Hiippala Anita, Serwer Gerald A, Clausson Eva, Davenport Lynn, Brand Trina, Happonen Juha-Matti
Pediatric Cardiology, Hospital for Children and Adolescents, Helsinki University Hospital, Helsinki, Finland.
Pacing Clin Electrophysiol. 2010 Mar;33(3):309-13. doi: 10.1111/j.1540-8159.2009.02619.x. Epub 2009 Dec 1.
Automatic threshold measurement and output adjustment are used as default settings in modern pacemakers. The purpose of the study was to assess Atrial Capture Management (ACM) of Medtronic pacemakers in pediatric patients.
Forty children were enrolled in two centers. Median age was 9.8 years (range 0.8-17.5 years). Half had undergone surgery for congenital heart defects; 45% of patients had an epicardial atrial lead. The pacing indication was atrioventricular block in 82% of patients and sinus node disease in 18%. Manually determined atrial thresholds and ACM measurements were compared.
ACM measurements were within the expected variation in 37/40 (93%) of the patients. In one patient the threshold was 0.625-V lower manually than with ACM. One patient had too high an intrinsic atrial rate for ACM to be able to measure threshold. The mean threshold at 0.4 ms was 0.69 +/- 0.32 V manually and 0.68 +/- 0.35 V with ACM (two-tailed paired t-test, P = 0.52) in all patients. The mean difference was 0.012 V (95% confidence interval: -0.027, 0.053). The mean endocardial threshold was 0.70 +/- 0.36 V manually and 0.69 +/- 0.38 V with ACM; epicardial threshold was 0.67 +/- 0.27 V manually and 0.68 +/- 0.32 V with ACM. The difference between the measurements was 0.012 V for endocardial and 0.014 V for epicardial leads. No atrial arrhythmias due to ACM measurements were observed.
ACM measures atrial thresholds reliably in pediatric patients with both endocardial and epicardial leads, allowing its use in both. Constant high intrinsic atrial rate may prevent automatic threshold measurement in young children.
自动阈值测量和输出调整是现代起搏器的默认设置。本研究的目的是评估美敦力起搏器在儿科患者中的心房夺获管理（ACM）。
两个中心共纳入40名儿童。中位年龄为9.8岁（范围0.8 - 17.5岁）。一半患儿曾接受先天性心脏缺陷手术；45%的患者有 epicardial 心房电极。起搏适应证为82%的患者存在房室传导阻滞，18%为窦房结疾病。比较手动测定的心房阈值和ACM测量值。
37/40（93%）的患者ACM测量值在预期变异范围内。1例患者手动测定的阈值比ACM测定值低0.625V。1例患者的固有心房率过高，以至于ACM无法测量阈值。所有患者在0.4ms时的平均阈值，手动测定为0.69±0.32V，ACM测定为0.68±0.35V（双尾配对t检验，P = 0.52）。平均差值为0.012V（95%置信区间：-0.027，0.053）。平均心内膜阈值手动测定为0.70±0.36V，ACM测定为0.69±0.38V；心外膜阈值手动测定为0.67±0.27V，ACM测定为0.68±0.32V。心内膜导联测量值之间的差异为0.012V，心外膜导联为0.014V。未观察到因ACM测量导致的房性心律失常。
ACM能够可靠地测量有内膜和外膜导联的儿科患者的心房阈值，二者均可使用。持续的高固有心房率可能会妨碍幼儿的自动阈值测量。
