X0303 4 2010-03-24 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 1 0 1 0 Common Stock 2010-03-24 4 P 0 24000 2.35 A 3473685 I By Limited Partnership Common Stock 2010-03-25 4 P 0 6200 2.38 A 3479885 I By Limited Partnership Common Stock 2010-03-25 4 P 0 10000 3.35 A 3489885 I By Limited Partnership Common Stock 2010-03-25 4 P 0 300000 2.3 A 3789885 I By Limited Partnership 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). 1,635,386 shares of Common Stock are owned by QP, 593,998 shares of CS are owned by Cayman, 593,997 shares of CS are owned by PE and 284,923 shares of CS are owned by LS. Marxe individually owns 489,533 shares of CS and Greenhouse individually owns 192,048 shares of CS. The interest of Marxe and Greenhouse in the shares of Common Stock owned by QP, Cayman, PE, LS, Marxe and Greenhouse are limited to the extent of his pecuniary interest. Austin Marxe 2010-03-26 David Greenhouse 2010-03-26