A NEW STEROID-ELUTING EPICARDIAL LEAD - EXPERIENCE WITH ATRIAL AND VENTRICULAR IMPLANTATION IN THE IMMATURE SWINE

The first study with investigational steroid epicardial leads was carried out in mature canine with prototype leads. Because the demand for epicardial leads is highest in small infants and the prototype steroid‐eluting lead has been redesigned, this study was carried out in immature swine to evaluate the newly designed lead. Six immature swine (2 at 5 weeks of age and 4 at 6 weeks) underwent epicardial implantation of four porous platinized tip leads: one steroid and one non‐steroid on the right atrium; one steroid and one nonsteroid on the right ventricle. At implantation, the lead terminals were connected to a percutaneous access device subcutaneously placed in the right lateral neck. This allowed chronic measurements by using an insulated needle connected with a cable to the pacing systems analyzer. Measurements were obtained at implantation and weekly for 3 weeks. Compared to the nonsteroid atrial leads, the steroid atrial leads had lower mean thresholds (P < 0.01) at 1,2, and 3 weeks after implantation. The mean threshold values from ventricular steroid leads were also lower and exhibited little increase from implant with the highest mean threshold of only 1.02 V, however, a statisticly significant difference between steroid and nonsteroid was not reached. This newly designed steroid epicardial lead provided favorable results for continual human clinical study. Copyright © 1990, Wiley Blackwell. All rights reserved