UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No.__10_) World Heart Corporation (Name of Issuer) Common Stock, No Par Value (Title of Class of Securities) 980905202 (CUSIP Number) with a copy to: Austin W. Marxe Allen B. Levithan, Esq. 527 Madison Avenue, Suite 2600 Lowenstein Sandler PC New York, New York 10022 65 Livingston Avenue Roseland, N.J. 07068 (973) 597-2424 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) January 31, 2010 (Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule l3G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ? Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See sections 240.13d-7 for other parties to whom copies are to be sent. *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page. The information required on the remainder of this cover page shall not be deemed to be ?filed? for the purpose of Section 18 of the Securities Exchange Act of 1934 (?Act?) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). Cusip No. 980905202 1. Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only): Austin W. Marxe and David M. Greenhouse 2. Check the Appropriate Box if a Member of a Group (See Instructions): (a) [ ] Not Applicable (b) [ ] 3. SEC Use Only 4. Source of Funds (See Instructions): 00 5. Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e): Not Applicable 6. Citizenship or Place of Organization: United States Number of 7(a).Sole Voting Power (Marxe): 333,333* 7(b).Sole Voting Power (Greenhouse): 8,048* Shares Beneficially 8. Shared Voting Power: 3,885,004* Owned by Each Reporting 9(a).Sole Dispositive Power (Marxe): 333,333* 9(b).Sole Dispositive Power (Greenhouse): 8,048* Person With 10. Shared Dispositive Power: 3,885,004* 11. Aggregate Amount Beneficially Owned by Each Reporting Person: 4,226,385 * 12. Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions): Not Applicable 13. Percent of Class Represented by Amount in Row (11): 27.3% * 14. Type of Reporting Person (See Instructions): IA, IN * This is a joint filing by Austin W. Marxe (?Marxe?) and David M. Greenhouse (?Greenhouse?). Marxe and Greenhouse share sole voting and investment power over 593,998 Common Stock and 121,300 Warrants owned by Special Situations Cayman Fund, L.P., 1,635,386 shares of Common Stock and 334,040 Warrants owned by Special Situations Fund III QP, L.P., 593,997 shares and 121,300 of Common Stock owned by Special Situations Private Equity Fund, L.P., and 284,923 shares of Common Stock and 200,000 Warrants owned by Special Situations Life Sciences Fund, L.P. Marxe has sole voting and investment power over 333,333 shares held in the name of Austin W. Marxe. Greenhouse has sole voting and investment power over 8,048 shares held in the name of David M. Greenhouse. See Items 2 and 5 of this Schedule 13D for additional information. Item 1. Security and Issuer. This schedule relates to the common of World Heart Corporation (the ?Issuer?). The Issuer?s principal executive officers are located at 7799 Pardee Lane, Oakland, CA 94621. Item 2. Identity and Background. The persons filing this report are Austin W. Marxe (?Marxe?) and David M. Greenhouse (?Greenhouse?), who are the controlling principals of AWM Investment Company, Inc. (?AWM?), the general partner of and investment adviser to Special Situations Cayman Fund, L.P. (?Cayman?). AWM serves as the general partner of MGP Advisers Limited Partnership (?MGP?), the general partner of Special Situations Fund III QP, L.P. (?SSFQP?). Marxe and Greenhouse are also members of MG Advisers, L.L.C. (?MG?), the general partner of Special Situations Private Equity Fund, L.P. (?SSPE?) and LS Advisers. L.L.C. (?LS?), the general partner of Special Situations Life Sciences Fund, L.P. (?SSLS?). AWM also serves as the investment adviser to SSFQP, SSPE and SSLS. (SSF3, SSFQP, Cayman, SSPE and SSLS will hereafter be referred to as, the ?Funds?). The principal office and business address of the Reporting Persons, is 527 Madison Avenue, Suite 2600, New York NY 10022. The principal business of each Fund is to invest in equity and equity- related securities and other securities of any kind or nature. Mr. Marxe and Mr. Greenhouse have never been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors), nor have either of them been a party to any civil proceeding commenced before a judicial or administrative body of competent jurisdiction as a result of which he was or is now subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws. Mr. Marxe and Mr. Greenhouse are citizens of the United States. Item 3. Source and Amount of Funds or Other Consideration. Each Fund utilized its own available net assets to purchase the securities referred to in this Schedule. Item 4. Purpose of Transaction. The securities referred to in this Schedule have been acquired by each of the Funds for investment purposes and not with the purpose or effect of changing or influencing control of the Issuer. Each Fund acquired the securities in the ordinary course of business and is holding the securities for the benefit of its investors. Item 5. Interest in Securities of the Issuer. Cayman owns 593,998 shares of Common Stock and 121,300 Warrants or 4.8% of the shares outstanding. SSFQP owns 1,635,386 shares of Common Stock and 334,040 Warrants or 13.1% of the shares outstanding. SSPE owns 593,997 shares of Common Stock and 121,300 Warrants or 4.8% of the outstanding shares. SSLS owns 284,923 shares of Common Stock and 200,000 Warrants or 3.2% of the shares outstanding. Marxe owns 333,333 shares of Common Stock or 2.3% of the shares outstanding. Greenhouse owns 8,048 shares of Common Stock or 0.2% of the shares outstanding. Marxe has sole power to vote and direct the disposition of all the shares held in the name of Austin W. Marxe. Greenhouse has sole power to vote and direct the disposition of all shares held in the name of David M. Greenhouse. Marxe and Greenhouse share the power to vote and direct the disposition of all shares of Common Stock owned by each of, the Funds. Messrs. Marxe and Greenhouse are deemed to beneficially own a total of 4,226,385 shares of Common Stock or 27.3% of the outstanding shares. The following table reflects the acquisition of Common Stock (C.S.) and Warrants (Wts) pursuant to the January 2010 Private Placement. There have been no other transactions during the sixty days preceding the date of the event that requires the filing of this statement. A. Special Situations Cayman Fund, L.P. Date Quantity Average Price January 2010 (Purchases) 60,665 C.S. 121,300 Wts $5.15 0 Date Quantity Average Price (Sales) B. Special Situations Life Sciences Fund, L.P. Date Quantity Average Price January 2010 (Purchases) 100,000 C.S. 200,000 Wts $5.15 0 Date Quantity Average Price (Sales) C. Special Situations Fund III QP, L.P. Date Quantity Average Price January 2010 (Purchases) 167,020 C.S. 334,040 Wts $5.15 0 Date Quantity Average Price (Sales) D. Special Situations Private Equity Fund, L.P. Date Quantity Average Price January 2010 (Purchases) 60,665 C.S. 121,300 Wts $5.15 0 Date Quantity Average Price (Sales) Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer. Austin W. Marxe serves as a member of the board of directors. No other contracts, arrangements, understandings or similar relationships exist with respect to the securities of the Company between Messrs. Marxe and Greenhouse and any other individual or entity. Item 7. Material to be Filed as Exhibits. Joint Filing Agreement. Signature After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Date: February 10, 2010 /s/_Austin W. Marxe Austin W. Marxe /s/_David M. Greenhouse David M. Greenhouse Attention: Intentional misstatements or omissions of fact constitute Federal criminal violations (See 18 U.S.C. 1001). JOINT FILING AGREEMENT Austin W. Marxe and David M. Greenhouse hereby agree that the Schedule 13D to which this agreement is attached is filed on behalf of each of them. /s/_Austin W. Marxe Austin W. Marxe /s/_David M. Greenhouse David M. Greenhouse - -5- S5313/1 02/09/10 1278889.03 - -2- S5313/1 1278889.03