By Liz White, UT staffSt Paul, Minnesota-St. Jude Medical Inc. says its IsoFlex P (polyurethane) bipolar endocardial pacing lead has been approved by the US Food and Drug Administration, and that it intends to start marketing the product. St Jude said the lead, which haspolyurethane outer insulation, features steroid-elution and other advances designed to improve performance and device longevity. Pacing leads are the insulated wires which connect a pacemaker to a patient's heart. A pacemaker works by transmitting electrical impulses through these leads to stabilise the heart rhythm. Such therapy is often recommended for patients with bradycardia, a slow and debilitating heart rhythm, the medical device supplier said. "The IsoFlex P lead demonstrated great pushability and handled very well for precise placement in the heart," said Dr Thomas Sullivan Jr of Internal Medicine Associates in Anderson, South Carolina. "It was easy to manoeuvre and thresholds were very stable." St Jude designed the new lead to provide physicians with greater flexibility, said Michael Coyle, president of St Jude Medical's Cardiac Rhythm Management Division. "Polyurethane leads comprise approximately 20 percent of the US market and 25 to 30 percent of the additional world market, so this introduction represents an important extension to our leads portfolio," he added. "