Permanent pervenous atrial pacing.

A new J-lead has now been designed and manufactured for both animal and clinical studies. This lead has silastic tines proximal to the electrode, arranged so that they become entangled in the trabeculae of the appendage and hold the lead in place. Studies in ten dogs have shown excellent tissue fixation at the site of the tines, and only minimal scarring occurs at the site of the terminal electrode, with preservation of good P-wave amplitude and good stimulating thresholds for a period of four to five months (Figure 8, see next page). The lead designed for humans has been used successfully in 12 patients. Follow-up now extends to 19 months, with stable P-wave-triggered atrial pacing in eight patients, fixed rate atrial pacing in one, and A-V synchronized pacing in three. No lead dislodgement has occurred.