Transvenous magnetic tip lead system for permanent pacing of the heart. A preliminary report.

An electrode for transvenous permanent ventricular pacing equipped with a supermagnet was implanted in six dogs in the apex of the right ventricle for several weeks. As no signs of myocardial perforation occurred, the device which consists of the magnetic tip lead and an external supermagnet applied to the precordial region of the chest wall was implanted in 14 patients. The lead was introduced through the right cephalic vein in 12 patients and through the right external jugular vein in the remaining 2 patients. Threshold values were measured twice a day in 12 patients who received a Siemens-Elema Vario pacemaker 629. The average peak threshold was reached on the 11th day after implantation. No pacing failure or other signs of acute dislodgement of leads occurred during the first 30 days.