8-K").
</TABLE>

                                       10
<PAGE>

<TABLE>
<S>         <C>
10.27*      Amendment 7 to OEM Supply Contract by and between Sulzer
            Carbomedics, Inc. and ATS Medical, Inc., dated December 29, 1999
            (confidential treatment granted) (Incorporated by reference to
            Exhibit 99.2 to the January 2000 Form 8-K).

10.28*      Amendment 2 to License Agreement by and between Sulzer Carbomedics,
            Inc. and ATS Medical, Inc., dated December 29, 1999 (confidential
            treatment granted) (Incorporated by reference to Exhibit 99.3 to the
            January 2000 Form 8-K).

10.29       Amendment No. 7 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated May 18, 2000 (Incorporated by reference to
            Exhibit 10.2 to the Company's Form 10-Q for the quarter ended June
            30, 2000).

10.30       Lease Agreement between the Company and St. Paul Properties, Inc.,
            dated April 29, 2000 (Incorporated by reference to Exhibit 10.1 to
            the Company's Form 10-Q for the quarter ended June 30, 2000).

10.31       Amendment No. 8 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated December 14, 2000 (Incorporated by reference
            to Exhibit 10.32 to the Company's Annual Report on Form 10-K for the
            year ended December 31, 2000 (the "2000 Form 10-K")).

10.32*      Amendment 8 to OEM Supply Contract by and between Sulzer
            Carbomedics, Inc. and ATS Medical, Inc., dated November 3, 2000
            (confidential treatment granted) (Incorporated by reference to
            Exhibit 10.33 to the 2000 Form 10-K).

10.33       Form of U.S. Distribution Agreement (incorporated by reference to
            Exhibit 10.34 to the 2002 Form 10-K).

10.34       Amendment No. 9 to Lease Agreement between the Company and St. Paul
            Properties, Inc., dated September 8, 2003 (incorporated by reference
            to Exhibit 10.1 to the Company's Form 10-Q for the quarter ended
            September 30, 2003).

10.35       Form of Employee Stock Option Agreement under the company's 2000
            Stock Incentive Plan (Incorporated by reference to Exhibit 10.2 to
            the Company's Quarterly Report of Form 10-Q for the quarter ended
            September 30, 2004).

10.36       Form of Non-Qualified Stock Option Agreement under the Company's
            2000 Stock Incentive Plan (Incorporated by reference to Exhibit 10.3
            to the Company's Quarterly Report on Form 10-Q for the quarter ended
            September 30, 2004).

10.37       Form of Non-Plan Non-Qualified Stock Option Agreement (Incorporated
            by reference to Exhibit 10.4 to the Company's Quarterly Report on
            Form 10-Q for the quarter ended September 30, 2004).

10.38*      Development and License Agreement dated as of April 26, 2004 between
            the Company and ErySave AB (Incorporated by reference to Exhibit
            10.1 to the company's Quarterly Report on Form 10-Q for the quarter
            ended June 30, 2004).

10.39       Credit Agreement between Silicon Valley Bank and the Company, dated
            July 28, 2004 (Incorporated by reference to Exhibit 10.1 to the
            Company's Quarterly Report on Form 10-Q for the quarter ended
            September 30, 2004).

+10.40      Amendment No. 10 to Lease Agreement between the Company and St. Paul
            Properties, Inc. dated as of October 1, 2004.

+10.41*     Agent Agreement dated November 9, 2004 between the Company and
            CryoCath Technologies, Inc.
</TABLE>

                                       11
<PAGE>

<TABLE>
<S>         <C>
+10.42*     Distribution Agreement dated November 9, 2004 between the Company
            and CryoCath Technologies, Inc.

10.43       Letter Agreement between the company and Centerpulse USA Holding co.
            dated July 9, 2003 (Incorporated by reference to Exhibit 10.1 to the
            company's Form 8-K filed on September 26, 2003).

10.44**     2004 Management Incentive Compensation Plan (Incorporated by
            reference to Exhibit 10.36 to the Company's Form 10-K for the year
            ended December 31, 2003).

21          List of Subsidiaries (incorporated by reference to Exhibit 21 to the
            Company's Form 10-K for the year ended 2002).

+23         Consent of Ernst & Young LLP.

31.1        Certification of Chief Executive Officer pursuant to Rule 13a-14(a)
            and Rule 15d-14(a) of the Securities Exchange Act, as amended.

31.2        Certification of Chief financial Officer pursuant to Rule 13a-14(a)
            and Rule 15d-14(a) of the Securities Exchange Act, as amended.

+32.1       Certification of the Chief Executive Officer pursuant to 18 U.S.C.
            Section 1350 as adopted pursuant to Section 906 of the
            Sarbanes-Oxley Act of 2002.

+32.2       Certification of the Chief Financial Officer pursuant to 18 U.S.C.
            Section 1350 as adopted pursuant to Section 906 of the
            Sarbanes-Oxley Act of 2002.
</TABLE>

* Pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as amended,
confidential portions of these exhibits have been deleted and filed separately
with the Securities and Exchange Commission pursuant to a request for
confidential treatment.

** Represents a management contract or compensatory plan or arrangement required
to be filed as an exhibit pursuant to Item 15 of Form 10-K.

+ Previously filed with the original Form 10-K for the fiscal year ended
December 31, 2004.

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