In a heartbeat.

St. Jude Medical Inc.'s cardiac device unit in Sylmar has scored another win, obtaining U.S. Food and Drug Administration approval of an implantable defibrillator it developed that helps patients with heart failure and irregular heartbeats.

The Atlas II+ HF CRT-D is the first U.S. heart failure device to be programmed to maintain control of the rhythm of the heart's upper chambers, or atria. The device, about the size of a pocket watch, is placed below the skin under the left collarbone with wires attached to the heart.

An estimated 5 million Americans have heart failure, and a 2003 survey indicates that heart flutters called atrial fibrillation occur in about 40 percent of those cases. The condition increases the risk of stroke and complications from the extensive drug regimens most patients are prescribed.

CRT-Ds, short for cardiac resynchronization therapy defibrillator, are a small but growing segment of the implantable defibrillator market, particularly in replacement of conventional defibrillators. While a St. Jude Medical's spokeswoman was unable to provide a base price for the unit, industry analysts say less sophisticated CRT-Ds than the new device can run around $29,000, depending on the contracts that manufacturers strike with insurers.

St. Jude Medical's Cardiac Rhythm Management Division employs 1,880 people in the Los Angeles area, and contributes more than 62 percent of the parent company's revenue. The unit is the evolution of Pacesetter Systems, Los Angeles billionaire Alfred Mann's first foray into the medical device industry in the early 1970s. Siemens AG acquired the company in 1985, and later sold it to St. Jude., based in St. Paul, Minn.

Staff reporter Deborah Crowe can be reached at [phone], ext. 232, or at [e-mail].