Paradoxical nocturnal elevation of sympathetic tone and spontaneous ventricular fibrillation in Brugada syndrome
Paradoxical nocturnal elevation of sympathetic tone and spontaneous ventricular fibrillation in Brugada syndrome
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布鲁格达综合征夜间交感神经张力反常升高和自发性心室颤动
作者：
KUMAGAI;N.;OGAWA;M.;ZHANG;B.;KOYOSHI;R.;MORII;J.;YASUDA;T.;MATSUMOTO;N.;MATSUO;K. & SAKU;K.
据报道，Brugada综合征(BRS)患者自发性室性快速性心律失常的发生率在夜间占主导地位。方法在33例BRS患者中，14例有自发性室颤(VF-BRS)心肺骤停史(VF-BRS)，19例有无症状BRS(A-BRS)。结果14例自发性室性心动过速患者中，11例(79%)发生在夜间或静息状态。A-BRS患者白天QT/RR斜率明显大于夜间(P=0.031)，而VF-BRS患者白天QT/RR斜率无明显变化(P=0.00)。高频(HF)和低频(LF)/HF比值在A-BRS患者中有显著差异(P=0.019和P=0.019)，而在VF-BRS患者中无显著差异(P=0.019和P=0.00)。VF-BRS患者的特点是相对较高的LF/HF比率，而A-BRS患者的特点是白天和夜间的LF/HF比率相对较低。此外，VF-BRS患者夜间的LF/HF比值显著高于A-BRS患者(P=0.021)。结论VF-BRS患者的自发性室颤多发生在夜间或静息状态。夜间交感神经张力异常升高的自主神经失衡以及持续的交感神经张力可能在BRS患者自发室颤的发生中起关键作用。
BackgroundNocturnal dominance of the incidence of spontaneous ventricular tachyarrhythmias has been reported in patients with Brugada syndrome (BrS). The purpose of the present study is to analyze the QT dynamics and autonomic balance as well as their diurnal variations in BrS patients.MethodsOf the 33 consecutive patients with BrS included in the study, 14 had a history of cardiopulmonary arrest due to spontaneous ventricular fibrillation (VF) episodes (VF-BrS) and 19 had asymptomatic BrS (A-BrS). QT dynamics and heart rate variability were analyzed using 24-h Holter electrocardiogram recordings.ResultsOf the total 14 first cardiopulmonary arrest episodes due to spontaneous VF, 11 (79%) occurred in VF-BrS patients during the nighttime or at rest. The QT/RR slope during daytime was significantly steeper than that during nighttime in the A-BrS patients (p= 0.031), but not in the VF-BrS patients (p= 1.0). There were significant diurnal differences pertaining to the high-frequency (HF) and low-frequency (LF)/HF ratios in the A-BrS patients (p= 0.019 andp= 0.019, respectively), but not in the VF-BrS patients (p= 1.0 andp= 1.0, respectively). The VF-BrS patients were characterized by relatively high LF/HF ratios, whereas the A-BrS patients were characterized by relatively low LF/HF ratios throughout the daytime and nighttime. Furthermore, the LF/HF ratios during the nighttime in the VF-BrS patients were significantly higher than those in the A-BrS patients (p= 0.021).ConclusionsMost first episodes of spontaneous VF in the VF-BrS patients occurred during the nighttime or at rest. The autonomic imbalance of paradoxical nocturnal elevation of the sympathetic tone along with an underlying persistent sympathetic tone throughout the day may play a key role for spontaneous VF initiation in BrS patients.