CHICAGO--(BUSINESS WIRE)--Fitch Ratings has placed St. Jude Medical, Inc.'s (STJ/St. Jude) ratings on Negative Watch. The rating action follows St. Jude's recently announced intention to acquire Thoratec Corporation (Thoratec) for roughly $3.4 billion, net of cash acquired. This is an all-cash transaction, and Fitch anticipates that any rating downgrade would be limited to one-notch, if the acquisition is completed under the current proposed terms. KEY RATING DRIVERS The rating action reflects