Sadeh D, Shannon D C, Abboud S, Saul J P, Akselrod S, Cohen R J
Harvard-MIT Division of Health Sciences and Technology, Massachusetts General Hospital, Boston 02114.
N Engl J Med. 1987 Dec 10;317(24):1501-5. doi: 10.1056/NEJM198712103172404.
Abnormal prolongation of cardiac repolarization, as reflected by a long QT interval with respect to the RR interval on the electrocardiogram, is known to be associated with ventricular tachyarrhythmias. To test the hypothesis that prolonged cardiac repolarization may characterize some babies who die of sudden infant death syndrome (SIDS), we studied the dependence of the QT interval on the preceding RR interval in 10 babies with SIDS and 29 healthy control babies. We analyzed approximately 5000 pairs of QT and RR intervals in each subject over a wide range of RR intervals. We found that the QT intervals demonstrated less dependence on the preceding RR intervals in 5 of 10 babies who subsequently died of SIDS than in normal controls. No ventricular arrhythmias were observed, however, during the six-hour recording period. Our data suggest that in some babies with SIDS the ability to shorten the QT interval as the heart rate increases is impaired. These observations are consistent with the hypothesis that relatively prolonged cardiac repolarization may predispose such babies to ventricular arrhythmias.
心电图上QT间期相对于RR间期延长所反映的心脏复极异常延长，已知与室性快速心律失常有关。为了检验心脏复极延长可能是一些死于婴儿猝死综合征（SIDS）的婴儿的特征这一假设，我们研究了10例SIDS婴儿和29例健康对照婴儿中QT间期对前一个RR间期的依赖性。我们在每个受试者的广泛RR间期范围内分析了约5000对QT和RR间期。我们发现，在随后死于SIDS的10例婴儿中的5例中，QT间期对前一个RR间期的依赖性低于正常对照组。然而，在6小时的记录期间未观察到室性心律失常。我们的数据表明，在一些SIDS婴儿中，随着心率增加缩短QT间期的能力受损。这些观察结果与相对延长的心脏复极可能使这些婴儿易患室性心律失常的假设一致。
