Schmitz L, Stiller B, Koehne P, Koch H, Lange P E
Klinik für Pädiatrische Kardiologie, Charité Campus Virchow Klinikum, Humboldt-Universität zu Berlin.
Klin Padiatr. 2004 Jan-Feb;216(1):36-40. doi: 10.1055/s-2004-817684.
We studied the influence of preload augmentation on Doppler-derived left ventricular diastolic function parameters in infants with a birth weight <1500 g. In 44 neonates with a closed duct and 29 neonates with an open ductus arteriosus a complete echocardiographic study including Doppler investigations of the mitral inflow signals and analysis of diastolic time intervals was performed. Neonates with an open duct had a lower median gestational age (27.1 vs. 29, P<0.01), a higher cardiac index (425 vs. 260 ml/min/kg, P<0.001), and a different M-mode left atrial to aortic diameter ratio (1.36 vs. 0.79, P<0.001), but birth weight, age at examination (6.6 vs. 7.9 days), and heart rate were similar compared to the neonates with a closed duct. Main differences in diastolic indexes existed in early and atrial filling integrals and peak velocities, early filling acceleration time, and isovolumic relaxation time. Most informative in neonates with an open ductus peak early filling velocity (41.2 vs. 30.4 cm, P<0.01) and peak atrial filling velocity (49.2 vs. 35.9, P<0.001) are higher, and isovolumic relaxation time is shorter (45 vs. 53 ms, P<0.001) than in closed duct peers. Isovolumic relaxation time is inversely correlated with the cardiac index (R = -0.78). These parameter changes can be interpreted as incipient left ventricular diastolic failure in extremely low birth weight infants in the presence of a preload challenge. The coincidence of higher peak velocities with a shortened isovolumic relaxation time is very likely a result of left atrial pressure elevation. Preload mismatch has to be considered in preterm infants with a persistent ductus arteriosus. The results of this study can be helpful to find the indication for PDA-closure and to adjust volume replacement therapy, and catecholamine medication to a level appropriate for the individual cardiac performance.
我们研究了增加前负荷对出生体重<1500g婴儿经多普勒测量的左心室舒张功能参数的影响。对44例动脉导管闭合的新生儿和29例动脉导管未闭的新生儿进行了完整的超声心动图检查，包括二尖瓣血流信号的多普勒检查和舒张期时间间期分析。动脉导管未闭的新生儿胎龄中位数较低（27.1对29，P<0.01），心脏指数较高（425对260ml/min/kg，P<0.001），M型左心房与主动脉直径比值不同（1.36对0.79，P<0.001），但与动脉导管闭合的新生儿相比，出生体重、检查时年龄（6.6对7.9天）和心率相似。舒张期指标的主要差异存在于早期和心房充盈积分及峰值速度、早期充盈加速时间和等容舒张时间。在动脉导管未闭的新生儿中，最具信息量的是早期充盈峰值速度（41.2对30.4cm，P<0.01）和心房充盈峰值速度（49.2对35.9，P<0.001）较高，等容舒张时间较短（45对53ms，P<0.001），均高于动脉导管闭合的同龄儿。等容舒张时间与心脏指数呈负相关（R=-0.78）。这些参数变化可解释为极低出生体重儿在面临前负荷挑战时出现早期左心室舒张功能衰竭。较高的峰值速度与缩短的等容舒张时间同时出现很可能是左心房压力升高的结果。对于动脉导管持续未闭的早产儿，必须考虑前负荷不匹配的情况。本研究结果有助于确定动脉导管未闭封堵的指征，并将液体替代治疗和儿茶酚胺药物调整至适合个体心脏功能的水平。
