St. Jude Medical ( STJ) surged 7% early Monday after guiding higher on fourth-quarter sales. The medical-device maker said it expects to make 42 cents a share, after a 3-cent research-and-development tax credit. That's in line with the 39-cent Thomson Financial analysts' estimate. But the company said sales will come in at $864 million, above the $843 million target. Implantable cardioverter defibrillators, devices used to shock twitching hearts back to normal rhythms, brought in about $289 million. In its third-quarter earnings report, the company said it expected $265 million to $295 million in fourth-quarter sales of the devices. Sales of atrial fibrillation products, which treat a certain type of abnormal heart rhythm, were approximately $91 million, beating the company's own estimates of between $80 million to $85 million. This represents a more than 26% increase over the fourth quarter of 2005. Neuromodulation product sales were $50 million, compared with the company's previous estimates of $42 million to $47 million. Cardiology and cardiac surgery product sales also exceeded expectations, at $117 million and $71 million respectively. The company was expecting cardiology sales of $105 million to $115 million and cardiac surgery sales of $65 million to $70 million. Additionally, pacemaker sales for the fourth quarter were $246 million, up 6% over the fourth quarter of 2005. Shares were rising $2.37 to $37.37.