Shaddy R E, Tani L Y, Gidding S S, Pahl E, Orsmond G S, Gilbert E M, Lemes V
Department of Pediatrics, Primary Children's Medical Center and the University of Utah, Salt Lake City 84113, USA.
J Heart Lung Transplant. 1999 Mar;18(3):269-74. doi: 10.1016/s1053-2498(98)00030-8.
Dilated cardiomyopathy is the primary indication for heart transplantation in children beyond infancy. Although beta-blockers improve symptoms, ejection fraction, and survival in adults with congestive heart failure, little is known of their effects in children.
This study reviews our pediatric experience with the beta-blocker, metoprolol, at 3 institutions. We gave metoprolol to 15 children, age 8.6 +/- 1.3 years (range 2.5 to 15 years), with idiopathic dilated cardiomyopathy (n = 9), anthracycline cardiomyopathy (n = 3), and Duchenne muscular dystrophy cardiomyopathy, postmyocarditis cardiomyopathy, and post-surgical cardiomyopathy (n = 1 each). All had been treated with conventional medications (digoxin, diuretics, and ACE inhibitors) for 22.5 +/- 9 months before starting metoprolol. Metoprolol was started at 0.1 to 0.2 mg/kg/ dose given twice daily and slowly increased over a period of weeks to a dose of 1.1 +/- 0.1 mg/kg/day (range 0.5 to 2.3 mg/kg/day).
Between the time point of stabilization on conventional medications and the initiation of metoprolol therapy, there was no significant change in fractional shortening (13.1 +/- 1.2% vs 15.0 +/- 1.2%) or ejection fraction (25.6 +/- 2.1% vs 27.0 +/- 3.4%). However, after metoprolol therapy for 23.2 +/- 7 months, there was a significant increase in fractional shortening(23.3 +/- 2.6%) and ejection fraction (41.1 +/- 4.3%) (p < 0.05).
Metoprolol improves ventricular function in some children with dilated cardiomyopathy and congestive heart failure. Further study is warranted to better define which children may benefit most from beta-blocker therapy and which beta-blockers are most efficacious.
扩张型心肌病是婴儿期后儿童心脏移植的主要指征。虽然β受体阻滞剂可改善充血性心力衰竭成年患者的症状、射血分数并提高生存率，但对其在儿童中的作用了解甚少。
本研究回顾了我们在3家机构使用β受体阻滞剂美托洛尔治疗儿童的经验。我们将美托洛尔给予15名年龄为8.6±1.3岁（范围2.5至15岁）的儿童，其中特发性扩张型心肌病9例、蒽环类药物性心肌病3例、杜氏肌营养不良性心肌病、心肌炎后心肌病和手术后心肌病各1例。在开始使用美托洛尔之前，所有患儿均已接受常规药物（地高辛、利尿剂和ACE抑制剂）治疗22.5±9个月。美托洛尔起始剂量为0.1至0.2mg/kg/次，每日两次，数周内缓慢增加至1.1±0.1mg/kg/天（范围0.5至2.3mg/kg/天）。
在常规药物治疗稳定至开始美托洛尔治疗的时间点之间，缩短分数（13.1±1.2%对15.0±1.2%）或射血分数（25.6±2.1%对27.0±3.4%）无显著变化。然而，在美托洛尔治疗23.2±7个月后，缩短分数（23.3±2.6%）和射血分数（41.1±4.3%）显著增加（p<0.05）。
美托洛尔可改善部分扩张型心肌病和充血性心力衰竭患儿的心室功能。有必要进一步研究以更好地确定哪些儿童可能从β受体阻滞剂治疗中获益最大，以及哪种β受体阻滞剂最有效。
