Lindner W, Döhlemann C, Schneider K, Versmold H
Pediatr Cardiol. 1985;6(3):117-21. doi: 10.1007/BF02336549.
To determine the influence of heart rate (HR) on systolic time intervals (STI) in neonates, serial measurements of right ventricular (RVSTI) and left ventricular systolic time intervals (LVSTI) were made on 30 healthy term newborn infants at age 4-8 h, 24-30 h, eight days, and four weeks. STI was related to HR and age. Age-related changes were similar to previously reported results. The preejection periods (RPEP and LPEP) significantly shortened with increasing age, whereas the right and left ventricular ejection times (RVET and LVET) were unrelated to age. RPEP was unrelated to HR, but tended to be prolonged in restless infants. With increasing HR, RVET decreased and RPEP/RVET increased in all age groups, but less at four weeks. A rise in HR of 50/min resulted in an increase of RPEP/RVET by 26% of the mean value at age 4-8 h and by 20% at four weeks. In 14 infants, RVSTI was recorded during a change in HR. In all these infants, RPEP and RPEP/RVET increased with increasing HR. We conclude that HR-related changes of RVSTI in neonates are different from those in older subjects. It should be considered that in neonates elevated values of RPEP/RVET, suggesting increased pulmonary vascular resistance, may be caused by high HR and unrest.
为确定心率（HR）对新生儿收缩期时间间期（STI）的影响，对30名健康足月儿在4 - 8小时、24 - 30小时、8天和4周龄时进行了右心室（RVSTI）和左心室收缩期时间间期（LVSTI）的系列测量。STI与HR和年龄相关。年龄相关变化与先前报道的结果相似。射血前期（RPEP和LPEP）随年龄增长显著缩短，而右心室和左心室射血时间（RVET和LVET）与年龄无关。RPEP与HR无关，但在躁动不安的婴儿中往往会延长。随着HR增加，所有年龄组的RVET均降低，RPEP/RVET升高，但在4周龄时升高幅度较小。心率每增加50次/分钟，4 - 8小时龄时RPEP/RVET升高幅度为平均值的26%，4周龄时为20%。在14名婴儿中，记录了HR变化期间的RVSTI。在所有这些婴儿中，RPEP和RPEP/RVET均随HR增加而升高。我们得出结论，新生儿RVSTI与HR相关的变化不同于年龄较大的受试者。应考虑到，在新生儿中，RPEP/RVET值升高提示肺血管阻力增加，可能是由高HR和躁动引起的。
