Medtronic Inc said on Tuesday that quarterly earnings rose 59 percent on steady demand for its devices that protect against life-threatening heart rhythms, and it raised its fiscal-year forecast.

Net income for the medical device maker's fiscal second quarter ended October 30 was $868 million, or 78 cents a share, compared with $547 million, or 48 cents a share, a year earlier.

Excluding special items, the Minneapolis-based company said it earned 77 cents a share. Analysts on average expected 74 cents, according to Thomson Reuters I/B/E/S.

Medtronic raised its fiscal 2010 earnings forecast to a range of $3.17 to $3.22 per share, from its previous outlook of $3.10 to $3.20.

(Reporting by Susan Kelly and Lewis Krauskopf; Editing by Lisa Von Ahn)