Little Canada-based medical device maker St. Jude Medical will post net sales of about $1.45 billion for its most recent quarter, a preliminary result at the lower end of company projections, figures released Wednesday show.

Quarterly earnings are expected to be within previous estimates, in a range between $1.01 to $1.02 per share. Final results will be announced Jan. 27.

St. Jude's stock dropped 7 percent on the New York Stock Exchange on Wednesday, to $55.04 a share.

In anticipation of Chief Executive Michael Rousseau's presentation at the J.P. Morgan Healthcare Conference in San Francisco, the company announced preliminary sales results for its quarter ended Jan. 2. The figures show a 7 percent increase in sales compared to the same quarter last year, after adjusting for $91 million in negative foreign currency impact.

The 7 percent sales increase includes $136 million in sales of advanced heart devices made by a California company called Thoratec, which St. Jude acquired last year for $3.4 billion in its largest-ever corporate acquisition.

Sales in St. Jude's largest division, heart-rhythm devices, fell 10 percent during the quarter to $580 million. That performance was offset by sales growth in smaller divisions like neuromodulation (up 9 percent) and atrial fibrillation (4 percent).

"The pressures to our business that we communicated heading into the quarter were partially offset by continued growth in atrial fibrillation and neuromodulation as well as strong sales from the recent Thoratec acquisition," Rousseau said in the news release.

St. Jude's fourth quarter in 2014 included five extra sales days compared to 2015. The company said the difference in selling days impacted results by roughly 5 to 6 percentage points.

Joe Carlson • 612-673-4779

Twitter: @_JoeCarlson