Morita H, Yamanari H, Ohe T
Department of Cardiovascular Medicine, Okayama University Medical School, Japan.
Jpn Circ J. 1996 Oct;60(10):742-8. doi: 10.1253/jcj.60.742.
Congenital long QT syndrome (LQTS) is a rare hereditary disease characterized by a prolonged QT interval and lethal ventricular tachycardia (Torsades de Pointes: TdP). The pathogenesis of LQTS and the induction of TdP have been thought to be closely related to autonomic nervous abnormalities. We examined autonomic activity in 13 LQTS patients by analyzing heart rate variability from 24 h Holter ambulatory electrocardiographic recordings without medications. In a frequency-analysis of RR variability, we calculated the power in the low-frequency domain (LF) and the high-frequency domain (HF) over 24 h. The ratio of LF to HF (an index of sympathetic nervous activity) was lower in LQTS patients than in controls, whereas HF (an index of parasympathetic nervous activity) was higher. Moreover, LQTS patients with TdP had lower abnormal sympathetic nervous activity than those without TdP. The index of autonomic nervous activity obtained using this method could be useful for evaluating the severity in LQTS.
先天性长QT综合征（LQTS）是一种罕见的遗传性疾病，其特征为QT间期延长和致命性室性心动过速（尖端扭转型室速：TdP）。LQTS的发病机制以及TdP的诱发一直被认为与自主神经异常密切相关。我们通过分析13例未服用药物的LQTS患者24小时动态心电图记录中的心率变异性，来检测其自主神经活动。在RR间期变异性的频率分析中，我们计算了24小时内低频域（LF）和高频域（HF）的功率。LQTS患者的LF与HF之比（交感神经活动指标）低于对照组，而HF（副交感神经活动指标）则较高。此外，发生TdP的LQTS患者的异常交感神经活动低于未发生TdP的患者。使用这种方法获得的自主神经活动指标可能有助于评估LQTS的严重程度。
