1999 Volume 63 Issue 7 Pages 514-516
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 nonsteroid 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 nonsteroid leads. These results suggest that appropriate low-output atrial pacing is feasible immediately after implantation. (Jpn Circ J 1999; 63: 514 - 516)
