Development of quantitative evaluation of the repolarization changes in myocardial damage in children and an analysis of their origin

我们根据QRST等积分图的结果，对儿童年龄组心肌损害所致的复极异常进行了定量评估。此外，我们还通过激活恢复间期(ARI)的分布(据称与局部动作电位时程相关)来探讨异常的机制。将100例正常儿童的QRST等积分图与日本循环学会特别工作组委员会收集的年龄匹配的正常平均QRST等积分图进行比较，计算全身表面导联的相关系数(R值)。QRST等积分图所见各年龄组均相似，但胸前阳性面积略有改变。正常组R值在0.92~0.88之间。在对心肌损害患者R值的系列评估中，他们的QRST等积分图的R值在Pr…时显著降低心肌损害程度增加，在心肌损害消失或恢复时恢复正常。在先天性冠状动脉畸形和蒽环类药物心肌损害的儿童中，也可以通过R值进行定量评估。超声心动图R值能较好地反映充血性心力衰竭或左心功能不全的临床症状。结果表明，QRST等积分图R值定量评价心肌损伤复极异常具有临床应用价值。通过对ARI分布的进一步研究发现，与正常儿童相比，患者受损心肌面积ARI延长。下壁心肌梗死患者ARI值延长，广泛分布于下胸段。1例前壁梗死患者胸壁前壁ARI值延长。提示损伤心肌动作电位时程延长，可能是对患者心电图复极改变的反应。较少

We have developed a quantitative evaluation of the repolarization abnormalities due to myocardial damage in pediatric age group by findings of QRST isointegral maps. Furthermore, we also investigated the mechanism of the abnormalities by the distribution of activation recovery interval (ARI), which claimed to correlate to local action potential duration.QRST isointegral maps of 100 normal children without heart diseases were compared to age matched normal averaged QRST isointegral maps-collected by the Task Force Committee of Japanese Circulation Society and correlation coefficient from the whole body surface leads were calculated (R value). QRST isointegral map findings were resembled at any age groups except slight changes in positive area on anterior chest. R values of normal group were varied from 0.92 to 0.88 in their mean value. In serial evaluations of R values in patients with myocardial damage, the R -values of their QRST isointegral maps were significantly decreased at the pr … More esence of myocardial damage, and they normalized at absence or recovery of myocardial damage. The quantitative evaluation by R values were also possible in children with congenital coronary malformations and anthracycline myocardial damage. R values were well reflect the clinical symptoms of congestive heart failure or LV dysfunction in echocardiography. The results demonstrated that clinical usefulness of the quantitative evaluation of repolarization abnormalities of myocardial damage by R values of QRST isointegral maps.Further study by the distributions of ARI disclosed the presence of the prolonged ARI on the area of damaged myocardium in patients compared to normal children. A patient with inferior myocardial infarction, prolonged ARI values are widely distributed on the lower chest area. Another patient with anterior infarction showed prolonged-ARI values on anterior chest. The findings suggest that APD is prolonged in injured myocardium, and it may responsive for the repolarization changes of electrocardiogram of the patients. Less