De Wolf D, Matthys D, Verhaaren H, Sluysmans T
Department of Paediatrics, University Hospital UZGent, Ghent, Belgium.
Pediatr Res. 1998 Oct;44(4):600-6. doi: 10.1203/00006450-199810000-00022.
The relation between systolic meridional wall stress (WS) and velocity of circumferential fiber shortening (VcFc) is widely accepted as a preload-independent index of contractility, with a linear relation in most subjects older than 2 y. However, this relation seems to become different in infants and after administration of inotropic agents. We decided to study the nature of the stress-velocity relation by a cross-sectional assessment of the influence of age, low afterload, and increased contractility. Study subjects were 30 healthy infants, 32 healthy older children, and 35 asymptomatic older children after completion of anthracycline chemotherapy. WS and VcFc at rest were studied in these infants and children. WS and VcFc were also studied after dobutamine infusion in both groups of older children. Linear regression analysis of the stress-velocity relation showed parallel slopes between the older children at rest and the post anthracycline children after dobutamine. The regression lines between the infants at rest and the healthy older children after dobutamine were also parallel, but with a different and steeper slope compared with the former groups. When comparing the stress-velocity relation of the overall population at rest with the overall population after dobutamine, the resulting regression lines are curvilinear and parallel, with a steeper slope at low afterload. The stress-velocity relation in infants and after dobutamine, resulting in low afterload is different compared with the stress- velocity relation in older children at rest and at higher afterload. Data of the overall population at rest and after dobutamine suggest a curvilinear relation.
收缩期子午线壁应力（WS）与圆周纤维缩短速度（VcFc）之间的关系被广泛认为是一种与前负荷无关的收缩性指标，在大多数2岁以上的受试者中呈线性关系。然而，这种关系在婴儿和使用正性肌力药物后似乎有所不同。我们决定通过横断面评估年龄、低后负荷和收缩性增加的影响来研究应力-速度关系的本质。研究对象为30名健康婴儿、32名健康大龄儿童和35名完成蒽环类化疗后的无症状大龄儿童。对这些婴儿和儿童静息状态下的WS和VcFc进行了研究。两组大龄儿童在输注多巴酚丁胺后也对WS和VcFc进行了研究。应力-速度关系的线性回归分析显示，静息状态下的大龄儿童与多巴酚丁胺治疗后的蒽环类化疗后儿童之间的斜率平行。静息状态下的婴儿与多巴酚丁胺治疗后的健康大龄儿童之间的回归线也平行，但与前一组相比斜率不同且更陡。将静息状态下的总体人群与多巴酚丁胺治疗后的总体人群的应力-速度关系进行比较时，得到的回归线是曲线且平行的，在低后负荷时斜率更陡。婴儿和多巴酚丁胺治疗后导致低后负荷的应力-速度关系与静息状态下和高后负荷时大龄儿童的应力-速度关系不同。静息状态下和多巴酚丁胺治疗后的总体人群数据表明存在曲线关系。
