The U.S. Food and Drug Administration has given sales clearance to St. Jude Medical's latest heart-mapping tools, which are used to precisely create scar tissue on the heart to fix an abnormal heartbeat in atrial fibrillation.

The FDA cleared St. Jude's EnSite Precision heart-mapping system and the related Advisor FL mapping catheter, the Little Canada-based medical device maker announced on Thursday. In Europe, where the EnSite Precision has been available since January, sales of cardiac mapping systems grew 20 percent in the most recent quarter.

The EnSite Precision is an advanced computer system on a mobile cart that creates real-time, three-dimensional maps of the heart used by an electrophysiologist during a medical procedure. The Advisor FL is a narrow tool used inside the body to enable such mapping. St. Jude did not release prices for the new tools.

St. Jude, which is expected to be sold to Chicago-based Abbott Laboratories by month's end for about $25 billion, has been working to create the industry's broadest portfolio of devices to treat atrial fibrillation, including its EnSite systems.

"We have the most innovative and complete solutions across multiple product segments in AF (atrial fibrillation), and the success of our ablation catheter business and our new EnSite Precision cardiac mapping system continues to capture market share," CEO Michael Rousseau told investors in October.

Atrial fibrillation is an abnormal quivering of the cardiac muscle that makes the heart pump blood less effectively. The Heart Rhythm Society says AF by itself usually is not life-threatening but can cause problems by weakening the heart and allowing stroke-causing blood clots to form.

AF is sometimes treated with a therapy called ablation, in which radio-frequency energy is applied to a small section of the heart to deliberately kill the tissue and create a tiny scar that blocks the electrical signals in the muscle that cause the quivering.

EnSite systems create a 3-D map of the heart, displayed on a screen in the electrophysiology lab, that the doctor uses to precisely target the ablation. The new EnSite Precision system has features that map the heart 10 times faster than current systems, and allow for quicker "morphology matching" to identify the source of the irregular heart beat, St. Jude said in a news release.

"The system's intelligent automation tools enable faster, more accurate high-density maps with greater consistency across cases, which are important factors in addressing the needs of today's EP labs," said Dr. Srijoy Mahapatra, vice president of clinical, medical and scientific affairs, in the release.

Joe Carlson • 612-673-4779