Kato H, Yanagawa Y
Department of Pediatrics, University of Tokyo, Japan.
Acta Paediatr Jpn. 1994 Apr;36(2):176-82. doi: 10.1111/j.1442-200x.1994.tb03157.x.
The circadian changes in the activity of the autonomic nervous system in a group showing long QT duration in electrocardiogram (ECG) were studied in order to differentiate symptomatic congenital long QT syndrome from asymptomatic. The asymptomatic group presented only long QT duration (QTc > 0.46). Seven girls and two boys, including two subjects experiencing syncope of non-neurological origins, were examined by using heart rate (HR) power spectrum analysis. In three subjects, the peak of the high frequency band, indicating the parasympathetic activity, disappeared during night-time (sleep), which means the possibility of a high risk of sudden cardiac death. In two of three subjects, moreover, the averaged sympathetic activity during daytime was significantly increased compared to that during night-time, in addition to the abrupt increase of sympathetic activity in the morning. These two subjects, in which one boy had a family history of Romano-Ward syndrome, were the same people experiencing the syncope attack. We succeeded in objectively elucidating that congenital long QT syndrome is adrenergic-dependent, and suggest that HR power spectrum analysis may be of value in distinguishing symptomatic congenital long QT syndrome from asymptomatic showing only long QT duration.
为了区分症状性先天性长QT综合征和无症状性长QT综合征，对一组心电图（ECG）显示QT间期延长的人群的自主神经系统活动的昼夜变化进行了研究。无症状组仅表现为QT间期延长（校正QT间期>0.46）。通过心率（HR）功率谱分析对7名女孩和2名男孩进行了检查，其中包括2名有非神经源性晕厥的受试者。在3名受试者中，指示副交感神经活动的高频波段峰值在夜间（睡眠）消失，这意味着心脏性猝死风险较高。此外，在这3名受试者中的2名中，除了早晨交感神经活动突然增加外，白天的平均交感神经活动与夜间相比也显著增加。这两名受试者，其中一名男孩有罗曼诺-沃德综合征家族史，就是经历晕厥发作的人。我们成功地客观阐明了先天性长QT综合征是肾上腺素能依赖性的，并表明HR功率谱分析可能有助于区分症状性先天性长QT综合征和仅表现为QT间期延长的无症状性长QT综合征。
