Schmitz Lothar, Stiller Brigitte, Pees Christiane, Koch Heike, Xanthopoulos Athanasios, Lange Peter
Department of Pediatric Cardiology, Charité Medical Center, Humboldt-University, Augustenburger Platz 1, D-13353 Berlin, Germany.
Early Hum Dev. 2004 Feb;76(2):101-14. doi: 10.1016/j.earlhumdev.2003.11.003.
Transmitral flow parameters in preterm and term infants were compared in order to study differences in signal expression and temporal dynamics of left ventricular diastolic function. In 63 preterm infants between 26 and 33 weeks of gestation and 102 term infants, a Doppler survey was performed during 6 months after birth. Early and atrial filling-time velocity integrals and peak velocities were significantly lower in the preterm neonates. Atrial filling parameters reached the level observed in term infants by 2 months of age. Peak early filling velocity was still lower for 2-month-old preterms and attained the term infants' level by 3 months of age. Preterm infants continued having high atrial filling fraction (AFF) (0.51+/-0.07) during 2 months after birth, while in term infants the fraction decreased continuously from 0.41+/-0.06 to 0.37+/-0.05. Isovolumic relaxation time (IVRT) was the only parameter without differences between preterm and term infants, and it decreased from 54+/-7 ms in neonates to 41+/-4 ms over 3 months. Stroke volume passing the mitral valve doubled in preterm (4+/-1 to 7.9+/-1.5 ml/cm2), but increased by only 37% (6.9+/-1.6 to 9.5+/-2.2 ml/cm2) in term infants. Our observations show that the maturational period of diastolic function appears prolonged in preterm infants. As preterm infants have to cope with a higher physiologic preload augmentation during growth, part of the delay in parameter changes might be caused by preload stress rather than by persistence of functional impairment. Although doing well under physiological conditions, preterm neonates may be at higher risk for diastolic dysfunction than term infants when an additional preload challenge is encountered.
为研究左心室舒张功能的信号表达及时间动态变化的差异，对早产儿和足月儿的经二尖瓣血流参数进行了比较。在63例孕26至33周的早产儿和102例足月儿中，出生后6个月内进行了多普勒检查。早产儿的早期和心房充盈时间速度积分及峰值速度显著较低。心房充盈参数在2月龄时达到足月儿的水平。2月龄早产儿的早期充盈峰值速度仍较低，3月龄时达到足月儿水平。早产儿出生后2个月内持续有较高的心房充盈分数（AFF）（0.51±0.07），而足月儿的该分数从0.41±0.06持续下降至0.37±0.05。等容舒张时间（IVRT）是早产儿和足月儿之间唯一无差异的参数，且从新生儿期的54±7毫秒在3个月内降至41±4毫秒。通过二尖瓣的每搏量在早产儿中翻倍（4±1至7.9±1.5毫升/平方厘米），而在足月儿中仅增加了37%（6.9±1.6至9.5±2.2毫升/平方厘米）。我们的观察结果表明，早产儿舒张功能的成熟阶段似乎延长。由于早产儿在生长过程中必须应对更高的生理前负荷增加，参数变化延迟的部分原因可能是前负荷应激而非功能损害的持续存在。尽管在生理条件下情况良好，但当遇到额外的前负荷挑战时，早产儿发生舒张功能障碍的风险可能高于足月儿。
