Chiu C C, Gow R M, McCrindle B W, Hamilton R M
Division of Cardiology, Hospital for Sick Children, Toronto, Canada.
Pacing Clin Electrophysiol. 1997 Sep;20(9 Pt 1):2163-70. doi: 10.1111/j.1540-8159.1997.tb04232.x.
The relationship between the pacemaker sensitivity safety factor (PSSF) and atrial under- or oversensing as documented by 24-hour Holter monitoring was examined. Our study comprised 78 transvenous fixed atrial leads implanted between 1983-1995 in 71 children. Overall, 210 Holter reports identified 143 (68%) Holters with normal atrial sensing function, 31 (15%) with undersensing, 32 (15%) with oversensing, and 4 (2%) with both problems. From 161 Holter reports in which the PSSF was available, the incidence of undersensing at a PSSF of 2.0 (range 1.5-2.4) was 25% (14/57). There was a dramatic decline in undersensing when the PSSF was > or = 3 (3%) compared to a PSSF < 3 (21%) (P < 0.001). A PSSF cut-off point of 2.0 best predicted occurrence of undersensing with a sensitivity of 79% and a specificity of 67%. Other variable were also examined by multiple logistic regression analysis, but only PSSF remained highly associated with undersensing (odds ratio [OR] = 0.6, P = 0.03). In contrast, PSSF did not have a significant role in predicting oversensing, but presence of sick sinus syndrome (OR = 10.5) or unipolar lead (OR = 5.6) were significantly associated with oversensing (P = 0.0001). The majority of undersensing problems can be avoided by routinely allowing for at least a threefold or more programmed sensitivity margin. Other factors may increase the risk of oversensing, regardless of the PSSF.
我们通过24小时动态心电图监测，研究了起搏器感知灵敏度安全系数（PSSF）与心房感知不足或感知过度之间的关系。我们的研究纳入了1983年至1995年间为71名儿童植入的78根经静脉固定心房导线。总体而言，210份动态心电图报告显示，143份（68%）动态心电图的心房感知功能正常，31份（15%）感知不足，32份（15%）感知过度，4份（2%）同时存在这两种问题。在161份可获得PSSF的动态心电图报告中，PSSF为2.0（范围1.5 - 2.4）时感知不足的发生率为25%（14/57）。与PSSF < 3（21%）相比，当PSSF≥3时，感知不足显著下降（3%）（P < 0.001）。PSSF截止点为2.0时，对感知不足发生的预测效果最佳，灵敏度为79%，特异度为67%。我们还通过多因素逻辑回归分析研究了其他变量，但只有PSSF与感知不足高度相关（比值比[OR] = 0.6，P = 0.03）。相比之下，PSSF在预测感知过度方面没有显著作用，但病态窦房结综合征（OR = 10.5）或单极导线（OR = 5.6）与感知过度显著相关（P = 0.0001）。通过常规设置至少三倍或更高的程控感知灵敏度裕度，大多数感知不足问题可以避免。其他因素可能会增加感知过度的风险，而与PSSF无关。
