X0303 4 2008-10-09 0 0001024520 WORLD HEART CORP WHRT 0001044321 MARXE AUSTIN W & GREENHOUSE DAVID M C/O SPECIAL SITUATIONS FUNDS 527 MADISON AVENUE, SUITE 2600 NEW YORK NY 10022 0 0 1 0 Common Stock 2008-10-09 4 P 0 13010 0.1 A 93103647 I By Limited Partnerships This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse). They share voting and investment control over all securities owned by Special Situations Fund III QP, L.P (QP), Special Situations Cayman Fund, L.P. (Cayman), Special Situations Private Equity Fund, LP (PE) and Special Situations Life Sciences Fund, L.P. (LS). 45,765,145 shares of Common Stock are owned by QP, 16,587,810 shares of CS are owned by Cayman, 16,685,105 shares of CS are owned by PE and 4,000,000 shares of CS are owned by LS. Marxe individually owns 10,000,000 shares of CS and Greenhouse individually owns 65,587 shares of CS. The interest of Marxe and Greenhouse in the shares of Common Stock owned by QP, Cayman, PE, LS, Marxe and Greenhouse is limited to the extent of his pecuniary interest. Austin W. Marxe 2008-10-10 David M. Greenhouse 2008-10-10