Prediction of early secondary complications in patients with spontaneous subarachnoid hemorrhage based on accelerated sympathovagal ratios

I. Chang Su, Chien Hsun Li, Kuo Chuan Wang, Dar Ming Lai, Sheng Jean Huang, Jiann Shing Shieh, Yong Kwang Tu

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Purpose: The development of secondary complications following spontaneous subarachnoid hemorrhage (SAH) largely depends on sympathetic overexcitation. The roles of vagal activities, however, are poorly defined. Because both components of the autonomic nervous system can be explored in the frequency domain of heart rate variability (HRV), the present study aimed to determine the dynamic evolution of autonomic activities and to identify patients at high risk for complications following hemorrhage. Methods: Thirty patients with SAH were enrolled in our study. Those who suffered from symptomatic vasospasm, cerebral infarction, neurogenic pulmonary edema, or early mortality within 1 week of ictus were categorized into the complication group. Spectral analysis of HRV explored three important indices of sympathetic and vagal modulations: low-frequency (LF), high-frequency (HF), and LF/HF ratios. Patterns of HRV dynamics within the first 3 days were compared between complication and non-complication groups. The group trends, estimated by the slopes of HRV changes, were determined for further univariate and multivariate analysis. Results: Our study showed that daily HRV in the complication group exhibited an approximately 2.7-fold increase of sympathovagal ratio (denoted by LF/HF). This resulted from reciprocal changes of sympathoexcitation (LF) and vagal withdrawal (HF). Multivariate analysis revealed that LF/HF slope, an indicator of the trend of sympathovagal change, was an independent variable significantly associated with the development of complications. Conclusions: This study confirmed that during early SAH period, patients with and without complications presented different patterns of sympathovagal changes. LF/HF slope during the first 3 days was a significant predictor of secondary complications after SAH.

Original languageEnglish
Pages (from-to)1631-1637
Number of pages7
JournalActa Neurochirurgica
Issue number12
Publication statusPublished - Jan 1 2009
Externally publishedYes


  • Autonomic nervous system
  • Cerebral vasospasm
  • Heart rate variability
  • Neurogenic pulmonary edema
  • Spontaneous subarachnoid hemorrhage

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery


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