肥厚型心肌病患儿的心肌桥——猝死的一个危险因素。

Myocardial bridging in children with hypertrophic cardiomyopathy--a risk factor for sudden death.

作者信息

Yetman A T, McCrindle B W, MacDonald C, Freedom R M, Gow R

机构信息

Department of Pediatrics, Hospital for Sick Children, University of Toronto Faculty of Medicine, Canada.

出版信息

N Engl J Med. 1998 Oct 22;339(17):1201-9. doi: 10.1056/NEJM199810223391704.

DOI:10.1056/NEJM199810223391704

PMID:9780340

Abstract

BACKGROUND

Myocardial bridging may cause compression of a coronary artery, and it has been suggested that myocardial ischemia may result. The clinical significance and prognostic value of myocardial bridging of the left anterior descending coronary artery in children with hypertrophic cardiomyopathy are unknown. We sought to determine the prevalence and clinical effects of myocardial bridging in children with hypertrophic cardiomyopathy who underwent cardiac catheterization.

METHODS

Angiograms from 36 children with hypertrophic cardiomyopathy were reviewed to determine whether myocardial bridging was present and, if so, to assess the characteristics of systolic narrowing of the left anterior descending coronary artery caused by myocardial bridging and the duration of residual diastolic compression. We also reviewed clinical data on these patients.

RESULTS

Myocardial bridging was present in 10 (28 percent) of the patients. Compression of the left anterior descending coronary artery persisted for a mean (+/-SD) of 50+/-17 percent of diastole. As compared with patients without bridging, patients with bridging had a greater incidence of chest pain (60 percent vs. 19 percent, P=0.04), cardiac arrest with subsequent resuscitation (50 percent vs. 4 percent, P=0.004), and ventricular tachycardia (80 percent vs. 8 percent, P<0.001). On average, the patients with bridging had a reduction in systolic blood pressure with exercise of 17+/-27 mm Hg, as compared with an elevation of 43+/-31 mm Hg in those without bridging (P<0.001). The patients with bridging also had greater ST-segment depression with exercise (median, 5 vs. 0 mm, P=0.004) and a shorter duration of exercise (mean, 6.6+/-2.4 vs. 9.1+/-1.4 minutes, P=0.008). The degree of dispersion of the QT interval corrected for heart rate on the electrocardiogram was greater in patients with bridging than in those without bridging (104+/-46 vs. 48+/-31 msec, P=0.002). Kaplan-Meier estimates of the proportions of patients who had not died or had cardiac arrest with subsequent resuscitation five years after the diagnosis of hypertrophic cardiomyopathy were 67 percent among patients with bridging and 94 percent among those without bridging (P=0.004).

CONCLUSIONS

Myocardial bridging is associated with a poor outcome in children with hypertrophic cardiomyopathy. Our observations suggest that bridging is associated with myocardial ischemia

摘要

背景

心肌桥可能导致冠状动脉受压，有人认为这可能会导致心肌缺血。肥厚型心肌病患儿左前降支冠状动脉心肌桥的临床意义和预后价值尚不清楚。我们试图确定接受心脏导管检查的肥厚型心肌病患儿心肌桥的患病率及其临床影响。

方法

回顾了36例肥厚型心肌病患儿的血管造影图像，以确定是否存在心肌桥，若存在，则评估心肌桥导致的左前降支冠状动脉收缩期狭窄的特征以及舒张期残余受压的持续时间。我们还回顾了这些患者的临床资料。

结果

10例（28%）患者存在心肌桥。左前降支冠状动脉受压在舒张期平均持续时间（±标准差）为50±17%。与无心肌桥的患者相比，有心肌桥的患者胸痛发生率更高（60%对19%，P = 0.04）、心脏骤停后复苏的发生率更高（50%对4%，P = 0.004）以及室性心动过速的发生率更高（80%对8%，P<0.001）。平均而言，有心肌桥的患者运动时收缩压降低17±27 mmHg，而无心肌桥的患者运动时收缩压升高43±31 mmHg（P<0.001）。有心肌桥的患者运动时ST段压低也更明显（中位数，5对0 mm，P = 0.004），且运动持续时间更短（平均，6.6±2.4对9.1±1.4分钟，P = 0.008）。心电图上校正心率后的QT间期离散度在有心肌桥的患者中比无心肌桥的患者更大（104±46对48±31毫秒，P = 0.002）。肥厚型心肌病诊断后五年未死亡或未发生心脏骤停后复苏的患者比例，根据Kaplan-Meier估计，有心肌桥的患者为67%，无心肌桥的患者为94%（P = 0.004）。