Johns J A, Fish F A, Burger J D, Hammon J W
Division of Pediatric Cardiology, Vanderbilt University School of Medicine, Nashville, Tennessee.
J Am Coll Cardiol. 1992 Aug;20(2):395-401. doi: 10.1016/0735-1097(92)90108-y.
This study evaluated the pacing and sensing characteristics of a new porous-tipped steroid-eluting epicardial lead in a group of pediatric patients.
Pacing in children may be complicated by small patient size, patient growth and the prevalence of structural congenital heart disease in children requiring pacing. Epicardial pacing has been associated with a high incidence of problems with sensing and capture, prompting the use of transvenous endocardial pacing when possible. In some children, epicardial pacing may still be desirable because of small patient size, potential for caval obstruction, previous cardiac surgery limiting transvenous access to the heart, or the need to repair congenital heart disease at the time of pacemaker insertion.
Twelve patients aged 3 weeks to 18 years underwent placement of 23 epicardial pacing leads (8 atrial, 15 ventricular). Pulse width thresholds, sensing thresholds and lead impedance were measured weekly for 6 weeks, then at 3, 6, 12 and 18 months after pacemaker implantation. The median duration of follow-up was 12 months.
Ventricular pulse width thresholds did not change over time, whereas atrial pulse width thresholds improved significantly. At 6 months, the mean pulse width threshold at 2.5 V for the atrial and ventricular leads was 0.10 +/- 0.03 and 0.19 +/- 0.09 ms, respectively. The thresholds were slightly lower at 12 and 18 months. At the most recent follow-up, all atrial leads sensed appropriately at 2.5 mV and all ventricular leads at 5 mV.
These encouraging early results suggest that steroid-eluting epicardial pacing leads may be an attractive option for children needing epicardial pacing. Their excellent pacing and sensing characteristics may allow reliable dual-chamber pacing in infants who are too small for transvenous pacing.
本研究评估了一种新型多孔尖端类固醇洗脱心外膜导线在一组儿科患者中的起搏和感知特性。
儿童起搏可能因患者体型小、生长发育以及需要起搏的儿童中结构性先天性心脏病的患病率而变得复杂。心外膜起搏与感知和夺获问题的高发生率相关，因此在可能的情况下促使使用经静脉心内膜起搏。在一些儿童中，由于患者体型小、存在腔静脉阻塞的可能性、既往心脏手术限制了经静脉进入心脏的通路，或者在植入起搏器时需要修复先天性心脏病，心外膜起搏可能仍然是可取的。
12名年龄在3周至18岁的患者接受了23根心外膜起搏导线（8根心房导线，15根心室导线）的植入。在6周内每周测量脉冲宽度阈值、感知阈值和导线阻抗，然后在起搏器植入后3、6、12和18个月进行测量。随访的中位持续时间为12个月。
心室脉冲宽度阈值随时间未发生变化，而心房脉冲宽度阈值显著改善。在6个月时，心房和心室导线在2.5V时的平均脉冲宽度阈值分别为0.10±0.03和0.19±0.09ms。在12个月和18个月时阈值略低。在最近一次随访时，所有心房导线在2.5mV时感知正常，所有心室导线在5mV时感知正常。
这些令人鼓舞的早期结果表明，类固醇洗脱心外膜起搏导线对于需要心外膜起搏的儿童可能是一个有吸引力的选择。它们出色的起搏和感知特性可能允许对太小而无法进行经静脉起搏的婴儿进行可靠的双腔起搏。
