Acute performance of steroid-eluting screw-in leads for atrial free wall pacing.

The aim of this study was to clarify the acute performance of steroid-eluting screw-in leads in comparison with that of nonsteroid screw-in leads for atrial free wall pacing. In 114 cases (68 males, 46 females, average age 70 years) with atrial free wall pacing by screw-in leads, pacing thresholds and P-wave amplitudes were compared at the time of implantation and 1 week later between 68 cases of nonsteroid and 46 cases of steroid-eluting screw-in leads. No significant differences were seen between the 2 groups at implantation in either voltage or current thresholds measured at pulse widths of 0.1, 0.3, 0.6, 1.0, 2.0 ms, or P-wave amplitudes. Pulse width thresholds at outputs of 2.5 V and 5.0 V were significantly lower for steroid leads 1 week after implantation (2.5 V: 0.34+/-0.27 ms nonsteroid vs. 0.12+/-0.08 ms steroid, p<0.001; 5.0 V: 0.12+/-0.08 ms nonsteroid vs. 0.06+/-0.02 ms steroid, p<0.01). P-wave amplitudes after 1 week were significantly higher for steroid leads (2.6+/-0.7 mV nonsteroid vs 3.0+/-1.2 mV steroid, p<0.001). Threshold rise, including pacing failure, was observed in 15 (22%) of the non-steroid leads, but in only 1 (2%) of the steroid leads. In conclusion, steroid-eluting screw-in leads suppress the acute rise of pacing thresholds in the right atrial free wall and their acute performance is better than that of non-steroid leads. These results suggest that appropriate low-output atrial pacing is feasible immediately after implantation.